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Kritsiriwuthinan K, Ngrenngarmlert W, Patrapuvich R, Phuagthong S, Choosang K. Distinct Allelic Diversity of Plasmodium vivax Merozoite Surface Protein 3-Alpha ( PvMSP-3α) Gene in Thailand Using PCR-RFLP. J Trop Med 2023; 2023:8855171. [PMID: 37599666 PMCID: PMC10438972 DOI: 10.1155/2023/8855171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 07/20/2023] [Accepted: 08/04/2023] [Indexed: 08/22/2023] Open
Abstract
Considering the importance of merozoite surface proteins (MSPs) as vaccine candidates, this study was conducted to investigate the polymorphism and genetic diversity of Plasmodium vivax merozoite surface protein 3-alpha (PvMSP-3α) in Thailand. To analyze genetic diversity, 118 blood samples containing P. vivax were collected from four malaria-endemic areas in western and southern Thailand. The DNA was extracted and amplified for the PvMSP-3α gene using nested PCR. The PCR products were genotyped by PCR-RFLP with Hha I and Alu I restriction enzymes. The combination patterns of Hha I and Alu I RFLP were used to identify allelic variants. Genetic evaluation and phylogenic analysis were performed on 13 sequences, including 10 sequences from our study and 3 sequences from GenBank. The results revealed three major types of PvMSP-3α, 91.5% allelic type A (∼1.8 kb), 5.1% allelic type B (∼1.5 kb), and 3.4% allelic type C (∼1.2 kb), were detected based on PCR product size with different frequencies. Among all PvMSP-3α, 19 allelic subtypes with Hha I RFLP patterns were distinguished and 6 allelic subtypes with Alu I RFLP patterns were identified. Of these samples, 73 (61%) and 42 (35.6%) samples were defined as monoallelic subtype infection by Hha I and Alu I PCR-RFLP, respectively, whereas 77 (65.3%) samples were determined to be mixed-allelic subtype infection by the combination patterns of Hha I and Alu I RFLP. These results strongly indicate that PvMSP-3α gene is highly polymorphic, particularly in blood samples collected from the Thai-Myanmar border area (the western part of Thailand). The combination patterns of Hha I and Alu I RFLP of the PvMSP-3α gene could be considered for use as molecular epidemiologic markers for genotyping P. vivax isolates in Thailand.
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Affiliation(s)
| | - Warunee Ngrenngarmlert
- Department of Community Medical Technology, Faculty of Medical Technology, Mahidol University, Nakhon Pathom 73170, Thailand
| | - Rapatbhorn Patrapuvich
- Drug Research Unit for Malaria (DRUM), Center of Excellence in Malaria Research, Faculty of Tropical Medicine, Mahidol University, Bangkok 10400, Thailand
| | | | - Kantima Choosang
- Faculty of Medical Technology, Rangsit University, Pathumthani 12000, Thailand
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Ehrlich HY, Somé AF, Bazié T, Ebou CN, Dembélé EL, Balma R, Goodwin J, Wade M, Bei AK, Ouédraogo JB, Foy BD, Dabiré RK, Parikh S. Tracking antimalarial drug resistance using mosquito blood meals: a cross-sectional study. THE LANCET. MICROBE 2023; 4:e461-e469. [PMID: 37086737 PMCID: PMC10365133 DOI: 10.1016/s2666-5247(23)00063-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Revised: 02/06/2023] [Accepted: 02/07/2023] [Indexed: 04/24/2023]
Abstract
BACKGROUND Strong surveillance systems with wide geographic coverage are needed to detect and respond to reports of antimalarial drug resistance on the African continent. We aimed to assess the utility and feasibility of using blood-fed mosquitos (xenomonitoring) to conduct rapid surveillance of molecular markers associated with resistance in human populations. METHODS We conducted three cross-sectional surveys in two rainy seasons and the interim dry season in southwest Burkina Faso between Oct 10, 2018, and Sept 17, 2019. We collected human blood samples and blood-fed mosquitos residing in household clusters across seven village sectors. Samples were assessed for Plasmodium falciparum with ultrasensitive quantitative PCR, genotyped for two markers of reduced drug susceptibility, pfmdr1 256A>T (Asn86Tyr) and pfcrt 227A>C (Lys76Thr), and sequenced for four markers of clonality. We assessed statistical equivalence using a 10% margin of equivalence. FINDINGS We identified 551 infections in 1483 human blood samples (mean multiplicity of infection [MOI] 1·94, SD 1·47) and 346 infections in 2151 mosquito blood meals (mean MOI 2·2, SD 1·67). The frequency of pfmdr1 Asn86Tyr was 4% in survey 1, 2% in survey 2, and 12% in survey 3 in human samples, and 3% in survey 1, 0% in survey 2, and 8% in survey 3 in mosquito blood meals, and inter-host frequencies were statistically equivalent in surveys 1 and 2 (p<0·0001) but not Survey 3 (p=0·062) within a tolerability of 0·10. The frequency of pfcrt Lys76Thr was 16% in survey 1, 55% in survey 2, and 11% in survey 3 in humans and 40% in survey 1, 72% in survey 2, and 13% in survey 3 in mosquitos, and inter-host frequencies were equivalent in survey 3 only (p=0·032) within a tolerability of 0·10. In simulations, multiple but not preferential feeding behaviour in mosquitos reduced the accuracy of frequency estimates between hosts, particularly for markers circulating at higher frequencies. INTERPRETATION Molecular markers in mosquito blood meals and in humans exhibited similar temporal trends but frequencies were not statistically equivalent in all scenarios. More work is needed to determine empirical and pragmatic thresholds of difference. Xenomonitoring might be an efficient tool to provide rapid information on emerging antimalarial resistance in regions with insufficient surveillance. FUNDING National Institute of Allergy and Infectious Diseases. TRANSLATION For the French translation of the abstract see Supplementary Materials section.
