Role of YxdJK and DAK in the Enterococcal Envelope Stress Response

YxdJK 和 DAK 在肠球菌包膜应激反应中的作用

• 批准号: 10388366
• 负责人: William R Miller
• 金额: $ 18.58万
• 依托单位: METHODIST HOSPITAL RESEARCH INSTITUTE
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-05-03 至 2023-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10388366
• 关键词: ATP-Binding Cassette Transporters; Affect; Antibiotic Resistance; Antibiotics; Antimicrobial Resistance; Bacitracin; Bioinformatics; Calcium; Cancer Patient; Ceftriaxone; Cell Adhesion; Cell Death; Cell Wall; Cell division; Cell surface; Cells; Cellular Morphology; Cellular Stress; Centers for Disease Control and Prevention (U.S.); Cephalosporin Resistance; Cephalosporins; Cessation of life; Clinical; Critical Illness; DNA Binding; Daptomycin; Data; Development; Enterococcus; Enterococcus faecalis; Environment; Enzymes; Exhibits; FDA approved; Faculty; Fatty Acids; Gene Deletion; Gene Expression Profile; Genes; Genetic; Genetic Polymorphism; Genomics; Glycerone kinase; Goals; Gram-Positive Bacteria; Health Sciences; Homeostasis; Hospitals; Immunocompromised Host; In Vitro; Infection; Institution; K-Series Research Career Programs; Knowledge; Laboratories; Lead; Linezolid; Lipids; Mediating; Mediator of activation protein; Medical; Medical center; Medicine; Membrane; Membrane Biology; Membrane Fluidity; Membrane Proteins; Mentorship; Metabolism; Microbial Biofilms; Modern Medicine; Organism; Other Genetics; Pathway interactions; Patients; Pharmaceutical Preparations; Phenotype; Phosphatidylglycerols; Phospholipids; Phosphotransferases; Physicians; Play; Predisposition; Proteins; Public Health; Research Personnel; Resistance; Resistance to infection; Role; Scientist; Signal Transduction; Staphylococcus aureus; Stress; Structure; System; Tertiary Protein Structure; Texas; Therapeutic Intervention; Transplant Recipients; Universities; Vancomycin resistant enterococcus; Work; bactericide; biological adaptation to stress; cancer care; cell envelope; clinical practice; clinically relevant; combat; cost; design; differential expression; experience; experimental study; extracellular; genome sequencing; healthcare-associated infections; microbial genomics; multi-drug resistant pathogen; new therapeutic target; novel; novel therapeutic intervention; pathogen; programs; protein function; resistance mechanism; resistant strain; response; sensor histidine kinase; side effect; skill acquisition; transcriptome sequencing; whole genome

Project Summary This K08 Career Development Award application is intended to support the acquisition of skills and knowledge needed to fulfill my long-term goal of becoming an independent physician-scientist focused on combating antimicrobial resistant organisms, a serious threat to medical practice worldwide. Vancomycin resistant enterococci (VRE) are an example of these pathogens and are a leading cause of healthcare associated infections affecting critically ill and immunocompromised patients. VRE are categorized by the CDC as a serious threat requiring the urgent development of novel therapeutic strategies. The lipopeptide antibiotic daptomycin (DAP) is now a front line agent for VRE infections, but resistance to DAP can arise while on therapy. The LiaFSR system, a major mediator of the cell envelope stress response, has been strongly implicated in the development of DAP resistance. Inactivation of this system by deletion of the gene encoding the LiaR response regulator was shown to re-sensitize enterococci to DAP. However, adaptation of LiaR deficient strains of both clinical and laboratory origin resulted in DAP resistance, suggesting that alternate pathways can protect the cell from antibiotic attack. Using whole genome sequencing of adapted strain pairs, I identified two pathways with novel contributions to DAP and cephalosporin resistance in enterococci, i) the YxdJK stress response system, and ii) the dihydroxyacetone kinase (DAK) domain protein involved in the metabolism of extracellular fatty acids. The YxdJK system consists of a sensor histidine kinase (YxdK), a DNA binding response regulator (YxdJ) and two ATP-binding cassette (ABC) transporters required to confer resistance to bacitracin. Deletion of the gene encoding the YxdJ response regulator sensitizes Enterococcus faecalis to both DAP and cephalosporins, despite a functional LiaFSR system. DAP-resistant strains using the above pathways appear to display a very distinct mechanism of resistance to cell-envelope acting antibiotics. This proposal is designed to dissect the role of the YxdJK system and the DAK enzyme in two major specific aims. First, I will characterize the contributions of the YxdJK system to the cell envelope stress response to antibiotics by defining how the system senses antibiotic stress and what genes are differentially expressed when the system is active. Second, I will determine the DAK mediated changes that alter membrane susceptibility to antibiotics, by comparing the membranes of wild type and DAK deletion strains to assess for changes in phospholipids, envelope structure, membrane protein function, and biofilm formation. The Center for Antimicrobial Resistance and Microbial Genomics (CARMiG) at the University of Texas Health Science Center and adjacent institutions of the Texas Medical Center will provide an unparalleled environment to grow as an investigator, with both an institutional commitment to combating antimicrobial resistance and an intensive mentorship program dedicated to helping junior faculty make the transition to independence.

