马链球菌马亚种新疆株SeM基因的克隆及序列差异分析

Cloning and Sequence Difference Analysis of the SeM Gene of Streptococcus equi subsp.equi Isolated in Xinjiang

为研究马链球菌马亚种新疆株SeM基因的分子特征,分析新疆地区马链球菌马亚种的分子流行特征以及为马腺疫的防治提供依据,对分离并鉴定的5株马链球菌马亚种提取基因组、扩增并克隆其SeM基因（GenBank登录号分别为：KJ486792、KJ486793、KJ486794、KJ486795、KJ486796）,采用生物信息学方法对该基因及其编码蛋白进行疏水性、抗原性及三级结构分析,并与Genbank登录菌株的SeM基因序列进行系统进化分析和比较。克隆获得的SeM基因长度为1 530bp,包含1个1 527bp的完整开放阅读框,编码509个氨基酸;新疆分离株SeM基因与Genbank登录分离株SeM基因同源性为98.0%~99.4%。结果表明,新疆分离株KJ486793、KJ486796与美国分离株亲缘关系较近,属同一个进化分支,另外3株新疆分离株KJ486792、KJ486795、KJ486794构成一个独立分支。

To analysis molecular epidemic characteristics of SeM gene of Streptococcus equi subsp.equi isolated in Xinjiang and its infection control,the SeM genes of 5 Streptococcus equi subsp.equi isolates were amplified,cloned into pMD18-T plasmid and sequenced（GenBank accession KJ486792,KJ486793,KJ486794,KJ486795,KJ486796）.Some molecular characters of SeM gene were analyzed by the bioinformatic methods.Sequence comparison and phylogenetic analysis of SeM gene between 5isolates and 7foreign isolates were performed.The results showed that the acquired SeM gene was1 530 bp,containing the complete coding region,which was 1 527 bp,econding 509 aa,the sequence homology of these strains was 98.0%-99.4% compared with other published reference strains in GenBank.Phylogenetic analysis revealed that KJ486793 and KJ486796were on the same branch,the other 3Xinjiang strains KJ486792,KJ486795,KJ486794 were on the same branch with US isolates.