1
|
Abstract
Although the last two decades have seen a substantial decline in malaria incidence and mortality due to the use of insecticide-treated bed nets and artemisinin combination therapy, the threat of drug resistance is a constant obstacle to sustainable malaria control. Given that patients can die quickly from this disease, public health officials and doctors need to understand whether drug resistance exists in the parasite population, as well as how prevalent it is so they can make informed decisions about treatment. As testing for drug efficacy before providing treatment to malaria patients is impractical, researchers need molecular markers of resistance that can be more readily tracked in parasite populations. To this end, much work has been done to unravel the genetic underpinnings of drug resistance in Plasmodium falciparum. The aim of this review is to provide a broad overview of common genomic approaches that have been used to discover the alleles that drive drug response phenotypes in the most lethal human malaria parasite.
Collapse
Affiliation(s)
- Frances Rocamora
- Department of Pediatrics, School of Medicine, University of California, San Diego, La Jolla, California 92093, USA
| | - Elizabeth A Winzeler
- Department of Pediatrics, School of Medicine, University of California, San Diego, La Jolla, California 92093, USA
| |
Collapse
|
2
|
Analysis of Plasmodium falciparum Na +/H + exchanger (pfnhe1) polymorphisms among imported African malaria parasites isolated in Wuhan, Central China. BMC Infect Dis 2019; 19:354. [PMID: 31035938 PMCID: PMC6489200 DOI: 10.1186/s12879-019-3921-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Accepted: 03/19/2019] [Indexed: 11/30/2022] Open
Abstract
Background Quinine (QN) remains an effective drug for malaria treatment. However, quinine resistance (QNR) in Plasmodium falciparum has been reported in many malaria-endemic regions particularly in African countries. Genetic polymorphism of the P. falciparum Na+/H+ exchanger (pfnhe1) is considered to influence QN susceptibility. Here, ms4760 alleles of pfnhe1 were analysed from imported African P. falciparum parasites isolated from returning travellers in Wuhan, Central China. Methods A total of 204 dried-blood spots were collected during 2011–2016. The polymorphisms of the pfnhe1 gene were determined using nested PCR with DNA sequencing. Results Sequences were generated for 99.51% (203/204) of the PCR products and 68.63% (140/204) of the isolates were analysed successfully for the pfnhe1 ms4760 haplotypes. In total, 28 distinct ms4760 alleles containing 0 to 5 DNNND and 1 to 3 NHNDNHNNDDD repeats were identified. For the alleles, ms4760–1 (22.86%, 32/140), ms4760–3 (17.86%, 25/140), and ms4760–7 (10.71%, 15/140) were the most prevalent profiles. Furthermore, 5 undescribed ms4760 alleles were reported. Conclusions The study offers an initial comprehensive analysis of pfnhe1 ms4760 polymorphisms from imported P. falciparum isolates in Wuhan. Pfnhe1 may constitute a good genetic marker to evaluate the prevalence of QNR in malaria-endemic and non-endemic regions.
Collapse
|
3
|
Xiao B, Kuang Z, Zhan Y, Chen D, Gao Y, Li M, Luo S, Hao W. A Novel Polyclonal Antiserum against Toxoplasma gondii Sodium Hydrogen Exchanger 1. THE KOREAN JOURNAL OF PARASITOLOGY 2016; 54:21-9. [PMID: 26951975 PMCID: PMC4792324 DOI: 10.3347/kjp.2016.54.1.21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Revised: 12/21/2015] [Accepted: 12/29/2015] [Indexed: 11/23/2022]
Abstract
The sodium hydrogen exchanger 1 (NHE1), which functions in maintaining the ratio of Na+ and H+ ions, is widely distributed in cell plasma membranes. It plays a prominent role in pH balancing, cell proliferation, differentiation, adhesion, and migration. However, its exact subcellular location and biological functions in Toxoplasma gondii are largely unclear. In this study, we cloned the C-terminal sequence of T. gondii NHE1 (TgNHE1) incorporating the C-terminal peptide of NHE1 (C-NHE1) into the pGEX4T-1 expression plasmid. The peptide sequence was predicted to have good antigenicity based on the information obtained from an immune epitope database. After induction of heterologous gene expression with isopropyl-b-D-thiogalactoside, the recombinant C-NHE1 protein successfully expressed in a soluble form was purified by glutathione sepharose beads as an immunogen for production of a rabbit polyclonal antiserum. The specificity of this antiserum was confirmed by western blotting and immunofluorescence. The antiserum could reduce T. gondii invasion into host cells, indicated by the decreased TgNHE1 expression in T. gondii parasites that were pre-incubated with antiserum in the process of cell entry. Furthermore, the antiserum reduced the virulence of T. gondii parasites to host cells in vitro, possibly by blocking the release of Ca2+. In this regard, this antiserum has potential to be a valuable tool for further studies of TgNHE1.
