1
|
Sridapan T, Rattanakoch P, Kijprasong K, Srisutham S. Drug resistance markers in Plasmodium vivax isolates from a Kanchanaburi province, Thailand between January to May 2023. PLoS One 2024; 19:e0304337. [PMID: 38968216 PMCID: PMC11226124 DOI: 10.1371/journal.pone.0304337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2023] [Accepted: 05/10/2024] [Indexed: 07/07/2024] Open
Abstract
BACKGROUND Plasmodium vivax has become the predominant species in the border regions of Thailand. The emergence and spread of antimalarial drug resistance in P. vivax is one of the significant challenges for malaria control. Continuous surveillance of drug resistance is therefore necessary for monitoring the development of drug resistance in the region. This study aims to investigate the prevalence of the mutation in the P. vivax multidrug resistant 1 (Pvmdr1), dihydrofolate reductase (Pvdhfr), and dihydropteroate synthetase (Pvdhps) genes conferred resistance to chloroquine (CQ), pyrimethamine (P) and sulfadoxine (S), respectively. METHOD 100 P. vivax isolates were obtained between January to May 2023 from a Kanchanaburi province, western Thailand. Nucleotide sequences of Pvmdr1, Pvdhfr, and Pvdhps genes were amplified and sequenced. The frequency of single nucleotide polymorphisms (SNPs)-haplotypes of drug-resistant alleles was assessed. The linkage disequilibrium (LD) tests were also analyzed. RESULTS In Pvmdr1, T958M, Y976F, and F1076L, mutations were detected in 100%, 21%, and 23% of the isolates, respectively. In Pvdhfr, the quadruple mutant allele (I57R58M61T117) prevailed in 84% of the samples, followed by (L57R58M61T117) in 11%. For Pvdhps, the double mutant allele (G383G553) was detected (48%), followed by the triple mutant allele (G383M512G553) (47%) of the isolates. The most prevalent combination of Pvdhfr (I57R58M61T117) and Pvdhps (G383G553) alleles was sextuple mutated haplotypes (48%). For LD analysis, the association in the SNPs pairs was found between the intragenic and intergenic regions of the Pvdhfr and Pvdhps genes. CONCLUSION The study has recently updated the high prevalence of three gene mutations associated with CQ and SP resistance. Genetic monitoring is therefore important to intensify in the regions to further assess the spread of drug resistant. Our data also provide evidence on the distribution of drug resistance for the early warning system, thereby threatening P. vivax malaria treatment policy decisions at the national level.
Collapse
Affiliation(s)
- Thanawat Sridapan
- Department of Clinical Microscopy, Faculty of Allied Health Sciences, Chulalongkorn University, Bangkok, Thailand
| | - Paweesuda Rattanakoch
- Department of Clinical Microscopy, Faculty of Allied Health Sciences, Chulalongkorn University, Bangkok, Thailand
| | | | - Suttipat Srisutham
- Department of Clinical Microscopy, Faculty of Allied Health Sciences, Chulalongkorn University, Bangkok, Thailand
| |
Collapse
|
2
|
Kaur D, Sinha S, Sehgal R. Global scenario of Plasmodium vivax occurrence and resistance pattern. J Basic Microbiol 2022; 62:1417-1428. [PMID: 36125207 DOI: 10.1002/jobm.202200316] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 08/20/2022] [Accepted: 09/04/2022] [Indexed: 11/06/2022]
Abstract
Malaria caused by Plasmodium vivax is comparatively less virulent than Plasmodium falciparum, which can also lead to severe disease and death. It shows a wide geographical distribution. Chloroquine serves as a drug of choice, with primaquine as a radical cure. However, with the appearance of resistance to chloroquine and treatment has been shifted to artemisinin combination therapy followed by primaquine as a radical cure. Sulphadoxine-pyrimethamine, mefloquine, and atovaquone-proguanil are other drugs of choice in chloroquine-resistant areas, and later resistance was soon reported for these drugs also. The emergence of drug resistance serves as a major hurdle to controlling and eliminating malaria. The discovery of robust molecular markers and regular surveillance for the presence of mutations in malaria-endemic areas would serve as a helpful tool to combat drug resistance. Here, in this review, we will discuss the endemicity of P. vivax, a historical overview of antimalarial drugs, the appearance of drug resistance and molecular markers with their global distribution along with different measures taken to reduce malaria burden due to P. vivax infection and their resistance.
Collapse
Affiliation(s)
- Davinder Kaur
- Department of Medical Parasitology, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Shweta Sinha
- Department of Medical Parasitology, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Rakesh Sehgal
- Department of Medical Parasitology, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| |
Collapse
|
3
|
Huang F, Li S, Tian P, Pu LJS, Cui Y, Liu H, Yang L, Bi DY. Genetic polymorphisms in genes associated with drug resistance in Plasmodium vivax parasites from northeastern Myanmar. Malar J 2022; 21:66. [PMID: 35241080 PMCID: PMC8892751 DOI: 10.1186/s12936-022-04084-y] [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: 10/11/2021] [Accepted: 02/11/2022] [Indexed: 11/10/2022] Open
Abstract
Background Anti-malarial drug resistance is still a major threat to malaria elimination in the Great Mekong Sub-region. Plasmodium vivax parasites resistant to anti-malarial drugs are now found in Myanmar. Molecular surveillance on drug resistance genes in P. vivax parasites from northeastern Myanmar was aimed at estimating the underlying drug resistance in this region. Methods Blood samples from patients with vivax malaria were collected from Laiza city in northeastern Myanmar in 2020. Drug resistance genes including Pvcrt-o, Pvmdr1, Pvdhfr and Pvdhps were amplified and sequenced. Genetic polymorphisms and haplotypes were analysed to evaluate the prevalence of mutant alleles associated with drug resistance. Results A total of 149 blood samples from P. vivax patients were collected. The prevalence of Pvmdr1 mutations at codons 958 and 1076 was 100.0% and 52.0%, respectively, whereas no single nucleotide polymorphism was present at codon 976. The proportions of single and double mutant types were 48.0% and 52.0%, respectively. A K10 “AAG” insertion in the Pvcrt-o gene was not detected. Mutations in Pvdhfr at codons 57, 58, 61, 99 and 117 were detected in 29.9%, 54.3%, 27.6%, 44.9% and 55.1% of the samples, respectively. Wild type was predominant (46.3%), followed by quadruple and double mutant haplotypes. Of three types of tandem repeat variations of Pvdhfr, Type B, with three copies of GGDN repeats, was the most common. Pvdhps mutations were only detected at codons 383 and 553 and the wild type Pvdhps was dominant (78.0%). Eleven haplotypes were identified when combining the mutations of Pvdhfr and Pvdhps, among which the predominant one was the wild type (33.9%), followed by double mutant alleles S58R/S117N /WT (24.6%). Conclusions This study demonstrated resistant P. vivax phenotypes exists in northeastern Myanmar. Continued surveillance of drug resistance markers is needed to update treatment guidelines in this region. Supplementary Information The online version contains supplementary material available at 10.1186/s12936-022-04084-y.
Collapse
Affiliation(s)
- Fang Huang
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, China. .,Chinese Center for Tropical Diseases Research, Shanghai, China. .,NHC Key Laboratory of Parasite and Vector Biology, Shanghai, China. .,WHO Collaborating Centre for Tropical Diseases; National Center for International Research on Tropical Diseases, Shanghai, China.
