[Analysis of drug - resistant gene polymorphisms in Plasmodium falciparum imported from Equatorial Guinea to Shandong Province in 2015 and 2016].

Objective To investigate the drug-resistant gene polymorphisms in Plasmodium falciparum imported from Equatorial Guinea to Shandong Province. Methods From 2015 to 2016, blood samples were collected from imported P. falciparum malaria patients returning from Equatorial Guinea to Shandong Province, and genome DNA of the malaria parasite was extracted. The drug-resistant Pfcrt , Pfmdr1 , Pfdhfr , Pfdhps , and K13 genes of P. falciparum were amplified using a PCR assay, followed by DNA sequencing, and the sequences were aligned. Results The target fragments of all 5 drug-resistant genes of P. falciparum were successfully amplified and sequenced. There were 72.8%, 18.6%, and 8.6% of P. falciparum parasites carrying the wild-, mutant-, and mixed-type Pfcrt gene, respectively, and all mutant haplotypes were CVI ET (the underline indicates the mutation site). There were 20.0%, 61.4% and 18.6% of P. falciparum parasites carrying the wild-, mutant-, and mixed-type Pfmdr1 gene, respectively, and the mutant haplotypes mainly included YF and NF (the underlines indicate the mutation sites). There were 1.4%, 98.6%, and 0 of P. falciparum parasites carrying the wild-, mutant-, and mixed-type Pfdhfr gene, respectively, and A IRN I was the predominant mutant haplotype (the underline indicates the mutation site). There were 1.4%, 94.3%, and 4.3% of P. falci parum parasites carrying the wild-, mutant-, and mixed-type Pfdhps gene, respectively, and S G KAA was the predominant mutant haplotype (the underline indicates the mutation site). The complete drug-resistant IRNGE genotype consisted of 8.6% of the Pfdhfr and Pfdhps genes, and the K13 gene A578S mutation occurred in 1.4% of the parasite samples. Conclusion There are mutations in the Pfcrt , Pfmdr1 , Pfdhfr , Pfdhps , and K13 genes of P. falciparum imported from Equatorial Guinea to Shandong Province, with a low frequency in the Pfcrt gene mutation and a high frequency in the Pfmdr1 , Pfdhfr , and Pfdhps gene mutations, and the K13 gene A578S mutation is detected in the parasite samples. ［摘要］ 目的 了解山东省由赤道几内亚输入的恶性疟原虫抗性基因多态性情况。 方法 采集2015—2016年山东省 由赤道几内亚务工返乡的输入性恶性疟患者血样, 提取疟原虫基因组DNA, 对恶性疟原虫抗性基因 Pfcrt 、 Pfmdr1 、 Pfdhfr 、 Pfdhps 、 K13 进行套式PCR扩增、DNA测序和序列对比分析。 结果 全部样本5种抗性基因目的片段均成功扩增和测序。 Pfcrt 野生型、突变型、混合型分别占72.8%、18.6%、8.6%, 突变型全部为CVIET (下划线表示突变位点, 下同) ; Pfmdr1 野生 型、突变型、混合型分别占20.0%、61.4%、18.6%, 突变型主要为YF和NF; Pfdhfr 野生型、突变型、混合型分别占1.4%、 98.6%、0, 突变型主要为AIRNI; Pfdhps 野生型、突变型、混合型分别占1.4%、94.3%、4.3%, 突变型主要为SGKAA; Pfdhfr 和 Pfdhps 完全抗性基因型IRNGE占8.6%; 1.4%的样本 K13 基因发生A578S突变。 结论 山东省由赤道几内亚输入的恶性 疟原虫 Pfcrt 、 Pfmdr1 、 Pfdhfr 、 Pfdhps 、 K13 基因均发生不同程度突变; Pfcrt 突变型比例较低, Pfmdr1 、 Pfdhfr 、 Pfdhps 突变型比 例较高; 检测到 K13 基因发生A578S突变。