Collapse
Affiliation(s)
- Bin Xiao
- State Key Laboratory of Organ Failure, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Biotechnology, Southern Medical University, Guangzhou 510515, People's Republic of China
| | - Zhenzhan Kuang
- State Key Laboratory of Organ Failure, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Biotechnology, Southern Medical University, Guangzhou 510515, People's Republic of China
| | - Yanli Zhan
- State Key Laboratory of Organ Failure, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Biotechnology, Southern Medical University, Guangzhou 510515, People's Republic of China
| | - Daxiang Chen
- State Key Laboratory of Organ Failure, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Biotechnology, Southern Medical University, Guangzhou 510515, People's Republic of China
| | - Yang Gao
- State Key Laboratory of Organ Failure, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Biotechnology, Southern Medical University, Guangzhou 510515, People's Republic of China
| | - Ming Li
- State Key Laboratory of Organ Failure, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Biotechnology, Southern Medical University, Guangzhou 510515, People's Republic of China
| | - Shuhong Luo
- State Key Laboratory of Organ Failure, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Biotechnology, Southern Medical University, Guangzhou 510515, People's Republic of China
| | - Wenbo Hao
- State Key Laboratory of Organ Failure, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Biotechnology, Southern Medical University, Guangzhou 510515, People's Republic of China
| |
Collapse
|
4
|
Pascual A, Fall B, Wurtz N, Fall M, Camara C, Nakoulima A, Baret E, Diatta B, Fall KB, Mbaye PS, Diémé Y, Bercion R, Bogreau H, Briolant S, Rogier C, Wade B, Pradines B. In vitro susceptibility to quinine and microsatellite variations of the Plasmodium falciparum Na+/H+ exchanger transporter (Pfnhe-1) gene in 393 isolates from Dakar, Senegal. Malar J 2013; 12:189. [PMID: 23758769 PMCID: PMC3679854 DOI: 10.1186/1475-2875-12-189] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2013] [Accepted: 06/03/2013] [Indexed: 11/10/2022] Open
Abstract
Background Although the World Health Organization recommends replacing quinine (QN) by artesunate due to its increased efficacy and the higher tolerance to the drug in both adults and children, QN remains a first-line treatment for severe malaria, especially in Africa. Investigations of microsatellite Pfnhe-1 ms4760 polymorphisms in culture-adapted isolates from around the world have revealed that an increase in the number of DNNND amino acid motifs was associated with decreased QN susceptibility, whereas an increase in the number of DDNHNDNHNND motifs was associated with increased QN susceptibility. Methods In this context, to further analyse associations between Pfnhe-1 ms4760 polymorphisms and QN susceptibility, 393 isolates freshly collected between October 2009 and January 2010 and July 2010 and February 2011, respectively, at the Hôpital Principal de Dakar, Senegal were assessed ex vivo for QN susceptibility, and their genes were amplified and sequenced. Results Of the 393 Plasmodium falciparum clinical isolates collected, 145 were successfully cultured. The 145 QN IC50s ranged from 2.1 to 1291 nM, and 17 isolates (11.7%) exceed the QN reduced susceptibility threshold of 611 nM. Among the 393 P. falciparum clinical isolates, 47 different alleles were observed. The three most prevalent profiles were ms4760-1 (no = 72; 18.3%), ms4760-3 (no = 65; 16.5%) and ms4760-7 (no = 40; 10.2%). There were no significant associations observed between QN IC50 values and i) the number of repeats of DNNND in block II (p = 0.0955, Kruskal-Wallis test); ii) the number of repeats of DDNHNDNHNND in block V (p = 0.1455, Kruskal-Wallis test); or iii) ms4760 profiles (p = 0.1809, Kruskal-Wallis test). Conclusions Pfnhe-1 ms4760 was highly diverse in parasite isolates from Dakar (47 different profiles). Three profiles (ms4760-1, ms4760-3 and ms4760-7) were predominant. The number of repeats for block II (DNNND) or block V (DDNHNDNHNND) was not significantly associated with QN susceptibility. New studies, and especially in vivo studies, are necessary to confirm the role of Pfnhe-1 ms4760 as a marker of QN resistance.