项目概要 此 K08 职业发展奖申请旨在支持技能和知识的获取 需要实现我成为一名专注于抗击疾病的独立医师科学家的长期目标 耐药微生物，对全世界的医疗实践构成严重威胁。万古霉素耐药 肠球菌 (VRE) 是这些病原体的一个例子，是导致医疗保健相关问题的主要原因 影响危重患者和免疫功能低下患者的感染。 VRE 被 CDC 归类为 严重的威胁需要紧急开发新的治疗策略。脂肽抗生素 达托霉素 (DAP) 现在是治疗 VRE 感染的一线药物，但在使用时可能会出现对 DAP 的耐药性 治疗。 LiaFSR 系统是细胞包膜应激反应的主要调节者，已被强烈 与 DAP 耐药性的发展有关。通过删除编码基因使该系统失活 LiaR 反应调节剂被证明可以使肠球菌对 DAP 重新敏感。然而，LiaR 的改编 临床和实验室来源的缺陷菌株导致 DAP 抗性，这表明替代 途径可以保护细胞免受抗生素的攻击。使用适应菌株对的全基因组测序，我 确定了肠球菌中对 DAP 和头孢菌素耐药性具有新贡献的两条途径，i) YxdJK 应激反应系统，以及 ii) 参与应激反应的二羟基丙酮激酶 (DAK) 结构域蛋白 细胞外脂肪酸的代谢。 YxdJK 系统由传感器组氨酸激酶 (YxdK)、DNA 结合反应调节器 (YxdJ) 和两个 ATP 结合盒 (ABC) 转运蛋白需要赋予 对杆菌肽的耐药性。编码 YxdJ 反应调节因子的基因缺失使肠球菌敏感 尽管 LiaFSR 系统功能正常，但粪杆菌对 DAP 和头孢菌素均产生耐药性。使用 DAP 抗性菌株 上述途径似乎表现出一种非常独特的对细胞包膜作用抗生素的耐药机制。 该提案旨在剖析 YxdJK 系统和 DAK 酶在两个主要特定领域中的作用 目标。首先，我将描述 YxdJK 系统对细胞包膜应激响应的贡献 通过定义系统如何​​感知抗生素应激以及哪些基因差异表达来识别抗生素 当系统处于活动状态时。其次，我将确定 DAK 介导的改变膜的变化 通过比较野生型和 DAK 缺失菌株的膜来评估对抗生素的敏感性 磷脂、包膜结构、膜蛋白功能和生物膜形成的变化。中心 德克萨斯大学健康科学分校抗菌素耐药性和微生物基因组学 (CARMiG) 博士 中心和德克萨斯医学中心的邻近机构将提供无与伦比的成长环境 作为一名研究者，既具有对抗抗菌素耐药性的制度承诺，又具有深入的研究 导师计划致力于帮助初级教师过渡到独立。

项目成果

Consider the 'Hole' Differential: Pulmonary Malignancy Presenting as a Cavitary Lesion.

考虑“空洞”差异：肺部恶性肿瘤表现为空洞病变。

• DOI: 10.1016/j.amjmed.2019.08.045
• 发表时间: 2020
• 期刊: The American journal of medicine
• 作者: Kohnke,LuanaQ;Hostetter,LoganJ;Subramanian,SruthiK;Miller,WilliamR
• 通讯作者: Miller,WilliamR

Bacterial cell membranes and their role in daptomycin resistance: A review.

• DOI: 10.3389/fmolb.2022.1035574
• 发表时间: 2022
• 期刊: Frontiers in molecular biosciences
• 影响因子: 5

The response of mpox-associated inflammatory syndrome to steroid therapy.

MPOX 相关炎症综合征对类固醇治疗的反应。

• DOI: 10.1016/s1473-3099(22)00876-3
• 发表时间: 2023
• 期刊: The Lancet. Infectious diseases
• 作者: Arias,CesarA;Miller,WilliamR;Olsen,Randall;Gollihar,Jimmy;Armstrong,Andrea
• 通讯作者: Armstrong,Andrea

Evolving landscape of carbapenem-resistant Pseudomonas aeruginosa at a single centre in the USA.

• DOI: 10.1093/jacamr/dlad070
• 发表时间: 2023-06
• 期刊: JAC-antimicrobial resistance
• 影响因子: 3.4