Intra-species regulatory functions of fsr

描述（由申请人提供）：粪肠球菌是心内膜炎、院内菌血症和尿路感染的主要原因。造成肠球菌感染治疗困难的两个特点是：(1)对-内酰胺类抗生素的耐受性和(2)引起生物膜相关感染的倾向。β -内酰胺耐受性和生物膜形成的调控仍不完全明确。该研究职业奖的申请人Satish K. Pillai博士提出，粪肠球菌群体感应位点fsr基于其与金黄色葡萄球菌调节因子agr的同源性，也具有全球调节因子的功能。使用agr范式，fsr代表了粪肠球菌调节病原体增强特性（如抗生素耐受性和生物膜形成）的可能候选基因。通过对等基因fsr阳性和fsr阴性的粪肠球菌分离株的研究，申请人将(1)研究fsr介导的生物膜相关基因的转录控制，并评估环境线索（如葡萄糖浓度）如何通过fsr传递来调节生物膜的形成；(2)表征FSR调控β -内酰胺诱导死亡的自溶依赖性和自溶非依赖性机制；(3)在改良的罗宾斯装置中制备生物膜，模拟慢性肠球菌感染情况，以确定fsr如何影响粪肠球菌对β -内酰胺类抗生素、万古霉素和氨基糖苷类药物的整体反应。申请人是贝斯以色列女执事医疗中心的传染病研究员，他将在他的赞助人dr。Robert C. Moellering, Jr., Roger T. Inouye, Peter F. Weller。除了他的指导研究，申请人的职业发展将辅以哈佛医学院的微生物学和遗传学课程，冷泉港实验室的细菌遗传学培训，以及哈佛公共卫生学院的生物统计学课程。本申请的目标是：(1)定义肠球菌生物膜形成和β -内酰胺耐受性的调控，以指导应对这种日益流行的病原体的策略；(2)允许申请人培养成为独立研究者所需的技能。

DESCRIPTION (provided by applicant): Enterococcus faecalis is a leading cause of endocarditis, nosocomial bacteremia and urinary tract infections. Two characteristics contributing to the difficulty in treating enterococcal infections are (1) tolerance to beta- lactam antibiotics and (2) the propensity to cause biofilm-associated infections. The regulation of beta-lactam tolerance and biofilm formation remains incompletely defined. The applicant for this Research Career Award, Dr. Satish K. Pillai, proposes that the E. faecalis quorum-sensing locus fsr, based on its homology to the Staphylococcus aureus regulator agr, also functions as a global regulator. Using the agr paradigm, fsr represents a likely candidate by which E. faecalis regulates pathogenesis-enhancing characteristics like antibiotic tolerance and biofilm formation. Through proposed studies on isogenic fsr-positive and fsr-negative E. faecalis isolates, the applicant will (1) investigate fsr -mediated transcriptional control of biofilm associated genes and evaluate how environmental cues, such as glucose concentration, are relayed through fsr to modulate biofilm formation; (2) characterize fsr regulation of autolysis-dependent and autolysis-independent mechanisms of beta-lactam induced killing; and (3) simulate the conditions of chronic enterococcal infections by developing biofilms in the modified Robbins Device, in order to determine how fsr influences the overall response of E. faecalis to beta-lactam antibiotics, vancomycin, and aminoglycosides. The applicant is an Infectious Diseases fellow at Beth Israel Deaconess Medical Center, and will conduct this research under the mentorship of his sponsors, Drs. Robert C. Moellering, Jr., Roger T. Inouye and Peter F. Weller. In addition to his mentored research, the applicant's career development will by supplemented by course work in microbiology and genetics at Harvard Medical School, bacterial genetics training at Cold Springs Harbor Laboratory, and biostatistics courses at the Harvard School of Public Health. The goals of this application are to (1) define the regulation of enterococcal biofilm formation and beta-lactam tolerance in order to guide strategies to counter this increasingly prevalent pathogen and (2) allow the applicant to develop the skills needed to be an independent investigator.