Elucidating how CRISPR-Cas Modulates the Spread of S. aureus Pathogenicity Islands

阐明 CRISPR-Cas 如何调节金黄色葡萄球菌致病岛的传播

• 批准号: 10473519
• 负责人: Dalton Van Banh
• 金额: $ 5.18万
• 依托单位: WEILL MEDICAL COLL OF CORNELL UNIV
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-08-06 至 2025-08-05
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10473519
• 关键词: Affect; Antibiotic Resistance; Antibiotics; Antimicrobial Resistance; Automobile Driving; Bacteria; Bacterial Chromosomes; Bacterial Infections; Bacteriophages; Biological; Biological Assay; Cells; Clustered Regularly Interspaced Short Palindromic Repeats; Community-Acquired Infections; Complex; Data; Development; Disease; Doctor of Philosophy; Elements; Enterotoxins; Evolution; Excision; Fellowship; Foundations; GTP-Binding Protein alpha Subunits, Gs; Genes; Genetic; Genetic Transcription; Genome; Genus staphylococcus; Goals; Horizontal Gene Transfer; Immunity; Immunization; Infection; Invaded; Laboratories; Larva; Life Cycle Stages; Measures; Mediating; Medical; Mobile Genetic Elements; Modeling; Molecular; Molecular Genetics; Multi-Drug Resistance; Multiple Bacterial Drug Resistance; Nosocomial Infections; Pathogenesis; Pathogenicity Island; Physicians; Plasmids; Population; Principal Investigator; RNA; Research; Ribonucleases; Scientist; Staphylococcus aureus; Superantigens; System; Testing; Tetracycline Resistance; Therapeutic; Toxic Shock Syndrome; Toxin; Training; Virulence; Virulence Factors; Virulent; Work; adaptive immunity; antimicrobial; base; career; colonization resistance; commensal microbes; design; experimental study; genetic approach; global health; in vivo; insight; multi-drug resistant pathogen; mutant; novel therapeutic intervention; nuclease; particle; pathogen; prevent; programs; reproductive; resistance gene; staphylococcal enterotoxin; targeted treatment; transmission process

PROJECT SUMMARY/ABSTRACT Staphylococcus aureus is a major cause of both community-acquired and nosocomial infections, which have become increasingly challenging to treat due to the widespread evolution of antimicrobial resistance. There is a critical need for the development of alternative therapeutic approaches against multidrug-resistant bacteria that also spare the protective commensal microbiota, which often provide colonization resistance against pathogens. Bacterial disease is driven by S. aureus toxins and other virulence factors, which are mainly encoded by mobile genetic elements (MGEs). In particular, numerous enterotoxins and the superantigen toxin causing Toxic Shock Syndrome are all carried by a class of MGEs called the S. aureus Pathogenicity Islands (SaPIs), which spread between bacteria by hijacking the reproductive machinery of bacteriophages. Staphylococci also possess CRISPR-Cas systems, which provide adaptive immunity by blocking invading MGEs like phages and plasmids. In this proposal, building upon preliminary data, I will test the central hypothesis that CRISPR-Cas systems also prevent the transmission of SaPI elements and their associated virulence genes. In Aim 1, I will define the complex tripartite interplay between staphylococcal CRISPR systems, SaPIs, and their helper phages using various molecular and genetic approaches. In Aim 2, I will investigate the mechanisms by which SaPIs manage to overcome CRISPR-mediated restriction and disseminate throughout bacterial populations. I anticipate that these studies will elucidate both the molecular basis and biological consequences for CRISPR-SaPI interactions. In Aim 3, I will evaluate whether CRISPR can be used to selectively kill SaPI-harboring S. aureus and establish a proof-of-concept for CRISPR-based antimicrobials directed against virulence-encoding MGEs. The proposed experiments will contribute to the long-term goal of designing alternative therapeutic approaches in an effort to overcome the shortcomings of antibiotics in treating multidrug-resistant infections. This fellowship will support my training in the Weill Cornell/Rockefeller/Sloan Kettering Tri-Institutional MD-PhD Program, including my doctoral work in the laboratory of Dr. Luciano Marraffini at Rockefeller and the remainder of my medical training at Weill Cornell. The training plan outlined in this fellowship project is designed to optimally prepare me for a research career as an independent principal investigator and physician-scientist.

项目概要/摘要 金黄色葡萄球菌是社区获得性感染和医院感染的主要原因， 由于抗菌素耐药性的广泛演变，治疗变得越来越困难。有一个 迫切需要开发针对多重耐药细菌的替代治疗方法 还保留了保护性共生微生物群，这些微生物群通常对病原体具有定植抵抗力。 细菌性疾病是由金黄色葡萄球菌毒素和其他毒力因子驱动的，这些毒力因子主要由移动编码 遗传元件（MGE）。特别是多种肠毒素和超抗原毒素会引起中毒性休克 综合症均由一类称为金黄色葡萄球菌致病岛 (SaPI) 的 MGE 携带，这些 MGE 会传播 通过劫持噬菌体的生殖机制来在细菌之间进行传播。葡萄球菌还具有 CRISPR-Cas 系统，通过阻断噬菌体和质粒等入侵的 MGE 来提供适应性免疫。 在本提案中，基于初步数据，我将测试核心假设，即 CRISPR-Cas 系统还 防止 SaPI 元件及其相关毒力基因的传播。在目标 1 中，我将定义 葡萄球菌 CRISPR 系统、SaPI 及其辅助噬菌体之间复杂的三方相互作用 各种分子和遗传学方法。在目标 2 中，我将研究 SaPI 管理的机制 克服 CRISPR 介导的限制并在整个细菌群体中传播。我预计 这些研究将阐明 CRISPR-SaPI 相互作用的分子基础和生物学后果。 在目标 3 中，我将评估 CRISPR 是否可用于选择性杀死携带 SaPI 的金黄色葡萄球菌并建立 针对毒力编码 MGE 的基于 CRISPR 的抗菌药物的概念验证。拟议的 实验将有助于设计替代治疗方法的长期目标，以努力 克服抗生素治疗多重耐药感染的缺点。该奖学金将支持 我在威尔康奈尔/洛克菲勒/斯隆凯特琳三机构医学博士项目中接受的培训，包括我的 在洛克菲勒大学 Luciano Marraffini 博士的实验室进行博士研究，并完成剩余的医学培训 在威尔康奈尔大学。该奖学金项目中概述的培训计划旨在为我做好最佳准备 作为独立首席研究员和医师科学家的研究生涯。