O_(139,142,26)混合血清型大肠杆菌的O-抗原基因簇的破译

Sequence and analysis of O-antigen gene cluster in Escherichia coli O_(139,142,26)

应用鸟枪法扩增了一株从水肿病病死猪肠系膜淋巴结分离到的O混合血清型(O139,142,26)大肠杆菌的O-抗原基因,测序结果显示扩增的O-抗原基因长度为11 771 bp。通过生物信息学的方法对其结构进行分析,发现其具有10个开放阅读框架及功能基因种类。经与发表的大肠杆菌O139、O26和O142的O-抗原基因序列及O-抗原糖基链的结构进行比对,进化树分析,跨膜蛋白的结构分析以及对乳糖前体(Glc)添加乙酰基的机制分析,结果表明,该O混合血清型大肠杆菌的O-抗原基因与大肠杆菌O139的O-抗原基因进化关系最近。

The O-antigen gene of Escherichia coli O139,142,26 was amplified by the shotgun method,which was isolated in the mesenteric lymph node from a dead pig due to the edema disease.The sequencing results showed that the length of O-antigen gene was 11 771 bp.Ten open reading frames and their functions were found and predicted by bioinformatics methods.By comparing with the O-antigen gene sequences and the structure of glycosyl chain among the Escherichia coil.O139,O142 and O26,analyzing the phylogenetic tree,transmembrane protein structure and the process of adding acetyl to lactose precursors（Glc）,the results indicated that the Escherichia coli O139,142,26 and the Escherichia coli O139 had a close evolutionary relationship of O-antigen gene.