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Affiliation(s)
- Hanna Y Ehrlich
- Department of Epidemiology of Microbial Diseases, Yale University, New Haven, CT, USA; One Health Institute, University of California, Davis, CA, USA.
| | - A Fabrice Somé
- Department of Parasitology, Institut de Recherche en Sciences de la Santé, Bobo-Dioulasso, Burkina Faso
| | - Thomas Bazié
- Department of Parasitology, Institut de Recherche en Sciences de la Santé, Bobo-Dioulasso, Burkina Faso
| | - Cathérine Neya Ebou
- Department of Parasitology, Institut de Recherche en Sciences de la Santé, Bobo-Dioulasso, Burkina Faso
| | - Estelle Lotio Dembélé
- Department of Parasitology, Institut de Recherche en Sciences de la Santé, Bobo-Dioulasso, Burkina Faso
| | - Richard Balma
- Department of Medical Entomology, Institut de Recherche en Sciences de la Santé, Bobo-Dioulasso, Burkina Faso
| | - Justin Goodwin
- Department of Epidemiology of Microbial Diseases, Yale University, New Haven, CT, USA
| | - Martina Wade
- Department of Epidemiology of Microbial Diseases, Yale University, New Haven, CT, USA
| | - Amy K Bei
- Department of Epidemiology of Microbial Diseases, Yale University, New Haven, CT, USA
| | - Jean-Bosco Ouédraogo
- Department of Epidemiology of Microbial Diseases, Yale University, New Haven, CT, USA; Department of Parasitology, Institut de Recherche en Sciences de la Santé, Bobo-Dioulasso, Burkina Faso
| | - Brian D Foy
- Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, CO, USA
| | - Roch K Dabiré
- Department of Medical Entomology, Institut de Recherche en Sciences de la Santé, Bobo-Dioulasso, Burkina Faso
| | - Sunil Parikh
- Department of Epidemiology of Microbial Diseases, Yale University, New Haven, CT, USA
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Temporal trends in molecular markers of drug resistance in Plasmodium falciparum in human blood and profiles of corresponding resistant markers in mosquito oocysts in Asembo, western Kenya. Malar J 2022; 21:265. [PMID: 36100912 PMCID: PMC9472345 DOI: 10.1186/s12936-022-04284-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Accepted: 08/30/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Over the last two decades, the scale-up of vector control and changes in the first-line anti-malarial, from chloroquine (CQ) to sulfadoxine-pyrimethamine (SP) and then to artemether-lumefantrine (AL), have resulted in significant decreases in malaria burden in western Kenya. This study evaluated the long-term effects of control interventions on molecular markers of Plasmodium falciparum drug resistance using parasites obtained from humans and mosquitoes at discrete time points. METHODS Dried blood spot samples collected in 2012 and 2017 community surveys in Asembo, Kenya were genotyped by Sanger sequencing for markers associated with resistance to SP (Pfdhfr, Pfdhps), CQ, AQ, lumefantrine (Pfcrt, Pfmdr1) and artemisinin (Pfk13). Temporal trends in the prevalence of these markers, including data from 2012 to 2017 as well as published data from 1996, 2001, 2007 from same area, were analysed. The same markers from mosquito oocysts collected in 2012 were compared with results from human blood samples. RESULTS The prevalence of SP dhfr/dhps quintuple mutant haplotype C50I51R59N108I164/S436G437E540A581A613 increased from 19.7% in 1996 to 86.0% in 2012, while an increase in the sextuple mutant haplotype C50I51R59N108I164/H436G437E540A581A613 containing Pfdhps-436H was found from 10.5% in 2012 to 34.6% in 2017. Resistant Pfcrt-76 T declined from 94.6% in 2007 to 18.3% in 2012 and 0.9% in 2017. Mutant Pfmdr1-86Y decreased across years from 74.8% in 1996 to zero in 2017, mutant Pfmdr1-184F and wild Pfmdr1-D1246 increased from 17.9% to 58.9% in 2007 to 55.9% and 90.1% in 2017, respectively. Pfmdr1 haplotype N86F184S1034N1042D1246 increased from 11.0% in 2007 to 49.6% in 2017. No resistant mutations in Pfk13 were found. Prevalence of Pfdhps-436H was lower while prevalence of Pfcrt-76 T was higher in mosquitoes than in human blood samples. CONCLUSION This study showed an increased prevalence of dhfr/dhps resistant markers over 20 years with the emergence of Pfdhps-436H mutant a decade ago in Asembo. The reversal of Pfcrt from CQ-resistant to CQ-sensitive genotype occurred following 19 years of CQ withdrawal. No Pfk13 markers associated with artemisinin resistance were detected, but the increased haplotype of Pfmdr1 N86F184S1034N1042D1246 was observed. The differences in prevalence of Pfdhps-436H and Pfcrt-76 T SNPs between two hosts and the role of mosquitoes in the transmission of drug resistant parasites require further investigation.
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Abstract
Population genetic diversity of Plasmodium falciparum antigenic loci is high despite large bottlenecks in population size during the parasite life cycle. The prevalence of genetically distinct haplotypes at these loci, while well characterized in humans, has not been thoroughly compared between human and mosquito hosts. We assessed parasite haplotype prevalence, diversity, and evenness using human and mosquito P. falciparum infections collected from the same households during a 14-month longitudinal cohort study using amplicon deep sequencing of two antigenic gene fragments (ama1 and csp). To a prior set of infected humans (n = 1,175/2,813; 86.2% sequencing success) and mosquito abdomens (n = 199/1,448; 95.5% sequencing success), we added sequences from infected mosquito heads (n = 134/1,448; 98.5% sequencing success). The overall and sample-level parasite populations were more diverse in mosquitoes than in humans. Additionally, haplotype prevalences were more even in the P. falciparum human population than in the mosquito population, consistent with balancing selection occurring at these loci in humans. In contrast, we observed that infections in humans were more likely to harbor a dominant haplotype than infections in mosquitoes, potentially due to removal of unfit strains by the human immune system. Finally, within a given mosquito, there was little overlap in genetic composition of abdomen and head infections, suggesting that infections may be cleared from the abdomen during a mosquito’s lifespan. Taken together, our observations provide evidence for the mosquito vector acting as a reservoir of sequence diversity in malaria parasite populations.
