三株O_(78)、O_(137)混合血清型鸡大肠埃希菌iss基因的序列分析

Sequnce Analysis of iss Gene in Three Avian Escherichia coli Strains O_(78) and O_(137)

采用1日龄雏鸡对3株O78、O137混合血清型鸡大肠埃希菌的致病性进行了测定,并扩增了iss基因。结果表明,3株O78、O137混合血清型鸡大肠埃希菌均对1日龄雏鸡具有较强的毒力。iss基因在3株O78、O137混合血清型鸡大肠埃希菌中的序列与已知的禽大肠埃希菌iss基因序列的同源性为100%,与人源大肠埃希菌iss基因序列的同源性为90.9%,显示了此基因的保守性。

3 avian Escherichia coli strains O78/O137 were studied. The virulence of each avian E. coli strain O78//O137 for 1-day-old chicks was detected, and each isolate was examined for the presence of iss gene using PCR techniques. Results showed that each avian E. coli strain O78/O137 was strongly virulent. The sequence of iss from each avian E. coli strain O78/O137 had 100% identity with AF042279 in GenBank and 90.9% identity with the iss gene from the human E. coli isolate. It suggested that iss gene might be highly conserved.