Genetic Mechanisms of Sporulation Induction in C. difficile

艰难梭菌孢子诱导的遗传机制

• 批准号: 10331891
• 负责人: SHONNA M. MCBRIDE
• 金额: $ 47.8万
• 依托单位: EMORY UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-08-01 至 2026-01-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10331891
• 关键词: Anaerobic Bacteria; Antibiotic Resistance; Antibiotic Therapy; Award; Bacteria; Bacterial Infections; Biochemical; Biological Process; Cells; Cessation of life; Clostridium; Clostridium difficile; Complex; DNA Binding; Data; Development; Digestive System Disorders; Disease; Disinfectants; Environment; Exposure to; Feces; Gastrointestinal tract structure; Gene Expression Regulation; Genes; Genetic; Genetic Transcription; Genome; Goals; Health Care Costs; Individual; Infection; Intestinal Diseases; Intestines; Lead; Mission; Molecular; Molecular Genetics; Oral; Orthologous Gene; Pathogenesis; Pathway interactions; Peptide Initiation Factors; Phosphotransferases; Positioning Attribute; Process; Protein Analysis; Proteins; Publishing; Recurrence; Refractory; Regulation; Regulatory Pathway; Relapse; Reproduction spores; Research; Resistance; Role; Route; Toxin; United States; United States National Institutes of Health; Work; base; design; diarrheal disease; experience; experimental study; genetic approach; in vivo; innovation; particle; pathogen; prevent; protein function; transmission process

Project Summary/Abstract Clostridioides difficile (formerly Clostridium) is a major nosocomial pathogen that causes severe diarrheal disease that is highly infectious and difficult to treat. C. difficile is easily transmitted due to the formation and expulsion of contagious spores from infected hosts. The spore form of C. difficile is resistant to most disinfectants and is critical for the survival of the bacterium outside of the host intestine. The gastrointestinal tract is the only natural environment known to support C. difficile spore formation, but we understand little about how spore formation is initiated by the bacterium. The long-term goal of this project is to uncover the molecular mechanisms that control the initiation of C. difficile sporulation. Based on our data, we hypothesize that several early sporulation proteins function in independent pathways to regulate the initiation of sporulation by controlling activation of the master transcriptional regulator, Spo0A. The specific objectives of this application are to define the direct regulatory mechanisms that act upon Spo0A and to delineate the molecular pathways that control sporulation initiation. Capitalizing on our previous experiences in C. difficile molecular genetics, gene regulation, and Gram-positive intestinal pathogenesis, we will meet the objectives through the experiments detailed in two specific aims. In Aim 1, we will extend our current studies to uncover direct interacting partners of Spo0A using a combination of genetic and biochemical approaches. In parallel, Aim 2 expands epistatic analyses to construct Spo0A regulatory pathways, followed by functional analyses of the proteins within the initiation cascade. This research is innovative because it combines biomolecular and genetic approaches to resolve a fundamental question about this important and complex biological process. Completion of these aims is expected to expose potential vulnerabilities in spore initiation. This work is an essential step in the development of rational strategies to impede C. difficile transmission by preventing the formation of infectious spores in the host.

项目概要/摘要 艰难梭菌（以前称为梭状芽胞杆菌）是一种主要的院内病原体，可导致严重腹泻 传染性强且难以治疗的疾病。艰难梭菌由于其形成和传播而很容易传播 从受感染的宿主中排出传染性孢子。艰难梭菌的孢子形式对大多数消毒剂都有抵抗力 对于宿主肠道外细菌的生存至关重要。胃肠道是唯一 已知自然环境支持艰难梭菌孢子形成，但我们对孢子如何形成知之甚少 形成是由细菌引发的。该项目的长期目标是揭示分子 控制艰难梭菌孢子形成起始的机制。根据我们的数据，我们假设有几个 早期孢子形成蛋白在独立途径中发挥作用，通过控制来调节孢子形成的起始 主转录调节因子 Spo0A 的激活。该应用程序的具体目标是定义 作用于 Spo0A 的直接调节机制并描绘控制的分子途径 孢子形成起始。利用我们之前在艰难梭菌分子遗传学、基因调控方面的经验， 和革兰氏阳性肠道发病机制，我们将通过两个详细的实验来实现目标 具体目标。在目标 1 中，我们将扩展我们当前的研究，以使用 Spo0A 来发现 Spo0A 的直接相互作用伙伴 遗传和生化方法的结合。与此同时，目标 2 扩展了上位分析以构建 Spo0A 调控途径，然后对起始级联内的蛋白质进行功能分析。这 研究具有创新性，因为它结合了生物分子和遗传学方法来解决根本问题 关于这一重要而复杂的生物过程的问题。这些目标的完成预计将揭露 孢子产生的潜在漏洞。这项工作是制定合理策略的重要一步 通过防止宿主中感染性孢子的形成来阻止艰难梭菌的传播。