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Liu Y, Tessema SK, Murphy M, Xu S, Schwartz A, Wang W, Cao Y, Lu F, Tang J, Gu Y, Zhu G, Zhou H, Gao Q, Huang R, Cao J, Greenhouse B. Confirmation of the absence of local transmission and geographic assignment of imported falciparum malaria cases to China using microsatellite panel. Malar J 2020; 19:244. [PMID: 32660491 PMCID: PMC7359230 DOI: 10.1186/s12936-020-03316-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Accepted: 07/04/2020] [Indexed: 11/15/2022] Open
Abstract
Background Current methods to classify local and imported malaria infections depend primarily on patient travel history, which can have limited accuracy. Genotyping has been investigated as a complementary approach to track the spread of malaria and identify the origin of imported infections. Methods An extended panel of 26 microsatellites (16 new microsatellites) for Plasmodium falciparum was evaluated in 602 imported infections from 26 sub-Saharan African countries to the Jiangsu Province of People’s Republic of China. The potential of the 26 microsatellite markers to assign imported parasites to their geographic origin was assessed using a Bayesian method with Markov Chain Monte Carlo (MCMC) as implemented in the program Smoothed and Continuous Assignments (SCAT) with a modification to incorporate haploid genotype data. Results The newly designed microsatellites were polymorphic and are not in linkage disequilibrium with the existing microsatellites, supporting previous findings of high rate of recombination in sub-Saharan Africa. Consistent with epidemiology inferred from patients’ travel history, no evidence for local transmission was found; nearly all genetically related infections were identified in people who travelled to the same country near the same time. The smoothing assignment method assigned imported cases to their likely geographic origin with an accuracy (Angola: 59%; Nigeria: 51%; Equatorial Guinea: 40%) higher than would be achieved at random, reaching statistical significance for Angola and Equatorial Guinea. Conclusions Genotyping using an extended microsatellite panel is valuable for malaria case classification and programme evaluation in an elimination setting. A Bayesian method for assigning geographic origin of mammals based on genetic data was adapted for malaria and showed potential for identification of the origin of imported infections.
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Affiliation(s)
- Yaobao Liu
- National Health Commission Key Laboratory of Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, Jiangsu, China.,Medical College of Soochow University, Suzhou, Jiangsu, China
| | - Sofonias K Tessema
- EPPI Center Program, Division of HIV, Infectious Diseases, and Global Medicine, Department of Medicine, University of California San Francisco, San Francisco, CA, USA.
| | - Maxwell Murphy
- EPPI Center Program, Division of HIV, Infectious Diseases, and Global Medicine, Department of Medicine, University of California San Francisco, San Francisco, CA, USA
| | - Sui Xu
- National Health Commission Key Laboratory of Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, Jiangsu, China
| | - Alanna Schwartz
- EPPI Center Program, Division of HIV, Infectious Diseases, and Global Medicine, Department of Medicine, University of California San Francisco, San Francisco, CA, USA
| | - Weiming Wang
- National Health Commission Key Laboratory of Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, Jiangsu, China
| | - Yuanyuan Cao
- National Health Commission Key Laboratory of Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, Jiangsu, China
| | - Feng Lu
- National Health Commission Key Laboratory of Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, Jiangsu, China.,Department of Parasitology, Institute of Translational Medicine, Medical College, Yangzhou University, Jiangsu Key Laboratory of Experimental & Translational Non- coding RNA Research, Yangzhou, Jiangsu, China
| | - Jianxia Tang
- National Health Commission Key Laboratory of Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, Jiangsu, China
| | - Yaping Gu
- National Health Commission Key Laboratory of Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, Jiangsu, China
| | - Guoding Zhu
- National Health Commission Key Laboratory of Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, Jiangsu, China
| | - Huayun Zhou
- National Health Commission Key Laboratory of Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, Jiangsu, China
| | - Qi Gao
- National Health Commission Key Laboratory of Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, Jiangsu, China
| | - Rui Huang
- Medical College of Soochow University, Suzhou, Jiangsu, China
| | - Jun Cao
- National Health Commission Key Laboratory of Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, Jiangsu, China. .,Center for Global Health, School of Public Health, Nanjing Medical University, Nanjing, China. .,Public Health Research Center, Jiangnan University, Wuxi, China.
| | - Bryan Greenhouse
- EPPI Center Program, Division of HIV, Infectious Diseases, and Global Medicine, Department of Medicine, University of California San Francisco, San Francisco, CA, USA.,Chan Zuckerberg Biohub, San Francisco, CA, USA
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Jiang T, Chen J, Fu H, Wu K, Yao Y, Eyi JUM, Matesa RA, Obono MMO, Du W, Tan H, Lin M, Li J. High prevalence of Pfdhfr-Pfdhps quadruple mutations associated with sulfadoxine-pyrimethamine resistance in Plasmodium falciparum isolates from Bioko Island, Equatorial Guinea. Malar J 2019; 18:101. [PMID: 30914041 PMCID: PMC6434785 DOI: 10.1186/s12936-019-2734-x] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Accepted: 03/18/2019] [Indexed: 02/05/2023] Open
Abstract
BACKGROUND Sulfadoxine-pyrimethamine (SP) is recommended for intermittent preventive treatment of malaria in Africa. However, increasing SP resistance (SPR) affects the therapeutic efficacy of the SP. As molecular markers, Pfdhfr (dihydrofolate reductase) and Pfdhps (dihydropteroate synthase) genes are widely used for SPR surveillance. This study aimed to assess the prevalence of Pfdhfr and Pfdhps genes mutations and haplotypes in Plasmodium falciparum isolates collected from Bioko Island, Equatorial Guinea (EG). METHODS In total, 180 samples were collected in 2013-2014. The single nucleotide polymorphisms (SNPs) of the Pfdhfr and Pfdhps genes were identified with nested PCR and Sanger sequencing. The genotypes and linkage disequilibrium (LD) tests were also analysed. RESULTS Sequences of Pfdhfr and Pfdhps genes were obtained from 92.78% (167/180) and 87.78% (158/180) of the samples, respectively. For Pfdhfr, 97.60% (163/167), 87.43% (146/167) and 97.01% (162/167) of the samples carried N51I, C59R and S108N mutant alleles, respectively. The prevalence of the Pfdhps S436A, A437G, K540E, A581G, and A613S mutations were observed in 20.25% (32/158), 90.51% (143/158), 5.06% (8/158), 0.63% (1/158), and 3.16% (5/158) of the samples, respectively. In total, 3 unique haplotypes at the Pfdhfr locus and 8 haplotypes at the Pfdhps locus were identified. A triple mutation (CIRNI) in Pfdhfr was the most prevalent haplotype (86.83%), and a single mutant haplotype (SGKAA; 62.66%) was predominant in Pfdhps. A total of 130 isolates with 12 unique haplotypes were found in the Pfdhfr and Pfdhps combined haplotypes, 65.38% (85/130) of them carried quadruple allele combinations (CIRNI-SGKAA), whereas only one isolate (0.77%, 1/130) was found to carry the wild-type (CNCSI-SAKAA). For LD analysis, the Pfdhfr N51I was significantly associated with the Pfdhps A437G (P < 0.05). CONCLUSION Bioko Island possesses a high prevalence of the Pfdhfr triple mutation (CIRNI) and Pfdhps single mutation (SGKAA), which will undermine the pharmaceutical effect of SP for malaria treatment strategies. To avoid an increase in SPR, continuous molecular monitoring and additional control efforts are urgently needed in Bioko Island, Equatorial Guinea.
