Conserved Proteus mirabilis genetic requirements for colonization of the catheterized urinary tract

项目摘要/摘要 留置导尿管患者的死亡率几乎是未留置导尿管患者的两倍 患者由于有不良后果的倾向，包括功能下降，住院时间增加 医院环境、导尿管相关性尿路感染(CAUTI)和菌血症。导尿术也 增加了耐多药生物定居的可能性，抗生素耐药性正在增加 以惊人的速度，这使得确定治疗CAUTI和相关疾病的新的非抗生素治疗方法势在必行 并发症。革兰氏阴性杆菌奇异变形杆菌是引起CAUTI的主要原因，尤其是 在长期的导尿术中。CAUTI也经常是多菌的，这会增加严重的 疾病和菌血症。然而，在有关保守目标的知识上存在着根本的差距 治疗或预防由奇异肺炎杆菌引起的疾病，尤指在多种微生物感染期间。我们的初步数据 清楚地表明在感染过程中其他细菌物种的存在极大地影响了基因 奇异P.mirabilis在CAUTI期间的定植和持久性所需的，特别是 有利于细菌的生长和防御机制，用于逃避宿主的抗菌素 回应。然而，我们已经发现了一组由奇异P.mirabilis编码的217个基因，它们提供了一种适应性 另一种革兰氏阴性菌在单种感染和多菌感染时的优势， 普罗维登西亚·斯图亚蒂。这些基因中有57%(123/217)在全部106个公共场合中高度保守- 现有的奇异P.mirabilis基因组。这一提议的中心假设是奇异P.mirabilis编码一个核心集合 对建立CAUTI至关重要的保守基因，而不考虑其他细菌物种 现在时。我们还预计，这些因素的一部分将是治疗或预防的理想目标 疾病。这一假设将通过三个同时存在的具体目标来检验。在目标1中，我们将利用基因组- 广域转座子插入位点测序揭示两种常见转座子共定植的影响 泌尿病原体(大肠杆菌和粪肠球菌)对奇异肺炎杆菌定植所需基因的影响 留置尿路，包括123个保守的核心健康因素中的哪一个仍然对 确定感染以及它们是否在人类CAUTI期间表达。在目标2和目标3中，我们将探索 在当前的一组核心健康因素(氨基酸)中得到很好代表的两条途径的重要性 代谢和过氧化氢解毒)对奇异疫霉的致病性。这包括广泛的特征描述 在有或没有留置导尿管的情况下，氨基酸在小鼠尿路中的可利用性，以及氨基酸 5种尿路病原菌的偏好，以及这些尿路病原菌和 中性粒细胞对尿路病原体的反应。在这里获得的知识将揭示出独特的挑战 留置尿管的尿路呈现为侵入的尿路病原体，以及新的、保守的、临床相关的。 治疗或预防由于这些流行的和日益耐药的细菌而引起的感染的目标。

Project Summary/Abstract Patients with indwelling urinary catheters have nearly double the mortality rate compared to non-catheterized patients due to the propensity for adverse outcomes, including functional decline, increased length of stay in hospital settings, catheter-associated urinary tract infections (CAUTI), and bacteremia. Catheterization also increases the likelihood of colonization by multidrug-resistant organisms, and antibiotic resistance is increasing at an alarming rate, making it imperative to identify novel, non-antibiotic treatments for CAUTI and associated complications. The Gram-negative bacterium Proteus mirabilis is a predominant cause of CAUTI, particularly during long-term catheterization. CAUTI is also frequently polymicrobial, which can increase risk of severe disease and bacteremia. There is, however, a fundamental gap in knowledge regarding conserved targets for treating or preventing disease due to P. mirabilis, particularly during polymicrobial infection. Our preliminary data clearly demonstrates that the presence of other bacterial species during infection dramatically impacts the genes required by P. mirabilis for colonization and persistence during CAUTI, especially the metabolic pathways that are favored by the bacterium for growth and the defense mechanisms that are used to evade host antimicrobial responses. However, we have uncovered a set of 217 genes encoded by P. mirabilis that provide a fitness advantage during single-species infection and polymicrobial infection with another Gram-negative bacterium, Providencia stuartii. Fifty-seven percent of these genes (123/217) are highly conserved in all 106 publically- available P. mirabilis genomes. The central hypothesis of this proposal is that P. mirabilis encodes a core set of conserved genes that are critical for establishing CAUTI, regardless of which other bacterial species are present. We further anticipate that a subset of these factors will be ideal targets for treatment or prevention of disease. This hypothesis will be tested through three concurrent specific aims. In Aim 1, we will utilize genome- wide transposon insertion-site sequencing to uncover the impact of co-colonization by two common uropathogens (Escherichia coli and Enterococcus faecalis) on the genes required by P. mirabilis to colonize the catheterized urinary tract, including which of the 123 conserved core fitness factors remain important for establishing infection and whether they are expressed during human CAUTI. In Aims 2 and 3, we will explore the importance of two pathways that are well-represented in the current set of core fitness factors (amino acid metabolism and peroxide detoxification) to P. mirabilis pathogenicity. This includes broad characterization of amino acid availability within the murine urinary tract, with or without an indwelling catheter, and the amino acid preferences of 5 uropathogens, as well as production of reactive oxygen species by these uropathogens and by neutrophils in response to the uropathogens. The knowledge gained herein will uncover unique challenges that the catheterized urinary tract presents to invading uropathogens, as well as novel, conserved, clinically-relevant targets for treating or preventing infections due to these prevalent and increasingly drug-resistant bacteria.