151
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Niikura M, Inoue S, Mineo S, Asahi H, Kobayashi F. IFNGR1 signaling is associated with adverse pregnancy outcomes during infection with malaria parasites. PLoS One 2017; 12:e0185392. [PMID: 29117241 PMCID: PMC5678718 DOI: 10.1371/journal.pone.0185392] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2017] [Accepted: 09/12/2017] [Indexed: 11/19/2022] Open
Abstract
Complicated/severe cases of placental pathology due to Plasmodium falciparum and P. vivax, especially adverse pregnancy outcomes during P. vivax infection, have been increasing in recent years. However, the pathogenesis of placental pathology during severe malaria is poorly understood, while responses against IFN-γ are thought to be associated with adverse pregnancy outcomes. In the present study, we explored the role of IFN-γ receptor 1 (IFNGR1) signaling in placental pathology during severe malaria using luciferase-expressing rodent malaria parasites, P. berghei NK65 (PbNK65L). We detected luciferase activities in the lung, spleen, adipose tissue, and placenta in pregnant mice, suggesting that infected erythrocytes could accumulate in various organs during infection. Importantly, we found that fetal mortality in IFNGR1-deficient mice infected with PbNK65L parasites was much less than in infected wild type (WT) mice. Placental pathology was also improved in IFNGR1-deficient mice. In contrast, bioluminescence imaging showed that parasite accumulation in the placentas of IFNGR1-deficient pregnant mice was comparable to that in WT mice infected with PbNK65L. These findings suggest that IFNGR1 signaling plays a pivotal role in placental pathology and subsequent adverse pregnancy outcomes during severe malaria. Our findings may increase our understanding of how disease aggravation occurs during malaria during pregnancy.
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Affiliation(s)
- Mamoru Niikura
- Department of Infectious Diseases, Kyorin University School of Medicine, Tokyo, Japan
| | - Shin–Ichi Inoue
- Department of Infectious Diseases, Kyorin University School of Medicine, Tokyo, Japan
| | - Shoichiro Mineo
- Department of Molecular Pathology, Tokyo Medical University, Tokyo, Japan
| | - Hiroko Asahi
- Department of Infectious Diseases, Kyorin University School of Medicine, Tokyo, Japan
| | - Fumie Kobayashi
- Department of Infectious Diseases, Kyorin University School of Medicine, Tokyo, Japan
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152
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Zhou X, Tambo E, Su J, Fang Q, Ruan W, Chen JH, Yin MB, Zhou XN. Genetic Diversity and Natural Selection in 42 kDa Region of Plasmodium vivax Merozoite Surface Protein-1 from China-Myanmar Endemic Border. Korean J Parasitol 2017; 55:473-480. [PMID: 29103262 PMCID: PMC5678462 DOI: 10.3347/kjp.2017.55.5.473] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/19/2017] [Revised: 09/16/2017] [Accepted: 09/18/2017] [Indexed: 12/17/2022]
Abstract
Plasmodium vivax merozoite surface protein-1 (PvMSP1) gene codes for a major malaria vaccine candidate antigen. However, its polymorphic nature represents an obstacle to the design of a protective vaccine. In this study, we analyzed the genetic polymorphism and natural selection of the C-terminal 42 kDa fragment within PvMSP1 gene (Pv MSP142) from 77 P. vivax isolates, collected from imported cases of China-Myanmar border (CMB) areas in Yunnan province and the inland cases from Anhui, Yunnan, and Zhejiang province in China during 2009-2012. Totally, 41 haplotypes were identified and 30 of them were new haplotypes. The differences between the rates of non-synonymous and synonymous mutations suggest that PvMSP142 has evolved under natural selection, and a high selective pressure preferentially acted on regions identified of PvMSP133. Our results also demonstrated that PvMSP142 of P. vivax isolates collected on China-Myanmar border areas display higher genetic polymorphisms than those collected from inland of China. Such results have significant implications for understanding the dynamic of the P. vivax population and may be useful information towards China malaria elimination campaign strategies.
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Affiliation(s)
- Xia Zhou
- Medical College of Soochow University, Suzhou 215123, P. R. China
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, WHO Collaborating Centre for Tropical Diseases, National Center for International Research on Tropical Diseases, Key Laboratory of Parasite and Vector Biology, Ministry of Health, Shanghai 200025, P. R. China
| | - Ernest Tambo
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, WHO Collaborating Centre for Tropical Diseases, National Center for International Research on Tropical Diseases, Key Laboratory of Parasite and Vector Biology, Ministry of Health, Shanghai 200025, P. R. China
- Department of Biochemistry, Higher Institute of Health Sciences, Université des Montagnes, Bangangté BP208, Cameroon
| | - Jing Su
- School of Life Science, Fudan University, Shanghai 200438, P. R. China
| | - Qiang Fang
- Department of Microbiology and Parasitology, Bengbu Medical College, Bengbu 233030, P. R. China
| | - Wei Ruan
- Department of Parasitic Disease Control and Prevention, Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou 310051, P. R. China
| | - Jun-Hu Chen
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, WHO Collaborating Centre for Tropical Diseases, National Center for International Research on Tropical Diseases, Key Laboratory of Parasite and Vector Biology, Ministry of Health, Shanghai 200025, P. R. China
| | - Ming-Bo Yin
- School of Life Science, Fudan University, Shanghai 200438, P. R. China
| | - Xiao-Nong Zhou
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, WHO Collaborating Centre for Tropical Diseases, National Center for International Research on Tropical Diseases, Key Laboratory of Parasite and Vector Biology, Ministry of Health, Shanghai 200025, P. R. China
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153
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Singh US, Siwal N, Pande V, Das A. Can Mixed Parasite Infections Thwart Targeted Malaria Elimination Program in India? Biomed Res Int 2017; 2017:2847548. [PMID: 28900620 PMCID: PMC5576395 DOI: 10.1155/2017/2847548] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/29/2017] [Revised: 07/09/2017] [Accepted: 07/13/2017] [Indexed: 12/31/2022]
Abstract
India is highly endemic to malaria with prevalence of all five species of human malaria parasites of Plasmodium genus. India is set for malaria elimination by 2030. Since cases of mixed Plasmodium species infections remain usually undetected but cause huge disease burden, in order to understand the distributional prevalence of both monospecies infections and mixed species infections in India, we collated published data on the differential infection incidences of the five different malaria parasites based on PCR diagnostic assay. About 11% of total cases were due to mixed species infection. Among several interesting observations on both single and mixed parasitic infections, incidences of Plasmodium falciparum monoinfection were found to be significantly higher than P. vivax monoinfection. Also, P. malariae seems to be emerging as a potential malaria threat in India. Putting all the facts together, it appears that the dream of achieving malaria elimination in India will not be completely successful without dealing with mixed species infection.
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Affiliation(s)
- Upasana Shyamsunder Singh
- Division of Genomic Epidemiology, ICMR-Centre for Research in Medical Entomology, No. 4, Sarojini Street, Chinna Chokkikulam, Madurai 625002, India
| | - Nisha Siwal
- Division of Genomic Epidemiology, ICMR-Centre for Research in Medical Entomology, No. 4, Sarojini Street, Chinna Chokkikulam, Madurai 625002, India
| | - Veena Pande
- Department of Biotechnology, Kumaun University, Nainital 263001, India
| | - Aparup Das
- Division of Genomic Epidemiology, ICMR-Centre for Research in Medical Entomology, No. 4, Sarojini Street, Chinna Chokkikulam, Madurai 625002, India
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154
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de Oliveira TC, Rodrigues PT, Menezes MJ, Gonçalves-Lopes RM, Bastos MS, Lima NF, Barbosa S, Gerber AL, Loss de Morais G, Berná L, Phelan J, Robello C, de Vasconcelos ATR, Alves JMP, Ferreira MU. Genome-wide diversity and differentiation in New World populations of the human malaria parasite Plasmodium vivax. PLoS Negl Trop Dis 2017; 11:e0005824. [PMID: 28759591 PMCID: PMC5552344 DOI: 10.1371/journal.pntd.0005824] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Revised: 08/10/2017] [Accepted: 07/20/2017] [Indexed: 01/15/2023] Open
Abstract
Background The Americas were the last continent colonized by humans carrying malaria parasites. Plasmodium falciparum from the New World shows very little genetic diversity and greater linkage disequilibrium, compared with its African counterparts, and is clearly subdivided into local, highly divergent populations. However, limited available data have revealed extensive genetic diversity in American populations of another major human malaria parasite, P. vivax. Methods We used an improved sample preparation strategy and next-generation sequencing to characterize 9 high-quality P. vivax genome sequences from northwestern Brazil. These new data were compared with publicly available sequences from recently sampled clinical P. vivax isolates from Brazil (BRA, total n = 11 sequences), Peru (PER, n = 23), Colombia (COL, n = 31), and Mexico (MEX, n = 19). Principal findings/Conclusions We found that New World populations of P. vivax are as diverse (nucleotide diversity π between 5.2 × 10−4 and 6.2 × 10−4) as P. vivax populations from Southeast Asia, where malaria transmission is substantially more intense. They display several non-synonymous nucleotide substitutions (some of them previously undescribed) in genes known or suspected to be involved in antimalarial drug resistance, such as dhfr, dhps, mdr1, mrp1, and mrp-2, but not in the chloroquine resistance transporter ortholog (crt-o) gene. Moreover, P. vivax in the Americas is much less geographically substructured than local P. falciparum populations, with relatively little between-population genome-wide differentiation (pairwise FST values ranging between 0.025 and 0.092). Finally, P. vivax populations show a rapid decline in linkage disequilibrium with increasing distance between pairs of polymorphic sites, consistent with very frequent outcrossing. We hypothesize that the high diversity of present-day P. vivax lineages in the Americas originated from successive migratory waves and subsequent admixture between parasite lineages from geographically diverse sites. Further genome-wide analyses are required to test the demographic scenario suggested by our data. Plasmodium vivax is the most common human malaria parasite in the Americas, but how and when this species arrived in the New World remains unclear. Here we describe high-quality whole-genome sequence data for nine P. vivax isolates from Brazil, a country that accounts for 37% of the malaria burden in this continent, and compare these data with additional publicly available P. vivax genomes from Brazil, Peru, Colombia, and Mexico. P. vivax populations from the New World were found to be as diverse as their counterparts from areas with substantially higher malaria transmission, such as Southeast Asia, and to carry several non-synonymous substitutions in candidate drug-resistance genes. Moreover, genome-wide patterns of linkage disequilibrium between pairs of polymorphic sites are consistent with very frequent outcrossing in these populations. Interestingly, local P. vivax is more polymorphic, with less between-population differentiation, than sympatric populations of P. falciparum, possibly as a result of different demographic histories of these two species in the Americas. We hypothesize that local P. vivax lineages originated from successive migratory waves and subsequent admixture between parasites from geographically diverse sites.
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Affiliation(s)
- Thais C. de Oliveira
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Priscila T. Rodrigues
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Maria José Menezes
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Raquel M. Gonçalves-Lopes
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Melissa S. Bastos
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Nathália F. Lima
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Susana Barbosa
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Alexandra L. Gerber
- Unit of Computational Genomics Darcy Fontoura de Almeida, Laboratory of Bioinformatics, National Laboratory of Scientific Computation, Petrópolis, Brazil
| | - Guilherme Loss de Morais
- Unit of Computational Genomics Darcy Fontoura de Almeida, Laboratory of Bioinformatics, National Laboratory of Scientific Computation, Petrópolis, Brazil
| | - Luisa Berná
- Unit of Molecular Biology, Pasteur Institute of Montevideo, Montevideo, Uruguay
| | - Jody Phelan
- London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Carlos Robello
- Unit of Molecular Biology, Pasteur Institute of Montevideo, Montevideo, Uruguay
| | - Ana Tereza R. de Vasconcelos
- Unit of Computational Genomics Darcy Fontoura de Almeida, Laboratory of Bioinformatics, National Laboratory of Scientific Computation, Petrópolis, Brazil
| | - João Marcelo P. Alves
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Marcelo U. Ferreira
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
- * E-mail:
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155
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Lo E, Hemming-Schroeder E, Yewhalaw D, Nguyen J, Kebede E, Zemene E, Getachew S, Tushune K, Zhong D, Zhou G, Petros B, Yan G. Transmission dynamics of co-endemic Plasmodium vivax and P. falciparum in Ethiopia and prevalence of antimalarial resistant genotypes. PLoS Negl Trop Dis 2017; 11:e0005806. [PMID: 28746333 PMCID: PMC5546713 DOI: 10.1371/journal.pntd.0005806] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Revised: 08/07/2017] [Accepted: 07/13/2017] [Indexed: 11/19/2022] Open
Abstract
Ethiopia is one of the few African countries where Plasmodium vivax is co-endemic with P. falciparum. Malaria transmission is seasonal and transmission intensity varies mainly by landscape and climate. Although the recent emergence of drug resistant parasites presents a major issue to malaria control in Ethiopia, little is known about the transmission pathways of parasite species and prevalence of resistant markers. This study used microsatellites to determine population diversity and gene flow patterns of P. falciparum (N = 226) and P. vivax (N = 205), as well as prevalence of drug resistant markers to infer the impact of gene flow and existing malaria treatment regimes. Plasmodium falciparum indicated a higher rate of polyclonal infections than P. vivax. Both species revealed moderate genetic diversity and similar population structure. Populations in the northern highlands were closely related to the eastern Rift Valley, but slightly distinct from the southern basin area. Gene flow via human migrations between the northern and eastern populations were frequent and mostly bidirectional. Landscape genetic analyses indicated that environmental heterogeneity and geographical distance did not constrain parasite gene flow. This may partly explain similar patterns of resistant marker prevalence. In P. falciparum, a high prevalence of mutant alleles was detected in codons related to chloroquine (pfcrt and pfmdr1) and sulfadoxine-pyrimethamine (pfdhps and pfdhfr) resistance. Over 60% of the samples showed pfmdr1 duplications. Nevertheless, no mutation was detected in pfK13 that relates to artemisinin resistance. In P. vivax, while sequences of pvcrt-o were highly conserved and less than 5% of the samples showed pvmdr duplications, over 50% of the samples had pvmdr1 976F mutation. It remains to be tested if this mutation relates to chloroquine resistance. Monitoring the extent of malaria spread and markers of drug resistance is imperative to inform policy for evidence-based antimalarial choice and interventions. To effectively reduce malaria burden in Ethiopia, control efforts should focus on seasonal migrant populations.
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MESH Headings
- Adolescent
- Adult
- Aged
- Aged, 80 and over
- Antimalarials/pharmacology
- Child
- Child, Preschool
- Drug Resistance
- Endemic Diseases
- Ethiopia/epidemiology
- Female
- Gene Flow
- Genes, Protozoan
- Genetics, Population
- Genotype
- Humans
- Infant
- Infant, Newborn
- Malaria, Falciparum/epidemiology
- Malaria, Falciparum/parasitology
- Malaria, Falciparum/transmission
- Malaria, Vivax/epidemiology
- Malaria, Vivax/parasitology
- Malaria, Vivax/transmission
- Male
- Microsatellite Repeats
- Middle Aged
- Plasmodium falciparum/drug effects
- Plasmodium falciparum/genetics
- Plasmodium falciparum/isolation & purification
- Plasmodium vivax/drug effects
- Plasmodium vivax/genetics
- Plasmodium vivax/isolation & purification
- Prevalence
- Young Adult
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Affiliation(s)
- Eugenia Lo
- Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, North Carolina, United States of America
- * E-mail: (EL); (GY)
| | | | - Delenasaw Yewhalaw
- Department of Medical Laboratory Sciences and Pathology, College of Public Health and Medical Sciences, Jimma University, Jimma, Ethiopia
| | - Jennifer Nguyen
- Program in Public Health, University of California, Irvine, California, United States of America
| | - Estifanos Kebede
- Department of Medical Laboratory Sciences and Pathology, College of Public Health and Medical Sciences, Jimma University, Jimma, Ethiopia
| | - Endalew Zemene
- Department of Medical Laboratory Sciences and Pathology, College of Public Health and Medical Sciences, Jimma University, Jimma, Ethiopia
| | - Sisay Getachew
- College of Natural Sciences, Addis Ababa University, Addis Ababa, Ethiopia
| | - Kora Tushune
- Department of Health Services Management, College of Public Health and Medical Sciences, Jimma University, Jimma, Ethiopia
| | - Daibin Zhong
- Program in Public Health, University of California, Irvine, California, United States of America
| | - Guofa Zhou
- Program in Public Health, University of California, Irvine, California, United States of America
| | - Beyene Petros
- College of Natural Sciences, Addis Ababa University, Addis Ababa, Ethiopia
| | - Guiyun Yan
- Program in Public Health, University of California, Irvine, California, United States of America
- * E-mail: (EL); (GY)
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156
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Rovira-Vallbona E, Contreras-Mancilla JJ, Ramirez R, Guzmán-Guzmán M, Carrasco-Escobar G, Llanos-Cuentas A, Vinetz JM, Gamboa D, Rosanas-Urgell A. Predominance of asymptomatic and sub-microscopic infections characterizes the Plasmodium gametocyte reservoir in the Peruvian Amazon. PLoS Negl Trop Dis 2017; 11:e0005674. [PMID: 28671944 PMCID: PMC5510906 DOI: 10.1371/journal.pntd.0005674] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Revised: 07/14/2017] [Accepted: 05/31/2017] [Indexed: 11/18/2022] Open
Abstract
Malaria transmission requires that Anopheles mosquitoes ingest Plasmodium gametocyte stages circulating in the human bloodstream. In the context of malaria elimination, understanding the epidemiology of gametocytes relative to all Plasmodium infections and the contribution of asymptomatic and sub-microscopic parasite carriers to the gametocyte reservoir is necessary, especially in low endemic settings with predominance of P.vivax. A 13-month longitudinal study was conducted in two communities (n = 1935 individuals) of Loreto Department, Peru, with five active screenings for Plasmodium infections and gametocyte stages by quantitative real-time PCR (qPCR) and reverse transcription (RT)-qPCR, respectively. Parasite prevalence by qPCR was 7.2% for P.vivax (n = 520/7235; range by survey 6.0%-8.1%) and 3.2% for P.falciparum (n = 235/7235; range by survey 0.4%-7.7%). Sub-microscopic infections accounted for 73.5% of P.vivax (range by survey 60%-89%) and almost the totality of P.falciparum cases. Gametocytes were found in 28.4% P.vivax infections (range by survey 18.7%-34.1%), with a peak of 61.5% in one community at the start of the transmission season. About 59.8% of all P.vivax gametocyte carriers were asymptomatic and 31.9% were sub-microscopic. Age patterns for gametocyte prevalence paralleled asexual stage infections and peaked among >15–25 year old individuals. Asexual parasite density was found to be the strongest predictor for P.vivax gametocyte presence in longitudinal multivariate analysis (odds ratio 2.33 [95% confidence interval 1.96, 2.78]; P<0.001). Despite significant differences in seasonality patterns and P.vivax prevalence found at the local scale, sub-microscopic and asymptomatic infections predominate and contribute significantly to the gametocyte reservoir in different communities of the Peruvian Amazon. Control and elimination campaigns need sensitive tools to detect all infections that escape routine malaria surveillance, which may contribute to maintain transmission in the region. Malaria elimination, i.e. the complete interruption of parasite transmission in a region, is in the agenda of health authorities in countries that achieved substantial reduction of the disease burden in the past decade. However, our understanding of transmission epidemiology for low transmission areas where Plasmodium vivax is endemic, like the Amazon basin, is still limited. In this study, we describe the prevalence and risk factors for carrying the parasite stages that are transmitted to the mosquito vectors, named gametocytes, in 1935 individuals from two communities of the Peruvian Amazon that were regularly screened during 1 year. We report that malaria infections with no clinical symptoms and those with parasite levels below microscopy detection threshold, account for two thirds of all P.vivax infections with gametocytes, and that the highest infection rate is found among young adults. In addition, almost the totality of P.falciparum infections detected was sub-microscopic. Because all these infections escape current malaria surveillance systems -based on passive case detection and/or microscopy diagnosis-, new approaches are necessary to target all infections in order to eliminate the malaria transmission reservoir in Peru.
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Affiliation(s)
- Eduard Rovira-Vallbona
- Department of Biomedical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
- * E-mail:
| | | | - Roberson Ramirez
- Laboratorio Satelite Iquitos UPCH-UCSD, Universidad Peruana Cayetano Heredia, Loreto, Peru
| | - Mitchel Guzmán-Guzmán
- Laboratorio Satelite Iquitos UPCH-UCSD, Universidad Peruana Cayetano Heredia, Loreto, Peru
| | - Gabriel Carrasco-Escobar
- Instituto de Medicina Tropical Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Alejandro Llanos-Cuentas
- Instituto de Medicina Tropical Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Joseph M. Vinetz
- Department of Medicine, University of California San Diego, San Diego, California, United States of America
| | - Dionicia Gamboa
- Instituto de Medicina Tropical Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Peru
- Departamento de Ciencias Celulares y Moleculares, Facultad de Ciencias y Filosofia, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Anna Rosanas-Urgell
- Department of Biomedical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
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157
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Wang B, Nyunt MH, Yun SG, Lu F, Cheng Y, Han JH, Ha KS, Park WS, Hong SH, Lim CS, Cao J, Sattabongkot J, Kyaw MP, Cui L, Han ET. Variable number of tandem repeats of 9 Plasmodium vivax genes among Southeast Asian isolates. Acta Trop 2017; 170:161-168. [PMID: 28119047 DOI: 10.1016/j.actatropica.2017.01.013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Revised: 01/12/2017] [Accepted: 01/16/2017] [Indexed: 02/01/2023]
Abstract
The variable number of tandem repeats (VNTRs) provides valuable information about both the functional and evolutionary aspects of genetic diversity. Comparative analysis of 3 Plasmodium falciparum genomes has shown that more than 9% of its open reading frames (ORFs) harbor VNTRs. Although microsatellites and VNTR genes of P. vivax were reported, the VNTR polymorphism of genes has not been examined widely. In this study, 230 P. vivax genes were analyzed for VNTRs by SERV, and 33 kinds of TR deletions or insertions from 29 P. vivax genes (12.6%) were found. Of these, 9 VNTR fragments from 8 P. vivax genes were used for PCR amplification and sequence analysis to examine the genetic diversity among 134 isolates from four Southeast Asian countries (China, Republic of Korea, Thailand, and Myanmar) with different malaria endemicity. We confirmed the existence of extensive polymorphism of VNTR fragments in field isolates. This detection provides several suitable markers for analysis of the molecular epidemiology of P. vivax field isolates.