Collapse
Affiliation(s)
- Aurélie Pascual
- Département d'Infectiologie de Terrain, Unité de Parasitologie, Institut de Recherche Biomédicale des Armées, Marseille, France
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
5
|
Andriantsoanirina V, Khim N, Ratsimbasoa A, Witkowski B, Benedet C, Canier L, Bouchier C, Tichit M, Durand R, Ménard D. Plasmodium falciparum Na+/H+ exchanger (pfnhe-1) genetic polymorphism in Indian Ocean malaria-endemic areas. Am J Trop Med Hyg 2012. [PMID: 23208889 DOI: 10.4269/ajtmh.2012.12-0359] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
To date, 11 studies conducted in different countries to test the association between Plasmodium falciparum Na(+)/H(+) exchanger gene (pfnhe-1; PF13_0019) polymorphisms and in vitro susceptibility to quinine have generated conflicting data. In this context and to extend our knowledge of the genetic polymorphism of Pfnhe gene, we have sequenced the ms4760 locus from 595 isolates collected in the Comoros (N = 250; an area with a high prevalence of chloroquine and sulfadoxine-pyrimethamine resistance) and Madagascar (N = 345; a low drug-resistance area). Among them, 29 different alleles were observed, including 8 (27%) alleles not previously described. Isolates from the Comoros showed more repeats in block II (DNNND), which some studies have found to be positively associated with in vitro resistance to quinine, compared with isolates from Madagascar. Additional studies are required to better define the mechanisms underlying quinine resistance, which involve multiple gene interactions.
Collapse
|
6
|
Kone A, Mu J, Maiga H, Beavogui AH, Yattara O, Sagara I, Tekete MM, Traore OB, Dara A, Dama S, Diallo N, Kodio A, Traoré A, Björkman A, Gil JP, Doumbo OK, Wellems TE, Djimde AA. Quinine treatment selects the pfnhe-1 ms4760-1 polymorphism in Malian patients with Falciparum malaria. J Infect Dis 2012; 207:520-7. [PMID: 23162138 DOI: 10.1093/infdis/jis691] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND The mechanism of Plasmodium falciparum resistance to quinine is not known. In vitro quantitative trait loci mapping suggests involvement of a predicted P. falciparum sodium-hydrogen exchanger (pfnhe-1) on chromosome 13. METHODS We conducted prospective quinine efficacy studies in 2 villages, Kollé and Faladié, Mali. Cases of clinical malaria requiring intravenous therapy were treated with standard doses of quinine and followed for 28 days. Treatment outcomes were classified using modified World Health Organization protocols. Molecular markers of parasite polymorphisms were used to distinguish recrudescent parasites from new infections. The prevalence of pfnhe-1 ms4760-1 among parasites before versus after quinine treatment was determined by direct sequencing. RESULTS Overall, 163 patients were enrolled and successfully followed. Without molecular correction, the mean adequate clinical and parasitological response (ACPR) was 50.3% (n = 163). After polymerase chain reaction correction to account for new infections, the corrected ACPR was 100%. The prevalence of ms4760-1 increased significantly, from 26.2% (n = 107) before quinine treatment to 46.3% (n = 54) after therapy (P = .01). In a control sulfadoxine-pyrimethamine study, the prevalence of ms4760-1 was similar before and after treatment. CONCLUSIONS This study supports a role for pfnhe-1 in decreased susceptibility of P. falciparum to quinine in the field.
Collapse
Affiliation(s)
- Aminatou Kone
- Malaria Research and Training Center, Department of Epidemiology of Parasitic Diseases, Faculty of Medicine, Pharmacy, and Odonto-Stomatology, University of Science, Techniques and Technology, Bamako, Mali
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
7
|
Ménard D, Andriantsoanirina V, Khim N, Ratsimbasoa A, Witkowski B, Benedet C, Canier L, Mercereau-Puijalon O, Durand R. Global analysis of Plasmodium falciparum Na(+)/H(+) exchanger (pfnhe-1) allele polymorphism and its usefulness as a marker of in vitro resistance to quinine. INTERNATIONAL JOURNAL FOR PARASITOLOGY-DRUGS AND DRUG RESISTANCE 2012; 3:8-19. [PMID: 24533289 DOI: 10.1016/j.ijpddr.2012.10.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2012] [Revised: 10/06/2012] [Accepted: 10/09/2012] [Indexed: 11/30/2022]
Abstract
The aim of this study was to provide a comprehensive analysis of the worldwide genetic polymorphism of ms4760 alleles of the pfnhe-1 gene and to discuss their usefulness as molecular marker of quinine resistance (QNR). A new numbering of ms4760 allele, classification grouping ms4760 alleles according to the number of DNNND and DDNHNDNHNND repeat motifs in blocks II and V was also proposed. A total of 1508 ms4760 sequences from isolates, culture-adapted parasites or reference strains from various geographical regions were retrieved from GenBank (last update on 15th June 2012) or from publications and were used for genetic analyses. The association of different alleles of pfnhe-1 with resistance to quinoline antimalarial drugs showed marked geographic disparities. The validity and reliability of candidate polymorphisms in pfnhe-1 gene as molecular markers of QNR appeared restricted to endemic areas from South Asia or possibly East African countries and needs to be confirmed.
