Bingen-Bidois Martine, Clermont Olivier, Bonacorsi Stéphane, Terki Mustapha, Brahimi Naïma, Loukil Chawki, Barraud Dominique, Bingen Edouard
Laboratoire de Bactériologie, Centre Hospitalier de Gonesse, Gonesse. Service de Microbiologie, Hôpital Robert Debré, Paris, France.
Infect Immun. 2002 Jun;70(6):3216-26. doi: 10.1128/IAI.70.6.3216-3226.2002.
We characterized 100 Escherichia coli urosepsis isolates from adult patients according to host compromise status by means of ribotyping, PCR phylogenetic grouping, and PCR detection of papG alleles and the virulence-related genes sfa/foc, fyuA, irp-2, aer, hly, cnf-1 and hra. We also tested these strains for copies of pap and hly and their direct physical linkage with other virulence genes in an attempt to look for pathogenicity islands (PAIs) described for the archetypal uropathogenic strains J96, CFT073, and 536. Most of the isolates belonged to E. coli phylogenetic groups B2 and D and bore papG allele II, aer, and fyuA/irp-2. papG allele II-bearing strains were more common in noncompromised patients, while papG allele-negative strains were significantly more frequent in compromised patients. Fifteen ribotypes were identified. The three archetypal strains harbored different ribotypes, and only one-third of our urosepsis strains were genetically related to one of the archetypal strains. Three and 18 strains harbored three and two copies of pap, respectively, and 5 strains harbored two copies of hly. papGIII was physically linked to hly, cnf-1, and hra (reported to be PAI II(J96)-like genetic elements) in 14% of the strains. The PAI II(J96)-like domain was inserted within pheR tRNA in 11 strains and near leuX tRNA in 3 strains. Moreover, the colocalized genes cnf-1, hra, and hly were physically linked to papGII in four strains and to no pap gene in three strains. papGII and hly (reported to be PAI I(CFT073)-like genetic elements) were physically linked in 16 strains, pointing to a PAI I(CFT073)-like domain. Three strains contained both a PAI II(J96)-like domain and a PAI I(CFTO73)-like domain. Forty-two strains harbored papGII but not hly, in keeping with the presence of a PAI II(CFT073)-like domain. Only one strain harbored a PAI I(536)-like domain (hly only), and none harbored a PAI I(J96)-like domain (papGI plus hly) or a PAI II(536)-like domain (papGIII plus hly). This study provides new data on the prevalence and variability of physical genetic linkage between pap and certain virulence-associated genes that are consistent with their colocalization on archetypal PAIs.
我们通过核糖体分型、PCR系统发育分组以及PCR检测papG等位基因和毒力相关基因sfa/foc、fyuA、irp-2、aer、hly、cnf-1和hra，根据宿主受损状态对100株来自成年患者的大肠埃希菌泌尿道感染分离株进行了特征分析。我们还检测了这些菌株的pap和hly拷贝数以及它们与其他毒力基因的直接物理连锁关系，试图寻找针对原型尿路致病性菌株J96、CFT073和536所描述的致病岛（PAIs）。大多数分离株属于大肠埃希菌系统发育组B2和D，携带papG等位基因II、aer和fyuA/irp-2。携带papG等位基因II的菌株在未受损患者中更为常见，而papG等位基因阴性的菌株在受损患者中明显更为频繁。鉴定出了15种核糖体分型。这三种原型菌株具有不同的核糖体分型，我们的泌尿道感染菌株中只有三分之一与其中一种原型菌株存在遗传关系。分别有3株和18株携带3个和2个pap拷贝，5株携带2个hly拷贝。在14%的菌株中，papGIII与hly、cnf-1和hra（据报道是PAI II(J96)样遗传元件）存在物理连锁。PAI II(J96)样结构域在11株菌株中插入到pheR tRNA内，在3株菌株中插入到leuX tRNA附近。此外，共定位基因cnf-1、hra和hly在4株菌株中与papGII存在物理连锁，在3株菌株中与任何pap基因都不存在物理连锁。papGII和hly（据报道是PAI I(CFT073)样遗传元件）在16株菌株中存在物理连锁，表明存在一个PAI I(CFT073)样结构域。3株菌株同时含有一个PAI II(J96)样结构域和一个PAI I(CFTO73)样结构域。42株菌株携带papGII但不携带hly，这与存在一个PAI II(CFT073)样结构域一致。只有1株菌株携带一个PAI I(536)样结构域（仅hly），没有菌株携带PAI I(J96)样结构域（papGI加hly）或PAI II(536)样结构域（papGIII加hly）。本研究提供了关于pap与某些毒力相关基因之间物理遗传连锁的患病率和变异性的新数据，这些数据与它们在原型PAIs上的共定位情况一致。
