Pfmdr1 gene polymorphism of Plasmodium falciparum isolates from asymptomatic individuals of Dienga, southeastern Gabon

Abstract

Background: In Gabon, studies on molecular epidemiology of malaria are mainly confined to urban and hospital settings; contrasting with rural areas where data are scarce, especially on asymptomatic P. falciparum infection. In this study, the polymorphism of P. falciparum multidrug resistance -1 gene (Pfmdr1) was investigated for the first time in P. falciparum specimens from asymptomatic individuals living in Dienga, a rural area in southeastern Gabon. Methods: P. falciparum specimens collected in 2013 and 2014 and diagnosed by standard microscopy (microscopic infection=MI) or by PCR (submicroscopic infection=SMI) were used in this study. The codons 86, 184 and 1246 of Pfmdr1 of P. falciparum specimens were genotyped by PCR and RFLP. Results: Among the three codons 86, 184 and 1246 of Pfmdr1, the wild-type alleles were the most prevalent in 2014. The frequency of mixed genotype N86Y was 19.23% in 2013 and 25.28% in 2014. The frequency of D1246Y mixed genotype was 10.40% in 2013 and 17.24% in 2014. On the other hand, no mixed genotype was observed for the codon 184. The most frequent haplotypes identified were NFY (33%) in 2013 and YYD (30.0%) in 2014. The frequencies of other haplotypes (YYY, YFD, NYD, YFY, NFD and NYY) did not show significant difference between 2013 and 2014. Conclusion: Data from Dienga showed moderate variations in the distribution of Pfmdr1 genotypes and a high haplotype diversity suggesting the low ACT drug pressure on parasites in this locality.