Collapse
Affiliation(s)
- Didier Ménard
- Unité d'Epidémiologie Moléculaire du Paludisme, Institut Pasteur du Cambodge, Phnom Penh, Cambodia
| | | | - Nimol Khim
- Unité d'Epidémiologie Moléculaire du Paludisme, Institut Pasteur du Cambodge, Phnom Penh, Cambodia
| | - Arsène Ratsimbasoa
- Ministère de la Santé, du Planning Familial et de la Protection Sociale, Programme National de Lutte contre le Paludisme, BP 1869 Antananarivo, Madagascar
| | - Benoit Witkowski
- Unité d'Epidémiologie Moléculaire du Paludisme, Institut Pasteur du Cambodge, Phnom Penh, Cambodia
| | - Christophe Benedet
- Unité d'Epidémiologie Moléculaire du Paludisme, Institut Pasteur du Cambodge, Phnom Penh, Cambodia
| | - Lydie Canier
- Unité d'Epidémiologie Moléculaire du Paludisme, Institut Pasteur du Cambodge, Phnom Penh, Cambodia
| | - Odile Mercereau-Puijalon
- Unité d'Immunologie Moléculaire des Parasites, Institut Pasteur & Centre National de la Recherche Scientifique, Unité de Recherche Associée 2581, Paris, France
| | - Rémy Durand
- Laboratoire de Parasitologie-Mycologie, Hôpital Avicenne, AP-HP, Bobigny, France
| |
Collapse
|
8
|
Polymorphisms of the pfmdr1 but not the pfnhe-1 gene is associated with in vitro quinine sensitivity in Thai isolates of Plasmodium falciparum. Malar J 2012; 11:7. [PMID: 22221394 PMCID: PMC3287963 DOI: 10.1186/1475-2875-11-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2011] [Revised: 07/12/2011] [Accepted: 01/05/2012] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The emergence of Plasmodium falciparum resistance to most currently used anti-malarial drugs is a major problem in malaria control along the Thai-Myanmar and Thai-Cambodia borders. Quinine (QN) with tetracycline/doxycycline has been used as the second-line treatment for uncomplicated falciparum malaria. In addition, QN monotherapy has been the first-line treatment for falciparum malaria in pregnant women. However, reduced in vitro and in vivo responses to QN have been reported. To date, a few genetic markers for QN resistance have been proposed including Plasmodium falciparum chloroquine resistance transporter (pfcrt), P. falciparum multidrug resistance 1 (pfmdr1), and P. falciparum Na+/H+ exchanger (pfnhe-1). This study was to investigate the role of the pfmdr1 and pfnhe-1 gene on in vitro QN sensitivity in Thai isolates of P. falciparum. METHODS Eighty-five Thai isolates of P. falciparum from the Thai-Myanmar and Thai-Cambodia borders from 2003-2008 were determined for in vitro QN sensitivity using radioisotopic assay. Polymorphisms of the pfmdr1 and pfnhe-1 gene were determined by PCR-RFLP and sequence analysis. Associations between the in vitro QN sensitivity and the polymorphisms of the pfmdr1 and pfnhe-1 gene were evaluated. RESULTS The mean QN IC50 was 202.8 nM (range 25.7-654.4 nM). Only four isolates were QN resistant when the IC50 of >500 nM was used as the cut-off point. Significant associations were found between the pfmdr1 mutations at codons N86Y and N1042D and in vitro QN sensitivity. However, no associations with the number of DNNND, DDNNNDNHNDD, and NHNDNHNNDDD repeats in the microsatellite ms4760 of the pfnhe-1 gene were identified. CONCLUSION Data from the present study put doubt regarding the pfnhe-1 gene as to whether it could be used as the suitable marker for QN resistance in Thailand. In contrast, it confirms the influence of the pfmdr1 gene on in vitro QN sensitivity.
