一株不产志贺毒素的肠出血性大肠杆菌O157:H7菌株的鉴定

目的 对一株不产志贺毒素的肠出血性大肠杆菌O157:H7菌株进行血清生化特征及毒力基因鉴定.方法 对154菌株进行常规血清生化鉴定,使用聚合酶链反应(PCR)方法检测该菌的志贺毒素基因及其他毒力因子,同时以southern杂交、Hela细胞毒实验进行证实.结果 菌株154的志贺毒素PCR检测、shouthern杂交为阴性,Hela细胞毒定量结果显示该菌株不产生志贺毒素,毒力因子eae,hly检测为阳性.结论 菌株154是不产志贺毒素的肠出血性大肠杆菌O157:H7菌株,且具有O157:H7菌株特异性的毒力因子.

Identification of a non-Shiga toxin-producing Enterohemorrhagic Escherichia coli O157:H7 strain

Objective The present investigation was conducted to identify the serological and biochemical characteristics of an non-Shiga toxin-producing Enterohemorrhagic Escherichia coli O157:H7 and its gene of toxicity. Methods The strain 154 was identified with routine serological and biochemical assays,and PCR,southern blot and Hela cell cytotoxicity assay were conducted to identify the specific gene of strain 154. Results PCR,southern blot and Hela cell cytotoxicity assay for Shiga toxin were negative,toxic factors of eae and hly were tested positive. Conclusion Strain 154 is an non-Shiga toxin producing Enterohemorrhagic Escherichia coli O157:H7 strain with specific toxic factors of O157:H7.