青海省2016-2017年人肠道病毒A组71型基因特征

Genetic characteristics of human enterovirus A type 71 in Qinghai province during 2016-2017

目的对青海省2016-2017年手足口病（hand，foot and mouth disease，HFMD）人肠道病毒A组71型（human enterovirus group A type71，EV—A71）的基因特征进行分析。方法对青海省2016-2017年采集的HFMD标本，用荧光定量逆转录-聚合酶链反应（reverse transcription．polymerase chain reaction，RT—PCR）方法进行筛查，对EV—A71阳性标本进行病毒分离，对分离到的病毒提取核酸，用RT—PCR方法对VPl编码区进行扩增及核苷酸序列测定和分析，并与EV．A71各基因型和基因亚型的代表株序列构建亲缘关系进化树。结果青海省2016-2017年共分离到114株EV-A71，均为C4基因亚型中的C4a进化分支。在亲缘性关系树中显示，又进一步分属2个不同的小分支。2016-2017年青海省流行的不同传播链上EV—A71与我国其他省流行的EV-A71基因亲缘关系较为接近。结论青海省2016-2017年流行的EV—A71以C4a为绝对优势基因亚型，未监测到其他基因型病毒。青海省EV—A71不是独立进化的，而是与我国其他地区流行的EV—A71共同进化。

Objective To investigate the genetic characteristics of enterovirus A 71 （ EV-A71 ） and etiological features of hand, foot and mouth disease （HFMD） in Qinghai province from 2016 to 2017. Methods Specimens were collected from HFMD patients in Qinghai province, and detected by real-time reverse transcription-polymerase chain reaction （RT-PCR）. For EV-A71 positive samples,virus was isolated and RNA was extracted, and then VP1 coding region was amplified by RT-PCR. The phylogenetic tree was constructed by comparing with other genotypes and sub-genotypes strains of EV-ATI. Results It was shown that 114 strains of EV-AT1 were isolated in Qinghai province from 2016 to 2017, which all belonged to genotype C4a, and could be divided to two different lineages by phylogenetic analysis. From 2016 to 2017, the epidemic strains of EV-A71 in the different transmission chains of Qinghai province was closely related to other provinces of China. Conclusions C4a was the dominant genotype of EV-A71 in Qinghai province from 2016 to 2017, and no other genotype was detected. In addition, EV-A71 isolated from Qinghai province co-evolved with EV-AT1 in other provinces of China.