Collapse
|
9
|
Differential association of Plasmodium falciparum Na+/H+ exchanger polymorphism and quinine responses in field- and culture-adapted isolates of Plasmodium falciparum. Antimicrob Agents Chemother 2011; 55:5834-41. [PMID: 21947391 DOI: 10.1128/aac.00477-11] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Plasmodium falciparum isolates with decreased susceptibility to quinine are increasingly being found in malaria patients. Mechanisms involved in this resistance are not yet understood. Several studies claim that alongside mutations in the Pfcrt and Pfmdr1 genes, the Pfnhe-1 Na(+)/H(+) exchanger polymorphism plays a role in decreasing susceptibility. However, conflicting results on the link between the Pfnhe-1 gene and quinine resistance arise from field- and culture-adapted isolates. We tested the association between Pfnhe-1, Pfcrt, and Pfmdr1 polymorphisms in field- and culture-adapted isolates from various countries with their in vitro susceptibility to quinine. Field isolates presented a higher diversity of the Pfnhe-1 microsatellite sequence than culture-adapted isolates. In culture-adapted isolates but not in field isolates, mutations in the Pfcrt and Pfmdr1 genes, as well as a higher number of DNNND repeats in the Pfnhe-1 gene, were associated with a higher 50% inhibitory concentration (IC(50)) of quinine. Furthermore, most of the culture-adapted isolates with more than one DNNND repeat in the Pfnhe-1 gene also harbored mutated Pfcrt and Pfmdr1 genes with an apparent cumulative effect on quinine susceptibility. This study supports the involvement of the Pfnhe-1 gene in the modulation of the in vitro quinine response when associated with mutated Pfcrt and Pfmdr1 genes. Culture adaptation could be responsible for selection of specific haplotypes of these three genes. Methods used for drug testing might thus influence the association between Pfnhe-1 polymorphism and quinine susceptibility. However, we do not exclude the possibility that in particular settings, Pfnhe-1 polymorphism can be used as a molecular marker for surveillance of quinine resistance.
Collapse
|
10
|
Limited ability of Plasmodium falciparum pfcrt, pfmdr1, and pfnhe1 polymorphisms to predict quinine in vitro sensitivity or clinical effectiveness in Uganda. Antimicrob Agents Chemother 2010; 55:615-22. [PMID: 21078941 DOI: 10.1128/aac.00954-10] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Quinine is a standard drug for treating severe malaria in Africa, and it is also increasingly used to treat uncomplicated disease. However, failures of quinine therapy are common, and it is unknown if failures in Africa are due to drug resistance. Recent studies have identified associations between in vitro quinine sensitivity and polymorphisms in genes encoding putative transporters, including well-described polymorphisms in pfcrt and pfmdr1 and varied numbers of DNNND or DDNHNDNHNND repeats in microsatellite 4760 (ms4760) of the predicted sodium-hydrogen exchanger, pfnhe1. To better characterize mediators of quinine response, we assessed associations between genetic polymorphisms, in vitro quinine sensitivity, and quinine treatment responses in Kampala, Uganda. Among 172 fresh clinical isolates tested in vitro, decreasing sensitivity to quinine was associated with accumulation of pfmdr1 mutations at codons 86, 184, and 1246. Nearly all parasites had pfcrt 76T, preventing analysis of associations with this mutation. pfnhe1 ms4760 was highly polymorphic. Parasites with 2 copies of either ms4760 repeat showed modest decreases in quinine sensitivity compared to those with 1 or ≥3 repeats, but the differences were not statistically significant. None of the above polymorphisms predicted treatment failure among 66 subjects treated with quinine for uncomplicated malaria. Our data suggest that quinine sensitivity is a complex trait and that known polymorphisms in pfcrt, pfmdr1, and pfnhe1, while associated with quinine sensitivity, are not robust markers for quinine resistance.
Collapse
|
11
|
Okombo J, Kiara SM, Rono J, Mwai L, Pole L, Ohuma E, Borrmann S, Ochola LI, Nzila A. In vitro activities of quinine and other antimalarials and pfnhe polymorphisms in Plasmodium isolates from Kenya. Antimicrob Agents Chemother 2010; 54:3302-7. [PMID: 20516285 PMCID: PMC2916339 DOI: 10.1128/aac.00325-10] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2010] [Revised: 04/25/2010] [Accepted: 05/23/2010] [Indexed: 01/24/2023] Open
Abstract
Resistance to the amino alcohol quinine has been associated with polymorphisms in pfnhe, a sodium hydrogen exchanger. We investigated the role of this gene in quinine resistance in vitro in isolates from Kenya. We analyzed pfnhe whole-gene polymorphisms, using capillary sequencing, and pfcrt at codon 76 (pfcrt-76) and pfmdr1 at codon 86 (pfmdr1-86), using PCR-enzyme restriction methodology, in 29 isolates from Kilifi, Kenya, for association with the in vitro activities of quinine and 2 amino alcohols, mefloquine and halofantrine. In vitro activity was assessed as the drug concentration that inhibits 50% of parasite growth (IC50). The median IC50s of quinine, halofantrine, and mefloquine were 92, 22, and 18 nM, respectively. The presence of 2 DNNND repeats in microsatellite ms4760 of pfnhe was associated with reduced susceptibility to quinine (60 versus 227 nM for 1 and 2 repeats, respectively; P<0.05), while 3 repeats were associated with restoration of susceptibility. The decrease in susceptibility conferred by the 2 DNNND repeats was more pronounced in parasites harboring the pfmdr1-86 mutation. No association was found between susceptibility to quinine and the pfcrt-76 mutation or between susceptibility to mefloquine or halofantrine and the pfnhe gene and the pfcrt-76 and pfmdr1-86 mutations. Using previously published data on the in vitro activities of chloroquine, lumefantrine, piperaquine, and dihydroartemisinin, we investigated the association of their activities with pfnhe polymorphism. With the exception of a modulation of the activity of lumefantrine by a mutation at position 1437, pfnhe did not modulate their activities. Two DNNND repeats combined with the pfmdr1-86 mutation could be used as an indicator of reduced susceptibility to quinine.