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Affiliation(s)
- Tingting Jiang
- Department of Human Parasitology, School of Basic Medical Sciences, Department of Infectious Diseases, Renmin Hospital, Hubei University of Medicine, Shiyan, 442000, People's Republic of China
| | - Jiangtao Chen
- The Chinese Medical Aid Team To the Republic of Equatorial Guinea; Laboratory Medical Center, Huizhou Municipal Central Hospital, Huizhou, 516001, People's Republic of China
| | - Hongxia Fu
- Clinical Laboratory, Taihe Hospital, Hubei University of Medicine, Shiyan, 442000, People's Republic of China
| | - Kai Wu
- Department of Schistosomiasis and Endemic Diseases, Wuhan City Center for Disease Prevention and Control, Wuhan, People's Republic of China
| | - Yi Yao
- Department of Human Parasitology, School of Basic Medical Sciences, Department of Infectious Diseases, Renmin Hospital, Hubei University of Medicine, Shiyan, 442000, People's Republic of China
| | | | - Rocio Apicante Matesa
- Department of Medical Laboratory, Malabo Regional Hospital, Malabo, Equatorial Guinea
| | | | - Weixing Du
- Department of Human Parasitology, School of Basic Medical Sciences, Department of Infectious Diseases, Renmin Hospital, Hubei University of Medicine, Shiyan, 442000, People's Republic of China
| | - Huabing Tan
- Department of Human Parasitology, School of Basic Medical Sciences, Department of Infectious Diseases, Renmin Hospital, Hubei University of Medicine, Shiyan, 442000, People's Republic of China
| | - Min Lin
- Department of Histology and Embryology, Shantou University Medical College, Shantou, People's Republic of China.
| | - Jian Li
- Department of Human Parasitology, School of Basic Medical Sciences, Department of Infectious Diseases, Renmin Hospital, Hubei University of Medicine, Shiyan, 442000, People's Republic of China.
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Guerra M, de Sousa B, Ndong-Mabale N, Berzosa P, Arez AP. Malaria determining risk factors at the household level in two rural villages of mainland Equatorial Guinea. Malar J 2018; 17:203. [PMID: 29776367 PMCID: PMC5960103 DOI: 10.1186/s12936-018-2354-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Accepted: 05/09/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND After the introduction of an artemisinin-based combination therapy, the reduction of prevalence of malaria infections has shown a remarkable progress during the last decade. However due to the lack of a consistent malaria control programme and socioeconomic inequalities, Plasmodium infection is still one of the major cause of disease in Equatorial Guinea, namely in the rural communities. This study explored the associated risk factors of malaria transmission at the microeconomic level (households) in two rural villages of mainland Equatorial Guinea. METHODS This survey involved 232 individuals living in 69 households located in two rural villages, Ngonamanga and Miyobo, of coastal and interior of Equatorial Guinea, respectively. Malaria prevalence was measured by PCR and parasitaemia level by optical microscopy; household socioeconomic status (SES) was measured based on house characteristics using a 2-step cluster analysis. Logistic regression analysis was performed to investigate the relationship of a diverse set of independent variables on being diagnosed with malaria and on showing high levels of parasitaemia. RESULTS The prevalence of Plasmodium spp. infection was 69%, with 80% of households having at least one parasitaemic member. The majority of houses have eaves (80%), walls of clay/wood (90%) and zinc roof (99%) and only 10% of them have basic sanitation facilities. The studied areas showed reduced rates of indoor residual spraying coverage (9%), and long-lasting insecticide-treated net ownership (35%), with none of these preventive tools showing any significant effects on malaria risk in these areas. Neither the risk of malaria infection (PCR positive result) or the development of high parasitaemia did show association with SES. CONCLUSIONS This study has contributed to reinforce the importance of living conditions associated to a high risk of malaria infection and vulnerability to develop high parasitaemia. This study also contributes to future malaria control interventions to be implemented in mainland Equatorial Guinea or in other countries with similar environmental conditions.
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Affiliation(s)
- Mónica Guerra
- Global Health and Tropical Medicine, GHTM, Instituto de Higiene e Medicina Tropical, IHMT, Universidade Nova de Lisboa, UNL, Rua da Junqueira 100, 1349-008, Lisbon, Portugal
| | - Bruno de Sousa
- Faculdade de Psicologia e de Ciências da Educação, CINEICC, Universidade de Coimbra, Coimbra, Portugal
| | - Nicolas Ndong-Mabale
- Centro de Referencia para el Control de Endemias, Instituto de Salud Carlos III, Bata, Equatorial Guinea
| | - Pedro Berzosa
- Centro Nacional de Medicina Tropical, Instituto de Salud Carlos III, Madrid, Spain
| | - Ana Paula Arez
- Global Health and Tropical Medicine, GHTM, Instituto de Higiene e Medicina Tropical, IHMT, Universidade Nova de Lisboa, UNL, Rua da Junqueira 100, 1349-008, Lisbon, Portugal.
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Grignard L, Gonçalves BP, Early AM, Daniels RF, Tiono AB, Guelbéogo WM, Ouédraogo A, van Veen EM, Lanke K, Diarra A, Nebie I, Sirima SB, Targett GA, Volkman SK, Neafsey DE, Wirth DF, Bousema T, Drakeley C. Transmission of molecularly undetectable circulating parasite clones leads to high infection complexity in mosquitoes post feeding. Int J Parasitol 2018; 48:671-677. [PMID: 29738740 PMCID: PMC6018601 DOI: 10.1016/j.ijpara.2018.02.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2017] [Revised: 01/04/2018] [Accepted: 02/26/2018] [Indexed: 11/24/2022]
Abstract
Additional parasite alleles were consistently identified in mosquitoes compared with the human blood sample they had fed on. Assessments of Plasmodium falciparum complexity relying on single time-point collections miss transmissible clones. Low-density gametocyte – producing clones are capable of successfully establishing infections in mosquitoes.
