Defining the role of Serratia marcescens nuclease in infection process

定义粘质沙雷氏菌核酸酶在感染过程中的作用

• 批准号: 10646829
• 负责人: Lydia M Bogomolnaya
• 金额: $ 7.4万
• 依托单位: MARSHALL UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-02-06 至 2025-01-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10646829
• 关键词: Address; Affect; Anatomy; Animal Model; Antibiotics; Bacteria; Bacterial Drug Resistance; Biological; Biology; Blood Circulation; Catheters; Cell Culture Techniques; Cells; Cessation of life; Clinical; Data; Development; Dialysis patients; Dose; Enzymes; Evaluation; Excision; Eye; Frequencies; Future; Goals; Gram-Negative Bacteria; Growth; HL-60 Cells; Healthcare; Hemodialysis; High Prevalence; Hospitals; Immune Evasion; Immune response; Infection; Kidney Failure; Knowledge; Mediating; Modeling; Morbidity - disease rate; Multi-Drug Resistance; Mus; Neutrophil Infiltration; Organism; Outcome; Pathogenesis; Patients; Peritoneal Dialysis; Peritonitis; Play; Positioning Attribute; Pre-Clinical Model; Predisposition; Process; Research; Resistance; Resolution; Role; SWR/J Mouse; Serratia; Serratia Infections; Serratia marcescens; Signal Transduction; Site; Surgical wound; System; Systemic infection; Testing; Time; Tissues; Urinary tract; Virulence Factors; World Health Organization; antimicrobial; endonuclease; experimental study; extracellular; in vivo; in vivo imaging; insight; intraperitoneal; mouse model; mutant; neutrophil; novel; nuclease; opportunistic pathogen; pathogen; pathogenic bacteria; priority pathogen; rational design; respiratory; spatiotemporal; sugar

Project Summary The emergence of bacterial drug resistance, especially in hospital settings, represents the next great challenge in healthcare. Serratia marcescens, the Gram-negative bacterial pathogen with intrinsic resistance to several classes of antibiotics, can cause infections with severe outcomes affecting multiple body sites. This bacterium is also associated with complications of peritoneal dialysis (PD) in patients with kidney failure. Importantly, Serratia-associated peritonitis accompanied by massive neutrophil infiltration was shown to have the highest nonresolution rate among episodes caused by Gram-negative bacteria, leading either to the death of the PD patient, or catheter removal and transfer to hemodialysis. The progress in our understanding of S. marcescens infections is hampered by the lack of reliable preclinical model, which represents a critical barrier to progress in the field. The current knowledge of strategies used by this opportunistic pathogen to colonize the mammalian host and to evade the immune response is not complete, and only a handful of virulence factors were identified to date. S. marcescens is known to secrete an array of hydrolytic enzymes, including sugar non-specific endonuclease; however, the biological role of this enzyme during infection has not been evaluated. In this proposal, we seek to establish a murine model to study the S. marcescens dynamic spread during intraperitoneal infection and to test a hypothesis that an extracellular S. marcescens enzyme nuclease plays a key role in bacterial escape from neutrophil extracellular traps (NETs) in this niche. In Aim 1 we will characterize the bioluminescent S. marcescens spread following intraperitoneal infection using in vivo imaging. In Aim 2 we will first evaluate the S. marcescens extracellular nuclease potential to degrade NETs in cultures of neutrophil-like cells, followed by infection study to determine the biological role of this enzyme in vivo. This proposal will advance current understanding of Serratia pathogenesis and provide insight into the bacterium’s strategy to avoid neutrophil-mediated clearance. Altogether, our experiments will establish a blueprint for future studies of other nuclease-producing pathogenic bacteria.

项目摘要 细菌耐药性的出现，尤其是在医院环境中，代表了下一个 医疗保健中的巨大挑战。 Serratia marcescens，革兰氏阴性细菌病原体 对几类抗生素的固有耐药性会引起严重预后的感染 影响多个身体部位。该细菌也与腹膜并发症有关 肾衰竭患者的透析（PD）。重要的是，与锯齿相关的腹膜炎 伴随着大量中性粒细胞的浸润显示为最高的非分辨率率 在革兰氏阴性细菌引起的发作中，要么导致PD患者死亡， 或切除导管并转移到血液透析中。我们对S的理解的进步 缺乏可靠的临床前模型，阻碍了马尔斯奇斯的感染，这代表了一个 该领域进步的关键障碍。当前对此使用的策略的了解 机会性病原体定居哺乳动物宿主并逃避免疫反应不是 迄今为止，完整的，只有少数病毒因素。 S. Marcescens是已知的 向一系列水解酶进行秘密，包括糖非特异性核酸内切酶；然而， 该酶在感染过程中的生物学作用尚未评估。在这个建议中，我们 寻求建立一个鼠模型，以研究Marcescens的动态传播 腹膜内感染并检验一个假设，即细胞外链球菌酶 核酸酶在细菌中起关键作用，从中嗜中性粒细胞外陷阱（NET）在此中起着关键作用 利基。在AIM 1中，我们将表征生物发光的S. marcescens蔓延。 使用体内成像的腹膜内感染。在AIM 2中，我们将首先评估S. Marcescens 细胞外核酸酶在中性粒细胞培养物中降解网的潜力，然后 感染研究确定该酶在体内的生物学作用。该提议将进步 当前了解锯齿发病机理并提供对细菌策略的见解 避免中性粒细胞介导的间隙。总之，我们的实验将建立一个蓝图 对其他产生核酸酶的致病细菌的未来研究。