Collapse
Affiliation(s)
- John Okombo
- Kenya Medical Research Institute (KEMRI)/Wellcome Trust Collaborative Research Program, P.O. Box 230, 80108 Kilifi, Kenya, University of Oxford, Nuffield Department of Medicine, John Radcliffe Hospital, Oxford, United Kingdom, Institute of Hygiene, University of Heidelberg School of Medicine, Heidelberg, Germany
| | - Steven M. Kiara
- Kenya Medical Research Institute (KEMRI)/Wellcome Trust Collaborative Research Program, P.O. Box 230, 80108 Kilifi, Kenya, University of Oxford, Nuffield Department of Medicine, John Radcliffe Hospital, Oxford, United Kingdom, Institute of Hygiene, University of Heidelberg School of Medicine, Heidelberg, Germany
| | - Josea Rono
- Kenya Medical Research Institute (KEMRI)/Wellcome Trust Collaborative Research Program, P.O. Box 230, 80108 Kilifi, Kenya, University of Oxford, Nuffield Department of Medicine, John Radcliffe Hospital, Oxford, United Kingdom, Institute of Hygiene, University of Heidelberg School of Medicine, Heidelberg, Germany
| | - Leah Mwai
- Kenya Medical Research Institute (KEMRI)/Wellcome Trust Collaborative Research Program, P.O. Box 230, 80108 Kilifi, Kenya, University of Oxford, Nuffield Department of Medicine, John Radcliffe Hospital, Oxford, United Kingdom, Institute of Hygiene, University of Heidelberg School of Medicine, Heidelberg, Germany
| | - Lewa Pole
- Kenya Medical Research Institute (KEMRI)/Wellcome Trust Collaborative Research Program, P.O. Box 230, 80108 Kilifi, Kenya, University of Oxford, Nuffield Department of Medicine, John Radcliffe Hospital, Oxford, United Kingdom, Institute of Hygiene, University of Heidelberg School of Medicine, Heidelberg, Germany
| | - Eric Ohuma
- Kenya Medical Research Institute (KEMRI)/Wellcome Trust Collaborative Research Program, P.O. Box 230, 80108 Kilifi, Kenya, University of Oxford, Nuffield Department of Medicine, John Radcliffe Hospital, Oxford, United Kingdom, Institute of Hygiene, University of Heidelberg School of Medicine, Heidelberg, Germany
| | - Steffen Borrmann
- Kenya Medical Research Institute (KEMRI)/Wellcome Trust Collaborative Research Program, P.O. Box 230, 80108 Kilifi, Kenya, University of Oxford, Nuffield Department of Medicine, John Radcliffe Hospital, Oxford, United Kingdom, Institute of Hygiene, University of Heidelberg School of Medicine, Heidelberg, Germany
| | - Lynette Isabella Ochola
- Kenya Medical Research Institute (KEMRI)/Wellcome Trust Collaborative Research Program, P.O. Box 230, 80108 Kilifi, Kenya, University of Oxford, Nuffield Department of Medicine, John Radcliffe Hospital, Oxford, United Kingdom, Institute of Hygiene, University of Heidelberg School of Medicine, Heidelberg, Germany
| | - Alexis Nzila
- Kenya Medical Research Institute (KEMRI)/Wellcome Trust Collaborative Research Program, P.O. Box 230, 80108 Kilifi, Kenya, University of Oxford, Nuffield Department of Medicine, John Radcliffe Hospital, Oxford, United Kingdom, Institute of Hygiene, University of Heidelberg School of Medicine, Heidelberg, Germany
| |
Collapse
|
12
|
In vitro sensitivity of Plasmodium falciparum clinical isolates from the China-Myanmar border area to quinine and association with polymorphism in the Na+/H+ exchanger. Antimicrob Agents Chemother 2010; 54:4306-13. [PMID: 20643902 DOI: 10.1128/aac.00321-10] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Quinine resistance (QNR) in Plasmodium falciparum has been detected in many regions of the world where malaria is endemic. Genetic polymorphisms in at least four genes are implicated in QN susceptibility, and their significance often depends on the genetic background of the parasites. In this study, we have culture-adapted 60 P. falciparum clinical isolates from the China-Myanmar border and assessed their in vitro responses to QN. Our results showed that >50% of the parasite isolates displayed reduced sensitivity to QN, with a half-maximal inhibitory concentration (IC(50)) above 500 nM. Genotyping of pfcrt found that an overwhelming proportion of the parasite population had the chloroquine-resistant genotype, whereas pfmdr1 mutation genotypes and gene amplification were rare. Genotyping of the P. falciparum Na(+)/H(+) exchanger gene (pfnhe1) at the minisatellite ms4760 locus identified 10 haplotypes. Haplotype 7, which harbors three copies of the DNNND repeat, was the most predominant, accounting for nearly half of the parasite isolates. Correlation studies did not reveal significant associations of the polymorphisms in pfcrt and pfmdr1 genes with QN response. However, the ms4760 haplotypes were highly associated with in vitro QN responses. In particular, parasite isolates with an increased DNNND copy number tended to have significantly reduced QN susceptibility, whereas parasite isolates with a higher NHNDNHNNDDD copy number had increased QN susceptibility. This study provided further support for the importance of pfnhe1 polymorphisms in influencing QNR in P. falciparum.