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Affiliation(s)
- Bo Wang
- Department of Medical Environmental Biology and Tropical Medicine, School of Medicine, Kangwon National University, Chuncheon, Gangwon-do 200-701, Republic of Korea; Department of Clinical Laboratory, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, People's Republic of China
| | - Myat Htut Nyunt
- Department of Medical Environmental Biology and Tropical Medicine, School of Medicine, Kangwon National University, Chuncheon, Gangwon-do 200-701, Republic of Korea; Department of Medical Research, Yangon 11191, Myanmar
| | - Seung-Gyu Yun
- Department of Laboratory Medicine, College of Medicine, Korea University, Seoul 152-703, Republic of Korea
| | - Feng Lu
- Department of Medical Environmental Biology and Tropical Medicine, School of Medicine, Kangwon National University, Chuncheon, Gangwon-do 200-701, Republic of Korea; Jiangsu Institute of Parasitic Diseases, Wuxi, Jiangsu 214064, People's Republic of China
| | - Yang Cheng
- Department of Medical Environmental Biology and Tropical Medicine, School of Medicine, Kangwon National University, Chuncheon, Gangwon-do 200-701, Republic of Korea; Laboratory of Pathogen Infection and Immunity, Wuxi School of Medicine, Jiangnan University, Wuxi, Jiangsu 214122, People's Republic of China
| | - Jin-Hee Han
- Department of Medical Environmental Biology and Tropical Medicine, School of Medicine, Kangwon National University, Chuncheon, Gangwon-do 200-701, Republic of Korea
| | - Kwon-Soo Ha
- Department of Molecular and Cellular Biochemistry, School of Medicine, Kangwon National University, Chuncheon, Gangwon-do 200-701, Republic of Korea
| | - Won Sun Park
- Department of Physiology, School of Medicine, Kangwon National University, Chuncheon, Gangwon-do 200-701, Republic of Korea
| | - Seok-Ho Hong
- Department of Internal Medicine, School of Medicine, Kangwon National University, Chuncheon, Gangwon-do 200-701, Republic of Korea
| | - Chae-Seung Lim
- Department of Laboratory Medicine, College of Medicine, Korea University, Seoul 152-703, Republic of Korea
| | - Jun Cao
- Jiangsu Institute of Parasitic Diseases, Wuxi, Jiangsu 214064, People's Republic of China
| | - Jetsumon Sattabongkot
- Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok 10400, Thailand
| | | | - Liwang Cui
- Department of Entomology, Pennsylvania State University, University Park, PA 16802, USA
| | - Eun-Taek Han
- Department of Medical Environmental Biology and Tropical Medicine, School of Medicine, Kangwon National University, Chuncheon, Gangwon-do 200-701, Republic of Korea.
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158
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Pava Z, Noviyanti R, Handayuni I, Trimarsanto H, Trianty L, Burdam FH, Kenangalem E, Utami RAS, Tirta YK, Coutrier F, Poespoprodjo JR, Price RN, Marfurt J, Auburn S. Genetic micro-epidemiology of malaria in Papua Indonesia: Extensive P. vivax diversity and a distinct subpopulation of asymptomatic P. falciparum infections. PLoS One 2017; 12:e0177445. [PMID: 28498860 PMCID: PMC5428948 DOI: 10.1371/journal.pone.0177445] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Accepted: 04/27/2017] [Indexed: 01/13/2023] Open
Abstract
BACKGROUND Genetic analyses of Plasmodium have potential to inform on transmission dynamics, but few studies have evaluated this on a local spatial scale. We used microsatellite genotyping to characterise the micro-epidemiology of P. vivax and P. falciparum diversity to inform malaria control strategies in Timika, Papua Indonesia. METHODS Genotyping was undertaken on 713 sympatric P. falciparum and P. vivax isolates from a cross-sectional household survey and clinical studies conducted in Timika. Standard population genetic measures were applied, and the data was compared to published data from Kalimantan, Bangka, Sumba and West Timor. RESULTS Higher diversity (HE = 0.847 vs 0.625; p = 0.017) and polyclonality (46.2% vs 16.5%, p<0.001) were observed in P. vivax versus P. falciparum. Distinct P. falciparum substructure was observed, with two subpopulations, K1 and K2. K1 was comprised solely of asymptomatic infections and displayed greater relatedness to isolates from Sumba than to K2, possibly reflecting imported infections. CONCLUSIONS The results demonstrate the greater refractoriness of P. vivax versus P. falciparum to control measures, and risk of distinct parasite subpopulations persisting in the community undetected by passive surveillance. These findings highlight the need for complimentary new surveillance strategies to identify transmission patterns that cannot be detected with traditional malariometric methods.
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Affiliation(s)
- Zuleima Pava
- Global and Tropical Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, Northern Territory, Australia
| | - Rintis Noviyanti
- Malaria Pathogenesis Unit, Eijkman Institute for Molecular Biology, Jakarta, Indonesia
| | - Irene Handayuni
- Global and Tropical Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, Northern Territory, Australia
| | - Hidayat Trimarsanto
- Bioinformatics Laboratory, Eijkman Institute for Molecular Biology, Jakarta, Indonesia
- Agency for Assessment and Application of Technology, Jakarta, Indonesia
| | - Leily Trianty
- Malaria Pathogenesis Unit, Eijkman Institute for Molecular Biology, Jakarta, Indonesia
| | - Faustina H. Burdam
- Mimika District Health Authority, Timika, Papua, Indonesia
- Timika Malaria Research Programme, Papuan Health and Community Development Foundation, Timika, Papua, Indonesia
- Pediatric Research Office, Department of Child Health, Faculty of Medicine, Universitas Gadjah Mada, Yogyakarta, Indonesia
| | - Enny Kenangalem
- Mimika District Health Authority, Timika, Papua, Indonesia
- Timika Malaria Research Programme, Papuan Health and Community Development Foundation, Timika, Papua, Indonesia
| | - Retno A. S. Utami
- Malaria Pathogenesis Unit, Eijkman Institute for Molecular Biology, Jakarta, Indonesia
| | - Yusrifar K. Tirta
- Malaria Pathogenesis Unit, Eijkman Institute for Molecular Biology, Jakarta, Indonesia
| | - Farah Coutrier
- Malaria Pathogenesis Unit, Eijkman Institute for Molecular Biology, Jakarta, Indonesia
| | - Jeanne R. Poespoprodjo
- Mimika District Health Authority, Timika, Papua, Indonesia
- Timika Malaria Research Programme, Papuan Health and Community Development Foundation, Timika, Papua, Indonesia
- Pediatric Research Office, Department of Child Health, Faculty of Medicine, Universitas Gadjah Mada, Yogyakarta, Indonesia
| | - Ric N. Price
- Global and Tropical Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, Northern Territory, Australia
- Centre for Tropical Medicine, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, United Kingdom
| | - Jutta Marfurt
- Global and Tropical Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, Northern Territory, Australia
| | - Sarah Auburn
- Global and Tropical Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, Northern Territory, Australia
- * E-mail:
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Diez Benavente E, Ward Z, Chan W, Mohareb FR, Sutherland CJ, Roper C, Campino S, Clark TG. Genomic variation in Plasmodium vivax malaria reveals regions under selective pressure. PLoS One 2017; 12:e0177134. [PMID: 28493919 PMCID: PMC5426636 DOI: 10.1371/journal.pone.0177134] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Accepted: 04/21/2017] [Indexed: 01/06/2023] Open
Abstract
BACKGROUND Although Plasmodium vivax contributes to almost half of all malaria cases outside Africa, it has been relatively neglected compared to the more deadly P. falciparum. It is known that P. vivax populations possess high genetic diversity, differing geographically potentially due to different vector species, host genetics and environmental factors. RESULTS We analysed the high-quality genomic data for 46 P. vivax isolates spanning 10 countries across 4 continents. Using population genetic methods we identified hotspots of selection pressure, including the previously reported MRP1 and DHPS genes, both putative drug resistance loci. Extra copies and deletions in the promoter region of another drug resistance candidate, MDR1 gene, and duplications in the Duffy binding protein gene (PvDBP) potentially involved in erythrocyte invasion, were also identified. For surveillance applications, continental-informative markers were found in putative drug resistance loci, and we show that organellar polymorphisms could classify P. vivax populations across continents and differentiate between Plasmodia spp. CONCLUSIONS This study has shown that genomic diversity that lies within and between P. vivax populations can be used to elucidate potential drug resistance and invasion mechanisms, as well as facilitate the molecular barcoding of the parasite for surveillance applications.
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Affiliation(s)
- Ernest Diez Benavente
- London School of Hygiene and Tropical Medicine, Keppel Street, London, United Kingdom
| | - Zoe Ward
- London School of Hygiene and Tropical Medicine, Keppel Street, London, United Kingdom
- The Bioinformatics Group, School of Water Energy and Environment, Cranfield University, Cranfield, Bedfordshire, United Kingdom
| | - Wilson Chan
- London School of Hygiene and Tropical Medicine, Keppel Street, London, United Kingdom
- Department of Pathology & Laboratory Medicine, Diagnostic & Scientific Centre, Faculty of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Fady R. Mohareb
- Department of Pathology & Laboratory Medicine, Diagnostic & Scientific Centre, Faculty of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Colin J. Sutherland
- London School of Hygiene and Tropical Medicine, Keppel Street, London, United Kingdom
| | - Cally Roper
- London School of Hygiene and Tropical Medicine, Keppel Street, London, United Kingdom
| | - Susana Campino
- London School of Hygiene and Tropical Medicine, Keppel Street, London, United Kingdom
| | - Taane G. Clark
- London School of Hygiene and Tropical Medicine, Keppel Street, London, United Kingdom
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160
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Shahwani MN, Nisar S, Aleem A, Panezai M, Afridi S, Malik SI. Amplification of Mitochondrial DNA for detection of Plasmodiumvivax in Balochistan. J PAK MED ASSOC 2017; 67:677-681. [PMID: 28507350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
OBJECTIVE To access a new step using PCR to amplify the targeted mtDNA sequence for detecting specifically Plasmodium vivax and its co-infections, false positive and false negative results with Plasmodium falciparum. METHODS In this study we have standardized a new technical approach in which the target mitochondrial DNA sequence (mtDNA) was amplified by using a PCR technique as a tool to detect Plasmodium spp. Species specific primers were designed to hybridize with cytochrome c oxidase gene of P. vivax (cox I) and P. falciparum (cox III). Two hundred blood samples were collected on the basis of clinical symptoms which were initially examined through microscopic analysis after preparing Giemsa stained thick and thin blood smears. Afterwards genomic DNA was extracted from all samples and was then subjected to PCR amplification by using species specific primers and amplified segments were sequenced for confirmation of results. RESULTS One-hundred and thirty-two blood samples were detected as positive for malaria by PCR, out of which 64 were found to be positive by PCR and 53 by both microscopy and PCR for P.vivax infection. Nine samples were found to be false negative, one P.vivax mono infection was declared as co infection by PCR and 3 samples identified as having P.falciparum gametes were confirmed as P.vivax by PCR amplification. Sensitivity and specificity were found to be 85% and 92% respectively. CONCLUSIONS Results obtained through PCR method were comparatively better and reliable than microscopy.
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Affiliation(s)
- Muhammad Naeem Shahwani
- Department of Biotechnology, Faculty of Life Sciences and Informatics (FLS&I), Balochistan University of Information Technology, Engineering and Management Sciences (BUITEMS), Quetta, Balochistan, Pakistan
| | - Samia Nisar
- Department of Biotechnology, Faculty of Life Sciences and Informatics (FLS&I), Balochistan University of Information Technology, Engineering and Management Sciences (BUITEMS), Quetta, Balochistan, Pakistan
| | - Abdul Aleem
- Department of Biotechnology, Faculty of Life Sciences and Informatics (FLS&I), Balochistan University of Information Technology, Engineering and Management Sciences (BUITEMS), Quetta, Balochistan, Pakistan
| | - Marina Panezai
- Department of Biotechnology, Faculty of Life Sciences and Informatics (FLS&I), Balochistan University of Information Technology, Engineering and Management Sciences (BUITEMS), Quetta, Balochistan, Pakistan
| | - Sarwat Afridi
- Department of Biotechnology, Faculty of Life Sciences and Informatics (FLS&I), Balochistan University of Information Technology, Engineering and Management Sciences (BUITEMS), Quetta, Balochistan, Pakistan
| | - Shaukat Iqbal Malik
- Department of Bioinformatics & Biological Sciences, Capital University of Science & Technology, Expressway, Islamabad, Pakistan
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Kochar SK, Kamath SD, Toshan N, Singhal Y, Kochar A. A case of Plasmodium vivax malaria presenting as acute cerebral infarct. J Vector Borne Dis 2017; 54:197-200. [PMID: 28748845] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023] Open
Affiliation(s)
- Sanjay Kumar Kochar
- Department of Medicine, Sardar Patel Medical College and Associated Group of Hospitals, Bikaner, Rajasthan, India
| | - Sneha Dayanand Kamath
- Department of Medicine, Sardar Patel Medical College and Associated Group of Hospitals, Bikaner, Rajasthan, India
| | - Nitesh Toshan
- Department of Medicine, Sardar Patel Medical College and Associated Group of Hospitals, Bikaner, Rajasthan, India
| | - Yamini Singhal
- Department of Ophthalmology, Sardar Patel Medical College and Associated Group of Hospitals, Bikaner, Rajasthan, India
| | - Anju Kochar
- Department of Ophthalmology, Sardar Patel Medical College and Associated Group of Hospitals, Bikaner, Rajasthan, India
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Bitencourt Chaves L, Perce-da-Silva DDS, Rodrigues-da-Silva RN, Martins da Silva JH, Cassiano GC, Machado RLD, Pratt-Riccio LR, Banic DM, Lima-Junior JDC. Plasmodium vivax Cell Traversal Protein for Ookinetes and Sporozoites (PvCelTOS) gene sequence and potential epitopes are highly conserved among isolates from different regions of Brazilian Amazon. PLoS Negl Trop Dis 2017; 11:e0005344. [PMID: 28158176 PMCID: PMC5310920 DOI: 10.1371/journal.pntd.0005344] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Revised: 02/15/2017] [Accepted: 01/21/2017] [Indexed: 01/07/2023] Open
Abstract
The Plasmodium vivax Cell-traversal protein for ookinetes and sporozoites (PvCelTOS) plays an important role in the traversal of host cells. Although essential to PvCelTOS progress as a vaccine candidate, its genetic diversity remains uncharted. Therefore, we investigated the PvCelTOS genetic polymorphism in 119 field isolates from five different regions of Brazilian Amazon (Manaus, Novo Repartimento, Porto Velho, Plácido de Castro and Oiapoque). Moreover, we also evaluated the potential impact of non-synonymous mutations found in the predicted structure and epitopes of PvCelTOS. The field isolates showed high similarity (99.3% of bp) with the reference Sal-1 strain, presenting only four Single-Nucleotide Polymorphisms (SNP) at positions 24A, 28A, 109A and 352C. The frequency of synonymous C109A (82%) was higher than all others (p<0.0001). However, the non-synonymous G28A and G352C were observed in 9.2% and 11.7% isolates. The great majority of the isolates (79.8%) revealed complete amino acid sequence homology with Sal-1, 10.9% presented complete homology with Brazil I and two undescribed PvCelTOS sequences were observed in 9.2% field isolates. Concerning the prediction analysis, the N-terminal substitution (Gly10Ser) was predicted to be within a B-cell epitope (PvCelTOS Accession Nos. AB194053.1) and exposed at the protein surface, while the Val118Leu substitution was not a predicted epitope. Therefore, our data suggest that although G28A SNP might interfere in potential B-cell epitopes at PvCelTOS N-terminal region the gene sequence is highly conserved among the isolates from different geographic regions, which is an important feature to be taken into account when evaluating its potential as a vaccine candidate. Cell-traversal protein for ookinetes and sporozoites (CelTOS) presents a pivotal role in the cell traversal of host cells in mosquito and vertebrate hosts. For this reason, it has been considered a potential novel alternative for a vaccine against malaria caused by P. falciparum. However, little is known about its orthologous P. vivax CelTOS. Although the genetic diversity of this protein could be a limiting factor for acquisition of immunity and present implications for an effective vaccine development, it has never been explored. Thus, considering that the epidemiology of malaria in Brazil presents variable transmission rates and the knowledge on the genetic polymorphism of PvCelTOS remains unknown, we aimed to identify the pvceltos gene in isolates from five different regions of the Brazilian Amazon and to study the potential impacts of the genetic diversity of PvCelTOS in protein structures and predicted epitopes. Our findings indicate that PvCelTOS is an extremely conserved protein, presenting only four SNPs in the entire sequences of field isolates from Brazilian Amazon. The two non-synonymous mutations found in our field isolates presented no significant effect on the protein structure and a very low impact on potential T and B-cell epitopes indicated by our epitope prediction. Collectively, our data suggest that the small need to avoid the immune recognition by the human host and its importance on the parasite’s survival and transmission reflects a very conservative profile of pvceltos gene in field samples from Brazil and other endemic areas worldwide.
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Affiliation(s)
- Lana Bitencourt Chaves
- Laboratory of Immunoparasitology, Oswaldo Cruz Institute, Fiocruz, Rio de Janeiro, Rio de Janeiro, Brazil
| | | | | | | | - Gustavo Capatti Cassiano
- Laboratory of Tropical Diseases - Prof. Luiz Jacintho da Silva, Department of Genetics, Evolution and Bioagents, University of Campinas, Campinas, São Paulo, Brazil
| | | | - Lilian Rose Pratt-Riccio
- Laboratory of Malaria Research, Oswaldo Cruz Institute, Fiocruz, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Dalma Maria Banic
- Laboratory of Clinical Immunology, Oswaldo Cruz Institute, Fiocruz, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Josué da Costa Lima-Junior
- Laboratory of Immunoparasitology, Oswaldo Cruz Institute, Fiocruz, Rio de Janeiro, Rio de Janeiro, Brazil
- * E-mail:
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163
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Castillo AI, Andreína Pacheco M, Escalante AA. Evolution of the merozoite surface protein 7 (msp7) family in Plasmodium vivax and P. falciparum: A comparative approach. Infect Genet Evol 2017; 50:7-19. [PMID: 28163236 DOI: 10.1016/j.meegid.2017.01.024] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Revised: 01/19/2017] [Accepted: 01/23/2017] [Indexed: 01/17/2023]
Abstract
Malaria parasites (genus Plasmodium) are a diverse group found in many species of vertebrate hosts. These parasites invade red blood cells in a complex process comprising several proteins, many encoded by multigene families, one of which is merozoite surface protein 7 (msp7). In the case of Plasmodium vivax, the most geographically widespread human-infecting species, differences in the number of paralogs within multigene families have been previously explained, at least in part, as potential adaptations to the human host. To explore this in msp7, we studied its orthologs in closely related nonhuman primate parasites; investigating both paralog evolutionary history and genetic polymorphism. The emerging patterns were then compared with the human parasite Plasmodium falciparum. We found that the evolution of the msp7 family is consistent with a birth-and-death model, where duplications, pseudogenizations, and gene loss events are common. However, all paralogs in P. vivax and P. falciparum had orthologs in their closely related species in non-human primates indicating that the ancestors of those paralogs precede the events leading to their origins as human parasites. Thus, the number of paralogs cannot be explained as an adaptation to human hosts. Although there is no functional information for msp7 in P. vivax, we found evidence for purifying selection in the genetic polymorphism of some of its paralogs as well as their orthologs in closely related non-human primate parasites. We also found evidence indicating that a few of P. vivax's paralogs may have diverged from their orthologs in non-human primates by episodic positive selection. Hence, they may had been under selection when the lineage leading to P. vivax diverged from the Asian non-human primates and switched into Homininae. All these lines of evidence suggest that msp7 is functionally important in P. vivax.
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Affiliation(s)
| | - M Andreína Pacheco
- Department of Biology, Institute for Genomics and Evolutionary Medicine (igem), Temple University, Philadelphia, PA, USA
| | - Ananias A Escalante
- Department of Biology, Institute for Genomics and Evolutionary Medicine (igem), Temple University, Philadelphia, PA, USA.