Plasmodium falciparum malaria infections often comprise multiple distinct parasite clones. Few datasets have directly assessed infection complexity in humans and mosquitoes they infect. Examining parasites using molecular tools may provide insights into the selective transmissibility of isolates. Using capillary electrophoresis genotyping and next generation amplicon sequencing, we analysed complexity of parasite infections in human blood and in the midguts of mosquitoes that became infected in membrane feeding experiments using the same blood material in two West African settings. Median numbers of clones in humans and mosquitoes were higher in samples from Burkina Faso (4.5, interquartile range 2–8 for humans; and 2, interquartile range 1–3 for mosquitoes) than in The Gambia (2, interquartile range 1–3 and 1, interquartile range 1–3, for humans and mosquitoes, respectively). Whilst the median number of clones was commonly higher in human blood samples, not all transmitted alleles were detectable in the human peripheral blood. In both study sample sets, additional parasite alleles were identified in mosquitoes compared with the matched human samples (10–88.9% of all clones/feeding assay, n = 73 feeding assays). The results are likely due to preferential amplification of the most abundant clones in peripheral blood but confirm the presence of low density clones that produce transmissible sexual stage parasites.
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Affiliation(s)
- Lynn Grignard
- Department of Immunology and Infection, London School of Hygiene & Tropical Medicine, London, UK.
| | - Bronner P Gonçalves
- Department of Immunology and Infection, London School of Hygiene & Tropical Medicine, London, UK
| | | | - Rachel F Daniels
- Broad Institute of MIT and Harvard, Cambridge, MA, USA; Department of Immunology and Infectious Disease, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Alfred B Tiono
- Department of Biomedical Sciences, Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Wamdaogo M Guelbéogo
- Department of Biomedical Sciences, Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Alphonse Ouédraogo
- Department of Biomedical Sciences, Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Elke M van Veen
- Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Kjerstin Lanke
- Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Amidou Diarra
- Department of Biomedical Sciences, Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Issa Nebie
- Department of Biomedical Sciences, Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Sodiomon B Sirima
- Department of Biomedical Sciences, Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Geoff A Targett
- Department of Immunology and Infection, London School of Hygiene & Tropical Medicine, London, UK
| | - Sarah K Volkman
- Broad Institute of MIT and Harvard, Cambridge, MA, USA; Department of Immunology and Infectious Disease, Harvard T.H. Chan School of Public Health, Boston, MA, USA; School of Nursing and Health Sciences, Simmons College, Boston, MA, USA
| | | | - Dyann F Wirth
- Broad Institute of MIT and Harvard, Cambridge, MA, USA; Department of Immunology and Infectious Disease, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Teun Bousema
- Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Chris Drakeley
- Department of Immunology and Infection, London School of Hygiene & Tropical Medicine, London, UK
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9
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Conrad MD, Mota D, Musiime A, Kilama M, Rek J, Kamya M, Dorsey G, Rosenthal PJ. Comparative Prevalence of Plasmodium falciparum Resistance-Associated Genetic Polymorphisms in Parasites Infecting Humans and Mosquitoes in Uganda. Am J Trop Med Hyg 2017; 97:1576-1580. [PMID: 29016309 PMCID: PMC5817777 DOI: 10.4269/ajtmh.17-0351] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Controlling malaria in high transmission areas, such as much of sub-Saharan Africa, will require concerted efforts to slow the spread of drug resistance and to impede malaria transmission. Understanding the fitness costs associated with the development of drug resistance, particularly within the context of transmission, can help guide policy decisions to accomplish these goals, as fitness constraints might lead to decreased transmission of drug-resistant strains. To determine if Plasmodium falciparum resistance-mediating polymorphisms impact on development at different parasite stages, we compared the genotypes of parasites infecting humans and mosquitoes from households in Uganda. Genotypes at 14 polymorphic loci in genes encoding putative transporters (pfcrt and pfmdr1) and folate pathway enzymes (pfdhfr and pfdhps) were characterized using ligase detection reaction-fluorescent microsphere assays. In paired analysis using the Wilcoxon signed-rank test, prevalences of mutations at 12 loci did not differ significantly between parasites infecting humans and mosquitoes. However, compared with parasites infecting humans, those infecting mosquitoes were enriched for the pfmdr1 86Y mutant allele (P = 0.0001) and those infecting Anopheles gambiae s.s. were enriched for the pfmdr1 86Y (P = 0.0001) and pfcrt 76T (P = 0.0412) mutant alleles. Our results suggest modest directional selection resulting from varied fitness costs during the P. falciparum life cycle. Better appreciation of the fitness implications of drug resistance mediating mutations can inform optimal malaria treatment and prevention strategies.
