Phylogenetic analysis and prevalence of urosepsis strains of Escherichia coli bearing pathogenicity island-like domains
Phylogenetic analysis and prevalence of urosepsis strains of Escherichia coli bearing pathogenicity island-like domains
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DOI：
10.1128/iai.70.6.3216-3226.2002
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发表时间：
2002-06-01
影响因子：
3.1
通讯作者：
Bingen, E
中科院分区：
文献类型：
--
作者：
Bingen-Bidois, M;Clermont, O;Bingen, E
我们根据宿主妥协状态对100株来自成人患者的大肠杆菌尿脓毒症分离株进行了特征分析，通过核糖体分型、PCR系统发育分组和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。我们还测试了这些菌株的pap和hly的副本，以及它们与其他毒力基因的直接物理联系，试图寻找致病岛（PAI）的原型尿路致病性菌株J 96，CFT 073和536。绝大多数菌株属于E.大肠杆菌系统发育群B2和D，携带papG等位基因11、aer和fyuA/irp-2。携带papG等位基因II的菌株在非受损患者中更常见，而papG等位基因阴性菌株在受损患者中更常见。鉴定了15种核糖体型。这三个原型菌株具有不同的核糖体型，只有三分之一的尿脓毒症菌株的基因相关的原型菌株之一。3株和18株分别携带3个和2个拷贝的pap，5株携带2个拷贝的hly。在14%的菌株中，papGIII与hly、cnf-1和hra（据报道为派IIJ 96样遗传元件）物理连锁。派IIJ 96样结构域插入pheR tRNA的II株和附近的leuX tRNA的3株。此外，共定位基因cnf-1，hra，和hly物理连锁papGII在四个菌株和没有pap基因在三个菌株。papGII和hly（报道为派I-CFT 073样遗传元件）在16个菌株中物理连锁，指向派I-CFT 073样结构域。三个菌株含有派IIJ 96样结构域和派I-CFT 073样结构域。42株含有papGII，但没有hly，与派IICFT 073样结构域的存在保持一致。只有一个菌株具有派I-536样结构域（仅hly），没有一个菌株具有派I-J 96样结构域（papGI + hly）或派II 536样结构域（papGIII + hly）。这项研究提供了新的数据的患病率和变异性之间的物理遗传连锁pap和某些毒力相关的基因是一致的，与他们的共定位原型PAI。
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-l 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 11, 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 IIJ96-like genetic elements) in 14% of the strains. The PAI IIJ96-like domain was inserted within pheR tRNA in I I 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 IIJ96-like domain and a PAI I-CFT073-like domain. Forty-two strains harbored papGII but not hly, in keeping with the presence of a PAI IICFT073-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 II536-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.