| | - Shigang Li
- Yingjiang County Center for Disease Control and Prevention, Yingjiang, Yunnan, China
| | - Peng Tian
- Yunnan Institute of Parasitic Diseases, Pu'er, Yunnan, China
| | | | - Yanwen Cui
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, China.,Chinese Center for Tropical Diseases Research, Shanghai, China.,NHC Key Laboratory of Parasite and Vector Biology, Shanghai, China.,WHO Collaborating Centre for Tropical Diseases; National Center for International Research on Tropical Diseases, Shanghai, China
| | - Hui Liu
- Yunnan Institute of Parasitic Diseases, Pu'er, Yunnan, China
| | - Lianzhi Yang
- Nabang Township Hospital, Yingjiang, Yunnan, China
| | | |
Collapse
|
4
|
Buyon LE, Elsworth B, Duraisingh MT. The molecular basis of antimalarial drug resistance in Plasmodium vivax. INTERNATIONAL JOURNAL FOR PARASITOLOGY-DRUGS AND DRUG RESISTANCE 2021; 16:23-37. [PMID: 33957488 PMCID: PMC8113647 DOI: 10.1016/j.ijpddr.2021.04.002] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 03/31/2021] [Accepted: 04/08/2021] [Indexed: 01/07/2023]
Abstract
Plasmodium vivax is the most geographically widespread cause of human malaria and is responsible for the majority of cases outside of the African continent. While great progress has been made towards eliminating human malaria, drug resistant parasite strains pose a threat towards continued progress. Resistance has arisen to multiple antimalarials in P. vivax, including to chloroquine, which is currently the first line therapy for P. vivax in most regions. Despite its importance, an understanding of the molecular mechanisms of drug resistance in this species remains elusive, in large part due to the complex biology of P. vivax and the lack of in vitro culture. In this review, we will cover the extent and challenges of measuring clinical and in vitro drug resistance in P. vivax. We will consider the roles of candidate drug resistance genes. We will highlight the development of molecular approaches for studying P. vivax biology that provide the opportunity to validate the role of putative drug resistance mutations as well as identify novel mechanisms of drug resistance in this understudied parasite. Validated molecular determinants and markers of drug resistance are essential for the rapid and cost-effective monitoring of drug resistance in P. vivax, and will be useful for optimizing drug regimens and for informing drug policy in control and elimination settings. Drug resistance is emerging in Plasmodium vivax, an important cause of malaria. The complex biology of P. vivax and the limited range of research tools make it difficult to identify drug resistance. The molecular mechanisms of drug resistance in P. vivax remain elusive. This review highlights the extent of drug resistance, the putative mechanisms of resistance and new technologies for the study of P. vivax drug resistance.
Collapse
Affiliation(s)
- Lucas E Buyon
- Department of Immunology and Infectious Diseases, Harvard T. H. Chan School of Public Health, Boston, 02115, MA, USA
| | - Brendan Elsworth
- Department of Immunology and Infectious Diseases, Harvard T. H. Chan School of Public Health, Boston, 02115, MA, USA
| | - Manoj T Duraisingh
- Department of Immunology and Infectious Diseases, Harvard T. H. Chan School of Public Health, Boston, 02115, MA, USA.
| |
Collapse
|
5
|
Kaur H, Sehgal R, Kumar A, Bharti PK, Bansal D, Mohapatra PK, Mahanta J, Sultan AA. Distribution pattern of amino acid mutations in chloroquine and antifolate drug resistance associated genes in complicated and uncomplicated Plasmodium vivax isolates from Chandigarh, North India. BMC Infect Dis 2020; 20:671. [PMID: 32933490 PMCID: PMC7493319 DOI: 10.1186/s12879-020-05397-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 09/06/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The increasing antimalarial drug resistance is a significant hindrance to malaria control and elimination programs. For the last six decades, chloroquine (CQ) plus pyrimethamine remains the first-line treatment for P. vivax malaria. Regions where both P. falciparum and P. vivax co-exist, P. vivax is exposed to antifolate drugs due to either misdiagnosis or improper treatment that causes selective drug pressure to evolve. Therefore, the present study aims to estimate antimalarial drug resistance among the complicated and uncomplicated P. vivax patients. METHODS A total of 143 P. vivax malaria positive patients were enrolled in this study, and DNA was isolated from their blood samples. Pvcrt-o, Pvmdr-1, Pvdhps, and Pvdhfr genes were PCRs amplified, and drug resistance-associated gene mutations were analyzed. Statistical analysis of the drug resistance genes and population diversity was performed using MEGA vs. 7.0.21 and DnaSP v software. RESULTS Among the CQ resistance marker gene Pvcrt-o, the prevalence of K10 insertion was 17.5% (7/40) and 9.5% (7/73) of complicated and uncomplicated P vivax group isolates respectively. In Pvmdr-1, double mutant haplotype (M958/L1076) was found in 99% of the clinical isolates. Among the pyrimethamine resistance-associated gene Pvdhfr, the double mutant haplotype I13P33F57R58T61N117I173 was detected in 23% (11/48) in complicated and 20% (17/85) in uncomplicated group isolates. In the sulphadoxine resistance-associated Pvdhps gene, limited polymorphism was observed with the presence of a single mutant (D459A) among 16 and 5% of the clinical isolates in the complicated and uncomplicated group respectively. CONCLUSION The study presents the situations of polymorphism in the antimalarial drug resistance-associated genes and emphasizes the need for regular surveillance. It is imperative for the development of suitable antimalarial drug policy in India.
Collapse
Affiliation(s)
- Hargobinder Kaur
- Department of Medical Parasitology, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Rakesh Sehgal
- Department of Medical Parasitology, Postgraduate Institute of Medical Education and Research, Chandigarh, India.
| | - Archit Kumar
- Department of Virology, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Praveen K Bharti
- National Institute for Research in Tribal Health, Indian Council of Medical Research, Nagpur Road, Garha, Jabalpur, Madhya Pradesh, India
| | - Devendra Bansal
- Department of Microbiology and Immunology, Weill Cornell Medicine - Qatar, Cornell University, Qatar Foundation, Education City, Doha, Qatar.,Present address: Ministry of Public Health, Doha, Qatar
| | - Pradyumna K Mohapatra
- Regional Medical Research Centre, NE, Indian Council of Medical Research, Post Box no.105, Dibrugarh, Assam, India
| | - Jagadish Mahanta
- Regional Medical Research Centre, NE, Indian Council of Medical Research, Post Box no.105, Dibrugarh, Assam, India
| | - Ali A Sultan
- Department of Microbiology and Immunology, Weill Cornell Medicine - Qatar, Cornell University, Qatar Foundation, Education City, Doha, Qatar
| |
Collapse
|
6
|
Molecular detection of antimalarial drug resistance in Plasmodium vivax from returned travellers to NSW, Australia during 2008-2018. Pathogens 2020; 9:pathogens9020101. [PMID: 32033493 PMCID: PMC7168284 DOI: 10.3390/pathogens9020101] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Revised: 01/27/2020] [Accepted: 01/27/2020] [Indexed: 12/02/2022] Open
Abstract
To monitor drug resistance in Plasmodium vivax, a multidrug resistance 1 (Pvmdr1) gene and a putative transporter protein (Pvcrt-o) gene were used as molecular markers for chloroquine resistance. The biomarkers, the dihydrofolate reductase (Pvdhfr) gene and the dihydropteroate synthetase (Pvdhps) gene, were also used for the detection of resistance to sulphadoxine-pyrimethamine (SP); this drug is often accidentally used to treat P. vivax infections. Clinical blood samples (n = 120) were collected from patients who had been to one of eight malaria-endemic countries and diagnosed with P. vivax infection. The chloroquine resistance marker, the Pvmdr1 gene, showed F976:L1076 mutations and L1076 mutation. A K10 insertion in the Pvcrt-o gene was also found among the samples successfully sequenced. A combination of L/I57:R58:M61:T117 mutations in the Pvdhfr gene and G383:G553 mutations in the Pvdhps gene were also observed. Mutations found in these genes indicate that drug resistance is present in these eight countries. Whether or not countries are using chloroquine to treat P. vivax, there appears to be an increase in mutation numbers in resistance gene markers. The detected changes in mutation rates of these genes do suggest that there is still a trend towards increasing P. vivax resistance to chloroquine. The presence of the mutations associated with SP resistance indicates that P. vivax has had exposure to SP and this may be a consequence of either misdiagnosis or coinfections with P. falciparum in the past.
