2011年河南省脑炎患者柯萨奇病毒B5型分离株基因组序列分析

Genome sequences of coxsackievirus B5 isolated from viral encephalitis patients in Henan province, 2011

目的分析河南省柯萨奇病毒B5（CVB5）分离株全基因序列，了解其遗传特性。方法采集2例脑炎患者临床标本，分离病毒，提取病毒阳性分离物RNA，进行RT-PCR扩增，产物直接测序。利用DNAStar5．01和Mega5．05软件进行全基因序列拼接及亲缘进化分析。结果获得2株CVB5分离株（03001N和17Y）全基因组序列，核苷酸长度分别为7408bp和7404bp，两者核苷酸同源性为97％，同2010年河南CVB5分离株同源性最高，分别为98％和99％。5’-UTR分别为747bp和743bp；3’-UTR区均为103bp；病毒基因组编码区全长同为6558bp，编码含2185个氨基酸残基的多聚蛋白，氨基酸同源性为99％。VPl区系统发生树分析显示，2株CVB5分离株进化关系较近，同近年来国内其他分离株成一簇，而2009年的河南省CVB5分离株同山东省CVB5分离株成一簇。结论河南省内存在不同CVB5株传播链的流行，此次分离株为近几年内的主要流行株。

Objective To analyze the complete genome sequences of two coxsackievirus B5 （CVB5） isolated in Henan province, 2011. Methods Specimens were collected from viral encephalitis patients and followed by viral isolation on them. RNA were extracted from positive isolates and the amplified products were sequenced. The full-length genomes of them were acquired by assembling the fragments, using DNAStar 5.01 software while phylogenetic analysis were performed with Mega 5.05 and other software. Results The genomes RNA of 03001N and 17Y showed 7408 bp and 7404 bp long, and the 5＇- and 3＇-untranslated regions were 747 bp, 743 bp and 103 bp, 103 bp, respectively. BLAST analysis of these two isolates, based on the complete genome, showed 97% identity, with both of them having the highest similarity （ 98%, 99% ） to the CVB5 strain isolated from Henan in 2010 rather than other CVB5 strains. Coding regions of both isolates were 6558 bp, code for a polyprotein of 2185 amino acids （aa） and both of them showed 99% amino acid identity. Phylogenetic tree in VP1 region showed that the two isolates belonged to the same clade with other strains isolated from all over the country in the past years, except for some CVB5 strains isolated from Henan and Shandong province in 2009 that formed the other cluster. Conclusion It seemed that more than one group of CVB5 were circulating in Henan province and these two isolates appeared the main epidemic strains circulating in the past years.