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Singh R, Singh DP, Savargaonkar D, Singh OP, Bhatt RM, Valecha N. Evaluation of SYBR green I based visual loop-mediated isothermal amplification (LAMP) assay for genus and species-specific diagnosis of malaria in P. vivax and P. falciparum endemic regions. J Vector Borne Dis 2017; 54:54-60. [PMID: 28352046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023] Open
Abstract
BACKGROUND & OBJECTIVES Loop-mediated isothermal amplification (LAMP) is an emerging nucleic acid based diag- nostic approach that is easily adaptable to the field settings with limited technical resources. This study was aimed to evaluate the LAMP assay for the detection and identification of Plasmodium falciparum and P. vivax infection in malaria suspected cases using genus and species-specific assay. METHODS The 18S rRNA-based LAMP assay was evaluated for diagnosis of genus Plasmodium, and species- specific diagnosis of P. falciparum and P. vivax, infection employing 317 malaria suspected cases, and the results were compared with those obtained by 18S nested PCR (n-PCR). All the samples were confirmed by microscopy for the presence of Plasmodium parasite. RESULTS The n-PCR was positive in all Plasmodium-infected cases (n=257; P. falciparum=133; P. vivax=124) and negative in microscopy negative cases (n=58) except for two cases which were positive for P. vivax, giving a sen- sitivity of 100% (95% CI: 97.04-100%) and a specificity of 100% (95% CI: 88.45-99.5%). Genus-specific LAMP assay missed 11 (3.2%) microscopy and n-PCR confirmed vivax malaria cases. Considering PCR results as a refer- ence, LAMP was 100% sensitive and specific for P. falciparum, whereas it exhibited 95.16% sensitivity and 96.7% specificity for P. vivax. The n-PCR assay detected 10 mixed infection cases while species-specific LAMP detected five mixed infection cases of P. vivax and P. falciparum, which were not detected by microscopy. INTERPRETATION & CONCLUSION Genus-specific LAMP assay displayed low sensitivity. Falciparum specific LAMP assay displayed high sensitivity whereas vivax specific LAMP assay displayed low sensitivity. Failed detection of vivax cases otherwise confirmed by the n-PCR assay indicates exploitation of new targets and improved detection methods to attain 100% results for P. vivax detection.
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Affiliation(s)
- Ruchi Singh
- National Institute of Malaria Research (ICMR), Dwarka; National Institute of Pathology (ICMR), Safdarjung Hospital Campus, New Delhi, India
| | | | | | - Om P Singh
- National Institute of Malaria Research (ICMR), Dwarka, India
| | - Rajendra M Bhatt
- National Institute of Malaria Research, Field Unit, Raipur, Chhattisgarh, India
| | - Neena Valecha
- National Institute of Malaria Research (ICMR), Dwarka, India
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Santos-Vega M, Bouma MJ, Kohli V, Pascual M. Population Density, Climate Variables and Poverty Synergistically Structure Spatial Risk in Urban Malaria in India. PLoS Negl Trop Dis 2016; 10:e0005155. [PMID: 27906962 PMCID: PMC5131912 DOI: 10.1371/journal.pntd.0005155] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Accepted: 11/02/2016] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND The world is rapidly becoming urban with the global population living in cities projected to double by 2050. This increase in urbanization poses new challenges for the spread and control of communicable diseases such as malaria. In particular, urban environments create highly heterogeneous socio-economic and environmental conditions that can affect the transmission of vector-borne diseases dependent on human water storage and waste water management. Interestingly India, as opposed to Africa, harbors a mosquito vector, Anopheles stephensi, which thrives in the man-made environments of cities and acts as the vector for both Plasmodium vivax and Plasmodium falciparum, making the malaria problem a truly urban phenomenon. Here we address the role and determinants of within-city spatial heterogeneity in the incidence patterns of vivax malaria, and then draw comparisons with results for falciparum malaria. METHODOLOGY/PRINCIPAL FINDINGS Statistical analyses and a phenomenological transmission model are applied to an extensive spatio-temporal dataset on cases of Plasmodium vivax in the city of Ahmedabad (Gujarat, India) that spans 12 years monthly at the level of wards. A spatial pattern in malaria incidence is described that is largely stationary in time for this parasite. Malaria risk is then shown to be associated with socioeconomic indicators and environmental parameters, temperature and humidity. In a more dynamical perspective, an Inhomogeneous Markov Chain Model is used to predict vivax malaria risk. Models that account for climate factors, socioeconomic level and population size show the highest predictive skill. A comparison to the transmission dynamics of falciparum malaria reinforces the conclusion that the spatio-temporal patterns of risk are strongly driven by extrinsic factors. CONCLUSION/SIGNIFICANCE Climate forcing and socio-economic heterogeneity act synergistically at local scales on the population dynamics of urban malaria in this city. The stationarity of malaria risk patterns provides a basis for more targeted intervention, such as vector control, based on transmission 'hotspots'. This is especially relevant for P. vivax, a more resilient parasite than P. falciparum, due to its ability to relapse and the operational shortcomings of delivering a "radical cure".
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Affiliation(s)
- Mauricio Santos-Vega
- Department of Ecology and Evolution, University of Chicago, Chicago, United States of America
| | - Menno J Bouma
- London School of Hygiene and Tropical Medicine, University of London, United Kingdom
- Institute for Climate Sciences (IC3), University of Barcelona, Barcelona, Spain
| | - Vijay Kohli
- Ahmedabad Municipal Corporation, Ahmedabad, India
| | - Mercedes Pascual
- Department of Ecology and Evolution, University of Chicago, Chicago, United States of America
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166
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Shahwani Z, Aleem A, Ahmed N, Mushtaq M, Afridi S. A PCR method based on 18S rRNA gene for detection of malaria parasite in Balochistan. J PAK MED ASSOC 2016; 66:1587-1591. [PMID: 28179695] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
OBJECTIVE To establish a polymerase chain reaction method based on 18S ribosomal ribonucleic acid gene for the detection of plasmodium deoxyribonucleic acid in patients suffering from malaria symptoms. METHODS This cross-sectional study was conducted from September 2013 to October 2014 in district Quetta of Pakistan's Balochistan province. Blood samples were collected from patients suffering from general symptoms of malaria. A polymerase chain reaction-based technique was applied for the diagnosis of malaria and detection of responsible species in the patients who were suspected to carry the parasite. Performance of this polymerase chain reaction method was compared against the microscopy results. Parasite number was also calculated for microscopy positive samples.All samples after the genomic deoxyribonucleic acid isolation were subjected to polymerase chain reaction amplification and agarose gel electrophoresis. RESULTS Of the 200 samples, 114(57%) were confirmed as positive and 86(43%) as negative for malaria by microscopy. Polymerase chain reaction identified 124(62%) samples as positive and 76(38%) as negative for malaria. The comparative analysis of both diagnostic methods confirmed 109(54.5%) samples as positive by both techniques. Besides, 5(6.58%) samples were identified as false positive and 15(12.1%) samples as false negative by polymerase chain reaction. Sensitivity, specificity and positive predictive values for polymerase chain reaction in comparison to microscopy were 87.98%, 93.42% and 96%, respectively. CONCLUSIONS Polymerase chain reaction-based methods in malaria diagnosis and species identification were found to be more effective than other techniques.
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Affiliation(s)
- Zubeda Shahwani
- Department of Biotechnology and Informatics, Balochistan University of Information Technology, Engineering and Management Sciences (BUITEMS), Quetta, Pakistan
| | - Abdul Aleem
- Department of Biotechnology and Informatics, Balochistan University of Information Technology, Engineering and Management Sciences (BUITEMS), Quetta, Pakistan
| | - Nazeer Ahmed
- Department of Biotechnology and Informatics, Balochistan University of Information Technology, Engineering and Management Sciences (BUITEMS), Quetta, Pakistan
| | - Muhammad Mushtaq
- Department of Biotechnology and Informatics, Balochistan University of Information Technology, Engineering and Management Sciences (BUITEMS), Quetta, Pakistan
| | - Sarwat Afridi
- Department of Biotechnology and Informatics, Balochistan University of Information Technology, Engineering and Management Sciences (BUITEMS), Quetta, Pakistan
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Hamedi Y, Sharifi-Sarasiabi K, Dehghan F, Safari R, To S, Handayuni I, Trimarsanto H, Price RN, Auburn S. Molecular Epidemiology of P. vivax in Iran: High Diversity and Complex Sub-Structure Using Neutral Markers, but No Evidence of Y976F Mutation at pvmdr1. PLoS One 2016; 11:e0166124. [PMID: 27829067 PMCID: PMC5102416 DOI: 10.1371/journal.pone.0166124] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Accepted: 10/24/2016] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Malaria remains endemic at low levels in the south-eastern provinces of Iran bordering Afghanistan and Pakistan, with the majority of cases attributable to P. vivax. The national guidelines recommend chloroquine (CQ) as blood-stage treatment for uncomplicated P. vivax, but the large influx of imported cases enhances the risk of introducing CQ resistance (CQR). METHODOLOGY AND PRINCIPAL FINDINGS The genetic diversity at pvmdr1, a putative modulator of CQR, and across nine putatively neutral short tandem repeat (STR) markers were assessed in P. vivax clinical isolates collected between April 2007 and January 2013 in Hormozgan Province, south-eastern Iran. One hundred blood samples were collected from patients with microscopy-confirmed P. vivax enrolled at one of five district clinics. In total 73 (73%) were autochthonous cases, 23 (23%) imported cases from Afghanistan or Pakistan, and 4 (4%) with unknown origin. 97% (97/100) isolates carried the F1076L mutation, but none carried the Y976F mutation. STR genotyping was successful in 71 (71%) isolates, including 57(57%) autochthonous and 11 (11%) imported cases. Analysis of population structure revealed 2 major sub-populations, K1 and K2, with further sub-structure within K2. The K1 sub-population had markedly lower diversity than K2 (HE = 0.06 vs HE = 0.82) suggesting that the sub-populations were sustained by distinct reservoirs with differing transmission dynamics, possibly reflecting local versus imported/introduced populations. No notable separation was observed between the local and imported cases although the sample size was limited. CONCLUSIONS The contrasting low versus high diversity in the two sub-populations (K1 and K2) infers that a combination of local transmission and cross-border malaria from higher transmission regions shape the genetic make-up of the P. vivax population in south-eastern Iran. There was no molecular evidence of CQR amongst the local or imported cases, but ongoing clinical surveillance is warranted.
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Affiliation(s)
- Yaghoob Hamedi
- Infectious and Tropical Diseases Research Center, Hormozgan University of Medical Sciences, Bandar Abbas, Hormozgan Province, Iran
| | - Khojasteh Sharifi-Sarasiabi
- Infectious and Tropical Diseases Research Center, Hormozgan University of Medical Sciences, Bandar Abbas, Hormozgan Province, Iran
| | - Farzaneh Dehghan
- Molecular Medicine Research Center, Hormozgan University of Medical Sciences, Bandar Abbas, Hormozgan Province, Iran
| | - Reza Safari
- Hormozgan University of Medical Sciences, Bandar Abbas, Hormozgan Province, Iran
| | - Sheren To
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, Northern Territory, Australia
| | - Irene Handayuni
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, Northern Territory, Australia
| | - Hidayat Trimarsanto
- Bioinformatics Laboratory, Eijkman Institute for Molecular Biology, Jakarta, Indonesia
- The Ministry of Research and Technology (RISTEK), Jakarta, Indonesia
- Agency for Assessment and Application of Technology, Jakarta, Indonesia
| | - Ric N. Price
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, Northern Territory, Australia
- Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, United Kingdom
| | - Sarah Auburn
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, Northern Territory, Australia
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Hostetler JB, Lo E, Kanjee U, Amaratunga C, Suon S, Sreng S, Mao S, Yewhalaw D, Mascarenhas A, Kwiatkowski DP, Ferreira MU, Rathod PK, Yan G, Fairhurst RM, Duraisingh MT, Rayner JC. Independent Origin and Global Distribution of Distinct Plasmodium vivax Duffy Binding Protein Gene Duplications. PLoS Negl Trop Dis 2016; 10:e0005091. [PMID: 27798646 PMCID: PMC5087946 DOI: 10.1371/journal.pntd.0005091] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Accepted: 10/03/2016] [Indexed: 11/23/2022] Open
Abstract
Background Plasmodium vivax causes the majority of malaria episodes outside Africa, but remains a relatively understudied pathogen. The pathology of P. vivax infection depends critically on the parasite’s ability to recognize and invade human erythrocytes. This invasion process involves an interaction between P. vivax Duffy Binding Protein (PvDBP) in merozoites and the Duffy antigen receptor for chemokines (DARC) on the erythrocyte surface. Whole-genome sequencing of clinical isolates recently established that some P. vivax genomes contain two copies of the PvDBP gene. The frequency of this duplication is particularly high in Madagascar, where there is also evidence for P. vivax infection in DARC-negative individuals. The functional significance and global prevalence of this duplication, and whether there are other copy number variations at the PvDBP locus, is unknown. Methodology/Principal Findings Using whole-genome sequencing and PCR to study the PvDBP locus in P. vivax clinical isolates, we found that PvDBP duplication is widespread in Cambodia. The boundaries of the Cambodian PvDBP duplication differ from those previously identified in Madagascar, meaning that current molecular assays were unable to detect it. The Cambodian PvDBP duplication did not associate with parasite density or DARC genotype, and ranged in prevalence from 20% to 38% over four annual transmission seasons in Cambodia. This duplication was also present in P. vivax isolates from Brazil and Ethiopia, but not India. Conclusions/Significance PvDBP duplications are much more widespread and complex than previously thought, and at least two distinct duplications are circulating globally. The same duplication boundaries were identified in parasites from three continents, and were found at high prevalence in human populations where DARC-negativity is essentially absent. It is therefore unlikely that PvDBP duplication is associated with infection of DARC-negative individuals, but functional tests will be required to confirm this hypothesis. Malaria parasites must be adaptable to evade the human immune system and successfully transmit themselves to different individuals. Key to this adaptability is the fact that malaria parasite genomes are highly variable, containing mutations ranging from simple small changes in DNA sequence to complex large-scale changes in the number of copies of individual genes. Some samples of Plasmodium vivax, the parasite that causes most malaria episodes outside Africa, have recently been found to have duplicated the gene encoding Duffy Binding Protein, which enables P. vivax parasites to recognize and invade human red blood cells. By studying parasites from Cambodian patients with P. vivax malaria, we have discovered that there are actually two different types of gene duplication, with the new duplication type identified in this study present in 20% to 38% of Cambodian P. vivax isolates tested. The same gene duplication was also found in parasites from Brazilian and Ethiopian patients with P. vivax malaria, suggesting that variation in this gene is more complex and common than previously thought. The functional significance and origin of these two gene duplications requires further study.
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Affiliation(s)
- Jessica B. Hostetler
- Malaria Programme, Wellcome Trust Sanger Institute, Hinxton, United Kingdom
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
| | - Eugenia Lo
- Program in Public Health, University of California, Irvine, California, United States of America
| | - Usheer Kanjee
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, United States of America
| | - Chanaki Amaratunga
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
| | - Seila Suon
- National Center for Parasitology, Entomology, and Malaria Control, Phnom Penh, Cambodia
| | - Sokunthea Sreng
- National Center for Parasitology, Entomology, and Malaria Control, Phnom Penh, Cambodia
| | - Sivanna Mao
- Sampov Meas Referral Hospital, Pursat, Cambodia
| | - Delenasaw Yewhalaw
- Department of Medical Laboratory Sciences and Pathology, College of Public Health and Medical Sciences, Jimma University, Jimma, Ethiopia
| | - Anjali Mascarenhas
- Department of Chemistry, University of Washington, Seattle, Washington, United States of America
- MESA-ICEMR, Goa Medical College and Hospital, Bambolim, Goa, India
| | | | - Marcelo U. Ferreira
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, Brazil
| | - Pradipsinh K. Rathod
- Department of Chemistry, University of Washington, Seattle, Washington, United States of America
- MESA-ICEMR, Goa Medical College and Hospital, Bambolim, Goa, India
| | - Guiyun Yan
- Program in Public Health, University of California, Irvine, California, United States of America
| | - Rick M. Fairhurst
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
| | - Manoj T. Duraisingh
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, United States of America
| | - Julian C. Rayner
- Malaria Programme, Wellcome Trust Sanger Institute, Hinxton, United Kingdom
- * E-mail:
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Requena P, Rui E, Padilla N, Martínez-Espinosa FE, Castellanos ME, Bôtto-Menezes C, Malheiro A, Arévalo-Herrera M, Kochar S, Kochar SK, Kochar DK, Umbers AJ, Ome-Kaius M, Wangnapi R, Hans D, Menegon M, Mateo F, Sanz S, Desai M, Mayor A, Chitnis CC, Bardají A, Mueller I, Rogerson S, Severini C, Fernández-Becerra C, Menéndez C, del Portillo H, Dobaño C. Plasmodium vivax VIR Proteins Are Targets of Naturally-Acquired Antibody and T Cell Immune Responses to Malaria in Pregnant Women. PLoS Negl Trop Dis 2016; 10:e0005009. [PMID: 27711158 PMCID: PMC5053494 DOI: 10.1371/journal.pntd.0005009] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Accepted: 08/29/2016] [Indexed: 11/19/2022] Open
Abstract
P. vivax infection during pregnancy has been associated with poor outcomes such as anemia, low birth weight and congenital malaria, thus representing an important global health problem. However, no vaccine is currently available for its prevention. Vir genes were the first putative virulent factors associated with P. vivax infections, yet very few studies have examined their potential role as targets of immunity. We investigated the immunogenic properties of five VIR proteins and two long synthetic peptides containing conserved VIR sequences (PvLP1 and PvLP2) in the context of the PregVax cohort study including women from five malaria endemic countries: Brazil, Colombia, Guatemala, India and Papua New Guinea (PNG) at different timepoints during and after pregnancy. Antibody responses against all antigens were detected in all populations, with PNG women presenting the highest levels overall. P. vivax infection at sample collection time was positively associated with antibody levels against PvLP1 (fold-increase: 1.60 at recruitment -first antenatal visit-) and PvLP2 (fold-increase: 1.63 at delivery), and P. falciparum co-infection was found to increase those responses (for PvLP1 at recruitment, fold-increase: 2.25). Levels of IgG against two VIR proteins at delivery were associated with higher birth weight (27 g increase per duplicating antibody levels, p<0.05). Peripheral blood mononuclear cells from PNG uninfected pregnant women had significantly higher antigen-specific IFN-γ TH1 responses (p=0.006) and secreted less pro-inflammatory cytokines TNF and IL-6 after PvLP2 stimulation than P. vivax-infected women (p<0.05). These data demonstrate that VIR antigens induce the natural acquisition of antibody and T cell memory responses that might be important in immunity to P. vivax during pregnancy in very diverse geographical settings. Naturally-acquired antibody responses to novel recombinant proteins and synthetic peptides based on sequences from P. vivax VIR antigens were evaluated in women from five distinct geographical regions endemic for malaria, during and after pregnancy. Levels of IgG to VIR antigens were indicative of cumulative malaria exposure and increased with current P. vivax infection and P. falciparum co-infection. Antibody data were consistent with levels of malaria endemicity and current prevalence in the diverse geographical areas studied. In addition, the magnitude of IgG response to two VIR antigens at delivery was associated with higher birth weight. Furthermore, T cell responses to VIR antigens were naturally induced and their magnitude varied according to P. vivax infectious status. Peripheral blood mononuclear cells from uninfected pregnant women from a highly endemic area produced higher TH1 (IFN-γ) and lower pro-inflammatory cytokines (TNF and IL-6) upon stimulation with a long synthetic peptide representing conserved globular domains of VIR antigens than P. vivax-infected women. Data suggest that further investigation on these antigens as potential targets of immunity in naturally-exposed individuals is warranted.
