Global Circuitry that Controls Acinetobacter Resistance and Virulence

控制不动杆菌耐药性和毒力的全球电路

• 批准号: 10279655
• 负责人: Edward Geisinger
• 金额: $ 38万
• 依托单位: NORTHEASTERN UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-07-26 至 2026-06-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10279655
• 关键词: Acinetobacter; Acinetobacter baumannii; Anabolism; Antibiotic Resistance; Antibiotic Therapy; Antibiotics; Bacteria; Bypass; Cell Membrane Permeability; Cell physiology; Cells; Clinical; Data; Defect; Dependence; Development; Disease; Drug resistance; Face; Failure; Gene Fusion; Genes; Goals; Growth; Healthcare; Heart; Homeostasis; Hospitals; Human; Immune; Immune Evasion; In Vitro; Infection; Innate Immune System; Knowledge; Lesion; Link; Membrane; Membrane Proteins; Microbe; Microbial Biofilms; Modeling; Multidrug-resistant Acinetobacter; Mus; Mutation; Names; Orthologous Gene; Pathogenicity; Pathway interactions; Patient Isolators; Patients; Penetration; Permeability; Pharmaceutical Preparations; Phospholipids; Phosphorylation; Predisposition; Production; Protein Biosynthesis; Proteins; Public Health; Regulation; Regulon; Reporter; Research; Resistance; Ribosomes; Sensory; Sepsis; Signal Transduction; Stress; Surface; System; Testing; Translations; Treatment Failure; Variant; Virulence; Virulence Factors; Virulent; Work; addiction; antimicrobial; base; biological adaptation to stress; cell envelope; chemical genetics; drug resistant bacteria; drug resistant pathogen; env Gene Products; experimental study; extensive drug resistance; genetic regulatory protein; infection management; knock-down; member; microorganism; mortality; pathogen; promoter; response; therapeutic target; transposon sequencing

PROJECT SUMMARY Acinetobacter baumannii is among the most antibiotic-resistant pathogens known, and the emergence of isolates with enhanced virulence poses an urgent public health challenge. Understanding how the microorganism thwarts antibiotic and immune attack via its protective cell envelope is essential to developing new strategies for controlling this threat. Envelope synthesis and integrity in bacteria are typically maintained by a large number of response systems that control specific aspects of the envelope. A. baumannii, however, has diverged substantially from this paradigm. The pathogen lacks orthologs of many canonical envelope response proteins and instead relies on a single two-protein regulatory system to globally modulate every layer of the envelope and control both antibiotic resistance and ability to cause disease. This unique system, known as BfmRS, lowers susceptibility to a wide range of drugs, antagonizes innate immune killing, and facilitates development of lethal disease in mice. Intriguingly, a clinical isolate showing enhanced virulence requires the system for growth. BfmRS is therefore tightly linked to the intractability of infections with the pathogen and represents a key potential therapeutic target. Despite its fundamental importance, we lack an understanding of how the large BfmRS regulon controls broad- range drug resistance and pathogenicity, and what signals the system senses. The objective of the proposed studies is to understand how A. baumannii uses a single control circuit to simultaneously modulate resistance and virulence. Our central hypothesis is that BfmRS jointly controls the barrier to both drug penetration and innate immune attack by modulating the level of key outer membrane (OM) structures in response to disruptions in envelope protein production. We will test this hypothesis by pursuing three Aims, which build on our extensive preliminary data defining the BfmRS regulon and its chemical-genetic profile, as well as the phosphorylation cascade it uses for signaling. In Aim 1 we will test the model that BfmRS controls the bacterial interface with both antibiotics and innate immune effectors by modulating the OM barrier. In Aim 2, we will identify the antibiotic-induced and intrinsic stress signals that are sensed by BfmRS. In Aim 3, we will define the relationship between variability in BfmRS activity, growth-dependence, and virulence across diverse patient isolates as a test of the model that variation in BfmRS signaling level is a driver of enhanced virulence in invasive strains. This work will elucidate the mechanisms by which a unique regulatory system controls both resistance and pathogenicity in a critically important nosocomial microbe. These results will inform strategies for potentiating antibiotic and immune action for killing extensively drug-resistant bacteria.

项目概要 鲍曼不动杆菌是已知对抗生素耐药性最强的病原体之一， 毒力增强的分离株的出现构成了紧迫的公共卫生挑战。理解 微生物如何通过其保护性细胞膜阻止抗生素和免疫攻击对于 制定新的战略来控制这一威胁。细菌中的包膜合成和完整性是 通常由控制信封特定方面的大量响应系统维护。一个。 然而，鲍曼不动杆菌与这一范式有很大不同。该病原体缺乏许多直向同源物 典型的包膜反应蛋白，而是依赖于单一的两种蛋白调节系统 全局调节包膜的每一层并控制抗生素耐药性和能力 引起疾病。这种独特的系统称为 BfmRS，可降低对多种药物的敏感性， 对抗先天免疫杀伤，并促进小鼠致命疾病的发展。有趣的是，一个 显示出增强毒力的临床分离株需要该系统来生长。因此，BfmRS 紧密相连 病原体感染的难治性，是一个关键的潜在治疗靶点。尽管 其根本重要性，我们缺乏对大型 BfmRS 调节子如何控制广泛的了解 范围耐药性和致病性，以及系统感知的信号。的目标 拟议的研究旨在了解鲍曼不动杆菌如何使用单个控制电路同时 调节耐药性和毒力。我们的中心假设是 BfmRS 共同控制两者的障碍 通过调节关键外膜 (OM) 结构的水平进行药物渗透和先天免疫攻击 响应包膜蛋白生产的中断。我们将通过追求三个来检验这个假设 目标，建立在我们定义 BfmRS 调节子及其化学遗传的广泛初步数据的基础上 配置文件，以及它用于信号传导的磷酸化级联。在目标 1 中，我们将测试模型 BfmRS 通过调节细菌与抗生素和先天免疫效应物的界面 OM 屏障。在目标 2 中，我们将识别由抗生素引起的和内在的应激信号 BfmRS。在目标 3 中，我们将定义 BfmRS 活性变异性、生长依赖性、 和不同患者分离株的毒力作为模型的测试，表明 BfmRS 信号水平的变化是 入侵菌株毒力增强的驱动因素。这项工作将阐明一个机制 独特的调节系统控制着极其重要的医院感染的耐药性和致病性 微生物。这些结果将为增强抗生素和免疫作用以杀死细菌的策略提供信息 广泛耐药细菌。