OmpR and acid regulation of Escherichia coli fim genes

描述（由申请人提供）：尿路致病性大肠杆菌（UPEC）是美国尿路感染的主要原因，每年导致数百万例病例。附着于上皮细胞是UPEC诱导的尿路感染中至关重要的第一步。1型皮利介导这种结合，动物研究表明这种菌毛类型在人类膀胱感染中起关键作用。1型皮利的表达受时相变化的影响，从而细胞可以在有毛和无毛状态之间切换。9个fim基因参与1型菌毛表达，包括编码结构亚基的fimA基因和影响由fimB和fimE编码的相位变化的位点特异性重组酶。一些环境因素影响这些fim基因的调控，但很少有人知道的环境线索调节fim基因表达的UPEC生活在人类泌尿道。由于UPEC每年引起许多尿路感染，该基金建议通过DNA酶足迹法，PCR，Western印迹和报告基因测定来阐明fimA，fimB和fimE表达，以回答OmpR和酸耐受基因蛋白如何调节UPEC中的1型菌毛表达。此外，该建议将首次研究这三个基因在UPEC细胞接种到小鼠泌尿道中使用报告系统的调节。fim基因是如何被调控的将被揭示，这可能对未来的预防策略有用，这些策略使用饮食变化来改变人类尿路的内部环境并防止UPEC结合。 本研究将有助于我们了解尿路致病性大肠杆菌中1型皮利fim基因的调控。通过了解fim基因是如何被调控的，我们也许能够在未来通过改变饮食或药物来治疗尿路感染，从而影响导致1型菌毛表达的调控级联反应。

DESCRIPTION (provided by applicant): Uropathogenic Escherichia coli (UPEC) are the leading cause of urinary tract infections in the United States, resulting in millions of cases each year. Attachment to epithelial cells is a vital first step in UPEC induced urinary tract infections. Type 1 pili mediate this binding, and animal studies have shown a critical role for this pilus type in human bladder infections. Expression of type 1 pili is affected by phase variation whereby cells can switch between piliated and nonpiliated states. Nine fim genes are involved in type 1 pilus expression, including the fimA gene that encodes the structural subunits and site-specific recombinases that affect phase variation encoded by fimB and fimE. Several environmental factors influence regulation of these fim genes, but little is known about the environmental cues regulating fim gene expression in UPEC living in the human urinary tract. Because UPEC cause many urinary tract infections each year, this grant proposes to answer how OmpR and acid tolerance gene proteins may be regulating type 1 pilus expression in UPEC by performing DNase footprinting, PCRs, Western blots, and reporter assays to elucidate fimA, fimB, and fimE expression. Moreover, this proposal will examine for the first time the regulation of these three genes in UPEC cells inoculated into murine urinary tracts using a reporter system. How the fim genes are regulated will be uncovered, which could be useful for future prevention strategies that use dietary changes to change the internal environment of the human urinary tract and prevent the UPEC from binding. This research will help us understand the regulation of type 1 pili fim genes in uropathogenic Escherichia coli growing in human urinary tracts. By understanding how the fim genes are regulated, we may be able to treat urinary tract infections in the future through dietary changes or drugs that affect the regulatory cascade that leads to type 1 pilus expression.