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Affiliation(s)
- Pilar Requena
- ISGlobal, Barcelona Ctr. Int. Health Res. (CRESIB), Hospital Clínic - Universitat de Barcelona, Barcelona, Spain
- Department of Parasitology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Edmilson Rui
- ISGlobal, Barcelona Ctr. Int. Health Res. (CRESIB), Hospital Clínic - Universitat de Barcelona, Barcelona, Spain
| | - Norma Padilla
- Centro de Estudios en Salud, Universidad del Valle de Guatemala, Guatemala City, Guatemala
| | - Flor E. Martínez-Espinosa
- Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus, Amazonas, Brazil
- Instituto Leônidas e Maria Deane (ILMD/Fiocruz Amazonia), Brazil
| | | | - Camila Bôtto-Menezes
- Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus, Amazonas, Brazil
- Universidade do Estado do Amazonas, Manaus, Amazonas, Brazil
| | - Adriana Malheiro
- Instituto de Ciências Biológicas. Universidade Federal do Amazonas, Manaus, Brazil
| | | | - Swati Kochar
- Department of Medicine, Medical College, Bikaner, Rajasthan, India
| | - Sanjay K. Kochar
- Department of Medicine, Medical College, Bikaner, Rajasthan, India
| | | | | | - Maria Ome-Kaius
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
| | - Regina Wangnapi
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
| | - Dhiraj Hans
- International Center for Genetic Engineering and Biotechnology, Delhi, India
| | - Michela Menegon
- Department of Infectious, Parasitic and Immunomediated Diseases, Istituto Superiore di Sanità, Rome, Italy
| | - Francesca Mateo
- ISGlobal, Barcelona Ctr. Int. Health Res. (CRESIB), Hospital Clínic - Universitat de Barcelona, Barcelona, Spain
| | - Sergi Sanz
- ISGlobal, Barcelona Ctr. Int. Health Res. (CRESIB), Hospital Clínic - Universitat de Barcelona, Barcelona, Spain
| | - Meghna Desai
- Centers for Disease Control and Prevention, Division of Parasitic Diseases and Malaria, Malaria Branch, Atlanta, Georgia, United States of America
| | - Alfredo Mayor
- ISGlobal, Barcelona Ctr. Int. Health Res. (CRESIB), Hospital Clínic - Universitat de Barcelona, Barcelona, Spain
| | - Chetan C. Chitnis
- International Center for Genetic Engineering and Biotechnology, Delhi, India
| | - Azucena Bardají
- ISGlobal, Barcelona Ctr. Int. Health Res. (CRESIB), Hospital Clínic - Universitat de Barcelona, Barcelona, Spain
| | - Ivo Mueller
- ISGlobal, Barcelona Ctr. Int. Health Res. (CRESIB), Hospital Clínic - Universitat de Barcelona, Barcelona, Spain
- Walter and Eliza Hall Institute, Parkville, Australia
| | - Stephen Rogerson
- Department of Medicine, University of Melbourne, Melbourne, Australia
| | - Carlo Severini
- Department of Infectious, Parasitic and Immunomediated Diseases, Istituto Superiore di Sanità, Rome, Italy
| | - Carmen Fernández-Becerra
- ISGlobal, Barcelona Ctr. Int. Health Res. (CRESIB), Hospital Clínic - Universitat de Barcelona, Barcelona, Spain
| | - Clara Menéndez
- ISGlobal, Barcelona Ctr. Int. Health Res. (CRESIB), Hospital Clínic - Universitat de Barcelona, Barcelona, Spain
| | - Hernando del Portillo
- ISGlobal, Barcelona Ctr. Int. Health Res. (CRESIB), Hospital Clínic - Universitat de Barcelona, Barcelona, Spain
- ICREA, Barcelona, Spain
- * E-mail: (HdP); (CD)
| | - Carlota Dobaño
- ISGlobal, Barcelona Ctr. Int. Health Res. (CRESIB), Hospital Clínic - Universitat de Barcelona, Barcelona, Spain
- * E-mail: (HdP); (CD)
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Alnasser Y, Ferradas C, Clark T, Calderon M, Gurbillon A, Gamboa D, McKakpo US, Quakyi IA, Bosompem KM, Sullivan DJ, Vinetz JM, Gilman RH. Colorimetric Detection of Plasmodium vivax in Urine Using MSP10 Oligonucleotides and Gold Nanoparticles. PLoS Negl Trop Dis 2016; 10:e0005029. [PMID: 27706158 PMCID: PMC5051960 DOI: 10.1371/journal.pntd.0005029] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2016] [Accepted: 09/09/2016] [Indexed: 11/19/2022] Open
Abstract
Plasmodium vivax is the most prevalent cause of human malaria in the world and can lead to severe disease with high potential for relapse. Its genetic and geographic diversities make it challenging to control. P. vivax is understudied and to achieve control of malaria in endemic areas, a rapid, accurate, and simple diagnostic tool is necessary. In this pilot study, we found that a colorimetric system using AuNPs and MSP10 DNA detection in urine can provide fast, easy, and inexpensive identification of P. vivax. The test exhibited promising sensitivity (84%), high specificity (97%), and only mild cross-reactivity with P. falciparum (21%). It is simple to use, with a visible color change that negates the need for a spectrometer, making it suitable for use in austere conditions. Using urine eliminates the need for finger-prick, increasing both the safety profile and patient acceptance of this model.
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Affiliation(s)
- Yossef Alnasser
- Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America
- Universidad Peruana Cayetano Heredia, Lima, Peru
- King Saud University, Riyadh, Saudi Arabia
| | | | - Taryn Clark
- Universidad Peruana Cayetano Heredia, Lima, Peru
- Section of Emergency Medicine, Department of Medicine, Louisiana State University Health Sciences Center, New Orleans, Louisiana, United States of America
| | | | | | | | - Uri S. McKakpo
- School of Public Health and Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Accra, Ghana
| | - Isabella A. Quakyi
- School of Public Health and Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Accra, Ghana
| | - Kwabena M. Bosompem
- School of Public Health and Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Accra, Ghana
| | - David J. Sullivan
- Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America
| | - Joseph M. Vinetz
- Universidad Peruana Cayetano Heredia, Lima, Peru
- University of California San Diego, San Diego, California, United States of America
| | - Robert H. Gilman
- Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America
- Universidad Peruana Cayetano Heredia, Lima, Peru
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171
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Sheikh IH, Kaushal DC, Chandra D, Kaushal NA. Immunogenicity of a plasmid DNA vaccine encoding 42kDa fragment of Plasmodium vivax merozoite surface protein-1. Acta Trop 2016; 162:66-74. [PMID: 27311385 DOI: 10.1016/j.actatropica.2016.06.013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2016] [Revised: 06/07/2016] [Accepted: 06/10/2016] [Indexed: 11/17/2022]
Abstract
Plasmodium vivax is the second major human malaria parasite that inflicts debilitating morbidity and consequent economic impact in South-East Asian countries. The relapsing nature of P. vivax along with the emergence of drug-resistant P. vivax strains has emphasized the urgent need for a vaccine. However, the development of an effective vivax vaccine is seriously hampered due to the diversity and variation in parasite antigens and non-availability of suitable animal models. DNA based vaccines represent an alternative approach in inducing immunity to multiple targets from different stages of malaria parasite. DNA prime-boosting strategies induce both antibody mediated and cell-mediated immune responses that are the major mechanisms of protection against malaria parasites. We have earlier studied the immunogenicity and protective efficacy of the soluble and refolded forms of recombinant 42kDa fragment of Plasmodium vivax merozoite surface protein-1 (PvMSP-142) using P. cynomolgi rhesus monkey model. In the present study, we have constructed a recombinant DNA vaccine encoding 42kDa fragment of P. vivax MSP-1 and studied the immunogenicity of PvMSP-142 DNA vaccine construct in mice. The 42kDa gene fragment of PvMSP-1 was PCR amplified using gene specific primers and subcloned into pcDNA 3.1 (+) eukaryotic expression vector. In vitro expression of PvMSP-142 plasmid construct was checked by transfection in COS-1 cell line. Indirect immunofluorescence of transfected COS-1 cells probed with monoclonal antibodies against PvMSP-142 exhibited positive fluorescence. Immunization of BALB/c mice with PvMSP-142-pcDNA vaccine construct revealed the immunogenicity of recombinant vaccine plasmid that can be enhanced by prime boosting with recombinant protein corresponding to the DNA vaccine as evidenced by significant elevation of antibody and the cytokines responses.
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Affiliation(s)
- Inayat Hussain Sheikh
- Division of Parasitology, CSIR- Central Drug Research Institute, Lucknow 226031, India; Department of Biochemistry, Lucknow University, Lucknow, India.
| | - Deep C Kaushal
- Amity University Uttar Pradesh, Lucknow Campus, Lucknow 226028, India.
| | - Deepak Chandra
- Department of Biochemistry, Lucknow University, Lucknow, India.
| | - Nuzhat A Kaushal
- Division of Parasitology, CSIR- Central Drug Research Institute, Lucknow 226031, India.
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172
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Atalay Şahar E, Karakavuk M, Can H, Nergiz Ş, Gül K, Değirmenci Döşkaya A, Gürüz Y, Döşkaya M. Diagnosis and Species Discrimination of Positive Malaria Samples by Real-Time Polymerase Chain Reaction. Turkiye Parazitol Derg 2016; 40:126-131. [PMID: 27905280 DOI: 10.5152/tpd.2016.4711] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
OBJECTIVE Malaria is an important tropical disease that is detected in 198 million people and causes 367-755 thousand deaths annually. Recently, the real-time Polymerase Chain Reaction (PCR) technique has enabled quick determination of Plasmodium spp. and species identification in the same assay with a low contamination risk. In the present study, we aimed to use real-time PCR targeting the 18S rRNA gene to diagnose Plasmodium spp. and perform species identification. METHODS DNA samples of 15 patients with malaria (14 caused by P. vivax, 1 caused by P. falciparum) confirmed by microscopy as well as positive control plasmids were used. As the negative control, DNA samples of 15 individuals without malaria were used. RESULTS According to the results of real-time PCR, samples of 15 patients with malaria were found to be positive for Plasmodium spp. Melting curve analysis showed that 14 of them were P. vivax and the remaining was P. falciparum. In addition, mixed infection with P. falciparum and P. vivax was successfully detected by real-time PCR when DNA of P. falciparum- and P. vivax-positive samples was experimentally mixed. CONCLUSION The present study showed that real-time PCR can be useful in the diagnosis and species identification of Plasmodium spp. as well as the detection of mixed infections in addition to microscopy in Turkey.
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Affiliation(s)
- Esra Atalay Şahar
- Ege Üniversitesi Tıp Fakültesi, Parazitoloji Anabilim Dalı, İzmir, Türkiye.
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173
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Pearson RD, Amato R, Auburn S, Miotto O, Almagro-Garcia J, Amaratunga C, Suon S, Mao S, Noviyanti R, Trimarsanto H, Marfurt J, Anstey NM, William T, Boni MF, Dolecek C, Hien TT, White NJ, Michon P, Siba P, Tavul L, Harrison G, Barry A, Mueller I, Ferreira MU, Karunaweera N, Randrianarivelojosia M, Gao Q, Hubbart C, Hart L, Jeffery B, Drury E, Mead D, Kekre M, Campino S, Manske M, Cornelius VJ, MacInnis B, Rockett KA, Miles A, Rayner JC, Fairhurst RM, Nosten F, Price RN, Kwiatkowski DP. Genomic analysis of local variation and recent evolution in Plasmodium vivax. Nat Genet 2016; 48:959-964. [PMID: 27348299 PMCID: PMC4966634 DOI: 10.1038/ng.3599] [Citation(s) in RCA: 140] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2016] [Accepted: 05/27/2016] [Indexed: 01/12/2023]
Abstract
The widespread distribution and relapsing nature of Plasmodium vivax infection present major challenges for the elimination of malaria. To characterize the genetic diversity of this parasite in individual infections and across the population, we performed deep genome sequencing of >200 clinical samples collected across the Asia-Pacific region and analyzed data on >300,000 SNPs and nine regions of the genome with large copy number variations. Individual infections showed complex patterns of genetic structure, with variation not only in the number of dominant clones but also in their level of relatedness and inbreeding. At the population level, we observed strong signals of recent evolutionary selection both in known drug resistance genes and at new loci, and these varied markedly between geographical locations. These findings demonstrate a dynamic landscape of local evolutionary adaptation in the parasite population and provide a foundation for genomic surveillance to guide effective strategies for control and elimination of P. vivax.
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Affiliation(s)
- Richard D Pearson
- Wellcome Trust Sanger Institute, Hinxton, Cambridge CB10 1SA, UK
- MRC Centre for Genomics and Global Health, Wellcome Trust Centre for Human Genetics, Oxford OX3 7BN, UK
| | - Roberto Amato
- Wellcome Trust Sanger Institute, Hinxton, Cambridge CB10 1SA, UK
- MRC Centre for Genomics and Global Health, Wellcome Trust Centre for Human Genetics, Oxford OX3 7BN, UK
| | - Sarah Auburn
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, Northern Territories 0811, Australia
| | - Olivo Miotto
- Wellcome Trust Sanger Institute, Hinxton, Cambridge CB10 1SA, UK
- MRC Centre for Genomics and Global Health, Wellcome Trust Centre for Human Genetics, Oxford OX3 7BN, UK
- Mahidol-Oxford Tropical Medicine Research Unit, Mahidol University, Bangkok 10400, Thailand
| | - Jacob Almagro-Garcia
- MRC Centre for Genomics and Global Health, Wellcome Trust Centre for Human Genetics, Oxford OX3 7BN, UK
| | - Chanaki Amaratunga
- National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland 20852, USA
| | - Seila Suon
- National Centre for Parasitology, Entomology, and Malaria Control, Phnom Penh, Cambodia
| | - Sivanna Mao
- Sampov Meas Referral Hospital, Pursat, Cambodia
| | - Rintis Noviyanti
- Eijkman Institute for Molecular Biology, Jakarta 10430, Indonesia
| | | | - Jutta Marfurt
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, Northern Territories 0811, Australia
| | - Nicholas M Anstey
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, Northern Territories 0811, Australia
| | - Timothy William
- Infectious Diseases Society Sabah-Menzies School of Health Research Clinical Research Unit and Queen Elizabeth Hospital Clinical Research Centre, Kota Kinabalu, Sabah, Malaysia
| | - Maciej F Boni
- Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | | | - Tinh Tran Hien
- Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | - Nicholas J White
- Mahidol-Oxford Tropical Medicine Research Unit, Mahidol University, Bangkok 10400, Thailand
| | - Pascal Michon
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
- Faculty of Medicine and Health Sciences, Divine Word University, Madang, Papua New Guinea
| | - Peter Siba
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
| | - Livingstone Tavul
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
| | - Gabrielle Harrison
- Division of Population Health and Immunity, The Walter and Eliza Hall Institute for Medical Research, Parkville, Victoria, Australia
- Department of Medical Biology, University of Melbourne, Parkville, Victoria, Australia
| | - Alyssa Barry
- Division of Population Health and Immunity, The Walter and Eliza Hall Institute for Medical Research, Parkville, Victoria, Australia
- Department of Medical Biology, University of Melbourne, Parkville, Victoria, Australia
| | - Ivo Mueller
- Division of Population Health and Immunity, The Walter and Eliza Hall Institute for Medical Research, Parkville, Victoria, Australia
- Department of Medical Biology, University of Melbourne, Parkville, Victoria, Australia
| | - Marcelo U Ferreira
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Nadira Karunaweera
- Department of Parasitology, Faculty of Medicine, University of Colombo, Sri Lanka
| | | | - Qi Gao
- Jiangsu Institute of Parasitic Diseases, Key Laboratory of Parasitic Disease Control and Prevention (Ministry of Health), Jiangsu Provincial Key Laboratory of Parasite Molecular Biology, Wuxi, Jiangsu, People's Republic of China
| | - Christina Hubbart
- MRC Centre for Genomics and Global Health, Wellcome Trust Centre for Human Genetics, Oxford OX3 7BN, UK
| | - Lee Hart
- MRC Centre for Genomics and Global Health, Wellcome Trust Centre for Human Genetics, Oxford OX3 7BN, UK
| | - Ben Jeffery
- MRC Centre for Genomics and Global Health, Wellcome Trust Centre for Human Genetics, Oxford OX3 7BN, UK
| | - Eleanor Drury
- Wellcome Trust Sanger Institute, Hinxton, Cambridge CB10 1SA, UK
| | - Daniel Mead
- Wellcome Trust Sanger Institute, Hinxton, Cambridge CB10 1SA, UK
| | - Mihir Kekre
- Wellcome Trust Sanger Institute, Hinxton, Cambridge CB10 1SA, UK
| | - Susana Campino
- Wellcome Trust Sanger Institute, Hinxton, Cambridge CB10 1SA, UK
| | - Magnus Manske
- Wellcome Trust Sanger Institute, Hinxton, Cambridge CB10 1SA, UK
| | - Victoria J Cornelius
- Wellcome Trust Sanger Institute, Hinxton, Cambridge CB10 1SA, UK
- MRC Centre for Genomics and Global Health, Wellcome Trust Centre for Human Genetics, Oxford OX3 7BN, UK
| | - Bronwyn MacInnis
- Wellcome Trust Sanger Institute, Hinxton, Cambridge CB10 1SA, UK
| | - Kirk A Rockett
- Wellcome Trust Sanger Institute, Hinxton, Cambridge CB10 1SA, UK
- MRC Centre for Genomics and Global Health, Wellcome Trust Centre for Human Genetics, Oxford OX3 7BN, UK
| | - Alistair Miles
- Wellcome Trust Sanger Institute, Hinxton, Cambridge CB10 1SA, UK
- MRC Centre for Genomics and Global Health, Wellcome Trust Centre for Human Genetics, Oxford OX3 7BN, UK
| | - Julian C Rayner
- Wellcome Trust Sanger Institute, Hinxton, Cambridge CB10 1SA, UK
| | - Rick M Fairhurst
- National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland 20852, USA
| | - Francois Nosten
- Mahidol-Oxford Tropical Medicine Research Unit, Mahidol University, Bangkok 10400, Thailand
- Shoklo Malaria Research Unit, Mae Sot, Tak 63110, Thailand
| | - Ric N Price
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, Northern Territories 0811, Australia
- Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, OX3 7LJ, UK
| | - Dominic P Kwiatkowski
- Wellcome Trust Sanger Institute, Hinxton, Cambridge CB10 1SA, UK
- MRC Centre for Genomics and Global Health, Wellcome Trust Centre for Human Genetics, Oxford OX3 7BN, UK
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Silvino ACR, Costa GL, de Araújo FCF, Ascher DB, Pires DEV, Fontes CJF, Carvalho LH, de Brito CFA, Sousa TN. Variation in Human Cytochrome P-450 Drug-Metabolism Genes: A Gateway to the Understanding of Plasmodium vivax Relapses. PLoS One 2016; 11:e0160172. [PMID: 27467145 PMCID: PMC4965052 DOI: 10.1371/journal.pone.0160172] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2016] [Accepted: 07/14/2016] [Indexed: 01/08/2023] Open
Abstract
Although Plasmodium vivax relapses are classically associated with hypnozoite activation, it has been proposed that a proportion of these cases are due to primaquine (PQ) treatment failure caused by polymorphisms in cytochrome P-450 2D6 (CYP2D6). Here, we present evidence that CYP2D6 polymorphisms are implicated in PQ failure, which was reinforced by findings in genetically similar parasites, and may explain a number of vivax relapses. Using a computational approach, these polymorphisms were predicted to affect the activity of CYP2D6 through changes in the structural stability that could lead to disruption of the PQ-enzyme interactions. Furthermore, because PQ is co-administered with chloroquine (CQ), we investigated whether CQ-impaired metabolism by cytochrome P-450 2C8 (CYP2C8) could also contribute to vivax recurrences. Our results show that CYP2C8-mutated patients frequently relapsed early (<42 days) and had a higher proportion of genetically similar parasites, suggesting the possibility of recrudescence due to CQ therapeutic failure. These results highlight the importance of pharmacogenetic studies as a tool to monitor the efficacy of antimalarial therapy.
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Affiliation(s)
- Ana Carolina Rios Silvino
- Molecular Biology and Malaria Immunology Research Group, Centro de Pesquisas René Rachou, Fundação Oswaldo Cruz (FIOCRUZ), Belo Horizonte, Minas Gerais, Brazil
| | - Gabriel Luiz Costa
- Molecular Biology and Malaria Immunology Research Group, Centro de Pesquisas René Rachou, Fundação Oswaldo Cruz (FIOCRUZ), Belo Horizonte, Minas Gerais, Brazil
| | - Flávia Carolina Faustino de Araújo
- Molecular Biology and Malaria Immunology Research Group, Centro de Pesquisas René Rachou, Fundação Oswaldo Cruz (FIOCRUZ), Belo Horizonte, Minas Gerais, Brazil
| | - David Benjamin Ascher
- Biosystems Informatics Research Group, Centro de Pesquisas René Rachou, Fundação Oswaldo Cruz (FIOCRUZ), Belo Horizonte, Minas Gerais, Brazil
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| | - Douglas Eduardo Valente Pires
- Biosystems Informatics Research Group, Centro de Pesquisas René Rachou, Fundação Oswaldo Cruz (FIOCRUZ), Belo Horizonte, Minas Gerais, Brazil
| | | | - Luzia Helena Carvalho
- Molecular Biology and Malaria Immunology Research Group, Centro de Pesquisas René Rachou, Fundação Oswaldo Cruz (FIOCRUZ), Belo Horizonte, Minas Gerais, Brazil
| | - Cristiana Ferreira Alves de Brito
- Molecular Biology and Malaria Immunology Research Group, Centro de Pesquisas René Rachou, Fundação Oswaldo Cruz (FIOCRUZ), Belo Horizonte, Minas Gerais, Brazil
| | - Tais Nobrega Sousa
- Molecular Biology and Malaria Immunology Research Group, Centro de Pesquisas René Rachou, Fundação Oswaldo Cruz (FIOCRUZ), Belo Horizonte, Minas Gerais, Brazil
- * E-mail:
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175
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Chaumeau V, Andolina C, Fustec B, Tuikue Ndam N, Brengues C, Herder S, Cerqueira D, Chareonviriyaphap T, Nosten F, Corbel V. Comparison of the Performances of Five Primer Sets for the Detection and Quantification of Plasmodium in Anopheline Vectors by Real-Time PCR. PLoS One 2016; 11:e0159160. [PMID: 27441839 PMCID: PMC4956213 DOI: 10.1371/journal.pone.0159160] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Accepted: 06/28/2016] [Indexed: 02/07/2023] Open
Abstract
Quantitative real-time polymerase chain reaction (qrtPCR) has made a significant improvement for the detection of Plasmodium in anopheline vectors. A wide variety of primers has been used in different assays, mostly adapted from molecular diagnosis of malaria in human. However, such an adaptation can impact the sensitivity of the PCR. Therefore we compared the sensitivity of five primer sets with different molecular targets on blood stages, sporozoites and oocysts standards of Plasmodium falciparum (Pf) and P. vivax (Pv). Dilution series of standard DNA were used to discriminate between methods at low concentrations of parasite and to generate standard curves suitable for the absolute quantification of Plasmodium sporozoites. Our results showed that the best primers to detect blood stages were not necessarily the best ones to detect sporozoites. Absolute detection threshold of our qrtPCR assay varied between 3.6 and 360 Pv sporozoites and between 6 and 600 Pf sporozoites per mosquito according to the primer set used in the reaction mix. In this paper, we discuss the general performance of each primer set and highlight the need to use efficient detection methods for transmission studies.
