VIRULENCE OF A LINEAGE OF UROPATHOGENIC ESCHERICHIA COLI

该项目的广泛、长期目标是 明确升尿症发病机制的作用 泌尿系致病原型株J96‘S的呼吸道感染 神秘的大肠杆菌P的I类和III类变异体 粘附素分子PapG，并描绘其地理位置 J96类克隆的范围、寄主范围和疾病相关性 致尿性大肠埃希菌群，其成员特征 拥有这些PapG粘附素中的一种或两种。 其具体目标是：1)构建单层和双层结构； 野生型“J96-like”大肠杆菌的PapG基因敲除突变 和每个的重新构建的派生，并评估它们的 尿路感染上升小鼠模型的尿毒力；以及2) 鸡肾综合征出血热典型致病株J96的亲缘关系 精心挑选的来自北方的动物和人类大肠杆菌分离株 美国和欧洲。 实验设计和方法：PapG突变体 将用自杀质粒在类J96菌株CP9中构建 等位基因交换系统，并将为 使用重组PapG质粒进行适当的PapG基因分型。 这些衍生物将进行比较，以进行尿毒力测试。 用野生型亲本株在已建立的小鼠模型中 提升的UTI。此外，225株临床分离的大肠杆菌 来自已知人类和动物来源的O4血清组将是 评估与J96在多个方面的相似性 利用聚合酶链法进行性状鉴别 基于反应的基因组指纹图谱，O：K：H；F 三个PapG等位基因的血清分型和基于PCR的检测 细胞毒性坏死因子1(CHF1)和需氧蛋白(Aer)的基因。 该项目与健康的相关性在于 需要更好地了解1)该病毒的致病机制 引起尿路感染的大肠埃希菌；2)这些菌株的地理分布 分布和致病行为。这样的信息将加速 尿路感染及相关预防措施的发展 感染。由于J96菌株的毒力已被广泛传播 对J96‘S的毒力机制进行了研究，并进一步阐明了其毒力机制 对“J96-like”菌株临床行为的澄清将扩大 关于菌株的已有信息的有用性 J96.

THE PROJECT'S BROAD, LONG TERM OBJECTIVES are to define the contributions to the pathogenesis of ascending urinary tract infection UTI) of prototypic uropathogenic strain J96's enigmatic Class I and Class III variants of the Escherichia coli P firmbrial adhersin molecule PapG, and to delineate the geographic extent, host range, and disease associations of a J96-like clonal group of uropathogenic E. Coli whose members characteristically possess one or both of these PapG adhesins. THE SPECIFIC AIMS are 1) to construct single and double- "knockout" PapG mutants of a wildtype "J96-like" E.coli strain and reconstituted derivates of each, and to evaluate their urovirulence in a mouse model of ascending UTI; and 2) to determine the relatedness ot prototypic uropathogenic strain J96 of carefully selected animal and human E.coli isolates from North America and Europe. EXPERIMENTAL DESIGN AND METHODS: PapG mutants will be constructed in "J96-like" strain CP9 using a suicide plasmid allele exchange system and will be reconstituted for the appropriate papG genotype using recombinant papG plasmids. These derivatives will be tested for urovirulence in comparison with the wild-type parent strain in an established mouse model of ascending UTI. In addition, 225 clinical E.coli isolaates of serogroup O4 from known human and animal sources will be evaluated for similarities to J96 with respect to multiple differentiating characteristics through the use of polymerase chain reaction- (PCR-) based genomic ifingerprinting, O:K:H;F serotyping, and PCR-based detection of the three papG alleles and genes for cytotoxic necrotizing factor 1 (chf1) and aerobactin (aer). THE HEALTH RELATEDNESS OF THE PROJECT lies in the need for a better understanding of 1) the virulence mechanisms of the Ecoli strains that cause UTI, and 2) these strains' geographic distribution and pathogenic behavior. Such information will speed the development of preventive measures against UTI and related infections. Since the virulence of strain J96 has been extensively studied, further elucidation of J96's virulence mechanisms, and clarification of the clinical behavior of "J96-like" strains, will extend the usefulness of the already-available information regarding strain J96.