Collapse
|
7
|
The genesis and evolution of bead-based multiplexing. Methods 2019; 158:2-11. [DOI: 10.1016/j.ymeth.2019.01.007] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2018] [Revised: 12/10/2018] [Accepted: 01/14/2019] [Indexed: 12/22/2022] Open
|
8
|
Tavul L, Hetzel MW, Teliki A, Walsh D, Kiniboro B, Rare L, Pulford J, Siba PM, Karl S, Makita L, Robinson L, Kattenberg JH, Laman M, Oswyn G, Mueller I. Efficacy of artemether-lumefantrine and dihydroartemisinin-piperaquine for the treatment of uncomplicated malaria in Papua New Guinea. Malar J 2018; 17:350. [PMID: 30290825 PMCID: PMC6173938 DOI: 10.1186/s12936-018-2494-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Accepted: 09/27/2018] [Indexed: 01/14/2023] Open
Abstract
BACKGROUND In 2009, the Papua New Guinea (PNG) Department of Health adopted artemether-lumefantrine (AL) and dihydroartemisinin-piperaquine (DHA-PPQ) as the first- and second-line treatments for uncomplicated malaria, respectively. This study was conducted to assess the efficacy of both drugs following adoption of the new policy. METHODS Between June 2012 and September 2014, a therapeutic efficacy study was conducted in East Sepik and Milne Bay Provinces of PNG in accordance with the standard World Health Organization (WHO) protocol for surveillance of anti-malarial drug efficacy. Patients ≥ 6 months of age with microscopy confirmed Plasmodium falciparum or Plasmodium vivax mono-infections were enrolled, treated with AL or DHA-PPQ, and followed up for 42 days. Study endpoints were adequate clinical and parasitological response (ACPR) on days 28 and 42. The in vitro efficacy of anti-malarials and the prevalence of selected molecular markers of resistance were also determined. RESULTS A total of 274 P. falciparum and 70 P. vivax cases were enrolled. The day-42 PCR-corrected ACPR for P. falciparum was 98.1% (104/106) for AL and 100% (135/135) for DHA-PPQ. The day-42 PCR-corrected ACPR for P. vivax was 79.0% (15/19) for AL and 92.3% (36/39) for DHA-PPQ. Day 3 parasite clearance of P. falciparum was 99.2% with AL and 100% with DHA-PPQ. In vitro testing of 96 samples revealed low susceptibility to chloroquine (34% of samples above IC50 threshold) but not to lumefantrine (0%). Molecular markers assessed in a sub-set of the study population indicated high rates of chloroquine resistance in P. falciparum (pfcrt SVMNT: 94.2%, n = 104) and in P. vivax (pvmdr1 Y976F: 64.8%, n = 54). CONCLUSIONS AL and DHA-PPQ were efficacious as first- and second-line treatments for uncomplicated malaria in PNG. Continued in vivo efficacy monitoring is warranted considering the threat of resistance to artemisinin and partner drugs in the region and scale-up of artemisinin-based combination therapy in PNG.
Collapse
Affiliation(s)
- Livingstone Tavul
- Papua New Guinea Institute of Medical Research, PO Box 378, Madang, Papua New Guinea.
| | - Manuel W Hetzel
- Swiss Tropical and Public Health Institute, PO Box, 4002, Basel, Switzerland.,University of Basel, Petersplatz 1, 4003, Basel, Switzerland
| | - Albina Teliki
- Papua New Guinea Institute of Medical Research, PO Box 378, Madang, Papua New Guinea
| | - Dorish Walsh
- Papua New Guinea Institute of Medical Research, PO Box 378, Madang, Papua New Guinea
| | - Benson Kiniboro
- Papua New Guinea Institute of Medical Research, PO Box 378, Madang, Papua New Guinea
| | - Lawrence Rare
- Papua New Guinea Institute of Medical Research, PO Box 378, Madang, Papua New Guinea
| | - Justin Pulford
- Papua New Guinea Institute of Medical Research, PO Box 378, Madang, Papua New Guinea.,Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L35QA, UK
| | - Peter M Siba
- Papua New Guinea Institute of Medical Research, PO Box 378, Madang, Papua New Guinea
| | - Stephan Karl
- Papua New Guinea Institute of Medical Research, PO Box 378, Madang, Papua New Guinea.,Infection and Immunity Division, Walter and Eliza Hall Institute, Melbourne, Australia.,Department of Medical Biology, University of Melbourne, Melbourne, Australia
| | - Leo Makita
- National Department of Health, PO Box 807, Waigani, NCD, Papua New Guinea
| | - Leanne Robinson
- Papua New Guinea Institute of Medical Research, PO Box 378, Madang, Papua New Guinea.,Infection and Immunity Division, Walter and Eliza Hall Institute, Melbourne, Australia.,Department of Medical Biology, University of Melbourne, Melbourne, Australia
| | - Johanna H Kattenberg
- Papua New Guinea Institute of Medical Research, PO Box 378, Madang, Papua New Guinea.,Institute of Tropical Medicine in Antwerp, Kronenburgstraat 43, 2000, Antwerp, Belgium
| | - Moses Laman
- Papua New Guinea Institute of Medical Research, PO Box 378, Madang, Papua New Guinea
| | - Gilchrist Oswyn
- Milne Bay Provincial Health Authority, Lock Bag 402, Alotau, Papua New Guinea
| | - Ivo Mueller
- Infection and Immunity Division, Walter and Eliza Hall Institute, Melbourne, Australia.,Department of Medical Biology, University of Melbourne, Melbourne, Australia.,Institut Pasteur, 25-28, rue du Docteur-Roux, Cedex 15, 75724, Paris, France
| |
Collapse
|
9
|
Parsaei M, Raeisi A, Spotin A, Shahbazi A, Mahami-Oskouei M, Hazratian T, Khorashad AS, Zaman J, Bazmani A, Sarafraz S. Molecular evaluation of pvdhfr and pvmdr-1 mutants in Plasmodium vivax isolates after treatment with sulfadoxine/pyrimethamine and chloroquine in Iran during 2001-2016. INFECTION GENETICS AND EVOLUTION 2018; 64:70-75. [PMID: 29929007 DOI: 10.1016/j.meegid.2018.06.021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Revised: 05/30/2018] [Accepted: 06/16/2018] [Indexed: 10/28/2022]
Abstract
The rising use of sulfadoxine/pyrimethamine (SP) in the treatment of chloroquine (CQ)-resistant Plasmodium falciparum has resulted in increased exposure to P. vivax isolates in Iran, where both species are being circulated. In this investigation, the frequency of pvdhfr and pvmdr-1 mutants was assessed in P. vivax strains during 2001-2016 after the introduction of SP/CQ in malarious areas of Iran. The P. vivax isolates (n, 52) were obtained from autochthonous samples in Southeast Iran during 2015-2016. The genomic DNA was extracted and examined using nested polymerase chain reaction-(PCR) and sequencing. Mutations were detected in pvdhfr codons P33L (21.2%), T61 M (25%), S93H (3.9%), and S117 T (1.9%) and 5 isolates showed double mutations (33 L/61 M, 7.7%; 33 L/117 T, 1.9%). No mutation was identified in pvdhfr codons F57 and S58. The pvmdr-1 1076 L mutation was detected in 93.3% of P. vivax isolates. The findings indicated that the frequency of three codons of pvdhfr F57/S58/S117 has decreased from 2001 (1.05%/7.0%/16.9%) to 2016 (0%/0%/1.9%). Genomic analysis of pvmdr-1 showed that the frequency of 1076 L has gradually increased from 2013 (93%) to 2016 (93.3%) (P > .05). The results demonstrated that P. vivax isolates are probably being exited under SP pressure, which reflects the appropriate level of training for field microscopists, as established by Iranian policymakers. Emergent pvdhfr codons 33L, 61M, and 93H should be noticed in plausible drug tolerance and treatment plans. The high prevalence of pvmdr-1 1076L mutation shows that efficacy of CQ combination with primaquine may be in danger of being compromised, however further investigations are needed to evaluate the clinical importance of CQ-resistant P. vivax isolates.
Collapse
Affiliation(s)
- Mahdi Parsaei
- Infectious and Tropical Diseases Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Ahmad Raeisi
- National Program Manager for Malaria Control, Ministry of Health & Medical Education, Tehran, Iran
| | - Adel Spotin
- Infectious and Tropical Diseases Research Center, Tabriz University of Medical Sciences, Tabriz, Iran; Student Research Committee, Tabriz University of Medical Sciences, Tabriz, Iran.
