Polymorphism Analysis of pfmdr1 and pfcrt from Plasmodium falciparum Isolates in Northwestern Nigeria Revealed the Major Markers Associated with Antimalarial Resistance.

Ruqayya Adam,Sulaiman S Ibrahim,Abdullahi Muhammad,Muhammad M Mukhtar,Umar F Abubakar,Hajara A Damudi

doi:10.3390/diseases9010006

Abstract

Suspicion of failure in the effectiveness of artemisinin-based combination therapies (currently the first-line treatment of malaria, worldwide) is leading to the unofficial use of alternative antimalarials, including chloroquine and sulfadoxine/pyrimethamine, across northern Nigeria. To facilitate evidence-based resistance management, antimalarial resistance mutations were investigated in Plasmodium falciparum multidrug resistance-1 (pfmdr1) and chloroquine resistance transporter (pfcrt), in isolates from Kano, northwestern Nigeria. Out of the 88 samples genotyped for pfmdr1 N86Y mutation using PCR/restriction fragment length polymorphism, one sample contained the 86Y mutation (86Yfrequency = 1.14%). The analysis of 610 bp fragments of pfmdr1 from 16 isolates revealed two polymorphic sites and low haplotype diversity (Hd = 0.492), with only 86 Y mutations in one isolate, and 184 F replacements in five isolates (184Ffrequency = 31.25%). The analysis of 267 bp fragments of pfcrt isolates revealed high polymorphism (Hd = 0.719), with six haplotypes and seven non-synonymous polymorphic sites. Eleven isolates (61.11%) were chloroquine-resistant, CQR (C72V73I74E75T76 haplotype), two of which had an additional mutation, D57E. An additional sequence was CQR, but of the C72V73M74E75T76 haplotype, while the rest of the sequences (33.33%) were chloroquine susceptible (C72V73M74N75K76 haplotype). The findings of these well characterized resistance markers should be considered when designing resistance management strategies in the northwestern Nigeria.

Highlights

Malaria killed approximately 405,000 people in 2018, of which 93% were in subSaharan Africa [1]
Antimalarials and vector control had significantly reduced malaria mortality in the last two decades [1,2], but antimalarial resistance is one of the problems stalling the progress of malaria control [3]
The P. falciparum multidrug resistance-1 transporter, shown to be involved in the modulation of resistance/susceptibility to several antimalarial drugs [10] and the implementation of artemisinin-based combination therapy (ACT) shown to select for pfcrt mutations, and treatment failure with the ACT partner drug amodiaquine [11,12,13]

Summary

Introduction

Malaria killed approximately 405,000 people in 2018, of which 93% were in subSaharan Africa [1]. A recent metadata analysis by the WorldWide Antimalaria Resistance Network (WWARN) has reported that kelch mutations in African sites remained at very low prevalence, generally below 3%, and there is still no evidence of slow-clearing parasites or selection for mutant parasites [9]. This suggests that in Africa, different resistance mechanisms could be responsible for artemisinin resistance. The P. falciparum multidrug resistance-1 transporter (pfmdr1), shown to be involved in the modulation of resistance/susceptibility to several antimalarial drugs [10] and the implementation of ACT shown to select for pfcrt mutations, and treatment failure with the ACT partner drug amodiaquine [11,12,13]

Methods

Results

Discussion

Conclusion