柯萨奇病毒B组3型的分子流行特征分析

Molecular evolution and genotyping analysis of coxsackievirus B3 strains in different countries

目的探讨已公布的不同国家不同时间分离的人类柯萨奇病毒B组3型(human coxsackievirus B3,CB3)VP1区基因特征和分子流行特点。方法在GenBank中用BLASTN软件搜索不同国家/地区、不同时间发表的CB3VP1区基因序列,共得到来自8个国家的92个可用序列,用MEGA软件计算不同毒株的核苷酸和氨基酸差异率,并构建系统进化树。结果 92株病毒可分为5个基因型(Genotype 1～5),基因型1由CB3原型株Nancy和3个法国株组成,基因型2由4株美国株组成,基因型3的地理分布最广,由德国、美国、罗马尼亚、法国、日本、荷兰、瑞典分离株组成,基因型4由5株中国台湾分离株组成,基因型5由中国山东株、云南株和台湾株组成,该基因型又分为A～E 5个亚型。不同毒株的核苷酸差异率为6.90%～24.64%(氨基酸差异率1.00%～10.20%),不同基因型之间的核苷酸差异率为15.91%～24.64%(氨基酸差异率4.02%～10.20%)。结论不同基因型/亚型可以在同一个地区流行很长时间,同一时间内不同的基因型/亚型又可在不同的地区流行,具有明显的时间和地域流行特点。

Objective To study the genetic variability and molecular features of coxsackievirus B3（CB3） strains isolated and identified in different countries.MethodsThe VP1 gene sequences of 92 CB3 strains isolated from 8 countries were obtained from GenBank.The nucleotide and amino acid diversity were analyzed to construct the phylogenetic tree using MEGA software.ResultsNinety-two CB3 strains from 8 countries were divided into 5 genotypes.Genotype I contained CB3 prototype strain Nancy and 3 French isolates.Four strains from United States and 5 from Taiwan,China were categorized into Genotype II and IV,respectively.Geographically,genotype III was more widely distributed in countries like Germany,USA,Romania,France,Japan,Netherlands and Sweden.Several strains from Shandong,Yunnan and Taiwan,China were grouped as genotype V which was further divided into 5 subgenotypes.The nucleotide and amino acid diversities among 92 CB3 strains were 6.90%-24.64% and 1.00%-10.20%,respectively.Genotype III had been widely distributed since 1970s in many Euopean countries especially Germany but kept very high homology of isolates from different times.Nine strains isolated in Taiwan,China before 2000 were genotypes V subtype C and D,while 12 isolates after 2000 were grouped as genotype V subtype B.Strains isolated from Yunnan and Shangdong,China from 1999 to 2002 were mostly genotype V subtype A,while shifted to subtype B isolates thereafter.ConclusionsThe geographic distribution of CB3 is various by countries or provinces in China for different genotypes of CB3 strains.Strains of a given genotype in the same area can either circulate constantly for ages or evolve into different subtypes in a short period.