| | - Abbas Shahbazi
- Infectious and Tropical Diseases Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Mahmoud Mahami-Oskouei
- Department of Parasitology and Mycology, Faculty of Medicine, Tabriz University of MedicalSciences, Tabriz, Iran
| | - Teimour Hazratian
- Department of Parasitology and Mycology, Faculty of Medicine, Tabriz University of MedicalSciences, Tabriz, Iran
| | - Alireza Salimi Khorashad
- Infection Diseases and Tropical Medicine Research center, Zahedan University of Medical Sciences, Zahedan, Iran
| | - Jalal Zaman
- Orumiyeh Military Hospital, Health Administration of Army, Orumiyeh, Iran
| | - Ahad Bazmani
- Infectious and Tropical Diseases Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Sedighe Sarafraz
- Department of Parasitology and Mycology, Faculty of Medicine, Zanjan University of Medical Sciences, Zanjan, Iran
| |
Collapse
|
10
|
Momčilović S, Cantacessi C, Arsić-Arsenijević V, Otranto D, Tasić-Otašević S. Rapid diagnosis of parasitic diseases: current scenario and future needs. Clin Microbiol Infect 2018; 25:290-309. [PMID: 29730224 DOI: 10.1016/j.cmi.2018.04.028] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Revised: 04/22/2018] [Accepted: 04/24/2018] [Indexed: 01/05/2023]
Abstract
BACKGROUND Parasitic diseases are one of the world's most devastating and prevalent infections, causing millions of morbidities and mortalities annually. In the past, many of these infections have been linked predominantly to tropical or subtropical areas. Nowadays, however, climatic and vector ecology changes, a significant increase in international travel, armed conflicts, and migration of humans and animals have influenced the transmission of some parasitic diseases from 'book pages' to reality in developed countries. It has also been noted that many patients who have never travelled to endemic areas suffer from blood-borne infections caused by protozoa. In the light of existing knowledge, this new trend can be explained by the fact that in the process of migration a large number of asymptomatic carriers become a part of the blood bank donor and transplant donor populations. Accurate and rapid diagnosis represents the crucial weapon in the fight against parasitic infections. AIMS To review old and new approaches for rapid diagnosis of parasitic infections. SOURCES Data for this review were obtained through searches of PubMed using combinations of the following terms: parasitological diagnostics, microscopy, lateral flow assays, immunochromatographic assays, multiplex-PCR, and transplantation. CONTENT In this review, we provide a brief account of the advantages and limitations of rapid methods for diagnosis of parasitic diseases and focus our attention on current and future research in this area. The approximate costs associated with the use of different techniques and their applicability in endemic and non-endemic areas are also discussed. IMPLICATIONS Microscopy remains the cornerstone of parasitological diagnostics, especially in the field and low-resource settings, and provides epidemiological assessment of parasite burden. However, increased use and availability of point-of-care tests and molecular assays in modern era allow more rapid and accurate diagnoses and increased sensitivity in the identification of parasitic infections.
Collapse
Affiliation(s)
- S Momčilović
- Department of Microbiology and Immunology, Faculty of Medicine, University of Niš, Serbia.
| | - C Cantacessi
- Department of Veterinary Medicine, University of Cambridge, UK
| | - V Arsić-Arsenijević
- Department for Microbiology and Immunology, Faculty of Medicine, University of Belgrade, Serbia
| | - D Otranto
- Dipartimento di Medicina Veterinaria, Università degli Studi di Bari, Italy
| | - S Tasić-Otašević
- Department of Microbiology and Immunology, Faculty of Medicine, University of Niš, Serbia; Center of Microbiology and Parasitology, Public Health Institute Niš, Serbia
| |
Collapse
|
11
|
Tantiamornkul K, Pumpaibool T, Piriyapongsa J, Culleton R, Lek-Uthai U. The prevalence of molecular markers of drug resistance in Plasmodium vivax from the border regions of Thailand in 2008 and 2014. INTERNATIONAL JOURNAL FOR PARASITOLOGY-DRUGS AND DRUG RESISTANCE 2018; 8:229-237. [PMID: 29677637 PMCID: PMC6039358 DOI: 10.1016/j.ijpddr.2018.04.003] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Revised: 04/09/2018] [Accepted: 04/11/2018] [Indexed: 02/08/2023]
Abstract
The prevalence of Plasmodium vivax is increasing in the border regions of Thailand; one potential problem confounding the control of malaria in these regions is the emergence and spread of drug resistance. The aim of this study was to determine the genetic diversity in genes potentially linked to drug resistance in P. vivax parasites isolated from four different border regions of Thailand; Thai-Myanmar (Tak, Mae Hong Son and Prachuap Khiri Khan Provinces), and Thai-Cambodian borders (Chanthaburi Province). Isolates were collected from 345 P. vivax patients in 2008 and 2014, and parasite DNA extracted and subjected to nucleotide sequencing at five putative drug-resistance loci (Pvdhfr, Pvdhps, Pvmdr1, Pvcrt-o and Pvk12). The prevalence of mutations in Pvdhfr, Pvdhps and Pvmdr1 were markedly different between the Thai-Myanmar and Thai-Cambodian border areas and also varied between sampling times. All isolates carried the Pvdhfr (58R and 117N/T) mutation, however, whereas the quadruple mutant allele (I57R58M61T117) was the most prevalent (69.6%) in the Thai-Myanmar border region, the double mutant allele (F57R58T61N117) was at fixation on the Thai-Cambodian border (100%). The most prevalent genotypes of Pvdhps and Pvmdr1 were the double mutant (S382G383K512G553) (65.1%) and single mutant (M958Y976F1076) (46.5%) alleles, respectively on the Thai-Myanmar border while the single Pvdhps mutant (S382G383K512A553) (52.7%) and the triple Pvmdr1 mutant (M958F976L1076) (81%) alleles were dominant on the Thai-Cambodian border. No mutations were observed in the Pvcrt-o gene in either region. Novel mutations in the Pvk12 gene, the P. vivax orthologue of PfK13, linked to artemisinin resistance in Plasmodium falciparum, were observed with three nonsynonymous and three synonymous mutations in six isolates (3.3%).
Collapse
Affiliation(s)
- Kritpaphat Tantiamornkul
- Department of Parasitology and Entomology, Faculty of Public Health, Mahidol University, Rajvithi Rd, Rajthewee District, Bangkok 10400, Thailand; Faculty of Graduate Studies, Mahidol University, Phuttamonthon 4 Rd, Nakorn Pathom 73170, Thailand
| | - Tepanata Pumpaibool
- College of Public Health Science, Chulalongkorn University, Phyathai Rd, Bangkok 10330, Thailand
| | - Jittima Piriyapongsa
- Genome Technology Research Unit, National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, Pathumthani 12120, Thailand
| | - Richard Culleton
- Malaria Unit, Department of Pathology, Institute of Tropical Medicine, Nagasaki University, Sakamoto, Nagasaki 8528523, Japan.
| | - Usa Lek-Uthai
- Department of Parasitology and Entomology, Faculty of Public Health, Mahidol University, Rajvithi Rd, Rajthewee District, Bangkok 10400, Thailand.
| |
Collapse
|
12
|
Abstract
Increasing antimalarial drug resistance once again threatens effective antimalarial drug treatment, malaria control, and elimination. Artemisinin combination therapies (ACTs) are first-line treatment for uncomplicated falciparum malaria in all endemic countries, yet partial resistance to artemisinins has emerged in the Greater Mekong Subregion. Concomitant emergence of partner drug resistance is now causing high ACT treatment failure rates in several areas. Genetic markers for artemisinin resistance and several of the partner drugs have been established, greatly facilitating surveillance. Single point mutations in the gene coding for the Kelch propeller domain of the K13 protein strongly correlate with artemisinin resistance. Novel regimens and strategies using existing antimalarial drugs will be needed until novel compounds can be deployed. Elimination of artemisinin resistance will imply elimination of all falciparum malaria from the same areas. In vivax malaria, chloroquine resistance is an increasing problem.