Collapse
|
13
|
Andriantsoanirina V, Ménard D, Rabearimanana S, Hubert V, Bouchier C, Tichit M, Bras JL, Durand R. Association of microsatellite variations of Plasmodium falciparum Na+/H+ exchanger (Pfnhe-1) gene with reduced in vitro susceptibility to quinine: lack of confirmation in clinical isolates from Africa. Am J Trop Med Hyg 2010; 82:782-7. [PMID: 20439955 DOI: 10.4269/ajtmh.2010.09-0327] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
We sought to test the association of polymorphisms in Plasmodium falciparum nhe-1 (Pfnhe-1, gene PF13_0019) with in vitro susceptibility to quinine, which was previously reported in a limited number of reference strains or culture-adapted isolates. Determination of in vitro susceptibility to quinine, genotyping of Pfnhe-1 ms4760 microsatellite and polymorphism in codon 76 of Pfcrt were performed for 83 isolates obtained from symptomatic malaria-infected travelers returning from various African countries to France or from subjects living in Madagascar. Nineteen different ms4760 microsatellite profiles of Pfnhe-1 were found including 14 not previously described. Multivariate analysis showed no significant association between the in vitro susceptibility to quinine with particular ms4760 profiles. Contrary to previous reports, we only observed that the number of NHNDNHNNDDD repeats was positively associated with the increased IC50 of QN (P = 0.01). We concluded that the studied polymorphisms in Pfnhe-1 did not appear as valid molecular markers of in vitro susceptibility to quinine in P. falciparum isolates from Africa. Because we did not include any isolate of Asian origin in our series, these results did not exclude the possibility of regional associations, for example in South-East Asia.
Collapse
Affiliation(s)
- Valérie Andriantsoanirina
- Institut Pasteur de Madagascar, Unité de Recherche sur le Paludisme, Antananarivo, Madagascar, France
| | | | | | | | | | | | | | | |
Collapse
|
14
|
Singh V, Mishra N, Awasthi G, Dash AP, Das A. Why is it important to study malaria epidemiology in India? Trends Parasitol 2009; 25:452-7. [PMID: 19734097 DOI: 10.1016/j.pt.2009.06.004] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2009] [Revised: 06/26/2009] [Accepted: 06/26/2009] [Indexed: 10/20/2022]
Abstract
Malaria is a major vector-borne disease in India. Based on vast geographic areas with associated topographic and climatic diversity, the variable malaria epidemiology in India is associated with high parasite genetic diversity and rapidly evolving drug resistance, differential distribution of vector species and emerging insecticide resistance and underlying human genetic diversity and past evolutionary histories. Further, changing climatic patterns have possibly changed malaria epidemiology to a great extent. The outcome of these changes is an increased incidence of Plasmodium falciparum over the P. vivax malaria in recent years. Accordingly, the drug and insecticide application policy in India has changed too. The above facts and associated rapid shifting trend of malaria epidemiology makes India a hot-spot for malaria research.
