沈阳地区2013-2017年手足口病肠道病毒柯萨奇A组6型的分子流行病学研究

摘要

目的 明确沈阳地区柯萨奇病毒A组6型(coxackievirus A6,CV-A6)的流行特点和基因特征.方法 收集2013-2017年沈阳地区手足口病非EV-A71非CV-A16肠道病毒阳性标本,应用荧光定量PCR方法进行CV-A6核酸的检测,对阳性标本进一步应用传统RT-PCR方法针对VP1全长基因进行扩增、序列测定和系统进化分析.结果 沈阳地区2013-2017年间CV-A6占肠道病毒阳性标本的27.83％ (575/2 066),2015年达68.38％ (240/351)成为绝对优势流行株.进化分析表明,沈阳地区毒株均位于D3a分支上,其中2013-2014年毒株分别位于D3a.1和D3a.2分支上,而2015-2017年毒株均位于D3a.2分支上.结论 CV-A6为近年来沈阳地区手足口病的主要病原之一,沈阳地区CV-A6毒株以D3亚群为主,且已由D3a.1分支进化到D3a.2分支.%Objective To study the epidemiologic and genetic characteristics of coxackievirus A6 (CV-A6) strains isolated in Shenyang.Methods Enterovirus strains positive for neither enterovirus A71 (EV-A71) nor CV-A16 were isolated from Shenyang during 2013 to 2017 to screen for CV-A6 isolates by real-time PCR.The entire sequences of viral genes encoding VP1 of CV-A6 positive samples were amplified and sequenced.The phylogenetic analysis was performed.Results CV-A6 strains accounted for 27.83％ (575/2 066) of the non-EV-A71 and non-CV-A16 enterovirus strains isolated in Shenyang during the years 2013 to 2017.And CV-A6 strains were the predominant enterovirus strains with positive rate of 68.38 ％ (240/351) in 2015.The CV-A6 isolates from Shenyang during 2013 to 2017 could be classified into the cluster D3a in the phylogenetic tree.Subtype D3a.1 strains circulated during 2013 to 2014 and subtype D3a.2 strains circulated during 2015 to 2017.Conclusions CV-A6 strains were the predominant enterovirus strains among non-EV-A71 and non-CV-A16 enterovirus strains circulated in Shenyang from 2013 to 2017.The CV-A6 isolates from Shenyang during 2013 to 2017 could be classified into the cluster D3a in the phylogenetic tree and subtype D3a.2 strains were evolved from subtype D3a.1 strains.