Collapse
Affiliation(s)
- Didier Menard
- Malaria Molecular Epidemiology Unit, Institut Pasteur in Cambodia, Phnom Penh 12201, Cambodia
| | - Arjen Dondorp
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok 73170, Thailand
| |
Collapse
|
13
|
Hetzel MW, Reimer LJ, Gideon G, Koimbu G, Barnadas C, Makita L, Siba PM, Mueller I. Changes in malaria burden and transmission in sentinel sites after the roll-out of long-lasting insecticidal nets in Papua New Guinea. Parasit Vectors 2016; 9:340. [PMID: 27301964 PMCID: PMC4908799 DOI: 10.1186/s13071-016-1635-x] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2016] [Accepted: 06/08/2016] [Indexed: 12/25/2022] Open
Abstract
Background Papua New Guinea exhibits a complex malaria epidemiology due to diversity in malaria parasites, mosquito vectors, human hosts, and their natural environment. Heterogeneities in transmission and burden of malaria at various scales are likely to affect the success of malaria control interventions, and vice-versa. This manuscript assesses changes in malaria prevalence, incidence and transmission in sentinel sites following the first national distribution of long-lasting insecticidal nets (LLINs). Methods Before and after the distribution of LLINs, data collection in six purposively selected sentinel sites included clinical surveillance in the local health facility, household surveys and entomological surveys. Not all activities were carried out in all sites. Mosquitoes were collected by human landing catches. Diagnosis of malaria infection in humans was done by rapid diagnostic test, light microscopy and PCR for species confirmation. Results Following the roll-out of LLINs, the average monthly malaria incidence rate dropped from 13/1,000 population to 2/1,000 (incidence rate ratio = 0.12; 95 % CI: 0.09–0.17; P < 0.001). The average population prevalence of malaria decreased from 15.7 % pre-LLIN to 4.8 % post-LLIN (adjusted odds ratio = 0.26; 95 % CI: 0.20–0.33; P < 0.001). In general, reductions in incidence and prevalence were more pronounced in infections with P. falciparum than with P. vivax. Additional morbidity indicators (anaemia, splenomegaly, self-reported fever) showed a decreasing trend in most sites. Mean Anopheles man biting rates decreased from 83 bites/person/night pre-LLIN to 31 post-LLIN (P = 0.008). Anopheles species composition differed between sites but everywhere diversity was lower post-LLIN. In two sites, post-LLIN P. vivax infections in anophelines had decreased but P. falciparum infections had increased despite the opposite observation in humans. Conclusions LLIN distribution had distinct effects on P. falciparum and P. vivax. Higher resilience of P. vivax may be attributed to relapses from hypnozoites and other biological characteristics favouring the transmission of P. vivax. The effect on vector species composition varied by location which is likely to impact on the effectiveness of LLINs. In-depth and longer-term epidemiological and entomological investigations are required to understand when and where residual transmission occurs and whether observed changes are sustained. Electronic supplementary material The online version of this article (doi:10.1186/s13071-016-1635-x) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Manuel W Hetzel
- Papua New Guinea Institute of Medical Research, Goroka and Madang, Papua New Guinea. .,Swiss Tropical and Public Health Institute, Basel, Switzerland. .,University of Basel, Basel, Switzerland.
| | - Lisa J Reimer
- Papua New Guinea Institute of Medical Research, Goroka and Madang, Papua New Guinea.,Case Western Reserve University, Cleveland, OH, USA.,Present address: Liverpool School of Tropical Medicine, Liverpool, UK
| | - Gibson Gideon
- Papua New Guinea Institute of Medical Research, Goroka and Madang, Papua New Guinea
| | - Gussy Koimbu
- Papua New Guinea Institute of Medical Research, Goroka and Madang, Papua New Guinea
| | - Céline Barnadas
- Papua New Guinea Institute of Medical Research, Goroka and Madang, Papua New Guinea.,Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Parkville, Vic, Australia.,Department of Medical Biology, University of Melbourne, Parkville, Vic, Australia.,Present address: European Public Health Microbiology (EUPHEM) training programme, European Centre for Disease Prevention and Control (ECDC), Stockholm, Sweden.,Present address: Statens Serum Institut, Copenhagen, Denmark
| | - Leo Makita
- National Department of Health, Waigani, Papua New Guinea
| | - Peter M Siba
- Papua New Guinea Institute of Medical Research, Goroka and Madang, Papua New Guinea
| | - Ivo Mueller
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Parkville, Vic, Australia.,Barcelona Centre for International Health Research (CRESIB, Hospital Clínic-Universitat de Barcelona), Barcelona, Spain
| |
Collapse
|
14
|
Hetzel MW, Morris H, Tarongka N, Barnadas C, Pulford J, Makita L, Siba PM, Mueller I. Prevalence of malaria across Papua New Guinea after initial roll-out of insecticide-treated mosquito nets. Trop Med Int Health 2015; 20:1745-55. [PMID: 26427024 DOI: 10.1111/tmi.12616] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
OBJECTIVES To assess the population prevalence of malaria in villages across Papua New Guinea (PNG) following the first roll-out of free long-lasting insecticidal nets (LLIN). METHODS Between October 2008 and August 2009, a household survey was conducted in 49 random villages in districts covered by the LLIN distribution campaign. The survey extended to 19 villages in sentinel sites that had not yet been covered by the campaign. In each village, 30 households were randomly sampled, household heads were interviewed and capillary blood samples were collected from all consenting household members for microscopic diagnosis of malaria. RESULTS Malaria prevalence ranged from 0% to 49.7% with a weighted average of 12.1% (95% CI 9.5, 15.3) in the national sample. More people were infected with Plasmodium falciparum (7.0%; 95% CI 5.4, 9.1) than with P. vivax (3.8%; 95% CI 2.4, 5.7) or P. malariae (0.3%; 95% CI 0.1, 0.6). Parasitaemia was strongly age-dependent with a P. falciparum peak at age 5-9 years and a P. vivax peak at age 1-4 years, yet with differences between geographical regions. Individual LLIN use and high community coverage were associated with reduced odds of infection (OR = 0.64 and 0.07, respectively; both P < 0.001). Splenomegaly in children and anaemia were common morbidities attributable to malaria. CONCLUSIONS Malaria prevalence across PNG is again at levels comparable to the 1970s. The strong association of LLIN use with reduced parasitaemia supports efforts to achieve and maintain high country-wide coverage. P. vivax infections will require special targeted approaches across PNG.
Collapse
Affiliation(s)
- Manuel W Hetzel
- Papua New Guinea Institute of Medical Research, Goroka, Papua New Guinea.,Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Hector Morris
- Papua New Guinea Institute of Medical Research, Goroka, Papua New Guinea
| | - Nandao Tarongka
- Papua New Guinea Institute of Medical Research, Goroka, Papua New Guinea
| | - Céline Barnadas
- Papua New Guinea Institute of Medical Research, Goroka, Papua New Guinea.,Walter and Eliza Hall Institute of Medical Research, Parkville, Vic., Australia.,Department of Medical Biology, University of Melbourne, Parkville, Vic., Australia
| | - Justin Pulford
- Papua New Guinea Institute of Medical Research, Goroka, Papua New Guinea.,School of Public Health, The University of Queensland, Herston, Qld, Australia
| | - Leo Makita
- National Department of Health, Waigani, Papua New Guinea
| | - Peter M Siba
- Papua New Guinea Institute of Medical Research, Goroka, Papua New Guinea
| | - Ivo Mueller
- Walter and Eliza Hall Institute of Medical Research, Parkville, Vic., Australia.,Department of Medical Biology, University of Melbourne, Parkville, Vic., Australia.,Barcelona Centre for International Health Research, Hospital Clínic-Universitat de Barcelona, Barcelona, Spain
| |
Collapse
|
15
|
Barnadas C, Timinao L, Javati S, Iga J, Malau E, Koepfli C, Robinson LJ, Senn N, Kiniboro B, Rare L, Reeder JC, Siba PM, Zimmerman PA, Karunajeewa H, Davis TM, Mueller I. Significant geographical differences in prevalence of mutations associated with Plasmodium falciparum and Plasmodium vivax drug resistance in two regions from Papua New Guinea. Malar J 2015; 14:399. [PMID: 26452541 PMCID: PMC4600278 DOI: 10.1186/s12936-015-0879-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Accepted: 08/31/2015] [Indexed: 12/22/2022] Open
Abstract
Background Drug resistance remains a major obstacle to malaria treatment and control. It can arise and spread rapidly, and vary substantially even at sub-national level. National malaria programmes require cost-effective and timely ways of characterizing drug-resistance at multiple sites within their countries. Methods An improved multiplexed post-PCR ligase detection reaction—fluorescent microsphere assay (LDR-FMA) was used to simultaneously determine the presence of mutations in chloroquine resistance transporter (crt), multidrug resistance 1 (mdr1), dihydrofolate reductase (dhfr) and dihydropteroate synthase (dhps) genes in Plasmodium falciparum (n = 727) and Plasmodium vivax (n = 574) isolates collected in 2006 from cross-sectional community population surveys in two geographically distinct regions (Madang and East Sepik) of Papua New Guinea (PNG) where strong regional differences in in vivo aminoquinoline and antifolate therapeutic efficacy had previously been observed. Data were compared to those of a follow-up survey conducted in 2010. Results Despite some very low parasite densities, the assay successfully amplified all P. falciparum and P. vivax loci in 77 and 69 % of samples, respectively. In 2006, prevalences of pfdhfr (59R-108 N) double mutation/wild type pfdhps haplotype, pfcrt SVMNT haplotype (72S-76T double mutation), and 86Y pfmdr1 mutation all exceeded 90 %. For P. vivax, 65 % carried at least two pvdhfr mutations, 97 % the 647P pvdhps mutation and 54 % the 976F pvmdr1 mutation. Prevalence of mutant haplotypes was higher in Madang than East Sepik for pfcrt SVMNT (97.4 vs 83.3 %, p = 0.001), pfdhfr (59R-108 N) (100 vs 90.6 %, p = 0.001), pvdhfr haplotypes (75.8 vs 47.6 %, p = 0.001) and pvmdr1 976F (71.2 vs 26.2 %, p < 0.001). Data from a subsequent Madang survey in 2010 showed that the prevalence of pfdhps mutations increased significantly from <5 % to >30 % (p < 0.001) as did the prevalence of pvdhfr mutant haplotypes (from 75.8 to 97.4 %, p = 0.012). Conclusions This LDR-FMA multiplex platform shows feasibility for low-cost, high-throughput, rapid characterization of a broad range of drug-resistance markers in low parasitaemia infections. Significant geographical differences in mutation prevalence correlate with previous genotyping surveys and in vivo trials and may reflect variable drug pressure and differences in health-care access in these two PNG populations. Electronic supplementary material The online version of this article (doi:10.1186/s12936-015-0879-9) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Céline Barnadas
- Vector Borne Diseases Unit, Papua New Guinea Institute of Medical Research, Goroka, Papua New Guinea. .,Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Parkville, Australia. .,Department of Medical Biology, University of Melbourne, Parkville, VIC, Australia.
