Fletcher J N, Saunders J R, Batt R M, Embaye H, Getty B, Hart C A
Department of Genetics and Microbiology, University of Liverpool, United Kingdom.
Infect Immun. 1990 May;58(5):1316-22. doi: 10.1128/iai.58.5.1316-1322.1990.
An enteropathogenic Escherichia coli (EPE) O111 serotype a,b,H- strain carried the following four plasmids: pLV501 (96.5 kilobase pairs [kbp]) specifying resistance to chloramphenicol, tetracycline, and kanamycin; pLV502 (8 kbp) specifying ampicillin resistance; pLV503 (1.9 kbp) specifying streptomycin resistance; and pLV504 (80 kbp) with no resistance markers. This EPEC attached to HEp-2 cells to produce localized clumps of bacteria (localized adhesion) and attached intimately to the enterocyte surface, leading to loss of the brush border (attaching effacement). Plasmid pLV501 was also found to specify the ability to produce localized adhesion on HEp-2 cells and attaching effacement in a rabbit ileal explant model system. Restriction maps showed considerable dissimilarities between pLV501 and pMAR-2, an EPEC plasmid carrying the EPEC adherence factor (EAF) genes. Furthermore, pLV501 did not hybridize with the EAF probe, whereas pLV504 did. There was sequence homology between pLV501 and large plasmids in all seven other well-characterized EPEC, only five of which hybridized with the EAF probe. These findings indicate that pLV501 carries at least one of the genes responsible for production of the brush border damage characteristic of EPEC.
一株肠致病性大肠杆菌（EPE）O111血清型a,b,H-菌株携带以下四种质粒：pLV501（96.5千碱基对[kbp]），赋予对氯霉素、四环素和卡那霉素的抗性；pLV502（8 kbp），赋予氨苄青霉素抗性；pLV503（1.9 kbp），赋予链霉素抗性；以及pLV504（80 kbp），无抗性标记。该肠致病性大肠杆菌附着于HEp-2细胞，产生局部细菌团块（局部黏附），并紧密附着于肠上皮细胞表面，导致刷状缘丧失（紧密黏附并消除）。还发现质粒pLV501赋予在HEp-2细胞上产生局部黏附以及在兔回肠外植体模型系统中产生紧密黏附并消除的能力。限制性图谱显示pLV501与携带肠致病性大肠杆菌黏附因子（EAF）基因的肠致病性大肠杆菌质粒pMAR-2之间存在显著差异。此外，pLV501不与EAF探针杂交，而pLV504则杂交。pLV501与其他七株特征明确的肠致病性大肠杆菌中的大质粒存在序列同源性，其中只有五株与EAF探针杂交。这些发现表明pLV501携带至少一个负责产生肠致病性大肠杆菌特征性刷状缘损伤的基因。
