大肠杆菌ERIC-PCR分子分型方法的建立及其初步应用

Generating of ERIC-PCR Molecular Typing Method and Its Application in Escherichia coli

为建立高效、敏感的肠杆菌科基因间重复一致序列PCR（ERIC-PCR）的分子分型方法,该研究提取大肠杆菌基因组DNA,以此为模板建立和优化ERIC-PCR分型体系,并采用ERIC-PCR方法对62株大肠杆菌进行分子分型和遗传相似性统计分析。结果显示从提取的大肠杆菌基因组中能够扩增到2~8条DNA片段,且大部分片段在100 bp至2 000 bp之间。通过4因素3水平正交试验,建立了较为稳定的ERIC-PCR分型方法。利用ERIC-PCR方法可将62株菌分为20型,其中以A型为优势菌群。遗传相似性结果表明,各菌株之间遗传相似性有较大的变化,但部分菌株高度同源。聚类分析表明,ERIC-PCR的分辨率系数为0.937,具有较高的分辨能力。表明应用ERIC-PCR分型技术在分子水平上对大肠杆菌进行鉴别和分型,具有简便和分辨力高等优点,能够对病原进行溯源分析,在大肠杆菌的分子流行病学研究中具有广泛的应用前景。

To generate an efficient enterobacterial repetitive intergenic consensus sequence（ERIC-PCR） typing method and analyze molecular type of different food-borne Escherichia coli（E.coli）,E.coli genomic DNAs were extracted and used as the template.Orthogonal experiment of four factors at three levels was involved to optimize the method.62 food-borne E.coli strains were typed using ERIC-PCR method and analyzed based on genetic similarity.The ERIC-PCR method exhibited better discriminative results in molecular typing with discrimination index of 0.937.The E.coli strains were grouped into 20 types,and the type A was predominant.ERIC-PCR system is an efficient method for identification,typing and tracking analysis.It will be a promising method in studying molecular epidemiology of E.coli.