| | - Lincoln Timinao
- Vector Borne Diseases Unit, Papua New Guinea Institute of Medical Research, Goroka, Papua New Guinea.
| | - Sarah Javati
- Vector Borne Diseases Unit, Papua New Guinea Institute of Medical Research, Goroka, Papua New Guinea.
| | - Jonah Iga
- Vector Borne Diseases Unit, Papua New Guinea Institute of Medical Research, Goroka, Papua New Guinea.
| | - Elisheba Malau
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Parkville, Australia. .,Department of Medical Biology, University of Melbourne, Parkville, VIC, Australia.
| | - Cristian Koepfli
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Parkville, Australia. .,Department of Medical Biology, University of Melbourne, Parkville, VIC, Australia.
| | - Leanne J Robinson
- Vector Borne Diseases Unit, Papua New Guinea Institute of Medical Research, Goroka, Papua New Guinea. .,Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Parkville, Australia. .,Department of Medical Biology, University of Melbourne, Parkville, VIC, Australia.
| | - Nicolas Senn
- Vector Borne Diseases Unit, Papua New Guinea Institute of Medical Research, Goroka, Papua New Guinea. .,Swiss Tropical and Public Health Institute, Basel, Switzerland.
| | - Benson Kiniboro
- Vector Borne Diseases Unit, Papua New Guinea Institute of Medical Research, Goroka, Papua New Guinea.
| | - Lawrence Rare
- Vector Borne Diseases Unit, Papua New Guinea Institute of Medical Research, Goroka, Papua New Guinea.
| | | | - Peter M Siba
- Vector Borne Diseases Unit, Papua New Guinea Institute of Medical Research, Goroka, Papua New Guinea.
| | - Peter A Zimmerman
- Center for Global Health and Diseases, Case Western Reserve University, Cleveland, USA.
| | - Harin Karunajeewa
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Parkville, Australia. .,Department of Medical Biology, University of Melbourne, Parkville, VIC, Australia.
| | - Timothy M Davis
- School of Medicine and Pharmacology, University of Western Australia, Perth, Australia.
| | - Ivo Mueller
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Parkville, Australia. .,Department of Medical Biology, University of Melbourne, Parkville, VIC, Australia. .,Centre de Recerca en Salut Internacional de Barcelona, Barcelona, Spain.
| |
Collapse
|
16
|
Thongdee P, Kuesap J, Rungsihirunrat K, Dumre SP, Espino E, Noedl H, Na-Bangchang K. Genetic Polymorphisms in Plasmodium vivax Dihydrofolate Reductase and Dihydropteroate Synthase in Isolates from the Philippines, Bangladesh, and Nepal. THE KOREAN JOURNAL OF PARASITOLOGY 2015; 53:227-32. [PMID: 25925184 PMCID: PMC4416376 DOI: 10.3347/kjp.2015.53.2.227] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Revised: 02/27/2015] [Accepted: 01/25/2015] [Indexed: 11/23/2022]
Abstract
Genetic polymorphisms of pvdhfr and pvdhps genes of Plasmodium vivax were investigated in 83 blood samples collected from patients in the Philippines, Bangladesh, and Nepal. The SNP-haplotypes of the pvdhfr gene at the amino acid positions 13, 33, 57, 58, 61, 117, and 173, and that of the pvdhps gene at the positions 383 and 553 were analyzed by nested PCR-RFLP. Results suggest diverse polymorphic patterns of pvdhfr alone as well as the combination patterns with pvdhps mutant alleles in P. vivax isolates collected from the 3 endemic countries in Asia. All samples carried mutant combination alleles of pvdhfr and pvdhps. The most prevalent combination alleles found in samples from the Philippines and Bangladesh were triple mutant pvdhfr combined with single mutant pvdhps allele and triple mutant pvdhfr combined with double wild-type pvdhps alleles, respectively. Those collected from Nepal were quadruple mutant pvdhfr combined with double wild-type pvdhps alleles. New alternative antifolate drugs which are effective against sulfadoxine-pyrimethamine (SP)-resistant P. vivax are required.
Collapse
Affiliation(s)
- Pimwan Thongdee
- Graduate Program in Bioclinical Sciences, Chulabhorn International College of Medicine, Thammasat University, Pathumthani, Thailand ; Graduate Program in Biomedical Sciences, Faculty of Allied Health Sciences, Thammasat University, Pathumthani, Thailand
| | - Jiraporn Kuesap
- Graduate Program in Biomedical Sciences, Faculty of Allied Health Sciences, Thammasat University, Pathumthani, Thailand
| | - Kanchana Rungsihirunrat
- Malaria Research Program, College of Public Health Sciences, Chulalongkorn University, Bangkok, Thailand
| | - Shyam Prakash Dumre
- World Health Organization-Nepal/Epidemiology and Disease Control Division (EDCD), DoHS, Teku Kathmandu, Nepal
| | - Effie Espino
- Research Institute for Tropical Medicine (RITM), Department of Health (DOH), Muntinlupa, Metro Manila, The Philippines
| | - Harald Noedl
- Institute of Specific Prophylaxis and Tropical Medicine, Medical University of Vienna, Vienna, Austria
| | - Kesara Na-Bangchang
- Graduate Program in Bioclinical Sciences, Chulabhorn International College of Medicine, Thammasat University, Pathumthani, Thailand ; Center of Excellence in Pharmacology and Molecular Biology of Malaria and Cholangiocarcinoma, Thammasat University, Pathumthani, Thailand
| |
Collapse
|
17
|
Koleala T, Karl S, Laman M, Moore BR, Benjamin J, Barnadas C, Robinson LJ, Kattenberg JH, Javati S, Wong RPM, Rosanas-Urgell A, Betuela I, Siba PM, Mueller I, Davis TME. Temporal changes in Plasmodium falciparum anti-malarial drug sensitivity in vitro and resistance-associated genetic mutations in isolates from Papua New Guinea. Malar J 2015; 14:37. [PMID: 25626445 PMCID: PMC4335551 DOI: 10.1186/s12936-015-0560-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Accepted: 01/13/2015] [Indexed: 01/19/2023] Open
Abstract
Background In northern Papua New Guinea (PNG), most Plasmodium falciparum isolates proved resistant to chloroquine (CQ) in vitro between 2005 and 2007, and there was near-fixation of pfcrt K76T, pfdhfr C59R/S108N and pfmdr1 N86Y. To determine whether the subsequent introduction of artemisinin combination therapy (ACT) and reduced CQ-sulphadoxine-pyrimethamine pressure had attenuated parasite drug susceptibility and resistance-associated mutations, these parameters were re-assessed between 2011 and 2013. Methods A validated fluorescence-based assay was used to assess growth inhibition of 52 P. falciparum isolates from children in a clinical trial in Madang Province. Responses to CQ, lumefantrine, piperaquine, naphthoquine, pyronaridine, artesunate, dihydroartemisinin, artemether were assessed. Molecular resistance markers were detected using a multiplex PCR ligase detection reaction fluorescent microsphere assay. Results CQ resistance (in vitro concentration required for 50% parasite growth inhibition (IC50) >100 nM) was present in 19% of isolates. All piperaquine and naphthoquine IC50s were <100 nM and those for lumefantrine, pyronaridine and the artemisinin derivatives were in low nM ranges. Factor analysis of IC50s showed three groupings (lumefantrine; CQ, piperaquine, naphthoquine; pyronaridine, dihydroartemisinin, artemether, artesunate). Most isolates (96%) were monoclonal pfcrt K76T (SVMNT) mutants and most (86%) contained pfmdr1 N86Y (YYSND). No wild-type pfdhfr was found but most isolates contained wild-type (SAKAA) pfdhps. Compared with 2005–2007, the geometric mean (95% CI) CQ IC50 was lower (87 (71–107) vs 167 (141–197) nM) and there had been no change in the prevalence of pfcrt K76T or pfmdr1 mutations. There were fewer isolates of the pfdhps (SAKAA) wild-type (60 vs 100%) and pfdhfr mutations persisted. Conclusions Reflecting less drug pressure, in vitro CQ sensitivity appears to be improving in Madang Province despite continued near-fixation of pfcrt K76T and pfmdr1 mutations. Temporal changes in IC50s for other anti-malarial drugs were inconsistent but susceptibility was preserved. Retention or increases in pfdhfr and pfdhps mutations reflect continued use of sulphadoxine-pyrimethamine in the study area including through paediatric intermittent preventive treatment. The susceptibility of local isolates to lumefantrine may be unrelated to those of other ACT partner drugs. Trial registration Australian New Zealand Clinical Trials Registry ACTRN12610000913077.
