Function and maintenance of molecules at the surface of Acinetobacter baumannii

鲍曼不动杆菌表面分子的功能和维持

• 批准号: 10231048
• 负责人: Brent Simpson
• 金额: $ 6.64万
• 依托单位: UNIVERSITY OF GEORGIA
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-09-01 至 2022-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10231048
• 关键词: Academia; Acinetobacter baumannii; Address; Anabolism; Antibiotic Resistance; Antibiotics; Antimicrobial Cationic Peptides; Bacteria; Bacterial Physiology; Binding; Biogenesis; Biology; Blood; Cell surface; Cells; Charge; Core Facility; Cytolysis; Development; Disease; Educational process of instructing; Encapsulated; Environment; Escherichia coli; Extravasation; Fellowship; Genes; Genetic; Genomics; Glycerophospholipids; Gram-Negative Bacteria; Gram-Negative Bacterial Infections; Human; Immune system; Infection; Lipid A; Lipids; Lipopolysaccharides; Lipoproteins; Lung; Maintenance; Membrane; Membrane Lipids; Mentors; Microscopy; Modification; Mucous Membrane; Multi-Drug Resistance; Mutation; Nosocomial Infections; Nutrient; O Antigens; Oligosaccharides; Operative Surgical Procedures; Order Spirochaetales; Pathogenesis; Pathway interactions; Peptidoglycan; Permeability; Pharmacotherapy; Polymyxin Resistance; Polymyxins; Principal Investigator; Process; Research; Research Personnel; Resistance; Resort; Resource Development; Role; Signal Transduction; Structure; Surface; Techniques; Training; Universities; Up-Regulation; Urinary tract infection; Virulence; World Health Organization; analog; antimicrobial; bacterial fitness; career; career development; cell envelope; drug resistant bacteria; emerging pathogen; extensive drug resistance; fighting; human pathogen; inorganic phosphate; lipidomics; lipooligosaccharide; nephrotoxicity; neurotoxicity; novel; novel therapeutics; null mutation; pathogen; prevent; priority pathogen; resistance mechanism; response; skills; tool; transposon sequencing; wound

Abstract Bacteria have evolved different cell envelope compositions that provide them specific advantages in their natural environments or as human pathogens. Two major types of didermic bacteria, containing cell envelopes with two lipid membranes, have been discovered that differ by the composition of the surface of their outer membranes (OM). Gram-negative bacteria (e.g. Escherichia coli) contain a surface layer of lipopolysaccharides (LPS) that produces a stringent permeability barrier at the OM and make them resistant to many antibiotics. In addition, LPS biogenesis is essential in most Gram-negative bacteria, although the reason why has remained elusive. Other diderms (e.g. many spirochetes) have glycerophospholipids (GPLs) and lipoproteins at the surface of the OM. Surface lipoproteins have many critical roles in pathogenesis, nutrient acquisition, and signaling. However, how lipoproteins reach the surface of the OM has remained unknown for most bacteria in which they are found. The high-priority Gram-negative pathogen, Acinetobacter baumannii, is remarkably able to survive with an OM containing either LPS or GPLs and lipoproteins at the surface. A. baumannii naturally produces an LPS- containing OM. However, this bacterium is able to survive with complete inactivation of LPS biogenesis. Loss of LPS at the cell surface is accompanied by up-regulation of surface-exposed lipoproteins. The primary objective of this application is to investigate the function and assembly of molecules on the surface of the cell, LPS and lipoproteins, using LPS-containing and LPS-deficient A. baumannii. In Aim 1, we will take both a directed approach, to investigate the role of surface lipoproteins during LPS-deficiency, and a non-biased approach, to identify additional genetic requirements for LPS-deficient A. baumannii. In Aim 2, we will characterize how lipoproteins reach the surface of the OM in A. baumannii. We will target genes implicated in lipoprotein transport in other bacteria, and perform an unbiased screen to identify genes involved in surface localization. The remarkable ability of A. baumannii to grow with two different OM compositions, provides a unique opportunity to explore the advantages each provides to bacterial cells. This application is built on a strong scientific premise addressing major gaps in our understanding of the pathogen, A. baumannii, that will have broad implications towards cell envelope biogenesis and possible treatment of both Gram-negative and other didermic bacteria. The application will be completed by the principal investigator in the lab of Dr. M. Stephen Trent (sponsor) at the University of Georgia. Both of which are committed to providing trainees with research (e.g. core facilities in genomics, microscopy, etc.) and career development resources (e.g. training in grantsmanship, teaching, mentoring, etc.). Completion of the fellowship will provide training in new techniques (e.g. lipidomics), new fields of research (e.g. genomics), and critical skills to prepare for a career as an independent researcher in academia.

抽象的 细菌已经进化出不同的细胞包膜成分，这为它们在天然条件下提供了特定的优势。 环境或人类病原体。两种主要类型的真皮细菌，含有两种细胞膜 已发现脂质膜的外膜表面成分不同 （哦）。革兰氏阴性细菌（例如大肠杆菌）含有脂多糖 (LPS) 的表面层， 在 OM 处产生严格的渗透性屏障，使其对许多抗生素产生耐药性。此外， LPS 的生物合成对于大多数革兰氏阴性细菌至关重要，但其原因仍然难以捉摸。 其他二胚层（例如许多螺旋体）的表面含有甘油磷脂 (GPL) 和脂蛋白 哦。表面脂蛋白在发病机制、营养获取和信号传导中具有许多关键作用。然而， 对于大多数发现脂蛋白的细菌来说，脂蛋白如何到达 OM 表面仍然未知。 高优先级革兰氏阴性病原体鲍曼不动杆菌能够在 OM 中存活 表面含有 LPS 或 GPL 和脂蛋白。鲍曼不动杆菌自然产生 LPS- 含有OM。然而，这种细菌能够在 LPS 生物发生完全失活的情况下生存。损失 细胞表面的脂多糖伴随着表面暴露的脂蛋白的上调。主要目标 该应用的目的是研究细胞表面分子的功能和组装，脂多糖和 脂蛋白，使用含有 LPS 和缺乏 LPS 的鲍曼不动杆菌。在目标 1 中，我们将采取定向 方法，研究表面脂蛋白在 LPS 缺乏期间的作用，以及无偏见的方法， 确定缺乏 LPS 的鲍曼不动杆菌的额外遗传要求。在目标 2 中，我们将描述如何 脂蛋白到达鲍曼不动杆菌的 OM 表面。我们将针对与脂蛋白运输有关的基因 在其他细菌中，并进行无偏见的筛选来识别参与表面定位的基因。这 鲍曼不动杆菌在两种不同的 OM 组合物中生长的卓越能力，提供了独特的机会 探索每种细菌细胞的优势。该应用程序建立在强大的科学前提之上 解决我们对病原体鲍曼不动杆菌理解的主要差距，这将产生广泛的影响 细胞被膜生物发生和革兰氏阴性细菌和其他白皮细菌的可能治疗。 该申请将由 M. Stephen Trent 博士（申办者）实验室的首席研究员完成。 佐治亚大学。两者都致力于为学员提供研究（例如， 基因组学、显微镜学等）和职业发展资源（例如资助、教学、 辅导等）。完成该奖学金将提供新技术（例如脂质组学）、新领域的培训 研究（例如基因组学）的知识，以及为学术界独立研究人员的职业生涯做好准备的关键技能。