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Affiliation(s)
- V. Chaumeau
- Centre hospitalier universitaire de Montpellier, Montpellier, France
- Maladies Infectieuses et Vecteurs, Ecologie, Génétique, Evolution et Contrôle, Institut de Recherche pour le Développement, Montpellier, France
- Centre for Advanced Studies for Agriculture and Food, Institute of Advanced Studies, Faculty of Agriculture, Kasetsart University, Bangkok, Thailand
- * E-mail: (V. Chaumeau); (V. Corbel)
| | - C. Andolina
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, Thailand
| | - B. Fustec
- Maladies Infectieuses et Vecteurs, Ecologie, Génétique, Evolution et Contrôle, Institut de Recherche pour le Développement, Montpellier, France
- Centre for Advanced Studies for Agriculture and Food, Institute of Advanced Studies, Faculty of Agriculture, Kasetsart University, Bangkok, Thailand
| | - N. Tuikue Ndam
- Institut de Recherche pour le développement, UMR216, Mère et enfant face aux infections tropicales, Paris, France
- Communauté d’Universités et d’Etablissements Sorbonne Paris Cité, Faculté de Pharmacie, Paris, France
| | - C. Brengues
- Maladies Infectieuses et Vecteurs, Ecologie, Génétique, Evolution et Contrôle, Institut de Recherche pour le Développement, Montpellier, France
| | - S. Herder
- UMR Intertryp, Institut de Recherche pour le Développement, Montpellier, France
- Department of Parasitology, Faculty of Veterinary Medicine, Kasetsart University, Bangkok, Thailand
| | - D. Cerqueira
- Centre for Advanced Studies for Agriculture and Food, Institute of Advanced Studies, Faculty of Agriculture, Kasetsart University, Bangkok, Thailand
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, Thailand
| | - T. Chareonviriyaphap
- Department of Entomology, Faculty of Agriculture, Kasetsart University, Bangkok, Thailand
| | - F. Nosten
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - V. Corbel
- Maladies Infectieuses et Vecteurs, Ecologie, Génétique, Evolution et Contrôle, Institut de Recherche pour le Développement, Montpellier, France
- Centre for Advanced Studies for Agriculture and Food, Institute of Advanced Studies, Faculty of Agriculture, Kasetsart University, Bangkok, Thailand
- Department of Entomology, Faculty of Agriculture, Kasetsart University, Bangkok, Thailand
- * E-mail: (V. Chaumeau); (V. Corbel)
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Loy DE, Liu W, Li Y, Learn GH, Plenderleith LJ, Sundararaman SA, Sharp PM, Hahn BH. Out of Africa: origins and evolution of the human malaria parasites Plasmodium falciparum and Plasmodium vivax. Int J Parasitol 2016; 47:87-97. [PMID: 27381764 DOI: 10.1016/j.ijpara.2016.05.008] [Citation(s) in RCA: 115] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Revised: 05/25/2016] [Accepted: 05/28/2016] [Indexed: 12/22/2022]
Abstract
Plasmodium falciparum and Plasmodium vivax account for more than 95% of all human malaria infections, and thus pose a serious public health challenge. To control and potentially eliminate these pathogens, it is important to understand their origins and evolutionary history. Until recently, it was widely believed that P. falciparum had co-evolved with humans (and our ancestors) over millions of years, whilst P. vivax was assumed to have emerged in southeastern Asia following the cross-species transmission of a parasite from a macaque. However, the discovery of a multitude of Plasmodium spp. in chimpanzees and gorillas has refuted these theories and instead revealed that both P. falciparum and P. vivax evolved from parasites infecting wild-living African apes. It is now clear that P. falciparum resulted from a recent cross-species transmission of a parasite from a gorilla, whilst P. vivax emerged from an ancestral stock of parasites that infected chimpanzees, gorillas and humans in Africa, until the spread of the protective Duffy-negative mutation eliminated P. vivax from human populations there. Although many questions remain concerning the biology and zoonotic potential of the P. falciparum- and P. vivax-like parasites infecting apes, comparative genomics, coupled with functional parasite and vector studies, are likely to yield new insights into ape Plasmodium transmission and pathogenesis that are relevant to the treatment and prevention of human malaria.
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Affiliation(s)
- Dorothy E Loy
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Weimin Liu
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Yingying Li
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Gerald H Learn
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Lindsey J Plenderleith
- Institute of Evolutionary Biology, and Centre for Immunity, Infection and Evolution, University of Edinburgh, Edinburgh EH9 3FL, UK
| | - Sesh A Sundararaman
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Paul M Sharp
- Institute of Evolutionary Biology, and Centre for Immunity, Infection and Evolution, University of Edinburgh, Edinburgh EH9 3FL, UK
| | - Beatrice H Hahn
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
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Akhtar N, Nagpal BN, Kapoor N, Srivastava A, Valecha N. Role of An. culicifacies as a vector of malaria in changing ecological scenario of Northeastern states of India. J Vector Borne Dis 2016; 53:264-271. [PMID: 27681550] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023] Open
Abstract
BACKGROUND & OBJECTIVES Malaria has become endemic and subject of concern in most part of the India especially Northeastern states of India. Surveys before 2000 revealed that Anopheles minimus was major vector responsible for transmission of malaria in this region followed by An. dirus and An. fluviatilis. However, recent studies indicate replacement of An. minimus vector by An. culicifacies due to different ecological changes and change in landuse pattern etc. The objective of present study was to explore the vectorial role of An. culicifacies in transmission of malaria in four malaria endemic states, viz. Assam, Meghalaya, Manipur and Sikkim of India. METHODS The seven surveys were conducted in 176 selected villages belonging to eight districts of the four states in both pre-monsoon (March-April) and post-monsoon (September-October) seasons from 2010 to 2013. However, in 2011 surveys could not be carried out due to public inconvenience in pre-monsoon season. For vectorial role of all vector species collected, ELISA and PCR were assayed. RESULTS A total of 19,173 specimens belonging to 30 anopheline species were collected, out of which 4315 belonged to four established vector species. In total, 4183 specimens were processed through ELISA, out of which 236 specimens were found positive for circumsporozoite (CS) protein. Further, infectivity was confirmed by PCR in 35 samples, of which 12 samples were found positive for Plasmodium falciparum and three for P. vivax. Out of 12 Plasmodium falciparum positive samples, nine samples were positive for An. culicifacies, two for An. fluviatilis and one for An. minimus. While out of three Plasmodium vivax positive samples, two samples were positive for An. dirus and one sample was positive for An. culicifacies. INTERPRETATION & CONCLUSION Anopheles culicifacies replaced the An. minimus, the vector of malaria in Northeastern states of India, as it was found to be highly infected with malaria parasite as compared to An. minimus by ELISA and PCR analysis, and thus playing a major role in malaria transmission in this region. The ecological changes like deforestation, development of irrigation channels and change in landuse pattern, have helped in evolution of An. culicifacies in the study area. Therefore, modified vector control strategies are required on urgent basis.
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Affiliation(s)
- Nasreen Akhtar
- National Institute of Malaria Research (ICMR), New Delhi, India
| | - B N Nagpal
- National Institute of Malaria Research (ICMR), New Delhi, India
| | - Neera Kapoor
- Indira Gandhi National Open University, New Delhi, India
| | | | - Neena Valecha
- National Institute of Malaria Research (ICMR), New Delhi, India
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Chaurio RA, Pacheco MA, Cornejo OE, Durrego E, Stanley CE, Castillo AI, Herrera S, Escalante AA. Evolution of the Transmission-Blocking Vaccine Candidates Pvs28 and Pvs25 in Plasmodium vivax: Geographic Differentiation and Evidence of Positive Selection. PLoS Negl Trop Dis 2016; 10:e0004786. [PMID: 27347876 PMCID: PMC4922550 DOI: 10.1371/journal.pntd.0004786] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Accepted: 05/28/2016] [Indexed: 11/23/2022] Open
Abstract
Transmission-blocking (TB) vaccines are considered an important tool for malaria control and elimination. Among all the antigens characterized as TB vaccines against Plasmodium vivax, the ookinete surface proteins Pvs28 and Pvs25 are leading candidates. These proteins likely originated by a gene duplication event that took place before the radiation of the known Plasmodium species to primates. We report an evolutionary genetic analysis of a worldwide sample of pvs28 and pvs25 alleles. Our results show that both genes display low levels of genetic polymorphism when compared to the merozoite surface antigens AMA-1 and MSP-1; however, both ookinete antigens can be as polymorphic as other merozoite antigens such as MSP-8 and MSP-10. We found that parasite populations in Asia and the Americas are geographically differentiated with comparable levels of genetic diversity and specific amino acid replacements found only in the Americas. Furthermore, the observed variation was mainly accumulated in the EGF2- and EGF3-like domains for P. vivax in both proteins. This pattern was shared by other closely related non-human primate parasites such as Plasmodium cynomolgi, suggesting that it could be functionally important. In addition, examination with a suite of evolutionary genetic analyses indicated that the observed patterns are consistent with positive natural selection acting on Pvs28 and Pvs25 polymorphisms. The geographic pattern of genetic differentiation and the evidence for positive selection strongly suggest that the functional consequences of the observed polymorphism should be evaluated during development of TBVs that include Pvs25 and Pvs28. Plasmodium vivax is the most prevalent human malarial parasite outside Africa. The fact that patients can relapse due to the parasite dormant liver stages, among other biologic and epidemiologic characteristics of vivax malaria, facilitates the persistence of the disease in many endemic areas. These challenges have fueled the search for new control tools, including transmission blocking (TB) vaccines targeting the parasite sexual stages. Here we study the genetic diversity of two major TB vaccine antigens, Pvs25 and Pvs28. We show that these genes are relatively conserved worldwide but still harbor diversity that is not evenly distributed across the genes. These patterns are shared by the same proteins in closely related parasite species suggesting their functional importance. We also identify strong geographic differentiation between the circulating variants found in Asia and the Americas. Finally, evolutionary genetic analyses indicate that the observed variation in both genes could be maintained by natural selection. Thus, these polymorphisms may confer an adaptive advantage to the parasite. These results indicate that the genetic variation found in these genes and their geographic distribution should be considered by vaccine developers.
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Affiliation(s)
- Ricardo A Chaurio
- Instituto Venezolano de Investigaciones Científicas, Caracas, Venezuela
| | - M Andreína Pacheco
- Institute for Genomics and Evolutionary Medicine (iGEM), Temple University, Philadelphia, Pennsylvania, United States of America
- Department of Biology, Temple University, Philadelphia, Pennsylvania, United States of America
| | - Omar E Cornejo
- School of Biological Sciences, Washington State University, Pullman, Washington, United States of America
| | - Ester Durrego
- Instituto Venezolano de Investigaciones Científicas, Caracas, Venezuela
| | - Craig E Stanley
- Institute for Genomics and Evolutionary Medicine (iGEM), Temple University, Philadelphia, Pennsylvania, United States of America
- Department of Biology, Temple University, Philadelphia, Pennsylvania, United States of America
| | - Andreína I Castillo
- School of Life Sciences, Arizona State University, Tempe, Arizona, United States of America
| | | | - Ananias A Escalante
- Institute for Genomics and Evolutionary Medicine (iGEM), Temple University, Philadelphia, Pennsylvania, United States of America
- Department of Biology, Temple University, Philadelphia, Pennsylvania, United States of America
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179
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Chen E, Salinas ND, Huang Y, Ntumngia F, Plasencia MD, Gross ML, Adams JH, Tolia NH. Broadly neutralizing epitopes in the Plasmodium vivax vaccine candidate Duffy Binding Protein. Proc Natl Acad Sci U S A 2016; 113:6277-82. [PMID: 27194724 PMCID: PMC4896725 DOI: 10.1073/pnas.1600488113] [Citation(s) in RCA: 72] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Plasmodium vivax Duffy Binding Protein (PvDBP) is the most promising vaccine candidate for P. vivax malaria. The polymorphic nature of PvDBP induces strain-specific immune responses, however, and the epitopes of broadly neutralizing antibodies are unknown. These features hamper the rational design of potent DBP-based vaccines and necessitate the identification of globally conserved epitopes. Using X-ray crystallography, small-angle X-ray scattering, hydrogen-deuterium exchange mass spectrometry, and mutational mapping, we have defined epitopes for three inhibitory mAbs (mAbs 2D10, 2H2, and 2C6) and one noninhibitory mAb (3D10) that engage DBP. These studies expand the currently known inhibitory epitope repertoire by establishing protective motifs in subdomain three outside the receptor-binding and dimerization residues of DBP, and introduce globally conserved protective targets. All of the epitopes are highly conserved among DBP alleles. The identification of broadly conserved epitopes of inhibitory antibodies provides critical motifs that should be retained in the next generation of potent vaccines for P. vivax malaria.
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MESH Headings
- Amino Acid Sequence
- Antibodies, Monoclonal/immunology
- Antibodies, Neutralizing/immunology
- Antigens, Protozoan/genetics
- Antigens, Protozoan/immunology
- Crystallography, X-Ray
- Enzyme-Linked Immunosorbent Assay
- Epitopes, B-Lymphocyte/immunology
- Erythrocytes/immunology
- Erythrocytes/parasitology
- Erythrocytes/pathology
- Genetic Variation
- Humans
- Malaria Vaccines/immunology
- Malaria Vaccines/therapeutic use
- Malaria, Vivax/immunology
- Malaria, Vivax/parasitology
- Malaria, Vivax/prevention & control
- Models, Molecular
- Plasmodium vivax/genetics
- Plasmodium vivax/immunology
- Protein Binding
- Protein Conformation
- Protozoan Proteins/genetics
- Protozoan Proteins/immunology
- Receptors, Cell Surface/genetics
- Receptors, Cell Surface/immunology
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Affiliation(s)
- Edwin Chen
- Department of Molecular Microbiology, Washington University School of Medicine in St. Louis, St. Louis, MO 63110
| | - Nichole D Salinas
- Department of Molecular Microbiology, Washington University School of Medicine in St. Louis, St. Louis, MO 63110
| | - Yining Huang
- Department of Chemistry, Washington University School of Medicine in St. Louis, St. Louis, MO 63110
| | - Francis Ntumngia
- Global Health Infectious Disease Research, Department of Global Health, College of Public Health, University of South Florida, Tampa, FL 33620
| | - Manolo D Plasencia
- Department of Chemistry, Washington University School of Medicine in St. Louis, St. Louis, MO 63110
| | - Michael L Gross
- Department of Chemistry, Washington University School of Medicine in St. Louis, St. Louis, MO 63110
| | - John H Adams
- Global Health Infectious Disease Research, Department of Global Health, College of Public Health, University of South Florida, Tampa, FL 33620
| | - Niraj Harish Tolia
- Department of Molecular Microbiology, Washington University School of Medicine in St. Louis, St. Louis, MO 63110; Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine in St. Louis, St. Louis, MO 63110
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180
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Gunalan K, Lo E, Hostetler JB, Yewhalaw D, Mu J, Neafsey DE, Yan G, Miller LH. Role of Plasmodium vivax Duffy-binding protein 1 in invasion of Duffy-null Africans. Proc Natl Acad Sci U S A 2016; 113:6271-6. [PMID: 27190089 PMCID: PMC4896682 DOI: 10.1073/pnas.1606113113] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The ability of the malaria parasite Plasmodium vivax to invade erythrocytes is dependent on the expression of the Duffy blood group antigen on erythrocytes. Consequently, Africans who are null for the Duffy antigen are not susceptible to P. vivax infections. Recently, P. vivax infections in Duffy-null Africans have been documented, raising the possibility that P. vivax, a virulent pathogen in other parts of the world, may expand malarial disease in Africa. P. vivax binds the Duffy blood group antigen through its Duffy-binding protein 1 (DBP1). To determine if mutations in DBP1 resulted in the ability of P. vivax to bind Duffy-null erythrocytes, we analyzed P. vivax parasites obtained from two Duffy-null individuals living in Ethiopia where Duffy-null and -positive Africans live side-by-side. We determined that, although the DBP1s from these parasites contained unique sequences, they failed to bind Duffy-null erythrocytes, indicating that mutations in DBP1 did not account for the ability of P. vivax to infect Duffy-null Africans. However, an unusual DNA expansion of DBP1 (three and eight copies) in the two Duffy-null P. vivax infections suggests that an expansion of DBP1 may have been selected to allow low-affinity binding to another receptor on Duffy-null erythrocytes. Indeed, we show that Salvador (Sal) I P. vivax infects Squirrel monkeys independently of DBP1 binding to Squirrel monkey erythrocytes. We conclude that P. vivax Sal I and perhaps P. vivax in Duffy-null patients may have adapted to use new ligand-receptor pairs for invasion.
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Affiliation(s)
- Karthigayan Gunalan
- Laboratory of Malaria and Vector Research, National Institutes of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852
| | - Eugenia Lo
- Program in Public Health, College of Health Sciences, University of California, Irvine, CA 92697
| | - Jessica B Hostetler
- Laboratory of Malaria and Vector Research, National Institutes of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852; Malaria Programme, Wellcome Trust, Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge CB10 1RQ, United Kingdom
| | - Delenasaw Yewhalaw
- Department of Medical Laboratory Sciences and Pathology, College of Health Sciences, Jimma University, Jimma 5195, Ethiopia; Tropical and Infectious Diseases Research Center, Jimma University, Jimma 5195, Ethiopia
| | - Jianbing Mu
- Laboratory of Malaria and Vector Research, National Institutes of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852
| | | | - Guiyun Yan
- Program in Public Health, College of Health Sciences, University of California, Irvine, CA 92697
| | - Louis H Miller
- Laboratory of Malaria and Vector Research, National Institutes of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852;
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181
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França CT, Hostetler JB, Sharma S, White MT, Lin E, Kiniboro B, Waltmann A, Darcy AW, Li Wai Suen CSN, Siba P, King CL, Rayner JC, Fairhurst RM, Mueller I. An Antibody Screen of a Plasmodium vivax Antigen Library Identifies Novel Merozoite Proteins Associated with Clinical Protection. PLoS Negl Trop Dis 2016; 10:e0004639. [PMID: 27182597 PMCID: PMC4868274 DOI: 10.1371/journal.pntd.0004639] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2015] [Accepted: 03/29/2016] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Elimination of Plasmodium vivax malaria would be greatly facilitated by the development of an effective vaccine. A comprehensive and systematic characterization of antibodies to P. vivax antigens in exposed populations is useful in guiding rational vaccine design. METHODOLOGY/PRINCIPAL FINDINGS In this study, we investigated antibodies to a large library of P. vivax entire ectodomain merozoite proteins in 2 Asia-Pacific populations, analysing the relationship of antibody levels with markers of current and cumulative malaria exposure, and socioeconomic and clinical indicators. 29 antigenic targets of natural immunity were identified. Of these, 12 highly-immunogenic proteins were strongly associated with age and thus cumulative lifetime exposure in Solomon Islanders (P<0.001-0.027). A subset of 6 proteins, selected on the basis of immunogenicity and expression levels, were used to examine antibody levels in plasma samples from a population of young Papua New Guinean children with well-characterized individual differences in exposure. This analysis identified a strong association between reduced risk of clinical disease and antibody levels to P12, P41, and a novel hypothetical protein that has not previously been studied, PVX_081550 (IRR 0.46-0.74; P<0.001-0.041). CONCLUSION/SIGNIFICANCE These data emphasize the benefits of an unbiased screening approach in identifying novel vaccine candidate antigens. Functional studies are now required to establish whether PVX_081550 is a key component of the naturally-acquired protective immune response, a biomarker of immune status, or both.