Collapse
Affiliation(s)
- Tamarah Koleala
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea.
| | - Stephan Karl
- School of Medicine and Pharmacology, University of Western Australia, Fremantle Hospital, PO Box 480, Fremantle, 6959, WA, Australia. .,Infection and Immunity Division, Walter and Eliza Hall Institute, Parkville, VIC, Australia. .,Department of Medical Biology, University of Melbourne, Melbourne, VIC, Australia.
| | - Moses Laman
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea. .,School of Medicine and Pharmacology, University of Western Australia, Fremantle Hospital, PO Box 480, Fremantle, 6959, WA, Australia.
| | - Brioni R Moore
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea. .,School of Medicine and Pharmacology, University of Western Australia, Fremantle Hospital, PO Box 480, Fremantle, 6959, WA, Australia.
| | - John Benjamin
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea.
| | - Celine Barnadas
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea. .,Infection and Immunity Division, Walter and Eliza Hall Institute, Parkville, VIC, Australia. .,Department of Medical Biology, University of Melbourne, Melbourne, VIC, Australia.
| | - Leanne J Robinson
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea. .,Infection and Immunity Division, Walter and Eliza Hall Institute, Parkville, VIC, Australia. .,Department of Medical Biology, University of Melbourne, Melbourne, VIC, Australia.
| | - Johanna H Kattenberg
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea. .,Infection and Immunity Division, Walter and Eliza Hall Institute, Parkville, VIC, Australia.
| | - Sarah Javati
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea.
| | - Rina P M Wong
- School of Medicine and Pharmacology, University of Western Australia, Fremantle Hospital, PO Box 480, Fremantle, 6959, WA, Australia.
| | - Anna Rosanas-Urgell
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea. .,Institute of Tropical Medicine, Antwerp, Belgium.
| | - Inoni Betuela
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea.
| | - Peter M Siba
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea.
| | - Ivo Mueller
- Infection and Immunity Division, Walter and Eliza Hall Institute, Parkville, VIC, Australia. .,Center de Recerca en Salut Internacional de Barcelona (CRESIB), Barcelona, Spain.
| | - Timothy M E Davis
- School of Medicine and Pharmacology, University of Western Australia, Fremantle Hospital, PO Box 480, Fremantle, 6959, WA, Australia.
| |
Collapse
|
18
|
Liu H, Yang HL, Tang LH, Li XL, Huang F, Wang JZ, Li CF, Wang HY, Nie RH, Guo XR, Lin YX, Li M, Xu JW. Monitoring Plasmodium vivax chloroquine sensitivity along China-Myanmar border of Yunnan Province, China during 2008-2013. Malar J 2014; 13:364. [PMID: 25224069 PMCID: PMC4180583 DOI: 10.1186/1475-2875-13-364] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2014] [Accepted: 09/12/2014] [Indexed: 11/28/2022] Open
Abstract
Background Plasmodium vivax is the most widespread of the malaria parasites infecting human hosts. In malaria-eliminating settings, both imported and local malaria predominantly occurs in border areas, and most of them are P. vivax. Chloroquine (CQ) is the first-line drug for P. vivax treatment in China. To understand CQ sensitivity in P. vivax, in vivo monitoring of CQ resistance was conducted along the China-Myanmar border from 2008 to 2013. Methods Eligible patients with mono-infections of P. vivax were recruited to this study after obtaining full informed consent. CQ tablets for different categories of kg body weight ranges were given once a day for three days. Patients were followed up for 28 days. PCR was conducted to distinguish between re-infection and recrudescence, to confirm the Plasmodium species. The data were entered and analysed by the Kaplan-Meier method. Treatment outcome and sensitivity were classified according to the WHO recommended standards. Results 603 patients were completed valid follow-up. The fever clearance time and asexual parasite clearance times were, respectively, 22.2 ± 10.2 and 38.1 ± 12.6 hours. 594 (98.5%) patients were adequate clinical and parasitological response (ACPR), and nine (1.5%) patients, who were late clinical failure (LCF) or resistant response level I (RI), were imported from the neighbouring districts of Myanmar. Conclusion In terms of efficacy, CQ is still effective for vivax malaria treatment. Plasmodium vivax CQ sensitivity had not significantly changed along the China-Myanmar border of Yunnan Province, China.
Collapse
Affiliation(s)
| | - Heng-lin Yang
- Yunnan Institute of Parasitic Diseases, Puer 665000, China.
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
19
|
Huang B, Huang S, Su XZ, Tong X, Yan J, Li H, Lu F. Molecular surveillance of pvdhfr, pvdhps, and pvmdr-1 mutations in Plasmodium vivax isolates from Yunnan and Anhui provinces of China. Malar J 2014; 13:346. [PMID: 25179752 PMCID: PMC4161776 DOI: 10.1186/1475-2875-13-346] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2014] [Accepted: 07/10/2014] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND Plasmodium vivax is the predominant species of human malaria parasites present in China. Although sulphadoxine-pyrimethamine (SP) and chloroquine (CQ) have been widely used for malaria treatment in China, the resistance profiles of these drugs are not available. Analysis of dihydrofolate reductase (dhfr), dihydropteroate synthase (dhps), and multidrug resistance (mdr-1) gene mutations in P. vivax isolates is a valuable molecular approach for mapping resistance to SP and CQ. This study investigates the prevalence of pvdhfr, pvdhps, and pvmdr-1 of P. vivax clinical isolates from China and provides baseline molecular epidemiologic data on SP- and CQ-associated resistance in P. vivax. METHODS Plasmodium vivax clinical isolates were collected from two malaria-endemic regions of China, subtropical (Xishuangbanna, Yunnan province) and temperate (Bozhou, Anhui province), from 2009 to 2012. All isolates were analysed for single nucleotide polymorphism haplotypes in pvdhfr, pvdhps, and pvmdr-1 using direct DNA sequencing. RESULTS In pvdhfr, 15% of Xishuangbanna isolates carried wild-type (WT) allele, whereas the majority of isolates carried mutant genes with substitutions at five codons. Eight mutant haplotypes of pvdhfr were detected, while limited polymorphism of pvdhfr was found in Bozhou isolates. A size polymorphism was present in pvdhfr, with the three-repeat type being the most predominate in both Xishuangbanna (79%) and Bozhou (97%) isolates. In pvdhps, mutations at four codons were detected in Xishuangbanna isolates leading to six haplotypes, including WT allele, single-mutation, double-mutation, and triple-mutation alleles. All Bozhou isolates carried WT pvhdps. In pvmdr-1, isolates from Xishuangbanna carried mutations at codons Y976F and F1076L, whereas all isolates from Bozhou had only a single mutation at codon F1076L. CONCLUSIONS Plasmodium vivax isolates from subtropical and temperate zones of China are shown to have dramatically different frequencies and patterns of mutations in pvdhfr, pvdhps, and pvmdr-1. Whereas P. vivax populations in subtropical China are highly resistant to SP and CQ, those in the temperate zone may still be susceptible to SP and CQ. This information is useful for establishing treatment policy and provides a baseline for molecular surveillance of drug-resistant P. vivax in these areas.
