Archambaud M, Courcoux P, Ouin V, Chabanon G, Labigne-Roussel A
Laboratoire de Bactériologie, CHU Rangueil, Toulouse, France.
Ann Inst Pasteur Microbiol. 1988 Sep-Oct;139(5):557-73. doi: 10.1016/0769-2609(88)90155-x.
Four different gene clusters have been characterized so far which encode adhesins involved in the specific binding of pathogenic Escherichia coli to epithelial cells of the urinary tractus: the pap, sfa, afa and bma operons. The ability to adhere to uroepithelial cells and to interact with one or several of the specific receptors identified for each of the 4 adhesins, has been studied for 102 E. coli strains isolated from patients with pyelonephritis. These receptor-binding assays are referred to as phenotypic assays. Isolates which adhered to uroepithelial cells 68.6% produced at least 1 of the previously described adhesins. In addition, we used DNA probes to detect homologous sequences of the pap, sfa, and afa operons. Genotypic assays revealed that 87.2% of pyelonephretic E. coli contain DNA sequences related to at least 1 of the 4 operons; 78.4%, 22.5% and 11.8% of the strains harboured sequences related to pap, sfa and afa operons, respectively. The afa- and sfa-adhesion determinants were commonly found associated with the presence of the pap operon (8.8% and 18.6%, respectively). Detection of adhesins using the genotypic approach appears to be reliable (all adhesins detected using the phenotypic approach were also detected with probes). Detection by colony hybridization was significantly higher than by phenotypic assay. Discrepancies may have been due to absence of expression of the detected operons and may have resulted from improper in vitro growth conditions, phase variation, and/or heterogeneity of the genes encoding the adhesins within a family of related sequences.
迄今为止，已鉴定出四个不同的基因簇，它们编码致病性大肠杆菌与尿道上皮细胞特异性结合所涉及的黏附素：pap、sfa、afa和bma操纵子。对从肾盂肾炎患者中分离出的102株大肠杆菌进行了研究，以了解它们黏附于尿道上皮细胞以及与这四种黏附素各自鉴定出的一种或几种特异性受体相互作用的能力。这些受体结合试验被称为表型试验。黏附于尿道上皮细胞的分离株中有68.6%产生了至少一种先前描述的黏附素。此外，我们使用DNA探针检测pap、sfa和afa操纵子的同源序列。基因型分析显示，87.2%的肾盂肾炎大肠杆菌含有与这4个操纵子中至少1个相关的DNA序列；分别有78.4%、22.5%和11.8%的菌株含有与pap、sfa和afa操纵子相关的序列。afa和sfa黏附决定簇通常与pap操纵子的存在相关（分别为8.8%和18.6%）。使用基因型方法检测黏附素似乎是可靠的（所有通过表型方法检测到的黏附素也能用探针检测到）。通过菌落杂交检测的结果明显高于表型试验。差异可能是由于检测到的操纵子未表达，可能是由于体外生长条件不当、相变和/或相关序列家族中编码黏附素的基因的异质性所致。
