Sperandio V, Kaper J B, Bortolini M R, Neves B C, Keller R, Trabulsi L R
Departamento de Microbiologia, Universidade de Sao Paulo, Brazil.
FEMS Microbiol Lett. 1998 Jul 1;164(1):133-9. doi: 10.1111/j.1574-6968.1998.tb13078.x.
All proteins involved in the attachment and effacement lesion produced by enteropathogenic Escherichia coli (EPEC) and Shiga-toxin producing E. coli (STEC) are encoded by the locus of enterocyte effacement (LEE). We studied the presence and insertion site of the LEE in different EPEC and STEC strains. In serotypes O119:H6/H-, O55:H6, O55:H7, O142:H6, O111ac:H9/H-, O111ab:H9/H- LEE is inserted downstream of selC as previously described for EPEC O127:H6 and STEC O157:H7. In serotypes O111ac:H8/H- and O26:H11/H- the LEE is inserted in pheU as previously described for STEC O26:H-. However in EPEC from serotype O111ab:H25 the LEE is not inserted in either site suggesting a third insertion site in the K12 chromosome. We also cloned fragments of 2.3 kb and 1.0 kb from the right and left hand sides of the LEE of a O111ac:H- strain and identified additional insertion sequences on these LEE fragments, suggesting that the LEE may be larger and may have undergone more recombination events in these serotypes.
所有参与肠致病性大肠杆菌（EPEC）和产志贺毒素大肠杆菌（STEC）引起的黏附和抹平损伤的蛋白质均由肠细胞抹平位点（LEE）编码。我们研究了不同EPEC和STEC菌株中LEE的存在情况和插入位点。在血清型O119:H6/H-、O55:H6、O55:H7、O142:H6、O111ac:H9/H-、O111ab:H9/H-中，LEE如先前针对EPEC O127:H6和STEC O157:H7所述，插入到selC下游。在血清型O111ac:H8/H-和O26:H11/H-中，LEE如先前针对STEC O26:H-所述，插入到pheU中。然而，在血清型O111ab:H25的EPEC中，LEE未插入这两个位点中的任何一个，这表明在K12染色体上存在第三个插入位点。我们还从一株O111ac:H-菌株的LEE的右侧和左侧克隆了2.3 kb和1.0 kb的片段，并在这些LEE片段上鉴定出了额外的插入序列，这表明LEE可能更大，并且在这些血清型中可能经历了更多的重组事件。