Collapse
Affiliation(s)
- Bo Huang
- />Department of Parasitology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, 510080 Guangdong China
- />Key Laboratory of Tropical Disease Control (Sun Yat-sen University), Ministry of Education, Guangzhou, 510080 Guangdong China
| | - Shiguang Huang
- />School of Medicine, Jinan University, Guangzhou, 510632 Guangdong China
| | - Xin-zhuan Su
- />Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892 USA
- />State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen, 361005 Fujian China
| | - Xinxin Tong
- />Department of Parasitology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, 510080 Guangdong China
- />Key Laboratory of Tropical Disease Control (Sun Yat-sen University), Ministry of Education, Guangzhou, 510080 Guangdong China
| | - Junping Yan
- />Department of Parasitology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, 510080 Guangdong China
- />Key Laboratory of Tropical Disease Control (Sun Yat-sen University), Ministry of Education, Guangzhou, 510080 Guangdong China
| | - Hongbin Li
- />Xishuangbanna CDC, Xishuangbanna Prefecture Jinghong, 666100 Yunnan China
| | - Fangli Lu
- />Department of Parasitology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, 510080 Guangdong China
- />Key Laboratory of Tropical Disease Control (Sun Yat-sen University), Ministry of Education, Guangzhou, 510080 Guangdong China
| |
Collapse
|
20
|
Plasmodium falciparum and Plasmodium vivax genotypes and efficacy of intermittent preventive treatment in Papua New Guinea. Antimicrob Agents Chemother 2014; 58:6958-61. [PMID: 25155586 DOI: 10.1128/aac.03323-14] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Intermittent preventive treatment of infants (IPTi) reduces early childhood malaria-related morbidity. While genotypic drug resistance markers have proven useful in predicting the efficacy of antimalarial drugs in case management, there are few equivalent data relating to their protective efficacy when used as IPTi. The present data from an IPTi trial in Papua New Guinea demonstrate how these markers can predict protective efficacy of IPTi for both Plasmodium falciparum and Plasmodium vivax.
Collapse
|
21
|
Barry AE, Arnott A. Strategies for designing and monitoring malaria vaccines targeting diverse antigens. Front Immunol 2014; 5:359. [PMID: 25120545 PMCID: PMC4112938 DOI: 10.3389/fimmu.2014.00359] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2014] [Accepted: 07/13/2014] [Indexed: 01/28/2023] Open
Abstract
After more than 50 years of intensive research and development, only one malaria vaccine candidate, “RTS,S,” has progressed to Phase 3 clinical trials. Despite only partial efficacy, this candidate is now forecast to become the first licensed malaria vaccine. Hence, more efficacious second-generation malaria vaccines that can significantly reduce transmission are urgently needed. This review will focus on a major obstacle hindering development of effective malaria vaccines: parasite antigenic diversity. Despite extensive genetic diversity in leading candidate antigens, vaccines have been and continue to be formulated using recombinant antigens representing only one or two strains. These vaccine strains represent only a small fraction of the diversity circulating in natural parasite populations, leading to escape of non-vaccine strains and challenging investigators’ abilities to measure strain-specific efficacy in vaccine trials. Novel strategies are needed to overcome antigenic diversity in order for vaccine development to succeed. Many studies have now cataloged the global diversity of leading Plasmodium falciparum and Plasmodium vivax vaccine antigens. In this review, we describe how population genetic approaches can be applied to this rich data source to predict the alleles that best represent antigenic diversity, polymorphisms that contribute to it, and to identify key polymorphisms associated with antigenic escape. We also suggest an approach to summarize the known global diversity of a given antigen to predict antigenic diversity, how to select variants that best represent the strains circulating in natural parasite populations and how to investigate the strain-specific efficacy of vaccine trials. Use of these strategies in the design and monitoring of vaccine trials will not only shed light on the contribution of genetic diversity to the antigenic diversity of malaria, but will also maximize the potential of future malaria vaccine candidates.
Collapse
Affiliation(s)
- Alyssa E Barry
- Division of Infection and Immunity, Walter and Eliza Hall Institute of Medical Research , Parkville, VIC , Australia ; Department of Medical Biology, The University of Melbourne , Parkville, VIC , Australia
| | - Alicia Arnott
- Division of Infection and Immunity, Walter and Eliza Hall Institute of Medical Research , Parkville, VIC , Australia ; Department of Medical Biology, The University of Melbourne , Parkville, VIC , Australia
| |
Collapse
|
22
|
Thongdee P, Kuesap J, Rungsihirunrat K, Tippawangkosol P, Mungthin M, Na-Bangchang K. Distribution of dihydrofolate reductase (dhfr) and dihydropteroate synthase (dhps) mutant alleles in Plasmodium vivax isolates from Thailand. Acta Trop 2013; 128:137-43. [PMID: 23880285 DOI: 10.1016/j.actatropica.2013.07.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2012] [Revised: 07/08/2013] [Accepted: 07/11/2013] [Indexed: 01/06/2023]
Abstract
The analysis of prevalence and distribution of pvdhfr and pvdhps mutations were performed in 169 samples collected from patients with Plasmodium vivax infection who attended the malaria clinics in the provinces along the three international borders of Thailand (Thai-Myanmar, Thai-Cambodian, and Thai-Malaysian borders). SNP-haplotypes of the pvdhfr at amino acid positions 13, 33, 57, 58, 61, 117, and 173 and of the pvdhps at positions 383 and 553 were examined by nested PCR-RFLP. Significant differences in the prevalence and distribution of pvdhfr and pvdhps combination alleles were observed in P. vivax isolates collected from all the three border areas. The most prevalent combination alleles were triple mutant pvdhfr 57L/58R/117T alleles/double wild-type pvdhps alleles (n=18), double mutant pvdhfr 58R/117N alleles/double wild-type pvdhps alleles (n=10), and triple mutant pvdhfr 58R/61M/117N alleles/double wild-type pvdhps alleles (n=52) or with single mutant pvdhps 383G allele (n=28), respectively. These information on prevalence and patterns of pvdhfr and pvdhps polymorphisms obtained from the present study suggest the presence of SP pressure on P. vivax isolates in Thailand which could be linked to the introduction of malaria from neighboring countries. Results did not support the application of SP for P. vivax control program in Thailand as well as the neighboring countries.
Collapse
|
23
|
Tyagi RK, Sharma YD. Erythrocyte Binding Activity Displayed by a Selective Group of Plasmodium vivax Tryptophan Rich Antigens Is Inhibited by Patients' Antibodies. PLoS One 2012; 7:e50754. [PMID: 23236392 PMCID: PMC3516511 DOI: 10.1371/journal.pone.0050754] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2012] [Accepted: 10/24/2012] [Indexed: 01/03/2023] Open
Abstract
Plasmodium vivax is a very common but non-cultivable malaria parasite affecting large human population in tropical world. To develop therapeutic reagents for this malaria, the parasite molecules involved in host-parasite interaction need to be investigated as they form effective vaccine or drug targets. We have investigated here the erythrocyte binding activity of a group of 15 different Plasmodium vivax tryptophan rich antigens (PvTRAgs). Only six of them, named PvTRAg, PvTRAg38, PvTRAg33.5, PvTRAg35.2 PvTRAg69.4 and PvATRAg74, showed binding to host erythrocytes. That the PvTRAgs binding to host erythrocytes was specific was evident from the competitive inhibition and saturation kinetics results. The erythrocyte receptors for these six PvTRAgs were resistant to trypsin and neuraminidase. These receptors were also chymotrypsin resistant except the receptors for PvTRAg38 and PvATRAg74 which were partially sensitive to this enzyme. The cross-competition studies showed that the chymotrypsin resistant RBC receptor for each of these two proteins was different. Altogether, there seems to be three RBC receptors for these six PvTRAgs and each PvTRAg has two RBC receptors. Both RBC receptors for PvTRAg, PvTRAg69.4, PvTRAg33.5, and PvTRAg35.2 were common to all these four proteins. These four PvTRAgs also shared one of their RBC receptors with PvTRAg38 as well as with PvATRAg74. The erythrocyte binding activity of these six PvTRAgs was inhibited by the respective rabbit polyclonal antibodies as well as by the natural antibodies produced by the P. vivax exposed individuals. It is concluded that only selective few PvTRAgs show erythrocyte binding activity involving different receptor molecules which can be blocked by the natural antibodies. Further studies on these receptor and ligands may lead to the development of therapeutic reagents for P. vivax malaria.
Collapse
Affiliation(s)
- Rupesh Kumar Tyagi
- Department of Biotechnology, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, India
| | - Yagya Dutta Sharma
- Department of Biotechnology, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, India
- * E-mail:
| |
Collapse
|