Yan H, Wang X X, Feng J, Zhang L, Yin J H, Li M, Xia Z G, Huang F
National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention; Chinese Center for Tropical Diseases Research; WHO Collaborating Centre for Tropical Diseases; National Center for International Research on Tropical Diseases, Ministry of Science and Technology; Key Laboratory of Parasite and Vector Biology, National Health Commission, Shanghai 200025, China.
Zhongguo Xue Xi Chong Bing Fang Zhi Za Zhi. 2020 Mar 25;32(2):174-180. doi: 10.16250/j.32.1374.2019277.
To detect the chloroquine-resistant molecular marker polymorphisms in imported into China, investigate the mutation types of chloroquine resistant transporter () gene at positions 72 to 76, and analyze the specificity of the specimens with different origins.
A total of 674 filter paper blood samples were collected from the National Malaria Diagnosis Reference Laboratory of China in 2012 and 2018. The amino acid po- sitions 72 to 76 of the gene on chromosome 7 were amplified using nested PCR assay and sequenced, and the sequencing results of the target gene fragment and the geographical region-specific prevalence of the mutations in the gene were analyzed.
Among the 674 imported malaria cases in China in 2012 and 2018, 99.5% (644/674) were from Africa, which were predominantly from western and central Africa (80.4%, 518/644), and 4.5% (30/674) from Southeast Asia and Oceania (Papua New Guinea). A total of 4 site mutations (C72S, M74I, N75E and K76T) and 5 haplotypes (CVMNK, CVIET and SVMNT and two mixed types) were identified, with haplotypes CVMNK and CVIET present in parasites of both African and Southeast Asian origins, SVMNT detected in Southeast Asia (Myanmar) and Papua New Guinea isolates, the mixed type of haplo- types CVMNK/CVIET detected in of African and Southeast Asian origins, and the mixed type of haplotypes CVMNK/SVMNT detected only in the Myanmar isolate. Most parasites of the African origin carried the wild-type allele (77.7%, 478/615), and 68.0% (17/25) of the parasites of the Southeast Asian and Papua New Guinea or- igins harbored chloroquine resistant molecular markers ( = 28.5, < 0.05). The constituent ratio of the wild- and mutant-type allele varied in different geographical regions of Africa ( < 0.01), and the lowest prevalence of the wild-type allele was seen in western Africa.
Among the 674 imported malaria cases in China in 2012 and 2018, the imported from Sotheast Asia habors a higher proportion of resistance to chloroquine and a higher molecular polymophism at ami- no acid positions 72 to 76 of the gene than the parasite of the African origin.
检测输入我国的疟原虫氯喹抗性分子标记多态性，调查氯喹抗性转运蛋白（）基因第72至76位的突变类型，并分析不同来源标本的特异性。
2012年和2018年从中国国家疟疾诊断参考实验室共收集674份滤纸血样。采用巢式PCR扩增7号染色体上基因的第72至76位氨基酸，并进行测序，分析目标基因片段的测序结果以及该基因中突变的地理区域特异性流行情况。
在2012年和2018年我国输入的674例疟疾病例中，99.5%（644/674）来自非洲，主要来自非洲西部和中部（80.4%，518/644），4.5%（30/674）来自东南亚和大洋洲（巴布亚新几内亚）。共鉴定出4个位点突变（C72S、M74I、N75E和K76T）和5种单倍型（CVMNK、CVIET、SVMNT以及两种混合型），非洲和东南亚来源的疟原虫中均存在单倍型CVMNK和CVIET，东南亚（缅甸）和巴布亚新几内亚分离株中检测到SVMNT，非洲和东南亚来源的中检测到单倍型CVMNK/CVIET的混合型，仅在缅甸分离株中检测到单倍型CVMNK/SVMNT的混合型。大多数非洲来源的疟原虫携带野生型等位基因（77.7%，478/615），东南亚和巴布亚新几内亚来源的疟原虫中有68.0%（17/25）携带氯喹抗性分子标记（=28.5，<0.05）。非洲不同地理区域野生型和突变型等位基因的构成比有所不同（<0.01），野生型等位基因在西非的流行率最低。
在2012年和2018年我国输入的674例疟疾病例中，与非洲来源的疟原虫相比，东南亚输入的疟原虫对氯喹的抗性比例更高，且在基因第72至76位氨基酸处的分子多态性更高。