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Affiliation(s)
- Camila T. França
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia
- Department of Medical Biology, University of Melbourne, Melbourne, Australia
| | - Jessica B. Hostetler
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
- Malaria Programme, Wellcome Trust Sanger Institute, Hinxton, United Kingdom
| | - Sumana Sharma
- Malaria Programme, Wellcome Trust Sanger Institute, Hinxton, United Kingdom
| | - Michael T. White
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia
- Center for Outbreak Analysis and Modelling, Department of Infectious Disease Epidemiology, Imperial College London, London, United Kingdom
| | - Enmoore Lin
- Vector Borne Diseases Unit, PNG Institute of Medical Research, Madang, Papua New Guinea
| | - Benson Kiniboro
- Vector Borne Diseases Unit, PNG Institute of Medical Research, Madang, Papua New Guinea
| | - Andreea Waltmann
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia
- Department of Medical Biology, University of Melbourne, Melbourne, Australia
| | - Andrew W. Darcy
- National Health Training & Research Institute, Ministry of Health, Honiara, Solomon Islands
| | - Connie S. N. Li Wai Suen
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia
- Department of Medical Biology, University of Melbourne, Melbourne, Australia
| | - Peter Siba
- Vector Borne Diseases Unit, PNG Institute of Medical Research, Madang, Papua New Guinea
| | - Christopher L. King
- Center for Global Health & Diseases, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Julian C. Rayner
- Malaria Programme, Wellcome Trust Sanger Institute, Hinxton, United Kingdom
- * E-mail: (JCR); (RMF); (IM)
| | - Rick M. Fairhurst
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
- * E-mail: (JCR); (RMF); (IM)
| | - Ivo Mueller
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia
- Department of Medical Biology, University of Melbourne, Melbourne, Australia
- ISGlobal, Barcelona Ctr. Int. Health Res. (CRESIB), Hospital Clínic, Universitat de Barcelona, Barcelona, Spain
- * E-mail: (JCR); (RMF); (IM)
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Ross A, Koepfli C, Schoepflin S, Timinao L, Siba P, Smith T, Mueller I, Felger I, Tanner M. The Incidence and Differential Seasonal Patterns of Plasmodium vivax Primary Infections and Relapses in a Cohort of Children in Papua New Guinea. PLoS Negl Trop Dis 2016; 10:e0004582. [PMID: 27144482 PMCID: PMC4856325 DOI: 10.1371/journal.pntd.0004582] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Accepted: 03/07/2016] [Indexed: 12/11/2022] Open
Abstract
Plasmodium vivax has the ability to relapse from dormant parasites in the liver weeks or months after inoculation, causing further blood-stage infection and potential onward transmission. Estimates of the force of blood-stage infections arising from primary infections and relapses are important for designing intervention strategies. However, in endemic settings their relative contributions are unclear. Infections are frequently asymptomatic, many individuals harbor multiple infections, and while high-resolution genotyping of blood samples enables individual infections to be distinguished, primary infections and relapses cannot be identified. We develop a model and fit it to longitudinal genotyping data from children in Papua New Guinea to estimate the incidence and seasonality of P vivax primary infection and relapse. The children, aged one to three years at enrolment, were followed up over 16 months with routine surveys every two months. Blood samples were taken at the routine visits and at other times if the child was ill. Samples positive by microscopy or a molecular method for species detection were genotyped using high-resolution capillary electrophoresis for P vivax MS16 and msp1F3, and P falciparum msp2. The data were summarized as longitudinal patterns of success or failure to detect a genotype at each routine time-point (eg 001000001). We assume that the seasonality of P vivax primary infection is similar to that of P falciparum since they are transmitted by the same vectors and, because P falciparum does not have the ability to relapse, the seasonality can be estimated. Relapses occurring during the study period can be a consequence of infections occurring prior to the study: we assume that the seasonal pattern of primary infections repeats over time. We incorporate information from parasitological and entomology studies to gain leverage for estimating the parameters, and take imperfect detection into account. We estimate the force of P vivax primary infections to be 11.5 (10.5, 12.3) for a three-year old child per year and the mean number of relapses per infection to be 4.3 (4.0, 4.6) over 16 months. The peak incidence of relapses occurred in the two month interval following the peak interval for primary infections: the contribution to the force of blood-stage infection from relapses is between 71% and 90% depending on the season. Our estimates contribute to knowledge of the P vivax epidemiology and have implications for the timing of intervention strategies targeting different stages of the life cycle. Plasmodium vivax is the most widespread of the malaria species affecting humans. It has the ability for parasites to lie dormant in liver cells and then to relapse weeks or months later, causing further blood-stage infections and onward transmission. Relapses present a challenge to control and elimination programs. The contribution of relapses to the force of blood-stage infection is not well established. While genotyping can distinguish individual infections, the difficulty lies in the inability to distinguish primary infections (occurring shortly after an infectious mosquito bite) and relapses. This is a gap in the knowledge of the epidemiology of P vivax. We develop a statistical model to tease out and estimate the contributions of primary infections and relapses to the force of blood-stage infection. We use data from a cohort of children in Papua New Guinea with genotyped routine blood samples. The study area has both P vivax and P falciparum malaria: we use the seasonality of P falciparum to estimate the seasonality of P vivax primary infections. We also take into account infections occurring prior to the study period and their subsequent relapses during the study period. We find that approximately 80% of the force of blood-stage infection l is contributed by relapses and that primary infections and relapses have different seasonal patterns. The findings are important to the epidemiology of P vivax and for designing intervention strategies targeting different stages of the parasite life cycle.
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Affiliation(s)
- Amanda Ross
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
- * E-mail:
| | - Cristian Koepfli
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
- Population Health and Immunity Division, Walter and Eliza Hall Institute, Parkville, Australia
| | - Sonja Schoepflin
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Lincoln Timinao
- Papua New Guinea Institute of Medical Research, Goroka, Papua New Guinea
| | - Peter Siba
- Papua New Guinea Institute of Medical Research, Goroka, Papua New Guinea
| | - Thomas Smith
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Ivo Mueller
- Population Health and Immunity Division, Walter and Eliza Hall Institute, Parkville, Australia
- ISGlobal, Barcelona Centre for International Health Research (CRESIB), Barcelona, Spain
- Department of Medical Biology, University of Melbourne, Melbourne, Victoria, Australia
- Department of Parasites and Insect Vectors, Institut Pasteur, Paris, France
| | - Ingrid Felger
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Marcel Tanner
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
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Lo E, Nguyen J, Oo W, Hemming-Schroeder E, Zhou G, Yang Z, Cui L, Yan G. Examining Plasmodium falciparum and P. vivax clearance subsequent to antimalarial drug treatment in the Myanmar-China border area based on quantitative real-time polymerase chain reaction. BMC Infect Dis 2016; 16:154. [PMID: 27084511 PMCID: PMC4833920 DOI: 10.1186/s12879-016-1482-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Accepted: 03/25/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Recent emergence of artemisinin-resistant P. falciparum has posed a serious hindrance to the elimination of malaria in the Greater Mekong Subregion. Parasite clearance time, a measure of change in peripheral parasitaemia in a sequence of samples taken after treatment, can be used to reflect the susceptibility of parasites or the efficiency of antimalarials. The association of genetic polymorphisms and artemisinin resistance has been documented. This study aims to examine clearance time of P. falciparum and P. vivax parasitemia as well as putative gene mutations associated with residual or recurred parasitemia in Myanmar. METHODS A total of 63 P. falciparum and 130 P. vivax samples collected from two internally-displaced populations and one surrounding village were examined for parasitemia changes. At least four samples were taken from each patient, at the first day of diagnosis up to 3 months following the initial treatment. The amount of parasite gene copy number was estimated using quantitative real-time PCR based on a species-specific region of the 18S rRNA gene. For samples that showed residual or recurred parasitemia after treatment, microsatellites were used to identify the 'post-treatment' parasite genotype and compared such with the 'pre-treatment' genotype. Mutations in genes pfcrt, pfmdr1, pfatp6, pfmrp1 and pfK13 that are potentially associated with ACT resistance were examined to identify if mutation is a factor for residual or persistent parasitemia. RESULTS Over 30% of the P. falciprium infections showed delayed clearance of parasitemia after 2-3 days of treatment and 9.5% showed recurred parasitemia. Mutations in codon 876 of the pfmrp1 corroborated significance association with slow clearance time. However, no association was observed in the variation in pfmdr1 gene copy number as well as mutations of various codonsinpfatp6, pfcrt, and pfK13 with clearance time. For P. vivax, over 95% of the infections indicated cleared parasitemia at days 2-3 of treatment. Four samples were found to be re-infected with new parasite strains based on microsatellite genotypes after initial treatment. CONCLUSION The appearance of P.falciparum infected samples showing delayed clearance or recurred parasitemia after treatment raises concerns on current treatment and ACT drug resistance.
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Affiliation(s)
- Eugenia Lo
- />Program in Public Health, University of California at Irvine, Irvine, CA 92697-4050 USA
| | - Jennifer Nguyen
- />Program in Public Health, University of California at Irvine, Irvine, CA 92697-4050 USA
| | - Winny Oo
- />Program in Public Health, University of California at Irvine, Irvine, CA 92697-4050 USA
| | | | - Guofa Zhou
- />Program in Public Health, University of California at Irvine, Irvine, CA 92697-4050 USA
| | - Zhaoqing Yang
- />Department of Pathogen Biology and Immunology, Kunming Medical University, Kunming, China
| | - Liwang Cui
- />Department of Entomology, Pennsylvania State University, University Park, PA USA
| | - Guiyun Yan
- />Program in Public Health, University of California at Irvine, Irvine, CA 92697-4050 USA
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Friedrich LR, Popovici J, Kim S, Dysoley L, Zimmerman PA, Menard D, Serre D. Complexity of Infection and Genetic Diversity in Cambodian Plasmodium vivax. PLoS Negl Trop Dis 2016; 10:e0004526. [PMID: 27018585 PMCID: PMC4809505 DOI: 10.1371/journal.pntd.0004526] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Accepted: 02/18/2016] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Plasmodium vivax is the most widely distributed human malaria parasite with 2.9 billion people living in endemic areas. Despite intensive malaria control efforts, the proportion of cases attributed to P. vivax is increasing in many countries. Genetic analyses of the parasite population and its dynamics could provide an assessment of the efficacy of control efforts, but, unfortunately, these studies are limited in P. vivax by the lack of informative markers and high-throughput genotyping methods. METHODOLOGY/PRINCIPAL FINDINGS We developed a sequencing-based assay to simultaneously genotype more than 100 SNPs and applied this approach to ~500 P. vivax-infected individuals recruited across nine locations in Cambodia between 2004 and 2013. Our analyses showed that the vast majority of infections are polyclonal (92%) and that P. vivax displays high genetic diversity in Cambodia without apparent geographic stratification. Interestingly, our analyses also revealed that the proportion of monoclonal infections significantly increased between 2004 and 2013, possibly suggesting that malaria control strategies in Cambodia may be successfully affecting the parasite population. CONCLUSIONS/SIGNIFICANCE Our findings demonstrate that this high-throughput genotyping assay is efficient in characterizing P. vivax diversity and can provide valuable insights to assess the efficacy of malaria elimination programs or to monitor the spread of specific parasites.
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Affiliation(s)
- Lindsey R. Friedrich
- Genomic Medicine Institute, Cleveland Clinic Lerner Research Institute, Cleveland, Ohio, United States of America
| | - Jean Popovici
- Unite d’Epidemiologie Moleculaire, Institut Pasteur du Cambodge, Phnom Penh, Cambodia
| | - Saorin Kim
- Unite d’Epidemiologie Moleculaire, Institut Pasteur du Cambodge, Phnom Penh, Cambodia
| | - Lek Dysoley
- National Center for Parasitology, Entomology and Malaria Control, Phnom Penh, Cambodia
| | - Peter A. Zimmerman
- Center for Global Health and Diseases, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Didier Menard
- Unite d’Epidemiologie Moleculaire, Institut Pasteur du Cambodge, Phnom Penh, Cambodia
| | - David Serre
- Genomic Medicine Institute, Cleveland Clinic Lerner Research Institute, Cleveland, Ohio, United States of America
- * E-mail:
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Kim JY, Goo YK, Zo YG, Ji SY, Trimarsanto H, To S, Clark TG, Price RN, Auburn S. Further Evidence of Increasing Diversity of Plasmodium vivax in the Republic of Korea in Recent Years. PLoS One 2016; 11:e0151514. [PMID: 26990869 PMCID: PMC4798397 DOI: 10.1371/journal.pone.0151514] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2015] [Accepted: 02/29/2016] [Indexed: 01/10/2023] Open
Abstract
BACKGROUND Vivax malaria was successfully eliminated from the Republic of Korea (ROK) in the late 1970s but re-emerged in 1993. Two decades later as the ROK enters the final stages of malaria elimination, dedicated surveillance of the local P. vivax population is critical. We apply a population genetic approach to gauge P. vivax transmission dynamics in the ROK between 2010 and 2012. METHODOLOGY/PRINCIPAL FINDINGS P. vivax positive blood samples from 98 autochthonous cases were collected from patients attending health centers in the ROK in 2010 (n = 27), 2011 (n = 48) and 2012 (n = 23). Parasite genotyping was undertaken at 9 tandem repeat markers. Although not reaching significance, a trend of increasing population diversity was observed from 2010 (HE = 0.50 ± 0.11) to 2011 (HE = 0.56 ± 0.08) and 2012 (HE = 0.60 ± 0.06). Conversely, linkage disequilibrium declined during the same period: IAS = 0.15 in 2010 (P = 0.010), 0.09 in 2011 (P = 0.010) and 0.05 in 2012 (P = 0.010). In combination with data from other ROK studies undertaken between 1994 and 2007, our results are consistent with increasing parasite divergence since re-emergence. Polyclonal infections were rare (3% infections) suggesting that local out-crossing alone was unlikely to explain the increased divergence. Cases introduced from an external reservoir may therefore have contributed to the increased diversity. Aside from one isolate, all infections carried a short MS20 allele (142 or 149 bp), not observed in other studies in tropical endemic countries despite high diversity, inferring that these regions are unlikely reservoirs. CONCLUSIONS Whilst a number of factors may explain the observed population genetic trends, the available evidence suggests that an external geographic reservoir with moderate diversity sustains the majority of P. vivax infection in the ROK, with important implications for malaria elimination.
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Affiliation(s)
- Jung-Yeon Kim
- Division of Malaria and Parasitic Diseases, National Institute of Health, Korea CDC, Osong Saeng-myeong, 2 ro, Osong Health Technology Administration, Osong, Republic of Korea
| | - Youn-Kyoung Goo
- Division of Malaria and Parasitic Diseases, National Institute of Health, Korea CDC, Osong Saeng-myeong, 2 ro, Osong Health Technology Administration, Osong, Republic of Korea
- Department of Parasitology and Tropical Medicine, Kyungpook National University School of Medicine, Daegu, 700–422, Republic of Korea
| | - Young-Gun Zo
- Department of Molecular Parasitology, Sungkyunkwan University School of Medicine and Center for Molecular Medicine, Samsung Biomedical Research Institute, Suwon, Gyeonggi-do 440–746, Republic of Korea
| | - So-Young Ji
- Division of Malaria and Parasitic Diseases, National Institute of Health, Korea CDC, Osong Saeng-myeong, 2 ro, Osong Health Technology Administration, Osong, Republic of Korea
| | - Hidayat Trimarsanto
- Eijkman Institute for Molecular Biology, Jl. Diponegoro 69, Jakarta Pusat, 10430, Indonesia
- Agency for Assessment and Application of Technology, Jl. MH Thamrin 8, Jakarta, 10340, Indonesia
| | - Sheren To
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, NT 0810, Australia
| | - Taane G. Clark
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, United Kingdom
- Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, United Kingdom
| | - Ric N. Price
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, NT 0810, Australia
- Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, United Kingdom
| | - Sarah Auburn
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, NT 0810, Australia
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Ribeiro BDP, Cassiano GC, de Souza RM, Cysne DN, Grisotto MAG, de Azevedo dos Santos APS, Marinho CRF, Machado RLD, Nascimento FRF. Polymorphisms in Plasmodium vivax Circumsporozoite Protein (CSP) Influence Parasite Burden and Cytokine Balance in a Pre-Amazon Endemic Area from Brazil. PLoS Negl Trop Dis 2016; 10:e0004479. [PMID: 26943639 PMCID: PMC4778932 DOI: 10.1371/journal.pntd.0004479] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Accepted: 02/01/2016] [Indexed: 12/17/2022] Open
Abstract
Mechanisms involved in severe P. vivax malaria remain unclear. Parasite polymorphisms, parasite load and host cytokine profile may influence the course of infection. In this study, we investigated the influence of circumsporozoite protein (CSP) polymorphisms on parasite load and cytokine profile in patients with vivax malaria. A cross-sectional study was carried out in three cities: São Luís, Cedral and Buriticupu, Maranhão state, Brazil, areas of high prevalence of P. vivax. Interleukin (IL)-2, IL-4, IL-10, IL-6, IL-17, tumor necrosis factor alpha (TNF-α, interferon gamma (IFN-γ and transforming growth factor beta (TGF-β were quantified in blood plasma of patients and in supernatants from peripheral blood mononuclear cell (PBMC) cultures. Furthermore, the levels of cytokines and parasite load were correlated with VK210, VK247 and P. vivax-like CSP variants. Patients infected with P. vivax showed increased IL-10 and IL-6 levels, which correlated with the parasite load, however, in multiple comparisons, only IL-10 kept this association. A regulatory cytokine profile prevailed in plasma, while an inflammatory profile prevailed in PBMC culture supernatants and these patterns were related to CSP polymorphisms. VK247 infected patients showed higher parasitaemia and IL-6 concentrations, which were not associated to IL-10 anti-inflammatory effect. By contrast, in VK210 patients, these two cytokines showed a strong positive correlation and the parasite load was lower. Patients with the VK210 variant showed a regulatory cytokine profile in plasma, while those infected with the VK247 variant have a predominantly inflammatory cytokine profile and higher parasite loads, which altogether may result in more complications in infection. In conclusion, we propose that CSP polymorphisms is associated to the increase of non-regulated inflammatory immune responses, which in turn may be associated with the outcome of infection. Recent evidences have associated P. vivax infections with clinical complications, previously only attributed to P. falciparum malaria. The interaction between host and parasite may contribute to severity of the disease, however, the specific contribution of each factor remains unclear. Previous studies have shown that polymorphisms in Plasmodium vivax CSP may interfere in systemic reactions, response to drug treatments, leading to different symptoms as well as humoral responses. In this study, we investigate whether these polymorphisms could influence the parasite load and cytokine profile, which altogether may influence the malaria outcome. In this sense, studies have shown that subjects with high parasitic loads, responding with production of pro-inflammatory cytokines develop a more severe disease. The present data indicate that VK247 variant are associated with significant higher parasite loads and pro-inflammatory cytokine profile compared to VK210 variant. In this regard, this study demonstrates that P. vivax CSP polymorphisms have systemic effects in the host immune response, and the investigation of immunogenicity of parasite proteins may provide evidences for a better understanding of this infection.
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Affiliation(s)
- Bruno de Paulo Ribeiro
- Programa de Pós- graduação em Ciências da Saúde, Universidade Federal do Maranhão (UFMA), São Luís, Maranhão, Brazil
- Laboratório de Imunofisiologia, Universidade Federal do Maranhão (UFMA), São Luís, Maranhão, Brazil
| | - Gustavo Capatti Cassiano
- Centro de Investigação de Microrganismos, Faculdade de Medicina de São José do Rio Preto (FAMERP), São José do Rio Preto, São Paulo, Brazil
| | - Rodrigo Medeiros de Souza
- Departamento de Parasitologia, Universidade de São Paulo (ICB/USP), São Paulo, São Paulo, Brazil
- Centro Multidisciplinar, Campus Floresta (Universidade Federal do Acre), Cruzeiro do Sul, Acre, Brazil
| | - Dalila Nunes Cysne
- Laboratório de Imunofisiologia, Universidade Federal do Maranhão (UFMA), São Luís, Maranhão, Brazil
| | | | | | | | - Ricardo Luiz Dantas Machado
- Laboratório de Pesquisa Básica em Malária (Instituto Evandro Chagas / Secretaria de Vigilância em Saúde / Ministério da Saúde—IEC/SVS/MS), Belém, Pará, Brazil
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Britton S, Cheng Q, Grigg MJ, Poole CB, Pasay C, William T, Fornace K, Anstey NM, Sutherland CJ, Drakeley C, McCarthy JS. Sensitive Detection of Plasmodium vivax Using a High-Throughput, Colourimetric Loop Mediated Isothermal Amplification (HtLAMP) Platform: A Potential Novel Tool for Malaria Elimination. PLoS Negl Trop Dis 2016; 10:e0004443. [PMID: 26870958 PMCID: PMC4752294 DOI: 10.1371/journal.pntd.0004443] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Accepted: 01/18/2016] [Indexed: 11/19/2022] Open
Abstract
INTRODUCTION Plasmodium vivax malaria has a wide geographic distribution and poses challenges to malaria elimination that are likely to be greater than those of P. falciparum. Diagnostic tools for P. vivax infection in non-reference laboratory settings are limited to microscopy and rapid diagnostic tests but these are unreliable at low parasitemia. The development and validation of a high-throughput and sensitive assay for P. vivax is a priority. METHODS A high-throughput LAMP assay targeting a P. vivax mitochondrial gene and deploying colorimetric detection in a 96-well plate format was developed and evaluated in the laboratory. Diagnostic accuracy was compared against microscopy, antigen detection tests and PCR and validated in samples from malaria patients and community controls in a district hospital setting in Sabah, Malaysia. RESULTS The high throughput LAMP-P. vivax assay (HtLAMP-Pv) performed with an estimated limit of detection of 1.4 parasites/ μL. Assay primers demonstrated cross-reactivity with P. knowlesi but not with other Plasmodium spp. Field testing of HtLAMP-Pv was conducted using 149 samples from symptomatic malaria patients (64 P. vivax, 17 P. falciparum, 56 P. knowlesi, 7 P. malariae, 1 mixed P. knowlesi/P. vivax, with 4 excluded). When compared against multiplex PCR, HtLAMP-Pv demonstrated a sensitivity for P. vivax of 95% (95% CI 87-99%); 61/64), and specificity of 100% (95% CI 86-100%); 25/25) when P. knowlesi samples were excluded. HtLAMP-Pv testing of 112 samples from asymptomatic community controls, 7 of which had submicroscopic P. vivax infections by PCR, showed a sensitivity of 71% (95% CI 29-96%; 5/7) and specificity of 93% (95% CI87-97%; 98/105). CONCLUSION This novel HtLAMP-P. vivax assay has the potential to be a useful field applicable molecular diagnostic test for P. vivax infection in elimination settings.
