3株人源猪链球菌2型湖南株cps2J、gdh、ef基因进化分析

摘要

目的 对3株人源猪链球菌2 型(S.suis 2)湖南株(HNCS201001、HNCS201101、HNCS201102)cps2J、gdh、ef基因进行序列测定和进化分析,了解其变异和进化状况,为人感染S.suis疫情的防控提供数据.方法设计S.suis 2 cps2J、gdh、ef基因PCR引物,对HNCS201001、HNCS201101、HNCS201102株进行PCR扩增和序列测定,测序结果利用Lasergene 和Mega5软件进行分析.结果 cps2J、gdh、ef基因包含的完整开放阅读框( ORF) 分别为999 bp、1 347 bp、2 532 bp,分别编码333、448、843个氨基酸.在线BLAST 同源性分析表明,HNCS201001、HNCS201101、HNCS201102 株属于S.suis 2,3菌株cps2J、gdh、ef 基因组序列之间的核苷酸同源性均为100%;进化树显示,HNCS201001、HNCS201101、HNCS201102 株与国内外猪源和人源S.suis 2 菌株属于同一分支,同源性比较显示3株S.suis 2 湖南分离株cps2J、gdh、ef基因与其他国内外S.suis 株核苷酸序列同源性分别为99.8%~100%、96.4%~100%和99.7%~100%,氨基酸同源性分别为98.5%~100%、98.7%~100%和99.5%~100%.结论 3 株人源S.suis 2 湖南株cps2J、gdh、ef基因序列与国内外S.suis 2 菌株相应基因序列同源性高,变异程度小.%In order to explore the variation and evolutionary status of Streptococcus suis serotype 2 (S. suis 2) isolated in Hunan Province, gene sequences and evolution relationship of cps2], gdh and ef genes of HNCS201001, HNCS201101, and HNCS201102 of human-derived S. suis 2 strains were analyzed. PCR primers of cps2], gdh and ef genes of S. suis 2 were designed, and the genes of HNCS201001, HNCS201101, and HNCS201102 were amplified and sequenced. Then, the nucleotide sequences and the deduced amino acid sequences were analyzed with the Lasergene and Mega 5 software. Analysis of the nucleotide sequences of the cps2J, gdh and ef genes revealed that the length of open reading frames (ORF) were 999 bp, 1 347 bp, and 2 532 bp, coding for 333, 448 and 843 amino acid, respectively. Sequence similarity searches by using the BLAST network service showed HNCS201001, HNCS201101 and HNCS201102 strains belonged to S. suis 2 group, and the nucleotide homolo-gy of cps2], gdh and ef genes among the 3 strains were all 100% ; phylogenetic analysis revealed that the 3 strains in this study and the S. suis 2 strains derived from pigs and human isolated in mainland China and abroad belonged to the same branch. The cps2J, gdh and ef genes of the 3 strains of S. suis 2 isolated in Hunan Province had high homology with other S. suis strains isolated in mainland China and abroad (99. 8%-100% for cps2J gene, 96. 4%-100% for gdh gene, and 99. 7%-100% for ef gene at the nucleotide level; 98. 5%-100% for cps2J gene, 98. 7%-100% for gdh gene, and 99. 5%-100% for ef gene at the a-mino acid level, respectively). It's suggested that the cps2J, gdh and ef genes of the 3 human-derived S. suis 2 strains isolated in Hunan Province have high homology with other S. suis 2 strains isolated in mainland China and abroad, and have a low degree of variation in the gene sequences.