Identification of Pathways that can be Targeted for the Development of Novel Therapies for MRSA

项目总结（见说明）： MRSA和VRE菌株对C.该模型系统可用于研究涉及葡萄球菌和肠球菌毒力因子的宿主-病原体相互作用。重要的是，金黄色葡萄球菌的毒力决定因素参与哺乳动物的发病机制，包括群体感应全球毒力调节系统agr，全球毒力调节sarA，和替代西格玛因子西格玛（B）所需的线虫的完全致病性。 基于这些观察，我们开发了一个C。elegans-S.使用384孔板形式进行的金黄色葡萄球菌筛选测定。该整体动物测定可用于筛选化合物文库，允许鉴定在传统体外筛选中检测不到的防止宿主杀伤的化合物。我们的目标是实现这一C。基于elegans的测定，并利用自动化、高通量、全动物筛选来鉴定对MRSA、VRE和VRSA有效的化合物。将通过进行剂量-反应和时间-过程评价已鉴别的化合物 研究，确定体外MIC，确定毒性，并优先考虑在哺乳动物中测试的化合物。我们还建议对以前在C. elegans -秀丽隐杆线虫E. faecalis筛选，并与其他子项目协同，以研究通过C. elegans分析和表征来自其他Subrobians的化合物。 梭基于elegans的分析特别有吸引力，因为它们允许同时评价毒性和抗微生物活性，以及研究非增殖形式的细菌细胞。因此，可以尽早从进一步考虑中排除错误的线索，并明确识别新的线索。除了具有直接抗菌活性的化合物外，C.基于elegans的分析将鉴定影响细菌毒力因子和宿主功能的化合物，为探索宿主/病原体相互作用提供新的线索和新的化学生物学工具。

PROJECT SUMMARY (See instructions): MRSA and VRE strains kill C. elegans using traits that contribute to the pathogenesis of infection in mammals, and this model system can be used to study host-pathogen interactions involving staphylococcal and enterococcal virulence factors. Importantly, Staphylococcus aureus virulence determinants involved in mammalian pathogenesis, including the quorum-sensing global virulence regulatory system agr, the global virulence regulator sarA, and the alternative sigma factor sigma(B) are required for full pathogenicity in nematodes. Based on these observations, we developed a C. elegans-S. aureus screening assay that is performed using the 384-well plate format. This whole animal assay can be used to screen compound libraries, allowing the identification of compounds that prevent host killing that would not be detected in traditional in vitro screens. Our objective is to implement this C. elegans-based assay and utilize automated, high-throughput, whole animal screens to identify compounds with efficacy against MRSA, VRE and VRSA. Identified compounds will be evaluated by carrying out dose-response and time-course studies, determining in vitro MICs, determining toxicity, and by prioritizing the compounds for testing in mammals. We also propose to characterize the compounds previously identified in a C. elegans - E. faecalis screen, and synergize with other Subprojects in order to study compounds identified through the C. elegans assays and characterize compounds from other Subrojects. The C. elegans-based assays are particularly appealing in that they allow concurrent evaluation of toxicity and antimicrobial activity, as well as study of bacterial cells that are in a non-planktonic form. Thus false leads can be eliminated from further consideration early, and new leads will be clearly identified. In addition to compounds that have direct antibacterial activity, the C. elegans-based assays will identify compounds that affect bacterial virulence factors and host function, providing new leads, but also new chemical biology tools for exploring host/pathogen interaction.