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.

摘要 细菌已经进化出不同的细胞被膜组成，这为它们的自然生长提供了特定的优势。 环境或人类病原体。两种主要类型的二层细菌，含有两个 脂膜，已经发现，不同的组成，其表面的外膜 （OM）。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处产生严格的渗透屏障，并使它们对许多抗生素产生抗性。此外，本发明还提供了一种方法， LPS生物合成在大多数革兰氏阴性菌中是必不可少的，尽管原因仍然难以捉摸。 其他双胚层（例如许多螺旋体）在其表面具有甘油磷脂（GPL）和脂蛋白。 OM。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，在这方面， 脂蛋白如何到达OM的表面对于发现它们的大多数细菌来说仍然是未知的。 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 在表面含有LPS或GPL和脂蛋白。A.鲍曼不动杆菌自然产生LPS- 含有OM。然而，这种细菌能够在LPS生物合成完全失活的情况下存活。损失 细胞表面的LPS伴随着表面暴露的脂蛋白的上调。主要目的 本申请的目的是研究细胞表面分子的功能和组装，LPS和 脂蛋白，使用含LPS和LPS缺陷A.鲍曼不动杆菌。在目标1中，我们将采取定向 的方法，调查的作用，表面脂蛋白在脂蛋白缺乏症，和一个无偏见的方法， 确定LPS缺陷A的额外遗传要求。鲍曼不动杆菌。在目标2中，我们将描述如何 脂蛋白到达A中OM的表面。鲍曼不动杆菌。我们将靶向与脂蛋白转运有关的基因 在其他细菌中，并进行无偏筛选以鉴定参与表面定位的基因。的 A的能力。鲍曼不动杆菌与两种不同的OM组合物一起生长，提供了一个独特的机会， 探索每种细菌细胞的优势。这项申请是建立在一个强有力的科学前提之上的 解决了我们对病原体认识上的主要差距，A.鲍曼尼，这将产生广泛的影响， 对细胞包膜生物发生和可能的治疗革兰氏阴性和其他didermic细菌。 申请将由主要研究者在M博士的实验室完成。斯蒂芬·特伦特（赞助商）在 格鲁吉亚大学。两者均致力为学员提供研究服务（例如 基因组学、显微镜等）和职业发展资源（如培训，教学， 指导等）。完成研究金将提供新技术（如脂质组学）、新领域 研究（如基因组学），和关键技能，准备作为一个独立的研究人员在学术界的职业生涯。