High prevalence of Pfdhfr-Pfdhps quadruple mutations associated with sulfadoxine-pyrimethamine resistance in Plasmodium falciparum isolates from Bioko Island, Equatorial Guinea
High prevalence of Pfdhfr-Pfdhps quadruple mutations associated with sulfadoxine-pyrimethamine resistance in Plasmodium falciparum isolates from Bioko Island, Equatorial Guinea
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赤道几内亚比奥科岛恶性疟原虫中与磺胺多辛-乙胺嘧啶耐药性相关的 Pfdhfr-Pfdhps 四重突变的高发生率
DOI：
10.1186/s12936-019-2734-x
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发表时间：
2019-03-26
期刊：
影响因子：
3
通讯作者：
Li, Jian
中科院分区：
文献类型：
--
作者：
Jiang, Tingting;Chen, Jiangtao;Li, Jian
背景在非洲，磺胺多辛-乙胺(SP)被推荐用于疟疾的间歇预防性治疗。然而，SP抵抗(SPR)的增加影响SP的治疗效果。二氢叶酸还原酶(Pfdhfr)和二氢翼酸合成酶(Pfdhps)基因作为分子标记被广泛应用于SPR监测。本研究旨在评估来自赤道几内亚比奥科岛的恶性疟原虫分离株中Pfdhfr和Pfdhps基因突变及单倍型的发生率。用套式聚合酶链式反应和Sanger测序方法检测Pfdhfr和Pfdhps基因的单核苷酸多态。结果分别从92.78%(167/180)和87.78%(158/180)的样本中扩增出Pfdhfr和Pfdhps基因序列。Pfdhfr分别有97.60%(163/167)、87.43%(146/167)和97.01%(162/167)携带N51I、C59R和S108N突变等位基因。Pfdhps S436A、A437G、K540E、A581G和A613S突变的发生率分别为20.25%(32/158)、90.51%(143/158)、5.06%(8/158)、0.63%(1/158)和3.16%(5/158)。总共在Pfdhfr基因座上发现了3种独特的单倍型，在Pfdhps基因座上发现了8种单倍型。Pfdhfr基因三重突变(CIRNI)是Pfdhfr中最常见的单倍型(86.83%)，单突变单倍型(SGKAA；62.66%)在Pfdhp中占主导地位。在Pfdhfr和Pfdhps组合单倍型中，共有130株分离株具有12种独特的单倍型，其中65.38%(85/130)携带四重等位基因组合(CIRNI-SGKAA)，而只有1株(0.77%，1/130)携带野生型(CNCSI-SAKAA)。在LD分析中，Pfdhfr N51I与Pfdhps A437G显著相关(P
BackgroundSulfadoxine-pyrimethamine (SP) is recommended for intermittent preventive treatment of malaria in Africa. However, increasing SP resistance (SPR) affectsthe 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).MethodsIn 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.ResultsSequences 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 (CIRNI) in Pfdhfr was the most prevalent haplotype (86.83%), and a single mutant haplotype (SGKAA; 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 (CIRNI-SGKAA), 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