Genetic association between the Pfk13 gene mutation and artemisinin resistance phenotype in Plasmodium falciparum isolates from Yunnan Province, China
Genetic association between the Pfk13 gene mutation and artemisinin resistance phenotype in Plasmodium falciparum isolates from Yunnan Province, China
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中国云南省恶性疟原虫Pfk13基因突变与青蒿素耐药表型的遗传关联
DOI：
10.1186/s12936-018-2619-4
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发表时间：
2018-12-18
期刊：
影响因子：
3
通讯作者：
Xue, Jingpo
中科院分区：
文献类型：
--
作者：
Dong, Ying;Wang, Jian;Xue, Jingpo
背景：抗疟药耐药问题是云南省疟疾防治面临的长期挑战。近年来，抗氯喹分子标记（恶性疟原虫抗氯喹转运蛋白，Pfcrt）和抗青蒿素分子标记（恶性疟原虫kelch 13基因，ork 13）的检出率分别为85%和35%。为了解k13基因突变与恶性疟青蒿素耐药的关系，分析云南省2013 - 2015年连续确诊的所有恶性疟病例和缅甸拉扎尔发现的部分恶性疟病例k13基因在两个人群中的分化差异及对青蒿素耐药的表型。对前者进行k13基因突变的分子流行病学分析，对后者采用世界卫生组织推荐的体内检测方法观察恶性疟原虫青蒿素耐药表型。结果：云南省202份恶性疟患者血样和缅甸382份恶性疟患者血样均获得阳性结果，其中云南省202份，缅甸382份。通过全疗程观察，对382例缅甸病例中的49例进行了青蒿琥酯耐药表型体内检测。同时对所有受检者进行恶性疟原虫k13基因突变筛查。云南疟原虫k13基因的遗传多样性高于缅甸疟原虫。两个群体的遗传分化指数为0.0410，群体内变异和群体间变异分别为95.9%和4.1%。缅甸病例的青蒿素耐药表型与k13基因446位点突变的比值比为1.640，而根据12个位点突变的估计值为1.840.结论：云南省疟原虫分离株与缅甸疟原虫分离株虽来自不同地点，但仍属于同一地理种群。因此，将缅甸疟原虫种群的青蒿素抗性状况与云南省疟原虫种群的青蒿素抗性状况进行对比是合理的。结果表明，云南省疟原虫k13位点突变的分子流行病学调查和缅甸恶性疟病例青蒿素耐药的测定结果表明，k13位点突变与青蒿素耐药表型呈正相关。通过检测云南省疟原虫k13基因部分分子标记，为进一步监测云南省疟原虫对青蒿素的抗药性提供了依据。
Background:The problem of anti-malarial drug resistance is a long-term challenge faced by malaria control in Yunnan Province. Recently, the detection rates of chloroquine-resistant molecular markers (Plasmodium falciparum chloroquine resistant transporter, Pfcrt) and artemisinin-resistant molecular markers (P. falciparum kelch13 gene, ork13) were 85% and 35%, respectively. To understand the association of k13 gene mutation with artemisinin resistance in falciparum malaria cases, the difference in k13 gene differentiation between two populations and artemisinin resistance phenotype on falciparum malaria cases in Myanmar were analysed in this study.Methods:This research involved all of falciparum malaria cases diagnosed continuously in Yunnan Province from 2013 to 2015 and some of falciparum malaria cases found in Lazar, Myanmar. Blood samples were taken from the former group for molecular epidemiological analysis of k13 gene mutations, and artemisinin resistance phenotypes of P. falciparum were observed in the latter group using the in vivo testing method recommended by the World Health Organization. Nested PCR was used to amplify the propeller domain of the k13 gene in P. falciparum, followed by sequencing.Results:A total of 202 blood samples were collected from Yunnan Province and 382 blood samples were collected from falciparum malaria cases in Myanmar. 49 of 382 Myanmar cases were in vivo tested for artesunate resistance phenotype through full treatment course observation. At the same time, all the blood samples were screened for k13 gene mutation of P. falciparum. The genetic diversity of k13 was higher in the Plasmodium isolates from Yunnan Province than those from Myanmar cases. The genetic differentiation index of the two populations was 0.0410, where the intra- and inter-group variations were 95.9% and 4.1%, respectively. The odds ratio of artemisinin resistance phenotype and mutation at the locus 446 in k13 gene in Myanmar cases was 1.640, while the value was 1.840 based on the estimations of the mutations in the 12 loci.Conclusion:Although the Plasmodium isolates from Yunnan Province and those from Myanmar were collected from different sites, they still belong to the same geographical population. It is, therefore, reasonable to contrast the artemisinin resistance status of the Plasmodium population from Myanmar with the Plasmodium population from Yunnan Province. As a result, based on the molecular epidemiological investigation on k13 mutations of Plasmodium isolates in Yunnan Province and the determination of the artemisinin resistance on falciparum malaria cases in Myanmar, the positively genetic correlated was found between the k13 locus mutations with artemisinin resistance phenotype. This provides a basis for further monitoring the artemisinin resistance by detection some molecular markers in k13 gene of Plasmodium in Yunnan Province.