生鲜乳中大肠杆菌的分离及其ERIC-PCR指纹分析

Identification and Analysis on the DNA Fingerprints of E.coli in Fresh Milk Using ERIC-PCR

通过了解生鲜乳收购站的生鲜乳大肠杆菌污染情况及不同菌株间的遗传相似性,为日常生产中实时控制生鲜乳大肠杆菌提供了有效技术手段。采用国家规定的标准方法检验从生鲜乳分离的大肠杆菌,分析分离细菌的ERIC-PCR DNA指纹图谱。共采集115份样品,从23份中分离到大肠杆菌25株。ERIC-PCR DNA指纹图谱分析,25株分离菌遗传相似性在56%~100%之间。结果显示,生鲜乳中存在大肠杆菌污染,同一个生鲜乳收购站大肠杆菌的基因型可有不同,不同生鲜乳收购站之间也存在相同基因型大肠杆菌污染。

To determine the prevalence of E.coli infection in fresh milk and genetic similarities between different strains, and then provide an effective technological support for the real-time monitoring E.coli in the dairy production in raw and fresh milk acquisition station. A conventional culture-based study was performed and E.coli strains were isolated and identified. E.coli strains were amplified using ERIC-PCR and then their DNA fingerprints were analyzed. E.co/i was detected in 23/115 samples and 25 E.coli strains were obtained, the twenty-five E.coli strains genetic similarity index was 50%-100%. The results showed that fresh milk was contaminated with different strains of E.coli. Different genotypes of E.coli were present in the same raw and fresh milk acquisition station sample and same genotypes was present in different raw and fresh milk acquisition station sample.