肠集聚性大肠埃希菌分离株脉冲场凝胶电泳分析

目的 对我国散发腹泻患者肠集聚性大肠埃希菌(EAEC)分离株进行脉冲场凝胶电泳(PFGE)分析,以了解其分子流行病学特征并初步建立我国EAEC菌株的基础数据库。 方法 参照PulseNet大肠埃希菌O157:H7的PFGE实验方法对52株EAEC分离株进行分析,并使用BioNumerics软件进行聚类。 结果 在限制性内切酶XbaⅠ和PulseNet推荐的电泳参数下,菌株基因组酶切片段分布均匀,条带易于识别。52株EAEC分离株产生了48种PFGE带型,初步聚类为A~N 14个群,不同地区来源及不同HEp-2细胞黏附表型的菌株广泛分布在不同PFGE聚类群中。 结论 我国散发腹泻患者EAEC分离株呈现高度多态性,PFGE电泳参数和限制性内切酶XbaⅠ适用于我国EAEC菌株的分析。

Pulsed-field gel electrophoresis typing of enteroaggregative Escherichia coli isolates

Objective To understand the molecular epidemiological characteristics of enteroaggregative Escherichia coli （EAEC） isolates from sporadic diarrheal patients in China and establish related database. Methods Pulsed-field gel electrophoresis （PFGE） was performed according to the PulseNet protocol of Escherichia coli O157：H7 with minor modifications. An UIMA dendrogram was constructed with BioNumerics software. Results According to the PulseNet protocol, 48 PFGE patterns were obtained from 52 EAEC isolates, and then they were divided into 14 groups named from A to N. Isolates from different regions or isolates with different adherent phenotypes to HEp - 2 ceUs were widely distributed in different groups. Conclusion The EAEC isolates from sporadic diarrheal patients in China were highly polymorphic. The PFGE protocol developed in this study seemed to be suitable for the molecular ty0in~ of EAEC isolates in China.