牛源大肠杆菌O157:H7的分离鉴定

为调查新疆部分地区E.coli O157：H7的感染情况和菌株致病性，从新疆阿克苏、伊犁、塔城3个地区的牛场采集新鲜粪样564份，对E.coli O157：H7进行分离与鉴定。利用E.coli营养肉汤（EC肉汤）对样品进行增菌后，用山梨醇麦康凯培养基（SMAC）平板选择性培养，再经过4-甲基伞形酮-β-D葡萄糖醛酸苷培养基（MUG）的筛选，对疑似菌株进行生化和PCR鉴定，并将分离鉴定到的菌株进行小鼠攻毒试验。结果显示，从伊犁地区采集的样品中共分离出2株E.coli O157：H7（Y166和Y226），其检出率为0.88%；小鼠攻毒试验中，Y166和Y226试验组小鼠在48 h内全部死亡，具有一定致病性；从阿克苏、塔城所采样品中未分离到E.coli O157：H7。

Isolation and Identification of Escherichia coli O157: H7 from Cattle

The objective of this study was to investigate the infection and pathogenicity of E.coli O157:H7 from 564 fecal samples in three parts of Xinjiang,such as Akesu,Yili and Tacheng.Suspected strains were detected by biochemical and PCR after enrichment by EC broth,being chosen by SMAC plate and screened by MUG test.On the basis of this,the isolated strains were used in mice attack drug test.The results showed that there were two strains of E.coli O157:H7 (named Y166 and Y226,respectively) were isolated from the collected samples of Yili,and the detection rate was 0.88%.In the mice attack drug test,the mice of Y166 and Y226 groups were all died within 48 h.In conclusion,two strains of E.coli O157:H7 were isolated and identified with pathogenic from samples in Yili area,and no E.coli O157:H7 were identified in the samples from Akesu and Tacheng.