Epidemiology of an uropathogenic E coli clonal group

描述(由申请人提供)：这是一个试验性项目，旨在描述最近确定的被指定为CGA的泌尿系致病大肠杆菌克隆群的流行病学特征。CGA是指一组具有相同ERIC PCR图谱和相同或相似脉冲场凝胶电泳(PFGE)图谱的多重耐药大肠杆菌菌株，属于O11：NT和O77：NT血清型，并具有相同或相似的毒力因子图谱。在一项多中心研究中，我们发现在美国3个不同的大学社区，CGA在社区获得性耐药尿路感染(UTI)中占相当大的比例。CGA的广泛传播增加了这一克隆性大肠杆菌群可能通过受污染的可食用车辆传播的可能性。我们假设，一个社区中耐药UTI患病率的增加不仅受抗菌药物使用频率的影响，还受受污染的车辆将耐药致尿路病原性大肠杆菌克隆群引入此类社区的影响。在这项应用中，我们希望：(1)确定CGA的地理分布和由这种微生物引起的感染的临床谱系，包括尿路感染的并发症；(2)CGA感染的宿主和危险因素。CGA的地理分布将通过对来自加利福尼亚州北部、巴西和纽约的PI以及来自明尼苏达州、爱荷华州、华盛顿州和世卫组织参考实验室的合作者(James Johnson博士)获得的大肠杆菌档案进行分析来研究。CGA引起的尿路感染(肾盂肾炎和菌血症)并发症的发生率和流行率将通过与Francoise Perdreau-Remington博士合作从旧金山一家医院的患者身上获得的大肠杆菌分离株的分析来确定。将与Chobi Debroy博士合作，通过对动物中所有可用的O11：NT和O77：NT大肠杆菌分离株的分析，检查CGA的可能动物储存库。通过这项初步研究，我们希望提供初步证据，支持耐药致尿路病原性大肠杆菌可以通过受污染的可食用载体传播的假设，并利用该项目产生的数据来设计长期研究，以更好地表征与CGA感染相关的危险因素。

DESCRIPTION (provided by applicant): This is a pilot project that aims to characterize the epidemiology of a recently identified clonal group of uropathogenic Escherichia coli designated as CgA. CgA refers to a set of multidrug-resistant E. coli strains that have identical ERIC PCR patterns and identical or similar pulsed field gel electrophoresis (PFGE) patterns, that belong to serotypes O11:nt and O77:nt, and that share identical or similar virulence factor profiles. In a multicenter study, we discovered that CgA accounted for a substantial proportion of community-acquired drug-resistant urinary tract infections (UTI) in 3 distinct university communities in the United States. The widespread dissemination of CgA raised the possibility that this clonal group of E. coli may be spread by contaminated ingestible vehicles. We hypothesize that the increase in prevalence of drug-resistant UTI in a community is affected not only by the frequency in the use of antimicrobial agents, but also by the introduction into such communities of clonal groups of drug-resistant uropathogenic E. coli by contaminated vehicles. In this application, we wish to: (1) identify the geographic distribution of CgA and the clinical spectrum of infections caused by this organism, including complications of UTI; and (2) reservoir and risk factors for infection with CgA. The geographic distribution of CgA will be studied by the analyses of E. coli archives obtained by the PI from northern California, Brazil, and New York, and by the collaborator (Dr. James Johnson) from Minnesota, Iowa, Washington, and a WHO Reference Laboratory. The incidence and prevalence of complications of UTI (pyelonephritis and bacteremia) caused by CgA will be determined by the analyses of E. coli isolates obtained from patients in a San Francisco hospital in collaboration with Dr. Francoise Perdreau-Remington. The possible animal reservoir for CgA will be examined by the analysis of all available O11:nt and O77:nt E. coli isolates from animals in collaboration with Dr. Chobi DebRoy. Through this pilot study, we wish to provide preliminary evidence in support of the hypothesis that drug-resistant uropathogenic E. coli can be spread by contaminated ingestible vehicles, and use the data generated from this project to design long-term studies to better characterize risk factors associated with CgA infection.