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Affiliation(s)
- Melissa D. Conrad
- Department of Medicine, University of California, San Francisco, California
| | - Daniel Mota
- Department of Medicine, University of California, San Francisco, California
| | - Alex Musiime
- Infectious Disease Research Collaboration, Kampala, Uganda
| | - Maxwell Kilama
- Infectious Disease Research Collaboration, Kampala, Uganda
| | - John Rek
- Infectious Disease Research Collaboration, Kampala, Uganda
| | - Moses Kamya
- Infectious Disease Research Collaboration, Kampala, Uganda;,Makerere University College of Health Sciences, Kampala, Uganda
| | - Grant Dorsey
- Department of Medicine, University of California, San Francisco, California
| | - Philip J. Rosenthal
- Department of Medicine, University of California, San Francisco, California;,Address correspondence to Philip J. Rosenthal, Department of Medicine, University of California, Box 0811, San Francisco, CA 94946. E-mail:
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10
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Lu F, Zhang M, Culleton RL, Xu S, Tang J, Zhou H, Zhu G, Gu Y, Zhang C, Liu Y, Wang W, Cao Y, Li J, He X, Cao J, Gao Q. Return of chloroquine sensitivity to Africa? Surveillance of African Plasmodium falciparum chloroquine resistance through malaria imported to China. Parasit Vectors 2017; 10:355. [PMID: 28747223 PMCID: PMC5530567 DOI: 10.1186/s13071-017-2298-y] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2017] [Accepted: 07/18/2017] [Indexed: 01/08/2023] Open
Abstract
Background Chloroquine (CQ) was the cornerstone of anti-malarial treatment in Africa for almost 50 years, but has been widely withdrawn due to the emergence and spread of resistance. Recent reports have suggested that CQ-susceptibility may return following the cessation of CQ usage. Here, we monitor CQ sensitivity and determine the prevalence of genetic polymorphisms in the CQ resistance transporter gene (pfcrt) of Plasmodium falciparum isolates recently imported from Africa to China. Methods Blood samples were collected from falciparum malaria patients returning to China from various countries in Africa. Isolates were tested for their sensitivity to CQ using the SYBR Green I test ex vivo, and for a subset of samples, in vitro following culture adaptation. Mutations at positions 72–76 and codon 220 of the pfcrt gene were analyzed by sequencing and confirmed by PCR-RFLP. Correlations between drug sensitivity and pfcrt polymorphisms were investigated. Results Of 32 culture adapted isolates assayed, 17 (53.1%), 6 (18.8%) and 9 (28.1%) were classified as sensitive, moderately resistant, and highly resistant, respectively. In vitro CQ susceptibility was related to point mutations in the pfcrt gene, the results indicating a strong association between pfcrt genotype and drug sensitivity. A total of 292 isolates were typed at the pfcrt locus, and the prevalence of the wild type (CQ sensitive) haplotype CVMNK in isolates from East, South, North, West and Central Africa were 91.4%, 80.0%, 73.3%, 53.3% and 51.7%, respectively. The only mutant haplotype observed was CVIET, and this was almost always linked to an additional mutation at A220S. Conclusions Our results suggest that a reduction in drug pressure following withdrawal of CQ as a first-line drug may lead to a resurgence in CQ sensitive parasites. The prevalence of wild-type pfcrt CQ sensitive parasites from East, South and North Africa was higher than from the West and Central areas, but this varied greatly between countries. Further surveillance is required to assess whether the prevalence of CQ resistant parasites will continue to decrease in the absence of widespread CQ usage.
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Affiliation(s)
- Feng Lu
- Key Laboratory of National Health and Family Planning Commission on Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, 214064, Jiangsu Province, People's Republic of China.,Department of Pathogen Biology and Immunology, School of Medicine, Yangzhou University, Jiangsu Key Laboratory of Experimental & Translational Non-coding RNA Research, Yangzhou, 225001, Jiangsu Province, People's Republic of China
| | - Meihua Zhang
- Key Laboratory of National Health and Family Planning Commission on Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, 214064, Jiangsu Province, People's Republic of China
| | - Richard L Culleton
- Malaria Unit, Department of Pathology, Institute of Tropical Medicine, Nagasaki University, Sakamoto, Nagasaki, 852-8501, Japan
| | - Sui Xu
- Key Laboratory of National Health and Family Planning Commission on Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, 214064, Jiangsu Province, People's Republic of China
| | - Jianxia Tang
- Key Laboratory of National Health and Family Planning Commission on Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, 214064, Jiangsu Province, People's Republic of China
| | - Huayun Zhou
- Key Laboratory of National Health and Family Planning Commission on Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, 214064, Jiangsu Province, People's Republic of China
| | - Guoding Zhu
- Key Laboratory of National Health and Family Planning Commission on Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, 214064, Jiangsu Province, People's Republic of China
| | - Yaping Gu
- Key Laboratory of National Health and Family Planning Commission on Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, 214064, Jiangsu Province, People's Republic of China
| | - Chao Zhang
- Key Laboratory of National Health and Family Planning Commission on Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, 214064, Jiangsu Province, People's Republic of China
| | - Yaobao Liu
- Key Laboratory of National Health and Family Planning Commission on Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, 214064, Jiangsu Province, People's Republic of China
| | - Weiming Wang
- Key Laboratory of National Health and Family Planning Commission on Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, 214064, Jiangsu Province, People's Republic of China
| | - Yuanyuan Cao
- Key Laboratory of National Health and Family Planning Commission on Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, 214064, Jiangsu Province, People's Republic of China
| | - Julin Li
- Key Laboratory of National Health and Family Planning Commission on Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, 214064, Jiangsu Province, People's Republic of China
| | - Xinlong He
- The Third People's Hospital of Wuxi, Wuxi, 214041, Jiangsu Province, People's Republic of China
| | - Jun Cao
- Key Laboratory of National Health and Family Planning Commission on Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, 214064, Jiangsu Province, People's Republic of China. .,Public Health Research Center, Jiangnan University, Wuxi, 214122, Jiangsu Province, People's Republic of China.
| | - Qi Gao
- Key Laboratory of National Health and Family Planning Commission on Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, 214064, Jiangsu Province, People's Republic of China.
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11
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Moendeg KJ, Angeles JMM, Nakao R, Leonardo LR, Fontanilla IKC, Goto Y, Kirinoki M, Villacorte EA, Rivera PT, Inoue N, Chigusa Y, Kawazu SI. Geographic strain differentiation of Schistosoma japonicum in the Philippines using microsatellite markers. PLoS Negl Trop Dis 2017; 11:e0005749. [PMID: 28692692 PMCID: PMC5519200 DOI: 10.1371/journal.pntd.0005749] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Revised: 07/20/2017] [Accepted: 06/25/2017] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Microsatellites have been found to be useful in determining genetic diversities of various medically-important parasites which can be used as basis for an effective disease management and control program. In Asia and Africa, the identification of different geographical strains of Schistosoma japonicum, S. haematobium and S. mansoni as determined through microsatellites could pave the way for a better understanding of the transmission epidemiology of the parasite. Thus, the present study aims to apply microsatellite markers in analyzing the populations of S. japonicum from different endemic areas in the Philippines for possible strain differentiation. METHODOLOGY/ PRINCIPAL FINDINGS Experimental mice were infected using the cercariae of S. japonicum collected from infected Oncomelania hupensis quadrasi snails in seven endemic municipalities. Adult worms were harvested from infected mice after 45 days of infection and their DNA analyzed against ten previously characterized microsatellite loci. High genetic diversity was observed in areas with high endemicity. The degree of genetic differentiation of the parasite population between endemic areas varies. Geographical separation was considered as one of the factors accounting for the observed difference between populations. Two subgroups have been observed in one of the study sites, suggesting that co-infection with several genotypes of the parasite might be present in the population. Clustering analysis showed no particular spatial structuring between parasite populations from different endemic areas. This result could possibly suggest varying degrees of effects of the ongoing control programs and the existing gene flow in the populations, which might be attributed to migration and active movement of infected hosts from one endemic area to another. CONCLUSIONS/ SIGNIFICANCE Based on the results of the study, it is reasonable to conclude that genetic diversity could be one possible criterion to assess the infection status in highly endemic areas. Genetic surveillance using microsatellites is therefore important to predict the ongoing gene flow and degree of genetic diversity, which indirectly reflects the success of the control program in schistosomiasis-endemic areas.
