High prevalence of Pfdhfr–Pfdhps quadruple mutations associated with sulfadoxine–pyrimethamine resistance in Plasmodium falciparum isolates from Bioko Island, Equatorial Guinea

摘要: Sulfadoxine–pyrimethamine (SP) is recommended for intermittent preventive treatment of malaria in Africa. However, increasing SP resistance (SPR) affects the therapeutic efficacy the SP. As molecular markers, Pfdhfr (dihydrofolate reductase) and Pfdhps (dihydropteroate synthase) genes are widely used SPR surveillance. This study aimed to assess prevalence mutations haplotypes Plasmodium falciparum isolates collected from Bioko Island, Equatorial Guinea (EG). In total, 180 samples were 2013–2014. The single nucleotide polymorphisms (SNPs) identified with nested PCR Sanger sequencing. genotypes linkage disequilibrium (LD) tests also analysed. Sequences obtained 92.78% (167/180) 87.78% (158/180) samples, respectively. For Pfdhfr, 97.60% (163/167), 87.43% (146/167) 97.01% (162/167) carried N51I, C59R S108N mutant alleles, S436A, A437G, K540E, A581G, A613S observed 20.25% (32/158), 90.51% (143/158), 5.06% (8/158), 0.63% (1/158), 3.16% (5/158) 3 unique at locus 8 identified. A triple mutation (CIRNI) was most prevalent haplotype (86.83%), a (SGKAA; 62.66%) predominant Pfdhps. total 130 12 found combined haplotypes, 65.38% (85/130) them quadruple allele combinations (CIRNI-SGKAA), whereas only one isolate (0.77%, 1/130) carry wild-type (CNCSI-SAKAA). LD analysis, N51I significantly associated A437G (P < 0.05). Island possesses high (SGKAA), which will undermine pharmaceutical effect strategies. To avoid an increase SPR, continuous monitoring additional control efforts urgently needed Guinea.