Low prevalence of dihydro folate reductase (dhfr) and dihydropteroate synthase (dhps) quadruple and quintuple mutant alleles associated with SP resistance in Plasmodium vivax isolates of West Bengal, India.

Sabyasachi Das,Amiya Kumar Hati,Somenath Roy,Abhijit Banik

doi:10.1186/s12936-016-1445-9

Sabyasachi Das, Amiya Kumar Hati + Show 2 more

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https://doi.org/10.1186/s12936-016-1445-9

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Abstract

BackgroundEmergence of chloroquine resistant Plasmodium vivax is a serious obstacle towards malaria control in India. This study elucidates the temporal pattern of antifolate [sulfadoxine–pyrimethamine (SP)] resistance in P. vivax infection by means of genetic polymorphisms, especially analysing the single nucleotide polymorphisms of dihydrofolate reductase (pvdhfr) and dihydropteroate synthase (pvdhps) gene among the field isolates of urban Kolkata Municipal Corporation and rural Purulia region of West Bengal, India.MethodsBlood samples were collected from 99 microscopically diagnosed P. vivax patients (52 from Kolkata Municipal Corporation and 47 from Purulia). Parasitic DNA was extracted followed by polymerase chain reaction and sequencing of different codons of pvdhfr gene (15, 33, 50, 57, 58, 61, 64, 117, and 173 codons) and pvdhps gene (373, 380, 382, 383, 384, 512, 553, 585, and 601 codons) were performed to identify the mutations.ResultsPrevalence of double mutant dhfr A15P33N50F57R58T61V64N117I173 allele (53.85 %) was observed in Kolkata Municipal Corporation (KMC) whereas in Purulia, wild dhfr A15P33N50F57S58T61V64S117I173 allele was predominated (48.94 %). In pvdhps gene a significant number of isolates (17.31 %) in KMC contained the double mutant S373E380S382G383P384K512G553V585M601 allele. pvdhfr and pvdhps combination haplotype revealed the emergence of quadruple (13.46 %) and quintuple (3.84 %) mutant allele in KMC, which might result in poor clinical response against antifolate drugs.ConclusionThe study reveals that P. vivax parasites in rural Purulia may still be susceptible to SP but additional caution should be taken for treatment of vivax malaria in KMC to limit the blooming of quadruple and quintuple mutant allele in the remainder of the West Bengal, India.

Highlights

Emergence of chloroquine resistant Plasmodium vivax is a serious obstacle towards malaria control in India
Polymorphism in pvdhfr S58R and S117N are highly associated with pyrimethamine resistance; additional mutation in P33L, N50I, F57L, T61M, V64L, and I173L codons increases the degree of resistance, i.e., very high IC50 values for pyrimethamine [14,15,16,17]
Different field studies suggest that polymorphism at A383G and A553G of pvdhps gene are solely responsible for sulfadoxine resistance while additional mutations at S373T, E380K, S382A, P384L, K512E, V585G, and M601I codons confer higher levels of resistance [18, 19]

Summary

Introduction

Emergence of chloroquine resistant Plasmodium vivax is a serious obstacle towards malaria control in India. This study elucidates the temporal pattern of antifolate [sulfadoxine–pyrimethamine (SP)] resistance in P. vivax infection by means of genetic polymorphisms, especially analysing the single nucleotide polymorphisms of dihydrofolate reductase (pvdhfr) and dihydropteroate synthase (pvdhps) gene among the field isolates of urban Kolkata Municipal Corporation and rural Purulia region of West Bengal, India. In the case of P. falciparum infection, SP resistance has been predominantly observed with the polymorphism of dihydrofolate reductase (dhfr) and dihydropteroate synthase (dhps) genes, throughout the globe [8,9,10,11,12,13]. Predominance of pvdhfr codon S58R and S117N polymorphisms and pvdhps codon A383G mutation in clinical isolates was reported in studies, mainly from central, western, northern and south eastern regions of India [7, 20, 21], before the introduction of a new national drug policy. In 2010, 1.6 million confirmed malaria cases were reported in India; 134,795 patients were from West Bengal [1, 22]

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