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Affiliation(s)
- Kharleezelle J. Moendeg
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, Japan
- Department of Biology, School of Science and Engineering, Ateneo de Manila University, Quezon City, Manila, Philippines
| | - Jose Ma M. Angeles
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, Japan
| | - Ryo Nakao
- Laboratory of Parasitology, Department of Disease Control, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, Hokkaido, Japan
| | - Lydia R. Leonardo
- Department of Parasitology, College of Public Health, University of the Philippines Manila, Philippines
| | | | - Yasuyuki Goto
- Laboratory of Molecular Immunology, Department of Animal Resource Sciences, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Masashi Kirinoki
- Department of Tropical Medicine and Parasitology, Dokkyo Medical University School of Medicine, Tochigi, Japan
| | - Elena A. Villacorte
- Department of Parasitology, College of Public Health, University of the Philippines Manila, Philippines
| | - Pilarita T. Rivera
- Department of Parasitology, College of Public Health, University of the Philippines Manila, Philippines
| | - Noboru Inoue
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, Japan
| | - Yuichi Chigusa
- Department of Tropical Medicine and Parasitology, Dokkyo Medical University School of Medicine, Tochigi, Japan
| | - Shin-ichiro Kawazu
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, Japan
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12
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Guerra M, Neres R, Salgueiro P, Mendes C, Ndong-Mabale N, Berzosa P, de Sousa B, Arez AP. Plasmodium falciparum Genetic Diversity in Continental Equatorial Guinea before and after Introduction of Artemisinin-Based Combination Therapy. Antimicrob Agents Chemother 2017; 61:e02556-15. [PMID: 27795385 PMCID: PMC5192141 DOI: 10.1128/aac.02556-15] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2015] [Accepted: 10/17/2016] [Indexed: 11/20/2022] Open
Abstract
Efforts to control malaria may affect malaria parasite genetic variability and drug resistance, the latter of which is associated with genetic events that promote mechanisms to escape drug action. The worldwide spread of drug resistance has been a major obstacle to controlling Plasmodium falciparum malaria, and thus the study of the origin and spread of associated mutations may provide some insights into the prevention of its emergence. This study reports an analysis of P. falciparum genetic diversity, focusing on antimalarial resistance-associated molecular markers in two socioeconomically different villages in mainland Equatorial Guinea. The present study took place 8 years after a previous one, allowing the analysis of results before and after the introduction of an artemisinin-based combination therapy (ACT), i.e., artesunate plus amodiaquine. Genetic diversity was assessed by analysis of the Pfmsp2 gene and neutral microsatellite loci. Pfdhps and Pfdhfr alleles associated with sulfadoxine-pyrimethamine (SP) resistance and flanking microsatellite loci were investigated, and the prevalences of drug resistance-associated point mutations of the Pfcrt, Pfmdr1, Pfdhfr, and Pfdhps genes were estimated. Further, to monitor the use of ACT, we provide the baseline prevalences of K13 propeller mutations and Pfmdr1 copy numbers. After 8 years, noticeable differences occurred in the distribution of genotypes conferring resistance to chloroquine and SP, and the spread of mutated genotypes differed according to the setting. Regarding artemisinin resistance, although mutations reported as being linked to artemisinin resistance were not present at the time, several single nucleotide polymorphisms (SNPs) were observed in the K13 gene, suggesting that closer monitoring should be maintained to prevent the possible spread of artemisinin resistance in Africa.
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Affiliation(s)
- Mónica Guerra
- Global Health and Tropical Medicine (GHTM), Instituto de Higiene e Medicina Tropical (IHMT), Universidade Nova de Lisboa (UNL), Lisbon, Portugal
| | - Rita Neres
- Global Health and Tropical Medicine (GHTM), Instituto de Higiene e Medicina Tropical (IHMT), Universidade Nova de Lisboa (UNL), Lisbon, Portugal
| | - Patrícia Salgueiro
- Global Health and Tropical Medicine (GHTM), Instituto de Higiene e Medicina Tropical (IHMT), Universidade Nova de Lisboa (UNL), Lisbon, Portugal
| | - Cristina Mendes
- Global Health and Tropical Medicine (GHTM), Instituto de Higiene e Medicina Tropical (IHMT), Universidade Nova de Lisboa (UNL), Lisbon, Portugal
| | - Nicolas Ndong-Mabale
- Centro de Referencia para el Control de Endemias, Instituto de Salud Carlos III, Bata, Equatorial Guinea
| | - Pedro Berzosa
- Centro Nacional de Medicina Tropical, Instituto de Salud Carlos III, Madrid, Spain
| | - Bruno de Sousa
- Faculdade de Psicologia e de Ciências da Educação, Universidade de Coimbra, Coimbra, Portugal
| | - Ana Paula Arez
- Global Health and Tropical Medicine (GHTM), Instituto de Higiene e Medicina Tropical (IHMT), Universidade Nova de Lisboa (UNL), Lisbon, Portugal
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13
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Sharma J, Dutta P, Khan SA. Population genetic study of Plasmodium falciparum parasites pertaining to dhps gene sequence in malaria endemic areas of Assam. Indian J Med Microbiol 2015; 33:401-5. [PMID: 26068343 DOI: 10.4103/0255-0857.158565] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Plasmodium falciparum malaria parasite had developed resistance to almost all the currently used antimalarial drugs. The purpose of the study was to come across the genetic distances in P. falciparum dhps gene sequences circulating in Assam. A partial fragment of P. falciparum dhps gene containing major single nucleotide polymorphisms associated with sulphadoxine resistance were amplified and sequenced. Thereafter specific bioinformatics tools like BioEdit v7.0.9, ClustalW in Mega 5, DnaSP version v.5.10.01 etc were used for the analysis. A total of 100 P. falciparum positive cases in different malaria endemic areas of Assam were included for the study. Based upon the mutation analysis, a total of seven different P. falciparum dhps genotypes were observed with five variable sites. Maximum five haplotypes were found in the P. falciparum isolates from Jorhat district of Assam. Four polymorphic sites were observed in the P. falciparum dhps gene sequences in Karbi Anglong, NC Hills, Chirang and Jorhat whereas the isolates from other study areas had three polymorphic sites. A statistically significant positive value of Tajima's D were observed among the P. falciparum field isolates in Assam indicating that there is an excess of intermediate frequency alleles and can result from population bottlenecks, structure and/or balancing selection. Extensive gene flow took place among the P. falciparum population of Jorhat with Sivasagar, Chirang with Sivasagar and Chirang with Karbi Anglong. However, large genetic differentiation was observed among the P. falciparum isolates of NC Hills with Lakhimpur, Tinsukia, Dibrugarh and Golaghat and also the parasite population of Karbi Anglong with Lakhimpur and Tinsukia signifying little gene flow among the population. This finding has shown that mutant Pfdhps gene associated with sulphadoxine resistance is circulating in Assam. It is believed that, the parasite population may have undergone high level of breeding.