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Affiliation(s)
- Sumudu Britton
- University of Queensland, Brisbane, Australia and QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Qin Cheng
- Australian Army Malaria Institute, Brisbane, Australia
| | - Matthew J. Grigg
- Menzies School of Health Research and Charles Darwin University, Darwin, Australia
| | | | - Cielo Pasay
- University of Queensland, Brisbane, Australia and QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | | | - Kimberley Fornace
- London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Nicholas M. Anstey
- Menzies School of Health Research and Charles Darwin University, Darwin, Australia
| | | | - Chris Drakeley
- London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - James S. McCarthy
- University of Queensland, Brisbane, Australia and QIMR Berghofer Medical Research Institute, Brisbane, Australia
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Ogbunugafor CB, Hartl D. A pivot mutation impedes reverse evolution across an adaptive landscape for drug resistance in Plasmodium vivax. Malar J 2016; 15:40. [PMID: 26809718 PMCID: PMC4727274 DOI: 10.1186/s12936-016-1090-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2015] [Accepted: 01/10/2016] [Indexed: 12/03/2022] Open
Abstract
BACKGROUND The study of reverse evolution from resistant to susceptible phenotypes can reveal constraints on biological evolution, a topic for which evolutionary theory has relatively few general principles. The public health catastrophe of antimicrobial resistance in malaria has brought these constraints on evolution into a practical realm, with one proposed solution: withdrawing anti-malarial medication use in high resistance settings, built on the assumption that reverse evolution occurs readily enough that populations of pathogens may revert to their susceptible states. While past studies have suggested limits to reverse evolution, there have been few attempts to properly dissect its mechanistic constraints. METHODS Growth rates were determined from empirical data on the growth and resistance from a set of combinatorially complete set of mutants of a resistance protein (dihydrofolate reductase) in Plasmodium vivax, to construct reverse evolution trajectories. The fitness effects of individual mutations were calculated as a function of drug environment, revealing the magnitude of epistatic interactions between mutations and genetic backgrounds. Evolution across the landscape was simulated in two settings: starting from the population fixed for the quadruple mutant, and from a polymorphic population evenly distributed between double mutants. RESULTS A single mutation of large effect (S117N) serves as a pivot point for evolution to high resistance regions of the landscape. Through epistatic interactions with other mutations, this pivot creates an epistatic ratchet against reverse evolution towards the wild type ancestor, even in environments where the wild type is the most fit of all genotypes. This pivot mutation underlies the directional bias in evolution across the landscape, where evolution towards the ancestor is precluded across all examined drug concentrations from various starting points in the landscape. CONCLUSIONS The presence of pivot mutations can dictate dynamics of evolution across adaptive landscape through epistatic interactions within a protein, leaving a population trapped on local fitness peaks in an adaptive landscape, unable to locate ancestral genotypes. This irreversibility suggests that the structure of an adaptive landscape for a resistance protein should be understood before considering resistance management strategies. This proposed mechanism for constraints on reverse evolution corroborates evidence from the field indicating that phenotypic reversal often occurs via compensatory mutation at sites independent of those associated with the forward evolution of resistance. Because of this, molecular methods that identify resistance patterns via single SNPs in resistance-associated markers might be missing signals for resistance and compensatory mutation throughout the genome. In these settings, whole genome sequencing efforts should be used to identify resistance patterns, and will likely reveal a more complicated genomic signature for resistance and susceptibility, especially in settings where anti-malarial medications have been used intermittently. Lastly, the findings suggest that, given their role in dictating the dynamics of evolution across the landscape, pivot mutations might serve as future targets for therapy.
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Affiliation(s)
- C Brandon Ogbunugafor
- Department of Biology, University of Vermont, Burlington, VT, USA.
- Vermont Complex Systems Center, The University of Vermont, Burlington, VT, USA.
| | - Daniel Hartl
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, USA.
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Rodrigues-da-Silva RN, Martins da Silva JH, Singh B, Jiang J, Meyer EVS, Santos F, Banic DM, Moreno A, Galinski MR, Oliveira-Ferreira J, Lima-Junior JDC. In silico Identification and Validation of a Linear and Naturally Immunogenic B-Cell Epitope of the Plasmodium vivax Malaria Vaccine Candidate Merozoite Surface Protein-9. PLoS One 2016; 11:e0146951. [PMID: 26788998 PMCID: PMC4720479 DOI: 10.1371/journal.pone.0146951] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Accepted: 12/22/2015] [Indexed: 12/21/2022] Open
Abstract
Synthetic peptide vaccines provide the advantages of safety, stability and low cost. The success of this approach is highly dependent on efficient epitope identification and synthetic strategies for efficacious delivery. In malaria, the Merozoite Surface Protein-9 of Plasmodium vivax (PvMSP9) has been considered a vaccine candidate based on the evidence that specific antibodies were able to inhibit merozoite invasion and recombinant proteins were highly immunogenic in mice and humans. However the identities of linear B-cell epitopes within PvMSP9 as targets of functional antibodies remain undefined. We used several publicly-available algorithms for in silico analyses and prediction of relevant B cell epitopes within PMSP9. We show that the tandem repeat sequence EAAPENAEPVHENA (PvMSP9E795-A808) present at the C-terminal region is a promising target for antibodies, given its high combined score to be a linear epitope and located in a putative intrinsically unstructured region of the native protein. To confirm the predictive value of the computational approach, plasma samples from 545 naturally exposed individuals were screened for IgG reactivity against the recombinant PvMSP9-RIRII729-972 and a synthetic peptide representing the predicted B cell epitope PvMSP9E795-A808. 316 individuals (58%) were responders to the full repetitive region PvMSP9-RIRII, of which 177 (56%) also presented total IgG reactivity against the synthetic peptide, confirming it validity as a B cell epitope. The reactivity indexes of anti-PvMSP9-RIRII and anti-PvMSP9E795-A808 antibodies were correlated. Interestingly, a potential role in the acquisition of protective immunity was associated with the linear epitope, since the IgG1 subclass against PvMSP9E795-A808 was the prevalent subclass and this directly correlated with time elapsed since the last malaria episode; however this was not observed in the antibody responses against the full PvMSP9-RIRII. In conclusion, our findings identified and experimentally confirmed the potential of PvMSP9E795-A808 as an immunogenic linear B cell epitope within the P. vivax malaria vaccine candidate PvMSP9 and support its inclusion in future subunit vaccines.
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Affiliation(s)
| | | | - Balwan Singh
- Emory Vaccine Center, Yerkes National Primate Research Center, Emory University, Atlanta, GA, United States of America
| | - Jianlin Jiang
- Emory Vaccine Center, Yerkes National Primate Research Center, Emory University, Atlanta, GA, United States of America
| | - Esmeralda V. S. Meyer
- Environmental Health and Safety Office, Emory University, Atlanta, GA, United States of America
| | - Fátima Santos
- National Health Foundation, Department of Entomology, Central Laboratory, Porto Velho, RO, Brazil
| | - Dalma Maria Banic
- Laboratory of Simulids and Onchocerciasis "Malaria and Onchocerciasis Research", Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
| | - Alberto Moreno
- Emory Vaccine Center, Yerkes National Primate Research Center, Emory University, Atlanta, GA, United States of America
- Division of Infectious Diseases, Department of Medicine, Emory University School of Medicine, Emory University, Atlanta, GA, United States of America
| | - Mary R. Galinski
- Emory Vaccine Center, Yerkes National Primate Research Center, Emory University, Atlanta, GA, United States of America
- Division of Infectious Diseases, Department of Medicine, Emory University School of Medicine, Emory University, Atlanta, GA, United States of America
| | - Joseli Oliveira-Ferreira
- Laboratório de Imunoparasitologia, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, RJ, Brazil
- * E-mail: (JCLJ); (JO-F)
| | - Josué da Costa Lima-Junior
- Laboratório de Imunoparasitologia, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, RJ, Brazil
- * E-mail: (JCLJ); (JO-F)
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Nair CB, Manjula J, Subramani PA, Nagendrappa PB, Manoj MN, Malpani S, Pullela PK, Subbarao PV, Ramamoorthy S, Ghosh SK. Differential Diagnosis of Malaria on Truelab Uno®, a Portable, Real-Time, MicroPCR Device for Point-Of-Care Applications. PLoS One 2016; 11:e0146961. [PMID: 26784111 PMCID: PMC4718663 DOI: 10.1371/journal.pone.0146961] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2015] [Accepted: 12/23/2015] [Indexed: 11/27/2022] Open
Abstract
Background Sensitive and specific detection of malarial parasites is crucial in controlling the significant malaria burden in the developing world. Also important is being able to identify life threatening Plasmodium falciparum malaria quickly and accurately to reduce malaria related mortality. Existing methods such as microscopy and rapid diagnostic tests (RDTs) have major shortcomings. Here, we describe a new real-time PCR-based diagnostic test device at point-of-care service for resource-limited settings. Methods Truenat® Malaria, a chip-based microPCR test, was developed by bigtec Labs, Bangalore, India, for differential identification of Plasmodium falciparum and Plasmodium vivax parasites. The Truenat Malaria tests runs on bigtec’s Truelab Uno® microPCR device, a handheld, battery operated, and easy-to-use real-time microPCR device. The performance of Truenat® Malaria was evaluated versus the WHO nested PCR protocol. The Truenat® Malaria was further evaluated in a triple-blinded study design using a sample panel of 281 specimens created from the clinical samples characterized by expert microscopy and a rapid diagnostic test kit by the National Institute of Malaria Research (NIMR). A comparative evaluation was done on the Truelab Uno® and a commercial real-time PCR system. Results The limit of detection of the Truenat Malaria assay was found to be <5 parasites/μl for both P. falciparum and P. vivax. The Truenat® Malaria test was found to have sensitivity and specificity of 100% each, compared to the WHO nested PCR protocol based on the evaluation of 100 samples. The sensitivity using expert microscopy as the reference standard was determined to be around 99.3% (95% CI: 95.5–99.9) at the species level. Mixed infections were identified more accurately by Truenat Malaria (32 samples identified as mixed) versus expert microscopy and RDTs which detected 4 and 5 mixed samples, respectively. Conclusion The Truenat® Malaria microPCR test is a valuable diagnostic tool and implementation should be considered not only for malaria diagnosis but also for active surveillance and epidemiological intervention.
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Affiliation(s)
- Chandrasekhar Bhaskaran Nair
- bigtec Private Limited, 2nd Floor, Golden Heights, 59th C Cross, 4th M Block, Rajajinagar, Bangalore, 560 010, Karnataka, India
- School of Bio Sciences and Technology, School of Advanced Sciences VIT University, Vellore, Tamil Nadu, 632014, India
| | - Jagannath Manjula
- bigtec Private Limited, 2nd Floor, Golden Heights, 59th C Cross, 4th M Block, Rajajinagar, Bangalore, 560 010, Karnataka, India
| | - Pradeep Annamalai Subramani
- National Institute of Malaria Research, ICMR Complex, Poojanahalli, Kannamangala Post, Devanahalli, Bangalore, 562 110, Karnataka, India
| | - Prakash B. Nagendrappa
- Institute of Trans-disciplinary Health Sciences and Technology (IHST), FRLHT, 74/2, Jarakabande Kaval, Attur post, Via Yelahanka, Bangalore, 560 106, Karnataka, India
| | - Mulakkapurath Narayanan Manoj
- bigtec Private Limited, 2nd Floor, Golden Heights, 59th C Cross, 4th M Block, Rajajinagar, Bangalore, 560 010, Karnataka, India
| | - Sukriti Malpani
- bigtec Private Limited, 2nd Floor, Golden Heights, 59th C Cross, 4th M Block, Rajajinagar, Bangalore, 560 010, Karnataka, India
| | - Phani Kumar Pullela
- bigtec Private Limited, 2nd Floor, Golden Heights, 59th C Cross, 4th M Block, Rajajinagar, Bangalore, 560 010, Karnataka, India
| | - Pillarisetti Venkata Subbarao
- bigtec Private Limited, 2nd Floor, Golden Heights, 59th C Cross, 4th M Block, Rajajinagar, Bangalore, 560 010, Karnataka, India
| | - Siva Ramamoorthy
- School of Bio Sciences and Technology, School of Advanced Sciences VIT University, Vellore, Tamil Nadu, 632014, India
| | - Susanta K. Ghosh
- National Institute of Malaria Research, ICMR Complex, Poojanahalli, Kannamangala Post, Devanahalli, Bangalore, 562 110, Karnataka, India
- * E-mail:
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Delgado-Ratto C, Gamboa D, Soto-Calle VE, Van den Eede P, Torres E, Sánchez-Martínez L, Contreras-Mancilla J, Rosanas-Urgell A, Rodriguez Ferrucci H, Llanos-Cuentas A, Erhart A, Van geertruyden JP, D’Alessandro U. Population Genetics of Plasmodium vivax in the Peruvian Amazon. PLoS Negl Trop Dis 2016; 10:e0004376. [PMID: 26766548 PMCID: PMC4713096 DOI: 10.1371/journal.pntd.0004376] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2015] [Accepted: 12/18/2015] [Indexed: 11/18/2022] Open
Abstract
Background Characterizing the parasite dynamics and population structure provides useful information to understand the dynamic of transmission and to better target control interventions. Despite considerable efforts for its control, vivax malaria remains a major health problem in Peru. In this study, we have explored the population genetics of Plasmodium vivax isolates from Iquitos, the main city in the Peruvian Amazon, and 25 neighbouring peri-urban as well as rural villages along the Iquitos-Nauta Road. Methodology/ Results From April to December 2008, 292 P. vivax isolates were collected and successfully genotyped using 14 neutral microsatellites. Analysis of the molecular data revealed a similar proportion of monoclonal and polyclonal infections in urban areas, while in rural areas monoclonal infections were predominant (p = 0.002). Multiplicity of infection was higher in urban (MOI = 1.5–2) compared to rural areas (MOI = 1) (p = 0.003). The level of genetic diversity was similar in all areas (He = 0.66–0.76, p = 0.32) though genetic differentiation between areas was substantial (PHIPT = 0.17, p<0.0001). Principal coordinate analysis showed a marked differentiation between parasites from urban and rural areas. Linkage disequilibrium was detected in all the areas ( IAs = 0.08–0.49, for all p<0.0001). Gene flow among the areas was stablished through Bayesian analysis of migration models. Recent bottleneck events were detected in 4 areas and a recent parasite expansion in one of the isolated areas. In total, 87 unique haplotypes grouped in 2 or 3 genetic clusters described a sub-structured parasite population. Conclusion/Significance Our study shows a sub-structured parasite population with clonal propagation, with most of its components recently affected by bottleneck events. Iquitos city is the main source of parasite spreading for all the peripheral study areas. The routes of transmission and gene flow and the reduction of the parasite population described are important from the public health perspective as well for the formulation of future control policies. We present the population genetics of malaria vivax parasites in a large area of the Peruvian Amazon. Our results showed that the parasite population had a predominant clonal propagation, reproducing themselves with identically or closely related parasites; therefore, the same genetic characteristics are maintained in the offspring. The clonal propagation may favour the higher levels of genetic differentiation among the parasites from isolated areas compared to areas where human migration is common. The patterns of gene flow have been established, finding Iquitos city as a reservoir of parasite genetic variability. Moreover, a recent reduction of the parasite population was observed in areas where recent control activities were performed. This research provides a picture of the nature and dynamics of the parasite population which have a significant impact in the malaria epidemiology; therefore, this knowledge is crucial for the development of efficient control policies.
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Affiliation(s)
| | - Dionicia Gamboa
- Institute of Tropical Medicine Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Peru
- Departamento de Ciencias Celulares y Moleculares, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Veronica E. Soto-Calle
- Institute of Tropical Medicine Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Peter Van den Eede
- Department of Biomedical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
| | - Eliana Torres
- Institute of Tropical Medicine Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Luis Sánchez-Martínez
- Institute of Tropical Medicine Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Juan Contreras-Mancilla
- Institute of Tropical Medicine Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Anna Rosanas-Urgell
- Department of Biomedical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
| | | | - Alejandro Llanos-Cuentas
- Institute of Tropical Medicine Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Annette Erhart
- Department of Biomedical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
| | | | - Umberto D’Alessandro
- Department of Public Health, Institute of Tropical Medicine, Antwerp, Belgium
- Medical Research Council Unit, Fajara, The Gambia
- London School of Hygiene and Tropical Medicine, London, United Kingdom
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193
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Pacheco MA, Lopez-Perez M, Vallejo AF, Herrera S, Arévalo-Herrera M, Escalante AA. Multiplicity of Infection and Disease Severity in Plasmodium vivax. PLoS Negl Trop Dis 2016; 10:e0004355. [PMID: 26751811 PMCID: PMC4709143 DOI: 10.1371/journal.pntd.0004355] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2015] [Accepted: 12/11/2015] [Indexed: 11/19/2022] Open
Abstract
Background Multiplicity of infection (MOI) refers to the average number of distinct parasite genotypes concurrently infecting a patient. Although several studies have reported on MOI and the frequency of multiclonal infections in Plasmodium falciparum, there is limited data on Plasmodium vivax. Here, MOI and the frequency of multiclonal infections were studied in areas from South America where P. vivax and P. falciparum can be compared. Methodology/Principal Findings As part of a passive surveillance study, 1,328 positive malaria patients were recruited between 2011 and 2013 in low transmission areas from Colombia. Of those, there were only 38 P. vivax and 24 P. falciparum clinically complicated cases scattered throughout the time of the study. Samples from uncomplicated cases were matched in time and location with the complicated cases in order to compare the circulating genotypes for these two categories. A total of 92 P. vivax and 57 P. falciparum uncomplicated cases were randomly subsampled. All samples were genotyped by using neutral microsatellites. Plasmodium vivax showed more multiclonal infections (47.7%) than P. falciparum (14.8%). Population genetics and haplotype network analyses did not detect differences in the circulating genotypes between complicated and uncomplicated cases in each parasite. However, a Fisher exact test yielded a significant association between having multiclonal P. vivax infections and complicated malaria. No association was found for P. falciparum infections. Conclusion The association between multiclonal infections and disease severity in P. vivax is consistent with previous observations made in rodent malaria. The contrasting pattern between P. vivax and P. falciparum could be explained, at least in part, by the fact that P. vivax infections have lineages that were more distantly related among them than in the case of the P. falciparum multiclonal infections. Future research should address the possible role that acquired immunity and exposure may have on multiclonal infections and their association with disease severity. Previous studies on rodent malarias and mathematical models have postulated a link between multiclonal infections and disease severity. This association has been tested in Plasmodium falciparum mostly in Africa with limited information on P. vivax. Furthermore, there is a paucity of information from areas with low transmission. Here, we used samples available from a passive surveillance carried out in Colombia, South America. We found an association between multiclonal infections and disease severity in P. vivax but not in P. falciparum. Although the number of complicated malaria cases is low, the contrasting pattern between these two species emphasizes their epidemiological differences. We discuss how this pattern could be the result of a higher divergence among the P. vivax lineages co-infecting a patient. We hypothesize that low levels of acquired immunity may play a role in the association between multiclonal infections and disease severity.
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Affiliation(s)
- M. Andreína Pacheco
- Institute for Genomics and Evolutionary Medicine (igem), Temple University, Philadelphia, Pennsylvania, United States of America
| | - Mary Lopez-Perez
- Caucaseco Scientific Research Center and Malaria Vaccine and Drug Development Center, Cali, Colombia
| | - Andrés F. Vallejo
- Caucaseco Scientific Research Center and Malaria Vaccine and Drug Development Center, Cali, Colombia
| | - Sócrates Herrera
- Caucaseco Scientific Research Center and Malaria Vaccine and Drug Development Center, Cali, Colombia
| | - Myriam Arévalo-Herrera
- Caucaseco Scientific Research Center and Malaria Vaccine and Drug Development Center, Cali, Colombia
- Faculty of Health, Universidad del Valle, Cali, Colombia
| | - Ananias A. Escalante
- Institute for Genomics and Evolutionary Medicine (igem), Temple University, Philadelphia, Pennsylvania, United States of America
- * E-mail:
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Vizzi E, Bastidas G, Hidalgo M, Colman L, Pérez HA. Prevalence and molecular characterization of G6PD deficiency in two Plasmodium vivax endemic areas in Venezuela: predominance of the African A-(202A/376G) variant. Malar J 2016; 15:19. [PMID: 26753754 PMCID: PMC4710037 DOI: 10.1186/s12936-015-1069-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Accepted: 12/22/2015] [Indexed: 01/16/2023] Open
Abstract
BACKGROUND Glucose-6-phosphate dehydrogenase (G6PD) deficiency causes acute haemolytic anaemia triggered by oxidative drugs such as primaquine (PQ), used for Plasmodium vivax malaria radical cure. However, in many endemic areas of vivax malaria, patients are treated with PQ without any evaluation of their G6PD status. METHODS G6PD deficiency and its genetic heterogeneity were evaluated in northeastern and southeastern areas from Venezuela, Cajigal (Sucre state) and Sifontes (Bolívar state) municipalities, respectively. Blood samples from 664 randomly recruited unrelated individuals were screened for G6PD activity by a quantitative method. Mutation analysis for exons 4-8 of G6PD gen was performed on DNA isolated from G6PD-deficient (G6PDd) subjects through PCR-RFLP and direct DNA sequencing. RESULTS Quantitative biochemical characterization revealed that overall 24 (3.6%) subjects were G6PDd (average G6PD enzyme activity 4.5 ± 1.2 U/g Hb, moderately deficient, class III), while DNA analysis showed one or two mutated alleles in 19 of them (79.2%). The G6PD A-(202A/376G) variant was the only detected in 17 (70.8%) individuals, 13 of them hemizygous males and four heterozygous females. Two males carried only the 376A → G mutation. No other mutation was found in the analysed exons. CONCLUSIONS The G6PDd prevalence was as low as that one shown by nearby countries. This study contributes to the knowledge of the genetic background of Venezuelan population, especially of those living in malaria-endemic areas. Despite the high degree of genetic mixing described for Venezuelan population, a net predominance of the mild African G6PD A-(202A/376G) variant was observed among G6PDd subjects, suggesting a significant flow of G6PD genes from Africa to Americas, almost certainly introduced through African and/or Spanish immigrants during and after the colonization. The data suggest that 1:27 individuals of the studied population could be G6PDd and therefore at risk of haemolysis under precipitating factors. Information about PQ effect on G6PDd individuals carrying mild variant is limited, but since the regimen of 45 mg weekly dose for prevention of malaria relapse does not seem to be causing clinically significant haemolysis in people having the G6PD A-variant, a reasoned weighing of risk-benefit for its use in Venezuela should be done, when implementing public health strategies of control and elimination.
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Affiliation(s)
- Esmeralda Vizzi
- Laboratorio de Biología de Virus, Centro de Microbiología y Biología Celular, Instituto Venezolano de Investigaciones Científicas, Apdo 21827, Caracas, 1020-A, Venezuela.
| | - Gilberto Bastidas
- Laboratorio de Biología de Virus, Centro de Microbiología y Biología Celular, Instituto Venezolano de Investigaciones Científicas, Apdo 21827, Caracas, 1020-A, Venezuela.
