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

项目概要/摘要 留置导尿管的患者死亡率比未留置导尿管的患者高出近一倍 患者由于不良结局的倾向，包括功能下降， 医院环境、导管相关性尿路感染（CITTI）和菌血症。导管插入术还 增加了多重耐药微生物定植的可能性，抗生素耐药性正在增加 以惊人的速度，迫切需要确定新的，非抗生素的治疗方法， 并发症革兰氏阴性菌奇异变形杆菌是引起呼吸道感染的主要原因， 在长期的导管插入过程中。抗真菌药物也经常是多种微生物的，这会增加严重的 疾病和菌血症。然而，关于保守的靶点的知识存在根本性的差距， 治疗或预防由奇异变形杆菌引起的疾病，特别是在多种微生物感染期间。我们的初步数据 这清楚地表明，在感染过程中，其他细菌物种的存在极大地影响了基因， P. mirabilis在P. mirabilis期间定植和持续所需的代谢途径，特别是 有利于细菌的生长和防御机制，用于逃避宿主抗菌剂 应答然而，我们已经发现了一组由奇异变形杆菌编码的217个基因， 在单种感染和另一种革兰氏阴性菌的多微生物感染期间的优势， 斯氏普罗威登斯菌这些基因中的57%（123/217）在所有106个遗传学上高度保守- 可用的奇异变形杆菌基因组。这个提议的中心假设是奇异变形杆菌编码一个核心集合 保守的基因，这是关键的建立pneumaticTI，无论其他细菌物种是 礼物我们进一步预测，这些因素的一个子集将是治疗或预防 疾病这一假设将通过三个并行的具体目标进行检验。在目标1中，我们将利用基因组- 宽转座子插入位点测序，以揭示两种常见的 尿病原体（大肠杆菌和粪肠球菌）对奇异变形杆菌定植所需基因的影响 导尿管尿路，包括123个保守的核心健身因素仍然重要， 建立感染以及它们是否在人ESTTI期间表达。在目标2和3中，我们将探讨 在目前的核心适应性因子（氨基酸）中有两条途径的重要性 代谢和过氧化物解毒）对奇异变形杆菌致病性的影响。这包括广泛的表征， 在有或没有留置导管的情况下，小鼠泌尿道内的氨基酸可用性， 5尿路病原体的偏好，以及这些尿路病原体和 中性粒细胞对尿路病原体的反应。在此获得的知识将揭示独特的挑战， 插入导尿管的尿路呈现侵入性尿路病原体，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引起的感染的靶点。

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.