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Affiliation(s)
- J Sharma
- Entomology and Filariasis Division, Regional Medical Research Centre (ICMR), Dibrugarh, Assam, India
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14
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Iwalokun BA, Iwalokun SO, Adebodun V, Balogun M. Carriage of Mutant Dihydrofolate Reductase and Dihydropteroate Synthase Genes among Plasmodium falciparum Isolates Recovered from Pregnant Women with Asymptomatic Infection in Lagos, Nigeria. Med Princ Pract 2015; 24:436-43. [PMID: 26202938 PMCID: PMC5588254 DOI: 10.1159/000430987] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Accepted: 04/28/2015] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVE To assess N51I, C59R and S108N polymorphisms of dihydrofolate reductase (dhfr) and A437G and K540E of dihydropteroate synthase (dhps) genes of P. falciparum isolates recovered from pregnant women with asymptomatic malaria in a coastal setting in Nigeria. SUBJECTS AND METHODS A total of 107 consenting and consecutively enrolled pregnant women (mean age ± standard deviation, 26.6 ± 4.5 years) attending antenatal care at the Iru/Victoria Island Primary Health Centre, Lagos, were screened for peripheral malaria by microscopy, by a histidine-rich protein-2-based rapid diagnostic test (RDT) and by polymerase chain reaction (PCR) using finger-pricked and dot blood samples. DNA was extracted from the blood and used for dhfr and dhps gene polymorphism analyses by PCR and restriction fragment length polymorphism. The sociodemographic and parasite data obtained were analysed. RESULTS Of the 107 patients, 34 (31.8%), 46 (43%) and 40 (37.4%) were found to be P. falciparum infected using microscopy, RDT and corrected RDT-PCR, respectively (p < 0.05). The prevalence of P. falciparum isolates with mutant and mixed genotypes of dhfr at codons 51, 59 and 108 was 70, 75 and 80%, respectively, and the triple mutation in the homozygous form was 35%. The prevalence of the homozygous quintuple dhfr plus dhps mutant was 5%, while that of the P. falciparum isolates with mutant or mixed genotypes of dhps at codons 437 and 540 was 37.5 and 22.5%, respectively. CONCLUSION This study revealed the emergence of the K540E mutation among the parasite population in Lagos. However, it supports the implementation of the intermittent preventive treatment of malaria during pregnancy with sulphadoxine-pyrimethamine with continuous effectiveness monitoring in the study area.
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Affiliation(s)
- Bamidele Abiodun Iwalokun
- Department of Biochemistry and Nutrition, Nigerian Institute of Medical Research, Yaba, Lagos, Nigeria
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Analysis of polymorphisms in Plasmodium falciparum genes related to drug resistance: a survey over four decades under different treatment policies in Brazil. Malar J 2014; 13:372. [PMID: 25239550 PMCID: PMC4177603 DOI: 10.1186/1475-2875-13-372] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Accepted: 09/14/2014] [Indexed: 12/31/2022] Open
Abstract
Background Anti-malarial resistance in Plasmodium falciparum remains an obstacle for malaria control. Resistance-associated genes were analysed in Brazilian samples over four decades to evaluate the impact of different treatment regimens on the parasite genetic profile. Methods Samples were collected on filter paper from patients infected in the Amazon region from 1984 to 2011. DNA was extracted with Chelex® 100 and monoinfection confirmed by PCR. SNPs in the pfcrt, pfmdr1, pfdhfr and pfdhps genes were assessed by PCR-RFLP. The pfmdr1 copy number was estimated using real time quantitative PCR with SYBR® Green. Parasite response was assessed ex vivo with seven concentrations of each anti-malarial. Patients were treated according to Brazilian guidelines: quinine plus tetracycline or mefloquine in period 1 and ACT in period 2. Results All 96 samples presented the pfcrt 76T mutant throughout the assessed periods. In addition, all isolates showed ex vivo chloroquine resistance. The pfmdr1 86Y was detected in 1.5% of samples in period 1, and in 25% in period 2. All samples presented the pfmdr1 1246Y. The analysis of pfmdr1 copy number showed amplification in 37.3% in period 1 and in 42% in period 2. Mutations in pfdhfr were shown as follows: 51I in all samples in period 1 and in 81.2% in period 2; 59R in 6.4% in period 2. The pfdhfr 108N and the pfdhps 437G were seen in all samples along time; the pfdhps 540E in 93.7% in period 1 and in 75% in period 2. Conclusions The 76T mutation associated to chloroquine resistance is still present in the parasite population, although this anti-malarial was withdrawn from the chemotherapy of P. falciparum in Brazil in the mid-1980s. All isolates assayed ex vivo for chloroquine showed resistant phenotype and 76T. No association was observed between pfmdr1 mutations and resistance to quinine, mefloquine and artemisinin derivatives. Additionally, the pfdhfr 108N mutation was detected in all samples throughout the evaluated periods, demonstrating fixation of the mutant allele in the parasite population. Changes in Brazilian national guidelines for the malaria chemotherapy in the last 27 years yielded a discreet genetic impact in the parasite population.
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Kumari S, Mohana Priya A, Lulu S, Tauqueer M. Molecular modeling, simulation and virtual screening of ribosomal phosphoprotein P1 from Plasmodium falciparum. J Theor Biol 2014; 343:113-9. [DOI: 10.1016/j.jtbi.2013.10.014] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2013] [Revised: 09/26/2013] [Accepted: 10/23/2013] [Indexed: 11/16/2022]
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