- Laboratorio de Inmunoparasitología, Centro de Microbiología y Biología Celular, Instituto Venezolano de Investigaciones Científicas, Apdo 21827, Caracas, 1020-A, Venezuela.
- Departamento de Salud Pública, Facultad de Ciencias de la Salud, Universidad de Carabobo, Valencia, Edo. Carabobo, Venezuela.
| | - Mariana Hidalgo
- Laboratorio de Inmunoparasitología, Centro de Microbiología y Biología Celular, Instituto Venezolano de Investigaciones Científicas, Apdo 21827, Caracas, 1020-A, Venezuela.
| | - Laura Colman
- Laboratorio de Inmunoparasitología, Centro de Microbiología y Biología Celular, Instituto Venezolano de Investigaciones Científicas, Apdo 21827, Caracas, 1020-A, Venezuela.
| | - Hilda A Pérez
- Laboratorio de Inmunoparasitología, Centro de Microbiología y Biología Celular, Instituto Venezolano de Investigaciones Científicas, Apdo 21827, Caracas, 1020-A, Venezuela.
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Winter DJ, Pacheco MA, Vallejo AF, Schwartz RS, Arevalo-Herrera M, Herrera S, Cartwright RA, Escalante AA. Whole Genome Sequencing of Field Isolates Reveals Extensive Genetic Diversity in Plasmodium vivax from Colombia. PLoS Negl Trop Dis 2015; 9:e0004252. [PMID: 26709695 PMCID: PMC4692395 DOI: 10.1371/journal.pntd.0004252] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2015] [Accepted: 10/30/2015] [Indexed: 11/24/2022] Open
Abstract
Plasmodium vivax is the most prevalent malarial species in South America and exerts a substantial burden on the populations it affects. The control and eventual elimination of P. vivax are global health priorities. Genomic research contributes to this objective by improving our understanding of the biology of P. vivax and through the development of new genetic markers that can be used to monitor efforts to reduce malaria transmission. Here we analyze whole-genome data from eight field samples from a region in Cordóba, Colombia where malaria is endemic. We find considerable genetic diversity within this population, a result that contrasts with earlier studies suggesting that P. vivax had limited diversity in the Americas. We also identify a selective sweep around a substitution known to confer resistance to sulphadoxine-pyrimethamine (SP). This is the first observation of a selective sweep for SP resistance in this species. These results indicate that P. vivax has been exposed to SP pressure even when the drug is not in use as a first line treatment for patients afflicted by this parasite. We identify multiple non-synonymous substitutions in three other genes known to be involved with drug resistance in Plasmodium species. Finally, we found extensive microsatellite polymorphisms. Using this information we developed 18 polymorphic and easy to score microsatellite loci that can be used in epidemiological investigations in South America. Although P. vivax is not as deadly as the more widely studied P. falciparum, it remains a pressing global health problem. Here we report the results of a whole-genome study of P. vivax from Cordóba, Colombia, in South America. This parasite is the most prevalent in this region. We show that the parasite population is genetically diverse, which is contrary to expectations from earlier studies from the Americas. We also find molecular evidence that resistance to an anti-malarial drug has arisen recently in this region. This selective sweep indicates that the parasite has been exposed to a drug that is not used as first-line treatment for this malaria parasite. In addition to extensive single nucleotide and microsatellite polymorphism, we report 18 new genetic loci that might be helpful for fine-scale studies of this species in the Americas.
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Affiliation(s)
- David J. Winter
- The Biodesign Institute, Arizona State University, Tempe, Arizona, United States of America
- * E-mail: (DJW); (AAE)
| | - M. Andreína Pacheco
- The Biodesign Institute, Arizona State University, Tempe, Arizona, United States of America
- Institute for Genomics and Evolutionary Medicine (igem), Temple University, Philadelphia, Pennsylvania, United States of America
| | | | - Rachel S. Schwartz
- The Biodesign Institute, Arizona State University, Tempe, Arizona, United States of America
| | - Myriam Arevalo-Herrera
- Caucaseco Scientific Research Center, Cali, Colombia
- Faculty of Health, Universidad del Valle, Cali, Colombia
| | | | - Reed A. Cartwright
- The Biodesign Institute, Arizona State University, Tempe, Arizona, United States of America
- The School of Life Sciences, Arizona State University, Tempe, Arizona, United States of America
| | - Ananias A. Escalante
- The Biodesign Institute, Arizona State University, Tempe, Arizona, United States of America
- Institute for Genomics and Evolutionary Medicine (igem), Temple University, Philadelphia, Pennsylvania, United States of America
- * E-mail: (DJW); (AAE)
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Hostetler JB, Sharma S, Bartholdson SJ, Wright GJ, Fairhurst RM, Rayner JC. A Library of Plasmodium vivax Recombinant Merozoite Proteins Reveals New Vaccine Candidates and Protein-Protein Interactions. PLoS Negl Trop Dis 2015; 9:e0004264. [PMID: 26701602 PMCID: PMC4689532 DOI: 10.1371/journal.pntd.0004264] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2015] [Accepted: 11/05/2015] [Indexed: 11/27/2022] Open
Abstract
Background A vaccine targeting Plasmodium vivax will be an essential component of any comprehensive malaria elimination program, but major gaps in our understanding of P. vivax biology, including the protein-protein interactions that mediate merozoite invasion of reticulocytes, hinder the search for candidate antigens. Only one ligand-receptor interaction has been identified, that between P. vivax Duffy Binding Protein (PvDBP) and the erythrocyte Duffy Antigen Receptor for Chemokines (DARC), and strain-specific immune responses to PvDBP make it a complex vaccine target. To broaden the repertoire of potential P. vivax merozoite-stage vaccine targets, we exploited a recent breakthrough in expressing full-length ectodomains of Plasmodium proteins in a functionally-active form in mammalian cells and initiated a large-scale study of P. vivax merozoite proteins that are potentially involved in reticulocyte binding and invasion. Methodology/Principal Findings We selected 39 P. vivax proteins that are predicted to localize to the merozoite surface or invasive secretory organelles, some of which show homology to P. falciparum vaccine candidates. Of these, we were able to express 37 full-length protein ectodomains in a mammalian expression system, which has been previously used to express P. falciparum invasion ligands such as PfRH5. To establish whether the expressed proteins were correctly folded, we assessed whether they were recognized by antibodies from Cambodian patients with acute vivax malaria. IgG from these samples showed at least a two-fold change in reactivity over naïve controls in 27 of 34 antigens tested, and the majority showed heat-labile IgG immunoreactivity, suggesting the presence of conformation-sensitive epitopes and native tertiary protein structures. Using a method specifically designed to detect low-affinity, extracellular protein-protein interactions, we confirmed a predicted interaction between P. vivax 6-cysteine proteins P12 and P41, further suggesting that the proteins are natively folded and functional. This screen also identified two novel protein-protein interactions, between P12 and PVX_110945, and between MSP3.10 and MSP7.1, the latter of which was confirmed by surface plasmon resonance. Conclusions/Significance We produced a new library of recombinant full-length P. vivax ectodomains, established that the majority of them contain tertiary structure, and used them to identify predicted and novel protein-protein interactions. As well as identifying new interactions for further biological studies, this library will be useful in identifying P. vivax proteins with vaccine potential, and studying P. vivax malaria pathogenesis and immunity. Trial Registration ClinicalTrials.gov NCT00663546 Plasmodium vivax causes malaria in millions of people each year, primarily in Southeast Asia and Central and South America. P. vivax has a dormant liver stage, which can lead to disease recurrence in infected individuals even in the absence of mosquito transmission. The development of vaccines that target blood-stage P. vivax parasites is therefore likely to be an essential component of any worldwide effort to eradicate malaria. Studying P. vivax is very difficult as this parasite grows poorly in the laboratory and invades only small numbers of young red blood cells in patients. Due to these and other challenges, only a handful of P. vivax proteins have been tested as potential vaccines. To generate more vaccine candidates, we expressed the entire ectodomains of 37 proteins that are predicted to be involved in P. vivax invasion of red blood cells. Antibodies from Cambodian patients with P. vivax malaria recognized heat-sensitive epitopes in the majority of these proteins, suggesting that they are natively folded. We also used the proteins to screen for both predicted and novel protein-protein interactions, confirming that the proteins are functional and further supporting their potential as vaccine candidates. As a new community resource, this P. vivax recombinant protein library will facilitate future studies of P. vivax pathogenesis and immunity, and greatly expands the list of candidate vaccine antigens.
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Affiliation(s)
- Jessica B. Hostetler
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
- Malaria Programme, Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Sumana Sharma
- Malaria Programme, Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, United Kingdom
- Cell Surface Signalling Laboratory, Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, United Kingdom
| | - S. Josefin Bartholdson
- Malaria Programme, Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, United Kingdom
- Cell Surface Signalling Laboratory, Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Gavin J. Wright
- Malaria Programme, Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, United Kingdom
- Cell Surface Signalling Laboratory, Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Rick M. Fairhurst
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
- * E-mail: (RMF); (JCR)
| | - Julian C. Rayner
- Malaria Programme, Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, United Kingdom
- * E-mail: (RMF); (JCR)
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197
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Bhardwaj R, Shakri AR, Hans D, Gupta P, Fernandez-Becerra C, Del Portillo HA, Pandey G, Chitnis CE. Production of recombinant PvDBPII, receptor binding domain of Plasmodium vivax Duffy binding protein, and evaluation of immunogenicity to identify an adjuvant formulation for vaccine development. Protein Expr Purif 2015; 136:52-57. [PMID: 26578115 DOI: 10.1016/j.pep.2015.06.011] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Revised: 06/06/2015] [Accepted: 06/18/2015] [Indexed: 11/19/2022]
Abstract
Plasmodium vivax is dependent on interaction with the Duffy antigen receptor for chemokines (DARC) for invasion of human erythrocytes. The P. vivax Duffy binding protein (PvDBP) mediates interaction of P. vivax merozoites with DARC. The DARC receptor-binding domain lies in a conserved N-terminal cysteine-rich region of PvDBP referred to as region II (PvDBPII). PvDBPII is an attractive vaccine candidate since antibodies raised against PvDBPII block erythrocyte invasion by P. vivax. Here, we describe methods to produce recombinant PvDBPII in its correctly folded conformation. A synthetic gene optimized for expression of PvDBPII in Escherichia coli and fed batch fermentation process based on exponential feeding strategy was used to achieve high levels of expression of recombinant PvDBPII. Recombinant PvDBPII was isolated from inclusion bodies, refolded by rapid dilution and purified by ion exchange chromatography. Purified recombinant PvDBPII was characterized for identity, purity and functional activity using standardized release assays. Recombinant PvDBPII formulated with various human compatible adjuvants including glycosylpyranosyl lipid A-stable emulsion (GLA-SE) and alhydrogel was used for immunogenicity studies in small animals to downselect a suitable formulation for clinical development. Sera collected from immunized animals were tested for recognition of PvDBPII and inhibition of PvDBPII-DARC binding. GLA-SE formulations of PvDBPII yielded higher ELISA and binding inhibition titres compared to PvDBPII formulated with alhydrogel. These data support further development of a recombinant vaccine for P. vivax based on PvDBPII formulated with GLA-SE.
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MESH Headings
- Animals
- Antigens, Protozoan/biosynthesis
- Antigens, Protozoan/genetics
- Antigens, Protozoan/immunology
- Antigens, Protozoan/isolation & purification
- Humans
- Immunogenicity, Vaccine
- Malaria Vaccines/biosynthesis
- Malaria Vaccines/genetics
- Malaria Vaccines/immunology
- Malaria Vaccines/isolation & purification
- Mice
- Mice, Inbred BALB C
- Plasmodium vivax/genetics
- Plasmodium vivax/immunology
- Protein Domains
- Protozoan Proteins/biosynthesis
- Protozoan Proteins/genetics
- Protozoan Proteins/immunology
- Protozoan Proteins/isolation & purification
- Receptors, Cell Surface/biosynthesis
- Receptors, Cell Surface/genetics
- Receptors, Cell Surface/immunology
- Receptors, Cell Surface/isolation & purification
- Recombinant Proteins/biosynthesis
- Recombinant Proteins/immunology
- Recombinant Proteins/isolation & purification
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Affiliation(s)
- Rukmini Bhardwaj
- International Centre for Genetic Engineering and Biotechnology (ICGEB), New Delhi, India
| | - Ahmad Rushdi Shakri
- International Centre for Genetic Engineering and Biotechnology (ICGEB), New Delhi, India
| | - Dhiraj Hans
- International Centre for Genetic Engineering and Biotechnology (ICGEB), New Delhi, India
| | - Pankaj Gupta
- International Centre for Genetic Engineering and Biotechnology (ICGEB), New Delhi, India
| | | | - Hernando A Del Portillo
- Barcelona Centre for International Health (CRESIB), Barcelona, Spain; Institució Catalana de Recerca I Estudis Avançats (ICREA), Barcelona, Spain
| | - Gaurav Pandey
- Malaria Vaccine Development Program (MVDP), New Delhi, India
| | - Chetan E Chitnis
- International Centre for Genetic Engineering and Biotechnology (ICGEB), New Delhi, India.
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198
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Edwards HM, Canavati SE, Rang C, Ly P, Sovannaroth S, Canier L, Khim N, Menard D, Ashton RA, Meek SR, Roca-Feltrer A. Novel Cross-Border Approaches to Optimise Identification of Asymptomatic and Artemisinin-Resistant Plasmodium Infection in Mobile Populations Crossing Cambodian Borders. PLoS One 2015; 10:e0124300. [PMID: 26352262 PMCID: PMC4564195 DOI: 10.1371/journal.pone.0124300] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Accepted: 03/12/2015] [Indexed: 11/24/2022] Open
Abstract
Background Human population movement across country borders presents a real challenge for malaria control and elimination efforts in Cambodia and its neighbouring countries. To quantify Plasmodium infection among the border-crossing population, including asymptomatic and artemisinin resistant (AR) parasites, three official border crossing points, one from each of Cambodia's borders with Thailand, Laos and Vietnam, were selected for sampling. Methods and Findings A total of 3206 participants (of 4110 approached) were recruited as they crossed the border, tested for malaria and interviewed. By real-time polymerase chain reaction (RT-PCR), 5.4% of all screened individuals were found to harbour Plasmodium parasites. The proportion was highest at the Laos border (11.5%). Overall there were 97 P. vivax (55.7%), 55 P. falciparum (31.6%), two P. malariae (1.1%) and 20 mixed infections (11.5%). Of identified infections, only 20% were febrile at the time of screening. Of the 24 P. falciparum samples where a further PCR was possible to assess AR, 15 (62.5%) had mutations in the K13 propeller domain gene, all from participants at the Laos border point. Malaria rapid diagnostic test (RDT) pLDH/HRP-2 identified a positivity rate of 3.2% overall and sensitivity compared to RT-PCR was very low (43.1%). Main individual risk factors for infection included sex, fever, being a forest-goer, poor knowledge of malaria prevention methods and previous malaria infection. Occupation, day of the week and time of crossing (morning vs. afternoon) also appeared to play an important role in predicting positive cases. Conclusions This study offers a novel approach to identify asymptomatic infections and monitor AR parasite flow among mobile and migrant populations crossing the borders. Similar screening activities are recommended to identify other hot borders and characterise potential hot spots of AR. Targeted “customised” interventions and surveillance activities should be implemented in these sites to accelerate elimination efforts in the region.
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Affiliation(s)
| | | | | | - Po Ly
- National Center for Parasitology, Entomology and Malaria Control (CNM), Phnom Penh, Cambodia
| | - Siv Sovannaroth
- National Center for Parasitology, Entomology and Malaria Control (CNM), Phnom Penh, Cambodia
| | - Lydie Canier
- Malaria Molecular Epidemiology Unit, Institut Pasteur in Cambodia, Phnom Penh, Cambodia
| | - Nimol Khim
- Malaria Molecular Epidemiology Unit, Institut Pasteur in Cambodia, Phnom Penh, Cambodia
| | - Didier Menard
- Malaria Molecular Epidemiology Unit, Institut Pasteur in Cambodia, Phnom Penh, Cambodia
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199
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Abstract
In 2013 there were an estimated 584,000 deaths and 198 million clinical illnesses due to malaria, the majority in sub-Saharan Africa. Vaccines would be the ideal addition to the existing armamentarium of anti-malaria tools. However, malaria is caused by parasites, and parasites are much more complex in terms of their biology than the viruses and bacteria for which we have vaccines, passing through multiple stages of development in the human host, each stage expressing hundreds of unique antigens. This complexity makes it more difficult to develop a vaccine for parasites than for viruses and bacteria, since an immune response targeting one stage may not offer protection against a later stage, because different antigens are the targets of protective immunity at different stages. Furthermore, depending on the life cycle stage and whether the parasite is extra- or intra-cellular, antibody and/or cellular immune responses provide protection. It is thus not surprising that there is no vaccine on the market for prevention of malaria, or any human parasitic infection. In fact, no vaccine for any disease with this breadth of targets and immune responses exists. In this limited review, we focus on four approaches to malaria vaccines, (1) a recombinant protein with adjuvant vaccine aimed at Plasmodium falciparum (Pf) pre-erythrocytic stages of the parasite cycle (RTS,S/AS01), (2) whole sporozoite vaccines aimed at Pf pre-erythrocytic stages (PfSPZ Vaccine and PfSPZ-CVac), (3) prime boost vaccines that include recombinant DNA, viruses and bacteria, and protein with adjuvant aimed primarily at Pf pre-erythrocytic, but also asexual erythrocytic stages, and (4) recombinant protein with adjuvant vaccines aimed at Pf and Plasmodium vivax sexual erythrocytic and mosquito stages. We recognize that we are not covering all approaches to malaria vaccine development, or most of the critically important work on development of vaccines against P. vivax, the second most important cause of malaria. Progress during the last few years has been significant, and a first generation malaria candidate vaccine, RTS,S/AS01, is under review by the European Medicines Agency (EMA) for its quality, safety and efficacy under article 58, which allows the EMA to give a scientific opinion about products intended exclusively for markets outside of the European Union. However, much work is in progress to optimize malaria vaccines in regard to magnitude and durability of protective efficacy and the financing and practicality of delivery. Thus, we are hopeful that anti-malaria vaccines will soon be important tools in the battle against malaria.
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Affiliation(s)
| | | | | | - Patrick E Duffy
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852, USA
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200
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Talundzic E, Chenet SM, Goldman IF, Patel DS, Nelson JA, Plucinski MM, Barnwell JW, Udhayakumar V. Genetic Analysis and Species Specific Amplification of the Artemisinin Resistance-Associated Kelch Propeller Domain in P. falciparum and P. vivax. PLoS One 2015; 10:e0136099. [PMID: 26292024 PMCID: PMC4546394 DOI: 10.1371/journal.pone.0136099] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2015] [Accepted: 07/29/2015] [Indexed: 11/19/2022] Open
Abstract
Plasmodium falciparum resistance to artemisinin has emerged in the Greater Mekong Subregion and now poses a threat to malaria control and prevention. Recent work has identified mutations in the kelch propeller domain of the P. falciparum K13 gene to be associated artemisinin resistance as defined by delayed parasite clearance and ex vivo ring stage survival assays. Species specific primers for the two most prevalent human malaria species, P. falciparum and P. vivax, were designed and tested on multiple parasite isolates including human, rodent, and non- humans primate Plasmodium species. The new protocol described here using the species specific primers only amplified their respective species, P. falciparum and P. vivax, and did not cross react with any of the other human malaria Plasmodium species. We provide an improved species specific PCR and sequencing protocol that could be effectively used in areas where both P. falciparum and P. vivax are circulating. To design this improved protocol, the kelch gene was analyzed and compared among different species of Plasmodium. The kelch propeller domain was found to be highly conserved across the mammalian Plasmodium species.
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Affiliation(s)
- Eldin Talundzic
- Centers for Disease Control and Prevention, Center for Global Health, Division of Parasitic Diseases and Malaria, 1600 Clifton Rd, Mail Stop D-67, Atlanta, Georgia, United States of America
- Atlanta Research and Education Foundation/VA Medical Center, Decatur, Georgia, United States of America
- * E-mail:
| | - Stella M. Chenet
- Centers for Disease Control and Prevention, Center for Global Health, Division of Parasitic Diseases and Malaria, 1600 Clifton Rd, Mail Stop D-67, Atlanta, Georgia, United States of America
| | - Ira F. Goldman
- Centers for Disease Control and Prevention, Center for Global Health, Division of Parasitic Diseases and Malaria, 1600 Clifton Rd, Mail Stop D-67, Atlanta, Georgia, United States of America
| | - Dhruviben S. Patel
- Centers for Disease Control and Prevention, Center for Global Health, Division of Parasitic Diseases and Malaria, 1600 Clifton Rd, Mail Stop D-67, Atlanta, Georgia, United States of America
| | - Julia A. Nelson
- Atlanta Research and Education Foundation/VA Medical Center, Decatur, Georgia, United States of America
| | - Mateusz M. Plucinski
- Centers for Disease Control and Prevention, Center for Global Health, Division of Parasitic Diseases and Malaria, 1600 Clifton Rd, Mail Stop D-67, Atlanta, Georgia, United States of America
- President’s Malaria Initiative, Atlanta, Georgia, United States of America
| | - John W. Barnwell
- Centers for Disease Control and Prevention, Center for Global Health, Division of Parasitic Diseases and Malaria, 1600 Clifton Rd, Mail Stop D-67, Atlanta, Georgia, United States of America
| | - Venkatachalam Udhayakumar
- Centers for Disease Control and Prevention, Center for Global Health, Division of Parasitic Diseases and Malaria, 1600 Clifton Rd, Mail Stop D-67, Atlanta, Georgia, United States of America
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