Second Messenger Nucleotides of Enterococcus faecalis

粪肠球菌第二信使核苷酸

• 批准号: 10676471
• 负责人: Jose A Lemos
• 金额: $ 28.99万
• 依托单位: UNIVERSITY OF FLORIDA
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-03-17 至 2028-02-29
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10676471
• 关键词: Agonist; Antibiotic Therapy; Antibiotics; Area; Attenuated; Bacteria; Binding; Biological Process; Cell Maintenance; Cell physiology; Cells; Cellular Metabolic Process; Characteristics; Clinical; Complex; Cues; Cyclic Nucleotides; Data; Disease; Disinfectants; Enterococcus; Enterococcus faecalis; Enterococcus faecium; Environment; Exposure to; Functional disorder; Gastrointestinal tract structure; Goals; Growth; Homeostasis; Hospitalization; Hospitals; Human; Immune response; Immune system; Impairment; Infection; Innate Immune Response; Interferon Type I; Investigation; Knowledge; Light; Link; Mechanics; Mediating; Metabolism; Microbial Biofilms; Multi-Drug Resistance; Nosocomial Infections; Nucleotides; Osmoregulation; Pathogenesis; Pathogenicity; Patients; Phase; Physiological; Play; Process; Production; Proteins; Public Health; Regulation; Research; Research Design; Role; Second Messenger Systems; Signal Transduction; Solid; Stimulus; Stress; Surface; Time; Tissues; Virulence; Work; antibiotic tolerance; antimicrobial; bacterial fitness; biological adaptation to stress; catheter associated UTI; cell envelope; cellular targeting; fitness; implantable device; innovation; insight; interest; mouse model; multi-drug resistant pathogen; novel; opportunistic pathogen; pathogen; rational design; resident commensals; resistant strain; response; stress resilience; trait

ABSTRACT Enterococci are the 3rd most common cause of hospital-acquired infections and a major public health threat due to the continuous rise of multidrug-resistant (MDR) isolates. Because the pathogenic potential of enterococci is closely linked to their ubiquitous stress resilience, work in our lab aims to identify and dissect the mechanisms that allow Enterococcus faecalis, the most prevalent enterococcal species of human infections, to survive in the hostile host environment. Second messenger nucleotides such as (p)ppGpp (the effector molecule of the stringent response) and c-di-AMP are produced by bacteria in response to internal or external stimuli, playing major roles in the regulation of processes associated with cell homeostasis and virulence. In addition, cyclic nucleotides such as c-di-AMP act as agonists of the innate immune response of mammalians by stimulating a potent STING-dependent type I interferon response. Of interest, previous investigations have shown that the c-di-AMP and (p)ppGpp signaling networks are interconnected in other bacteria, but a clear understanding of the mechanics and physiological significance of this interaction are still lacking. In previous studies, we discovered that E. faecalis depends on small amounts of (p)ppGpp to maintain a balanced metabolism and to respond to external cues in an accurate and timely manner. We also found that lack of (p)ppGpp greatly increases antibiotic sensitivity and attenuates the virulence of E. faecalis. More recently, we showed that c-di-AMP is also critical to E. faecalis pathophysiology and that either accumulation or lack of c- di-AMP can drastically impair the virulence potential of E. faecalis. The goals of this application are: (i) to probe the multifaceted roles played by c-di-AMP during infection using a catheter-associated urinary tract infection (CAUTI) mouse model that recapitulates many of the clinical characteristics of the disease in humans, (ii) to identify and characterize the c-di-AMP binding/effector proteins in E. faecalis, and (iii) to investigate how integration of the c-di-AMP and (p)ppGpp regulatory networks controls specific processes that promote bacterial fitness and then determine how this association contributes to E. faecalis pathophysiology. This conceptually innovative application builds on our extensive preliminary data and the complementary expertise and solid track record of our research team in each specific area of this application. Significance of the proposed studies lies in unravelling the multifaceted role of c-di-AMP in host-pathogen interactions, uncovering the scope of c-di-AMP regulation in a major MDR pathogen, and shedding new light onto the intricate relationship between c-di-AMP and (p)ppGpp. Given the central role of regulatory nucleotides in bacterial pathogenesis, a better understanding of how they modulate cell physiology based on identification and characterization of their mechanisms of action and effectors can facilitate the rational design of new antimicrobial therapies.

摘要 肠球菌是医院获得性感染的第三大常见原因，也是一个主要的公共卫生威胁 由于多药耐药（MDR）菌株的不断增加。因为潜在的致病性 肠球菌与它们无处不在的压力恢复能力密切相关，我们实验室的工作旨在识别和分析 粪肠球菌（Enterococcus faecalis）是人类感染中最常见的肠球菌， 在恶劣的环境中生存。第二信使核苷酸如（p）ppGpp（效应子 严格反应的分子）和c-di-AMP是由细菌响应内部或外部反应而产生的 刺激，在调节与细胞稳态和毒力相关的过程中发挥主要作用。在 此外，环核苷酸如c-di-AMP通过以下方式作为人的先天性免疫应答的激动剂： 刺激有效的STING依赖性I型干扰素应答。有趣的是，以前的调查 表明c-di-AMP和（p）ppGpp信号网络在其他细菌中是相互连接的，但清楚地表明， 对这种相互作用的机制和生理意义的理解仍然缺乏。前几 研究发现，E.粪便依赖于少量的（p）ppGpp来维持平衡 以准确和及时的方式对外部线索作出反应。我们还发现，缺乏 （p）ppGpp显著提高了E.粪便最近，我们 表明c-di-AMP对E.粪便病理生理学，无论是积累或缺乏c- di-AMP能显著削弱E.粪便本申请的目的是：（i） 探讨c-di-AMP在使用导管相关尿路感染期间所起的多方面作用 感染（CITTI）小鼠模型，其再现了人类中该疾病的许多临床特征， (ii)鉴定和表征大肠杆菌中的c-di-AMP结合/效应蛋白。粪便，以及（iii）调查 c-di-AMP和（p）ppGpp调控网络的整合如何控制促进 细菌适应性，然后确定这种关联如何有助于E。粪便病理生理学这 概念上的创新应用建立在我们广泛的初步数据和补充 我们的研究团队在此应用的每个特定领域的专业知识和坚实的跟踪记录。意义 所提出的研究在于揭示c-di-AMP在宿主-病原体相互作用中的多方面作用， 揭示了c-di-AMP在主要MDR病原体中的调节范围，并为MDR病原体的治疗提供了新的思路。 c-di-AMP和（p）ppGpp之间存在复杂关系。考虑到调节核苷酸在 细菌的发病机制，更好地了解他们如何调节细胞生理学的基础上鉴定 其作用机制和效应器的表征可以促进新的药物的合理设计。 抗菌治疗