Collapse
Affiliation(s)
- Vineeta Singh
- National Institute of Malaria Research, Sector 8, Dwarka, New Delhi 110077, India
| | | | | | | | | |
Collapse
|
15
|
Plasmodium falciparum Na+/H+ exchanger 1 transporter is involved in reduced susceptibility to quinine. Antimicrob Agents Chemother 2009; 53:1926-30. [PMID: 19273668 DOI: 10.1128/aac.01243-08] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Polymorphisms in the Plasmodium falciparum crt (Pfcrt), Pfmdr1, and Pfmrp genes were not significantly associated with quinine (QN) 50% inhibitory concentrations (IC(50)s) in 23 strains of Plasmodium falciparum. An increased number of DNNND repeats in Pfnhe-1 microsatellite ms4760 was associated with an increased IC(50) of QN (P = 0.0007). Strains with only one DNNND repeat were more susceptible to QN (mean IC(50) of 154 nM). Strains with two DNNND repeats had intermediate susceptibility to QN (mean IC(50) of 548 nM). Strains with three DNNND repeats had reduced susceptibility to QN (mean IC(50) of 764 nM). Increased numbers of NHNDNHNNDDD repeats were associated with a decreased IC(50) of QN (P = 0.0020). Strains with profile 7 for Pfnhe-1 ms4760 (ms4760-7) were significantly associated with reduced QN susceptibility (mean IC(50) of 764 nM). The determination of DNNND and NHNDNHNNDDD repeats in Pfnhe-1 ms4760 could be a good marker of QN resistance and provide an attractive surveillance method to monitor temporal trends in P. falciparum susceptibility to QN. The validity of the markers should be further supported by analyzing more isolates.
Collapse
|
16
|
Choudhary V, Sharma YD. Extensive heterozygosity in flanking microsatellites of Plasmodium falciparum Na+/H+ exchanger (pfnhe-1) gene among Indian isolates. Acta Trop 2009; 109:241-4. [PMID: 19059371 DOI: 10.1016/j.actatropica.2008.11.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2008] [Revised: 11/07/2008] [Accepted: 11/11/2008] [Indexed: 11/27/2022]
Abstract
Plasmodium falciparum Na(+)/H(+) exchanger-1 (pfnhe-1) gene has been proposed to be a possible marker for quinine resistance. Here, we describe the sequence analysis of the flanking microsatellites of the pfnhe-1 gene among 108 Indian P.falciparum isolates. Among the parasite population, a high degree of polymorphism was observed at all the 10 microsatellite loci within +/-40kb region of the pfnhe-1 gene where the number of alleles varied from 2 to 16 with a high expected heterozygosity ranging from 0.43 to 0.91 at these loci. Also, higher levels of heterozygosity have been observed in P.falciparum isolates collected from both low and high transmission and drug resistant areas. Furthermore, there was no association between QN resistance associated DNNND repeats in PFNHE-1 and the flanking microsatellite haplotypes. In conclusion, the observed high level of microsatellite polymorphism and absence of selective sweep in the flanking +/-40kb region of the pfnhe-1 gene could be an indication that there is no strong selection pressure on this target gene.
Collapse
|
17
|
Nkrumah LJ, Riegelhaupt PM, Moura P, Johnson DJ, Patel J, Hayton K, Ferdig MT, Wellems TE, Akabas MH, Fidock DA. Probing the multifactorial basis of Plasmodium falciparum quinine resistance: evidence for a strain-specific contribution of the sodium-proton exchanger PfNHE. Mol Biochem Parasitol 2009; 165:122-31. [PMID: 19428659 DOI: 10.1016/j.molbiopara.2009.01.011] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2008] [Revised: 01/15/2009] [Accepted: 01/20/2009] [Indexed: 01/10/2023]
Abstract
Quinine (QN) continues to be an important treatment option for severe malaria, however resistance to this drug has emerged in field isolates of the etiologic agent Plasmodium falciparum. Quantitative trait loci investigations of QN resistance have mapped three loci of this complex trait. Two coincide with pfcrt and pfmdr1, involved in resistance to chloroquine (CQ) and other quinoline-based antimalarials. A third locus on chromosome 13 contains the sodium-proton exchanger (pfnhe) gene. Previous studies have associated pfnhe polymorphisms with reduced QN sensitivity in culture-adapted field isolates. Here, we provide direct evidence supporting the hypothesis that pfnhe contributes to QN resistance. Using allelic exchange, we reduced pfnhe expression by introducing a truncated 3' untranslated region (UTR) from pfcrt into the endogenous pfnhe 3'UTR. Transfections were performed with 1BB5 and 3BA6 (both CQ- and QN-resistant) as well as GC03 (CQ- and QN-sensitive), all progenies of the HB3xDd2 genetic cross. RNA and protein analyses of the ensuing recombinant clones demonstrated a approximately 50% decrease in pfnhe expression levels. A statistically significant 30% decrease in QN IC(50) values was associated with these decreased expression levels in 1BB5 and 3BA6 but not in GC03. CQ, mefloquine and lumefantrine IC(50) values were unaltered. Cytosolic pH values were similar in all parental lines and recombinant clones. Our observations support a role for pfnhe in QN resistance in a strain-dependent manner, which might be contingent on pre-existing resistance to CQ and/or QN. These data bolster observations that QN resistance is a complex trait requiring the contribution of multiple transporter proteins.
Collapse
Affiliation(s)
- Louis J Nkrumah
- Department of Microbiology and Immunology, Albert Einstein College of Medicine of Yeshiva University, Bronx, NY 10461, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|