Functional genomics analysis of colonization and persistence of Enterococcus faecalis in the gastrointestinal tract.

粪肠球菌在胃肠道中定植和持续存在的功能基因组学分析。

• 批准号: 9215645
• 负责人: GARY M DUNNY
• 金额: $ 49.47万
• 依托单位: UNIVERSITY OF MINNESOTA
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-02-04 至 2021-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9215645
• 关键词: Animals; Antibiotic Resistance; Antibiotic Therapy; Antibiotics; Bacteria; Behavior; Bile fluid; Blood Circulation; Cell Wall; Cells; Complex; Development; Disease; Ecology; Enterococcus; Enterococcus faecalis; Enterococcus faecium; Exhibits; Gastrointestinal tract structure; Gene Cluster; Gene Expression; Genetic; Genetic Determinism; Genetic Screening; Genome; Genus staphylococcus; Germ-Free; Growth; Habitats; Healthcare; Heart Valves; Host Defense; Human; Impairment; Infection; Innate Immune System; Insecta; Intestines; Invaded; Laboratories; Lead; Libraries; Life; Life Style; Methods; Microbe; Microbial Biofilms; Microscopic; Microscopy; Minor; Modeling; Mus; Mutation; Nosocomial Infections; Opportunistic Infections; Organism; Pathogenicity; Pilum; Polysaccharides; Production; Proteins; Regulation; Research; Research Personnel; Resistance; Resolution; Role; Scanning Electron Microscopy; Site; Streptococcus; Study models; Surface; Symbiosis; Techniques; Urinary tract; Virulence; Work; antimicrobial drug; base; experimental study; fitness; follow-up; functional genomics; genome-wide; gut microbiota; humanized mouse; in vivo; interest; killings; member; microbial; microbial community; microbiome; mouse model; mutant; novel; pathogen; pressure; prevent; public health relevance; resistant strain; screening; tool; trait; transcription factor; virtual

 DESCRIPTION (provided by applicant): This project will examine the role of determinants encoded within the core genome of Enterococcus faecalis in adaptation to survival, growth, and persistence in the mammalian gastrointestinal tract. E. faecalis is a leading cause of hospital-acquired infections whose treatment is impeded by the inherent and acquired antibiotic resistance of the organism, and by its propensity to grow and survive in hostile conditions, and by its ability to transition between commensal and pathogenic lifestyles. Virtually all enterococcal infections are caused by organisms residing in the gut that escape to other body sites. It is well understood that antibiotic treatment or impairment of normal host defenses can result in overgrowth of enterococci in the intestine. However, we know very little about the inherent traits that allow the organism to establish in a healthy intestine, an essential prelude t enterococcal diseases. We will study the model laboratory strain OG1RF in both germ-free mice, and in "humanized" animals carrying a human-derived gut microbial community. We will use a powerful new genetic screen we have termed "Smart TnSeq" to identify genetic determinants encoding proteins and small regulatory RNAs that contribute to competitive fitness in the GI tract, and begin to study their functions and mechanisms of action. We will use high-resolution microscopic techniques to examine the behavior of the organisms in vivo, and the expression of genes of interest. The results of this research will include the following: 1) A genome-wide picture of the role of determinants of intestinal fitness will emerge. 2) We will have a much better understanding of preferred sites of colonization of enterococci, and how gene expression is regulated in these favored niches. 3) In the longer term, we may identify new ecologically based strategies, which could prevent enterococcal infections without necessarily killing the bacteria, reducing selection for resistance.

 描述（由申请人提供）：该项目将研究粪肠球菌核心基因组中编码的决定簇在适应哺乳动物胃肠道中的生存、生长和持久性方面的作用。粪肠球菌是医院获得性感染的主要原因，其治疗受到生物体固有的和获得性的抗生素耐药性、其在恶劣条件下生长和生存的倾向以及其在共生和致病生活方式之间转换的能力的阻碍。事实上，所有肠球菌感染都是由肠道内的微生物逃逸到身体其他部位引起的。众所周知，抗生素治疗或正常宿主防御功能受损可能导致肠道内肠球菌过度生长。然而，我们对有机体在健康肠道中建立的内在特征知之甚少，健康肠道是肠球菌疾病的重要前奏。我们将在无菌小鼠和携带人类肠道微生物群落的“人源化”动物中研究模型实验室菌株 OG1RF。我们将使用一种强大的新型遗传筛选（我们称之为“Smart TnSeq”）来识别编码蛋白质和小调节RNA的遗传决定因素，这些因素有助于胃肠道的竞争适应性，并开始研究它们的功能和作用机制。我们将使用高分辨率显微技术来检查生物体内的行为以及感兴趣基因的表达。这项研究的结果将包括以下内容：1）将出现肠道健康决定因素作用的全基因组图景。 2）我们将更好地了解肠球菌定植的首选位点，以及这些有利位点中基因表达的调节方式。 3）从长远来看，我们可能会找到新的基于生态的策略，它可以预防肠球菌感染，而不必杀死细菌，从而减少耐药性的选择。