柯萨奇病毒A组天津分离株的分型鉴定及分子特征分析

摘要

目的 鉴定天津市手足口病病原体柯萨奇病毒A组2、4、5、6和10型,并分析其VP1区基因及分子流行病学特征.方法 提取45株非EV71非CV-A16肠道病毒分离株核酸,利用RT-PCR法扩增其VP1基因并测序,然后根据VP1区基因核酸序列,进行肠道病毒型别鉴定和同源性分析,构建种系发生树.结果 45株非EV71非CV-A16肠道病毒天津分离株分别为6株柯萨奇病毒A组2型(Coxsackie virus A2,CV-A2),14株CV-A4,3株CV-A5,8株CV-A6和14株CV-A10.柯萨奇病毒各型的株间核酸序列同源性均在80％以上,各型分离株与原型株的同源性均在71.2％ ～ 85.8％之间.天津各型分离株在种系发生树上均聚集于各自相对独立的分支,与国内流行株处在同一分支内,而与国外原型株处于不同的进化分支.结论柯萨奇病毒A组2、4、5、6和10型成为天津市手足口病的流行病原体,各型天津分离株株间核酸序列同源性较高,呈现一定的区域聚集性.%Objective To indentify the pathogens Coxsackievirus(CV) A2,A4,A5,A6 and A10 from the children patients with hand-foot-and-mouth disease (HFMD),and analyze the genetic and evalution characteristics.Methods Human enterovirus RNA of 45 non-enterovirus 71 or non-coxsackievirus A16 isolates were extracted,and viral VP1 genes of the isolates were amplified by RT-PCR and sequenced.Genotypes of the isolates were identified on the basis of the VP1 gene sequences.Phylogenetic tree of the isolates was constructed after homology analysis of the VP1 genes.Results The 45 non-enterovirus 71 or non-coxsackievirus A16 isolates from Tianjin included 6 CV-A2 isolates,14 CV-A4 isolates,3 CV-A5 isolates,8 CV-A6 isolates and 14 CV-A10 isolates.The nucleotide homologies of every genotype were more than 80％ between the isolates.The isolates of every genotype had a nucleotide homology of 71.2％-85.8％ with the prototype isolate respectively.The Tianjin isolates of every genotype were clustered in their respective independent branches with the domestic epidemic isolate,but not with the foreign prototype isolate of corresponding genotypes in the phylogenetic tree.Conclusions Coxsackievirus A2,A4,A5,A6 and A10 became the epidemic pathogens of HFMD in Tianjin.The Tianjin isolates of every Coxsackievirus genotype had high nucleotide homology and the characteristics of regional aggregation.