Contribution of extracellular enzymes to Staphylococcus aureus biofilm development

胞外酶对金黄色葡萄球菌生物膜发育的贡献

• 批准号: 10461797
• 负责人: Tammy L Kielian
• 金额: $ 45.33万
• 依托单位: UNIVERSITY OF NEBRASKA MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-07-01 至 2024-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10461797
• 关键词: Address; Adenosine; Anti-Inflammatory Agents; Antibiotics; Behavior; Biological Markers; Carbon; Catabolism; Cell physiology; Collaborations; DNA; Defect; Development; Devices; Digestion; Disaccharides; Disease; Environment; Enzymes; Excision; Foreign Bodies; Gene Expression; Genus staphylococcus; Glycosaminoglycans; Growth; Healthcare Systems; Human; Hyaluronan; Hyaluronidase; Immune; In Vitro; Infection; Inflammation; Inflammatory; Innovative Therapy; Joint Prosthesis; Knock-out; Label; Metabolic; Metabolism; Microbial Biofilms; Mutation; Nature; Nutrient; Nutritional; Nutritional status; Pathway interactions; Patient-Focused Outcomes; Patients; Phenotype; Polymers; Production; Property; Regulation; Reporting; Resistance; Role; Scheme; Site; Source; Staphylococcus aureus; Staphylococcus aureus infection; Synovial Fluid; System; Testing; bioimaging; cell community; chemotherapy; defined contribution; exoenzyme; extracellular; follow-up; genetic analysis; health care settings; inhibitor; joint infection; metabolomics; mutant; nuclease; pathogenic bacteria; sensor; transcriptome sequencing; transcriptomics

PROJECT SUMMARY Staphylococcus aureus is one of the most problematic bacterial pathogens in our healthcare settings. S. aureus can survive and persist in the host by developing into an encased community of cells called a biofilm, and numerous studies have demonstrated that biofilms are resistant to host immune defenses and chemotherapies. Our central PPG hypothesis is that S. aureus biofilm development creates unique metabolic niches that promote an immune suppressive environment. In this proposal (Project 3), we are focusing on the contribution of S. aureus extracellular enzymes to biofilm growth and maturation, persistence in the host, and ultimately dissemination to a new site. Of the many enzymes that S. aureus secretes, we will prioritize hyaluronidase (HysA) and nuclease (Nuc1), as they have commonalities in biofilm-host interaction phenotypes and regulatory schemes. We recently demonstrated that hyaluronan accumulates in an S. aureus biofilm infection and that HysA can degrade this host glycosaminoglycan to disaccharides (HA-DS). Our preliminary studies indicate that HA-DS can serve as a carbon source through an unknown catabolic pathway, and this disaccharide has additional anti-inflammatory properties that could be contributing to the persistent nature of S. aureus biofilm infections. In Specific Aim 1, we will determine the role and regulation of hyaluronan metabolism in S. aureus biofilm maturation. We will characterize the HA-DS catabolic pathway using genetic analysis and labeling studies in collaboration with the Metabolomics Core. We will also test catabolic pathway knockouts in biofilm maturation and foreign-body infections, and investigate the contribution of CodY and CcpA to regulation of hyaluronan catabolism. Additionally, S. aureus will be grown on HA-DS and RNAseq performed to identify global transcriptomic changes. In Specific Aim 2, we will investigate how S. aureus enzymatic degradation of host polymers impacts the biofilm anti-inflammatory state. In collaboration with Dr. Tammy Kielian (PPG Project 4), we will assess the effect of HA-DS, as well as Nuc1 and HysA enzymes and their regulators, on immune cell function. We will also determine the impact of HA-DS and HysA inhibitors on biofilm infection, and test whether HA-DS is a biomarker for S. aureus in human synovial fluid from patients with prosthetic joint infection (PJI). In Specific Aim 3, we will examine S. aureus exo-enzyme regulation and function in biofilm dispersal. We hypothesize that CodY controls dissemination from S. aureus biofilms in an enzyme and nutrient dependent manner. We will investigate the contribution of Nuc1 and HysA, along with CodY and SaeRS regulators, to biofilm dispersal in vitro and during foreign body infection. We will also examine the impact of nutritional status on CodY activity during biofilm formation and dispersal in collaboration with Dr. Ken Bayles (PPG Project 1) and the Bioimaging Core. Finally, we will determine the role of aureusimine molecules in S. aureus biofilm development. Collectively these studies will define the contribution of S. aureus exo-enzymes to biofilm metabolism, development and persistence, potentially leading to innovative therapies for biofilm infections.

项目概要 金黄色葡萄球菌是我们医疗保健环境中最成问题的细菌病原体之一。金黄色葡萄球菌 通过发育成称为生物膜的封闭细胞群落，可以在宿主体内存活并持续存在，并且 大量研究表明，生物膜对宿主免疫防御和化疗具有抵抗力。 我们的中心 PPG 假设是金黄色葡萄球菌生物膜的发育创造了独特的代谢生态位，促进 免疫抑制环境。在此提案（项目 3）中，我们重点关注 S. 金黄色葡萄球菌胞外酶促进生物膜的生长和成熟，在宿主体内持续存在，并最终 传播到新站点。在金黄色葡萄球菌分泌的多种酶中，我们将优先考虑透明质酸酶 (HysA) 和核酸酶 (Nuc1)，因为它们在生物膜-宿主相互作用表型和调节方面具有共同点 计划。我们最近证明透明质酸在金黄色葡萄球菌生物膜感染中积累，并且 HysA 可以将该宿主糖胺聚糖降解为二糖 (HA-DS)。我们的初步研究表明 HA-DS可以通过未知的分解代谢途径作为碳源，并且这种二糖具有 额外的抗炎特性可能有助于金黄色葡萄球菌生物膜的持久性 感染。在具体目标 1 中，我们将确定透明质酸代谢在金黄色葡萄球菌中的作用和调节 生物膜成熟。我们将使用遗传分析和标记研究来表征 HA-DS 分解代谢途径 与代谢组学核心合作。我们还将测试生物膜成熟中的分解代谢途径敲除 和异物感染，并研究 CodY 和 CcpA 对透明质酸调节的贡献 分解代谢。此外，金黄色葡萄球菌将在 HA-DS 上生长，并进行 RNAseq 来鉴定全局 转录组变化。在具体目标 2 中，我们将研究金黄色葡萄球菌如何酶促降解宿主 聚合物影响生物膜的抗炎状态。与 Tammy Kielian 博士（PPG 项目 4）合作， 我们将评估 HA-DS 以及 Nuc1 和 HysA 酶及其调节剂对免疫细胞的影响 功能。我们还将确定 HA-DS 和 HysA 抑制剂对生物膜感染的影响，并测试是否 HA-DS 是人工关节感染 (PJI) 患者滑液中金黄色葡萄球菌的生物标志物。在 具体目标 3，我们将研究金黄色葡萄球菌外切酶在生物膜分散中的调节和功能。我们 假设 CodY 以酶和营养依赖性方式控制金黄色葡萄球菌生物膜的传播 方式。我们将研究 Nuc1 和 HysA 以及 CodY 和 SaeRS 调节因子对生物膜的贡献 体外和异物感染期间的传播。我们还将研究营养状况对 CodY 的影响 与 Ken Bayles 博士（PPG 项目 1）和 生物成像核心。最后，我们将确定金黄色葡萄球菌亚胺分子在金黄色葡萄球菌生物膜发育中的作用。 总的来说，这些研究将确定金黄色葡萄球菌外切酶对生物膜代谢的贡献， 发展和持久性，可能导致生物膜感染的创新疗法。