MOLECULAR PATHOGENESIS OF BACTERIAL CYSTITIS

细菌性膀胱炎的分子发病机制

• 批准号: 6105693
• 负责人: JOHN W WARREN
• 金额: $ 18.7万
• 依托单位: UNIVERSITY OF MARYLAND BALTIMORE
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-07-01 至 2000-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6105693
• 关键词: Escherichia coli; adhesin; gene mutation; hemolysin; host organism interaction; interstitial cystitis; laboratory mouse; molecular cloning; molecular pathology; urinary bladder epithelium; virulence

Bacterial cystitis is overwhelmingly a syndrome of women and the kidney or urologic disease prompting the most visits to physician offices in the US. That the pathogenesis of this disease is poorly understood is ironic. It is the intention of this new project to direct the tools of molecular biology at pertinent E. coli strains in order to examine mechanisms of pathogenesis using human bladder epthelial cells (HBEC) in culture and an in vivo animal model of UTI modified to minimize kidney involvement. The majority of cystitis strains do not have P fimbriae, S fimbriae, hemolysin, and other E. coli characteristics identified as virulence factors for pyelonephritis. Therefore, we have developed an experimental plan that slows the study not only of those genes modestly epidemiologically associated with cystitis but also the identification, by functional roles, of heretofore unknown genes. Preliminary studies demonstrate the E. coli hemolysin, a pore-forming cytotoxin is active against HBEC, that HBEC internalize E. coli, and that mouse UTI virulence is not explained solely by known E. coli virulence factors. We will test the following hypotheses: 1) That strains causing cystitis in humans adhere to HBEC via specific known or as yet unrecognized adhesins. This will be demonstrated by mutagenesis of pertinent strains: isogenic for known adhesins and transposon to identify unknown adhesins. 2) That F54, a potent E. coli cystitis strain with no known virulence factors, causes cystitis in part through internalization into bladder epithelial cells. This will be approached via transposon mutagenesis to seek mutants with diminished internalization and virulence. 3) That the activities of E. coli hemolysin and cytotoxic necrotizing factor (CNF) in the living bacterium can be dissociated by genetic manipulation. Hemolysin is epidemiologically linked to cystitis and CNF is an interesting protein identified in 2/3 of hemolytic strains which enhances bacterial internalization and causes multinucleation of host epithelial cells. Our intent will be to dissociate hemolysin and CNF via isogenic mutagenesis and to study the four permutations of these two putative virulence factors in adherence, internalization, and cytotoxicity assays in order to generate hypotheses of the action and interaction of hemolysin and CNF.

细菌性膀胱炎绝大多数是女性和肾脏综合征 泌尿科疾病促使美国医师办公室访问最多。 这种疾病的发病机理知之甚少。 它 这个新项目的目的是指导分子的工具 相关大肠杆菌菌株的生物学，以检查 使用人膀胱遗传细胞（HBEC）在培养和A的发病机理 体内动物的UTI动物模型已修饰，以最大程度地减少肾脏的参与。 这 大多数膀胱炎菌株没有P纤维化，S fimbriae，Hemolysin， 和其他大肠杆菌特征被确定为毒力因子 肾盂肾炎。 因此，我们制定了一个实验计划 不仅减慢了这些基因的研究 与膀胱炎和识别相关，通过功能角色， 迄今未知基因。 初步研究证明了大肠杆菌血素素，一种孔形成 细胞毒素对HBEC的活性，HBEC内化的大肠杆菌，并且 小鼠UTI毒力不能仅通过已知的大肠杆菌毒力来解释 因素。 我们将检验以下假设： 1）引起人类膀胱炎的菌株通过特异性粘附于HBEC 已知或尚未识别的粘合剂。 这将由 相关菌株的诱变：已知粘附素的同源性 转座子以鉴定未知的粘附素。 2）F54，一种有效的大肠杆菌膀胱炎，没有已知的毒力 因素，部分通过内部化到膀胱而导致膀胱炎 上皮细胞。 这将通过转座子诱变到 寻求内在化和毒力减少的突变体。 3）大肠杆菌血解素和细胞毒性坏死的活性 活细菌中的因子（CNF）可以通过遗传分离 操纵。 血素素在流行病学上与膀胱炎联系在一起，CNF为 一种有趣的蛋白质，在2/3的溶血菌株中鉴定出来 增强细菌内在化并导致宿主的多核 上皮细胞。 我们的目的是通过 等生诱变并研究这两个排列 推定的毒力因子在依从性，内在化和细胞毒性中 为了产生动作和相互作用的假设的测定 血素和CNF。