Novel virulence and exoenzyme regulators

新型毒力和外酶调节剂

• 批准号: 8648986
• 负责人: ROBERT M SHANKS
• 金额: $ 36.04万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-05-15 至 2016-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8648986
• 关键词: Address; American; Anti-Infective Agents; Antibiotic Resistance; Antibiotics; Attenuated; Bacteremia; Bacteria; Blindness; Cell model; Cells; Clinical; Communities; Cornea; Custom; DNA-Protein Interaction; Data; Developed Countries; Developing Countries; Endocarditis; Epithelial Cells; Eye Infections; Figs - dietary; Foundations; Future; Gene Targeting; Genes; Genetic; Genetic Transcription; Hemolysin; In Vitro; Infection; Keratitis; Knock-out; Knowledge; Laboratories; Lead; Life; Metalloproteases; Methods; Modeling; Morbidity - disease rate; Mutate; Mutation; Nosocomial Infections; Organism; Oryctolagus cuniculus; Outcome; Pathogenesis; Pathogenicity; Pathway interactions; Peptide Hydrolases; Pharmaceutical Preparations; Pneumonia; Production; Proteins; RNA; Regulation; Regulator Genes; Regulatory Pathway; Research; Resistance; Resistance development; Reverse Transcriptase Polymerase Chain Reaction; Role; Serratia marcescens; System; Testing; Tissues; Transcriptional Regulation; United States; Urinary tract infection; Virulence; Virulence Factors; Vision; corneal epithelium; cytotoxicity; design; exoenzyme; in vivo; mortality; mutant; new therapeutic target; novel; novel strategies; pathogen; prevent; public health relevance; transcription factor

DESCRIPTION (provided by applicant): Bacterial keratitis is a costly and global problem that results in vision loss and blindness, and Serratia marcescens is a leading agent of community-acquired Gram-negative bacterial keratitis. S. marcescens also causes many hospital acquired infections including pneumonia, endocarditis, bacteremia and urinary tract infections that are commonly resistant to current antibiotics and whose outcomes are associated with significant morbidity and mortality. There is a lack of studies that investigate how S. marcescens genes contribute to ocular infections using isogenic mutant strains. The broad long-term objective of this research is to prevent vision loss following corneal infections caused by this organism. A better understanding of the mechanisms by S. marcescens virulence factors are regulated will allow for a novel approach to reduce tissue damage and corneal opacification that results from the expression of these factors. This new knowledge about specific pathways can be used to custom design novel anti-infectives. Establishing new therapeutic targets is becoming ever more important as bacteria continue to develop resistance to existing classes of antibiotics. Our overall specific hypothesis to be tested is that the transcription factor EepR/S is a critical virulence factor that controls expression of tissue damaging metalloprotease and hemolysin activities. Our preliminary data supports that the mutation of EepR/S in S. marcescens severely attenuates the pathogenesis of S. marcescens in an in vivo ocular model of keratitis. Our central hypothesis will be tested by accomplishing the following aims: Aim 1. Test the hypothesis that EepR/S, four metalloproteases and the ShlA hemolysin are required for S. marcescens cytotoxicity in vitro and ocular pathogenesis in vivo. Aim 2. Test the hypothesis that EepR and EepS regulate transcription of metalloprotease and hemolysin genes, and that EepR/S is in a regulatory pathway with other transcription factors (crp, hexS and pigP).

描述（由申请人提供）：细菌性角膜炎是一种昂贵的全球性问题，可导致视力丧失和失明，粘质沙雷氏菌是社区获得性革兰氏阴性细菌性角膜炎的主要病原体。粘质葡萄球菌还引起许多医院获得性感染，包括肺炎、心内膜炎、菌血症和尿路感染，这些感染通常对现有抗生素具有耐药性，其结果与显著的发病率和死亡率相关。目前还缺乏利用等基因突变株研究粘质葡萄球菌基因如何导致眼部感染的研究。这项研究的长期目标是预防由这种生物体引起的角膜感染后的视力丧失。更好地了解粘质葡萄球菌毒力因子调控的机制将为减少这些因子表达导致的组织损伤和角膜混浊提供一种新的方法。这种关于特定途径的新知识可用于定制设计新的抗感染药物。随着细菌不断对现有种类的抗生素产生耐药性，建立新的治疗靶点变得越来越重要。我们要测试的总体具体假设是转录因子EepR/S是控制组织损伤金属蛋白酶和溶血素活性表达的关键毒力因子。我们的初步数据支持，在角膜炎的体内眼模型中，粘质葡萄球菌中EepR/S的突变严重减弱了粘质葡萄球菌的发病机制。我们的中心假设将通过实现以下目标来检验：目标1。验证EepR/S、4种金属蛋白酶和ShlA溶血素参与粘质葡萄球菌体外细胞毒性和体内眼部发病的假设。目标2。验证EepR和EepS调控金属蛋白酶和溶血素基因转录的假说，以及EepR/S与其他转录因子（crp、hexS、pigP）的调控通路。