UREASE--MOLECULAR STUDIES & ROLE IN PATHOGENESIS

尿路感染在社区和医院都很常见。 布景。仅在女性人口中，感染率就是 在美国，每年大约有6%。尿路感染是最普遍的 医院感染形式及革兰氏阴性杆菌最常见原因 败血症伴随的高死亡率的菌血症。确实有 与尿路感染有关的一些细菌种类，其中大部分 是肠杆菌科的成员。这些尿路 病原体都有能力表达至少一种 毒力因子包括粘连、溶血素、需氧肌动蛋白和 尿素酶；后者是本研究的重点。尿素酶产生一种 尿路影响的数量，包括肾脏的形成 和膀胱结石，通常由鸟粪石，一种镁铵组成 磷酸盐沉淀。尿素酶产生菌通常与 对于医院获得性尿路感染，长期留置尿管的人可以 尿路中是否有一种以上的溶尿菌 病原体。肺炎克雷伯菌通常与这两个群落有关 获得性和医院获得性尿路感染。这项研究的目的有两个： I)确定尿素酶活性是否增强肺炎克雷伯菌的毒力 在UTI和ii)在分子和遗传水平上研究尿素酶 一株泌尿系致病性肺炎克雷伯菌的基因座。这项工作应该会有帮助 阐明尿素酶在尿路感染中的作用，并定义一种未知的K。 肺炎的特征。除了尿路病原体外，尿素酶一直是 在其他细菌病原体中被牵连为毒力因子，如 幽门弯曲菌和解脲支原体。对K. 肺炎克雷伯菌的尿素酶基因和肺炎克雷伯菌的尿素酶基因将提供基础 对尿素酶和其他菌株的尿素酶基因座进行比较研究。

Urinary tract infection (UTI) is common in both the community and hospital setting. In the female population alone, the rate of infection is approximately 6% per year in the United States. UTI is the most prevalent form of nosocomial infection and the most prevalent cause of gram negative bacteremia with its attendant high mortality rate due to sepsis. There are a number of bacterial species associated with UTI, the majority of which are members of the Enterobacteriaceae family. These urinary tract pathogens share the ability to express at least one of a number of virulence factors that include adhesions, hemolysins, aerobactin, and urease; the latter of these is the focus of this study. Urease produces a number of effects in the urinary tract, including the formation of renal and bladder stones, usually composed of struvite, a magnesium ammonium phosphate precipitate. Urease producing organisms are commonly associated with hospital acquired UTI, and chronically catheterized individuals can have urinary tracts colonized with more than one ureolytic bacterial pathogen. Klebsiella pneumomiae is often associated with both community acquired and hospital acquired UTI. The purpose of this study is twofold: i) to determine if urease activity enhances the virulence of K. pneumoniae in a UTI and ii) to study at the molecular and genetic level the urease locus of a uropathogenic K. pneumoniae isolate. This work should help elucidate the role of urease in UTI and define an uncharacterized K. pneumoniae trait. In addition to urinary tract pathogens, urease has been implicated as a virulence factor in other bacterial pathogens such as Campylobacter pylori and Ureaplasma urealyticum. An understanding of K. pneumoniae urease and the K. pneumoniae urease genes will provide a basis for comparative study of urease and the urease loci of these other strains.