Elucidating altered lipid pathways in daptomycin-resistant pathogens

阐明达托霉素耐药病原体中脂质途径的改变

• 批准号: 9890277
• 负责人: Kelly M. Hines
• 金额: $ 16.13万
• 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: 2020-06-12 至 2022-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9890277
• 关键词: Acyltransferase; Affect; Anabolism; Antibiotic Resistance; Antibiotics; Bacteria; Biophysics; Cell Wall; Collection; Corpus striatum structure; Corynebacterium; DNA Sequence Alteration; Daptomycin; Development; Diglycerides; Enterococcus faecalis; Enterococcus faecium; Environment; Fatty Acids; Fluorescence Polarization; Genes; Genomics; Glycolipids; Goals; Gram-Positive Bacteria; Infection; Intervention; Isotope Labeling; Lipid Synthesis Pathway; Lipids; Location; Mass Spectrum Analysis; Measurement; Mediating; Membrane; Membrane Fluidity; Membrane Lipids; Metabolic Pathway; Metabolism; Methicillin Resistance; Modification; Molecular; Mutation; Nature; Nonesterified Fatty Acids; Outcome; Pathogenicity; Pathway interactions; Phenotype; Phosphatidic Acid; Phosphatidylglycerols; Phospholipids; Predisposition; Property; Resistance; Source; Staphylococcus aureus; Streptococcus; Streptococcus oralis; System; Techniques; Testing; Treatment Efficacy; Vancomycin resistant enterococcus; Work; antimicrobial; bactericide; biological adaptation to stress; cell envelope; differential expression; extracellular; fatty acid biosynthesis; global health; improved; inhibitor/antagonist; knock-down; lipid biosynthesis; lipid metabolism; lipoteichoic acid; metabolome; metabolomics; methicillin resistant Staphylococcus aureus; new therapeutic target; novel; novel therapeutics; pathogen; pathogenic bacteria; pi bond; prevent; resistant strain; small molecule; small molecule inhibitor; transcriptome sequencing; transcriptomics

Project Summary Alteration of membrane lipids, particularly the reduction of total phosphatidylglycerols (PGs), is a common daptomycin resistance phenotype across many species of Gram-positive bacteria. These modifications to membrane lipid content and composition can occur through direct genetic mutations in lipid biosynthetic pathways or indirect mutations in cell envelope stress response systems that regulate expression of membrane and cell wall biosynthesis genes. We have previously characterized the altered membrane lipids in daptomycin- resistant strains of methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus faecalis (VRE), and Corynebacterium striatum and found that: i) daptomycin resistance also significantly affected non-PG lipids, and ii) the changes manifested only in membrane lipids with specific fatty acid compositions in MRSA and VRE. Lipid biosynthesis is a promising target for the development of novel therapies for the treatment of daptomycin resistance due to the lipid-dependent mechanism of daptomycin’s bactericidal action and the differences between eukaryotic and prokaryotic lipid biosynthetic pathways. However, the membrane lipidomes of Gram-positive bacteria are diverse in the variety and ratios of lipid classes present and the fatty acid compositions of those lipids. This diversity presents a challenge to finding common lipid pathways that can be exploited to disrupt daptomycin resistance, but the central pathways of lipid synthesis and metabolism are likely to be conserved across diverse daptomycin-resistant species. The long-term goals of this project are to identify the common and differential pathways in lipid biosynthesis and metabolism that contribute to daptomycin resistance among different species of Gram-positive bacteria and to identify small molecule modulators of these pathways that can reverse daptomycin resistance. In Aim 1, we will elucidate common and differential pathways in lipid metabolism and biosynthesis that are modified in a diverse collection of bacterial pathogens with daptomycin resistance. We will also examine the fatty acid-dependent nature of lipid changes in daptomycin-resistant MRSA and VRE. In Aim 2, we will modulate daptomycin resistance with small molecules targeting lipid biosynthesis and metabolism and evaluate the effects of extracellular free fatty acids on daptomycin resistance. We expect that the pathways that are conserved among diverse bacteria species with daptomycin resistance will be universal targets for modulation with small molecules, and these small molecules will improve daptomycin susceptibility by affecting the lipids and fatty acids that favor daptomycin resistance. This project will provide new fundamental understanding of the molecular alterations that contribute to daptomycin resistance and identify novel small molecule interventions that can be adapted into effective therapeutics for treating infections from multiple species of daptomycin-resistant pathogens.

项目摘要 膜脂质的改变，尤其是总磷脂酰甘油（PGS）的减少，是一种常见 革兰氏阳性细菌的二霉素抗性表型。这些修改 膜脂质含量和成分可以通过脂质生物合成中的直接基因突变发生 细胞包膜应力响应系统中调节膜表达的途径或间接突变 和细胞壁生物合成基因。我们先前已经表征了daptomycin-中的膜脂质变化 耐甲氧西林的金黄色葡萄球菌（MRSA），耐万古霉素的耐药性肠肠球菌的抗性菌株 Faecalis（VRE）和Corynebacterium Striatum，发现：i）daptomycin耐药性也显着影响 非PG脂质，ii）仅在具有特定脂肪酸组成的膜脂质中表现出的变化 MRSA和VRE。脂质生物合成是开发新疗法的有望靶点 Daptomycin耐药性是由于脂质霉素的细菌作用的脂质依赖性机制和 真核和原核脂质生物合成途径之间的差异。但是，膜脂质组 革兰氏阳性细菌的脂质类别和脂肪酸的多样性和比率是潜水员 这些脂质的组成。这种多样性给寻找可以是的常见脂质途径带来了挑战 利用破坏二霉素耐药性，但脂质合成和代谢的核心途径是 可能是在耐二霉素的物种上配置的。该项目的长期目标 确定脂质生物合成和代谢中的常见和差异途径有助于 革兰氏阳性细菌之间的二霉素耐药性，并鉴定小分子 这些途径的调节剂可以逆转Daptomycin耐药性。在AIM 1中，我们将阐明共同和 脂质代谢和生物合成中的差异途径在潜水员收集的细菌中被修饰 耐霉素耐药性的病原体。我们还将检查脂质变化的脂肪酸依赖性性质 耐达霉素的MRSA和VRE。在AIM 2中，我们将用小分子调节daptomycin耐药性 靶向脂质生物合成和代谢，并评估细胞外游离脂肪酸对 二霉素耐药性。我们希望在潜水细菌中保守的途径 Daptomycin耐药性将是针​​对小分子调制的通用靶标，而这些小分子 通过影响有利于daptomycin耐药性的脂质和脂肪酸来改善Daptomycin的敏感性。 该项目将对有助于分子变化的新基本理解 daptomycin耐药性并鉴定可改用有效的新型小分子干预措施 用于治疗多种耐达霉素病原体感染的治疗剂。