Prevalence of molecular markers of sulfadoxine–pyrimethamine and artemisinin resistance in Plasmodium falciparum from Pakistan

Abstract

BackgroundIn Pakistan, artesunate (AS) in combination with sulfadoxine–pyrimethamine (SP) is the recommended treatment for uncomplicated Plasmodium falciparum malaria. Monitoring molecular markers of anti-malarial drug resistance is crucial for early detection and containment of parasite resistance to treatment. Currently, no data are available on molecular markers of artemisinin resistance (K13 mutations) in P. falciparum isolates from Pakistan. In this study, the prevalence of mutations associated with SP and artemisinin resistance was estimated in different regions of Pakistan.MethodsA total of 845 blood samples that were positive for malaria parasites by microscopy or rapid diagnostic test were collected from January 2016 to February 2017 from 16 different sites in Pakistan. Of these samples, 300 were positive for P. falciparum by PCR. Polymorphisms in the P. falciparum dihydrofolate reductase (pfdhfr) and dihydropteroate synthase (pfdhps) genes were identified by pyrosequencing while polymorphisms in the propeller domain of the pfk13 gene were identified by Sanger sequencing.ResultsThe prevalence of the PfDHFR 108N and 59R mutations was 100% and 98.8%, respectively, while the prevalence of PfDHFR 50R and 51I mutations was 8.6%. No mutation was observed at PfDHFR position 164. In PfDHPS, the prevalence of mutations at positions 436, 437, and 613 was 9.9%, 45.2%, and 0.4%, respectively. No mutations were found at PfDHPS positions 540 and 581. The prevalence of double PfDHFR mutants (59R + 108N) ranged from 93.8% to 100%, while the prevalence of parasites having the PfDHFR 59R + 108N mutations in addition to the PfDHPS 437G mutation ranged from 9.5% to 83.3% across different regions of Pakistan. Nine non-synonymous and four synonymous mutations were observed in the PfK13 propeller domain, none of which correspond to mutations validated to contribute to artemisinin resistance.ConclusionThe absence of the highly resistant PfDHFR/PfDHPS quintuple mutant parasites and the lack of PfK13 mutations associated with artemisinin resistance is consistent with AS + SP being effective in Pakistan.Electronic supplementary materialThe online version of this article (10.1186/s12936-018-2620-y) contains supplementary material, which is available to authorized users.

Molecular Detection of Antimalarial Drug Resistance in Plasmodium vivax from Returned Travellers to NSW, Australia during 2008–2018

“…Other studies have found that all three types are present in India [54,55], whereas Indonesia, Thailand and South Korea have only Type 1 and Type 2 [7,52]. The role of the tandem repeat variants in SP resistance remains unclear [7,56] as these variants are not present in the Pfdhfr gene in P. falciparum [26,57]. However, Type 3 variants were exclusively linked to the L/I57:R58:M61:T117 mutations, which are associated with pyrimethamine resistance in P. vivax.…”

Stable high frequencies of sulfadoxine–pyrimethamine resistance associated mutations and absence of K13 mutations in Plasmodium falciparum 3 and 4 years after the introduction of artesunate plus sulfadoxine–pyrimethamine in Ujjain, Madhya Pradesh, India

“…Due to spreading chloroquine resistance most of the remainder of India adopted ASP as first-line treatment by 2012. ASP is similarly recommended in neighbouring Pakistan [5]. There is thus considerable regional artemisinin and SP drug pressure and consequently a high risk of resistance spreading further.…”

Characterization of putative drug resistant biomarkers in Plasmodium falciparum isolated from Ghanaian blood donors

“…In this study, five non-synonymous mutations P615L, A578S, I543V, A676S and C580Y were identified in the Kelch 13 gene. The P615L mutation was detected in Pakistan [33]. Also, A676S has been identified in Africa and South-East Asia [34].…”