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组成，它们在自然中提供了特定的优势 环境或人类病原体。两种主要类型的DIDERMIC细菌，其中包含两个细胞信封 脂质膜已经发现，其外膜表面的成分有所不同 （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处产生严格的渗透性屏障，使它们对许多抗生素具有抵抗力。此外， LPS生物发生在大多数革兰氏阴性细菌中都是必不可少的，尽管原因仍然难以捉摸。 其他doderms（例如许多螺旋体）具有甘油磷脂（GPLS）和脂蛋白在表面 om。表面脂蛋白在发病机理，养分获取和信号传导中具有许多关键作用。然而， 对于大多数发现它们的细菌，脂蛋白如何到达OM表面一直未知。 高优先级的革兰氏阴性病原体Acinetobacter Baumannii非常能够以OM生存 在表面含有LPS或GPLS和脂蛋白。 A. Baumannii自然会产生LPS- 包含OM。但是，该细菌能够通过完全失活LPS生物发生能够生存。损失 细胞表面的LP伴随着表面暴露的脂蛋白的上调。主要目标 该应用的是研究分子在细胞，LP和LPS表面上的功能和组装 脂蛋白，使用含LPS和LPS缺陷型baumannii。在AIM 1中，我们将同时指导 方法，研究表面脂蛋白在LPS缺乏性过程中的作用，以及一种无偏见的方法， 确定缺乏LPS的baumannii的其他遗传要求。在AIM 2中，我们将表征如何 脂蛋白在鲍曼尼曲霉中达到OM的表面。我们将靶向与脂蛋白转运有关的基因 在其他细菌中，并执行一个公正的筛选，以鉴定与表面定位有关的基因。这 A. baumannii具有出色的能力，具有两种不同的OM组成，为一个独特的机会提供了 探索每个提供给细菌细胞的优势。该应用是建立在强大的科学前提之上的 解决我们对病原体的主要差距，这将具有广泛的含义 朝着细胞包膜生物发生以及可能治疗革兰氏阴性菌和其他Dodermic细菌。 该申请将由主要调查员在M. Stephen Trent博士（赞助商）的实验室完成 佐治亚大学。两者都致力于向受训者提供研究（例如 基因组学，显微镜等）和职业发展资源（例如，教学培训， 指导等）。奖学金的完成将提供新技术的培训（例如脂质组学），新领域 研究（例如基因组学）以及为在学术界独立研究人员做准备的关键技能。