English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

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

malaria journal

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