Schmidt H, Henkel B, Karch H
Institut für Hygiene und Mikrobiologie, Universität Würzburg, Germany.
FEMS Microbiol Lett. 1997 Mar 15;148(2):265-72. doi: 10.1111/j.1574-6968.1997.tb10299.x.
Analysis of 14.162 kb of DNA derived from plasmid pO157 of enterohemorrhagic Escherichia coli (EHEC) O157:H7 strain EDL933, extending in the 5' direction of the recently described EHEC-hly operon, revealed 13 open reading frames (ORF) which showed great similarities to genes of members of the type II pathway secretion systems of Gram-negative bacteria. We named the ORFs etpC to etpO for EHEC type II secretion pathway. In addition, an IS911-like insertion element was found to separate the etp genes from the EHEC-hlyC gene. Hybridization experiments with a specific etp probe and various categories of enteric E. coli pathotypes revealed that the etp gene cluster occurred in all 30 EHEC strains of serogroup O157 (100%) tested and is distributed sporadically among other EHEC serogroups (60%). In addition, the etp genes were rarely detected in STEC isolated from bovine feces (10%). Moreover, it was found not to occur in enteropathogenic E. coli, enteroaggregative E. coli, enterotoxigenic E. coli and enteroinvasive E. coli. The results obtained with the etp probe were confirmed by a PCR approach to specifically detect an internal fragment of the etpD gene.
对来自肠出血性大肠杆菌（EHEC）O157:H7菌株EDL933的质粒pO157的14.162 kb DNA进行分析，该DNA在最近描述的EHEC - hly操纵子的5'方向上延伸，结果显示有13个开放阅读框（ORF），它们与革兰氏阴性菌II型途径分泌系统成员的基因有很大相似性。我们将这些ORF命名为etpC至etpO，用于EHEC II型分泌途径。此外，发现一个类似IS911的插入元件将etp基因与EHEC - hlyC基因分开。用特异性etp探针与各类肠道大肠杆菌致病型进行杂交实验，结果显示etp基因簇在所有测试的30株O157血清型EHEC菌株中均出现（100%），并在其他EHEC血清型中呈散在分布（60%）。此外，在从牛粪中分离的STEC中很少检测到etp基因（10%）。而且，发现它在肠致病性大肠杆菌、肠聚集性大肠杆菌、产肠毒素大肠杆菌和肠侵袭性大肠杆菌中不出现。用etp探针获得的结果通过PCR方法得以证实，该方法用于特异性检测etpD基因的一个内部片段。
