一株混合O血清型猪水肿病大肠杆菌的分离与鉴定

Isolation and Identification of a Escherichia coli strain of Mixed O serotypes in piglet

从具有典型临床症状和病理剖检变化的病死猪肠系膜淋巴结中分离到的1株革兰阴性细菌,通过菌体形态观察,染色、生化试验、SLT-Ⅱe基因检测、O血清型鉴定、动物试验,其结果证明分离菌为O26、O139、O142混合血清型,产SLT-Ⅱe大肠埃希氏杆菌。SLT-Ⅱe基因序列与GenBank上发表的参考序列(序列号为AY368993)的同源性达100%。用粗提的毒素经腹腔注射小鼠后引起小鼠后肢麻痹、死亡和胃肠水肿。

A Gram-negative bacteria was isolated from the mesenteric lymph nodes of a dead weaning piglet. The bacterial strain was identified as a SLT- IIe producing Escherichia coli with mixed O serotypes after morphological observation, biochemical identification, PCR detection of SLT-IIe gene and identification of O serotype. The sequence of SLT- IIe gene of isolated strain was identical to the published sequences in GenBank （AY368993）. Injection mice with crude SLT- IIe produced hind limb paralysis, death and gastrointestinal edema.