Antibiotic tolerance as a stepping stone to tuberculosis drug-resistance

抗生素耐受性是结核病耐药性的垫脚石

• 批准号: 10592979
• 负责人: Babak Javid
• 金额: $ 21.24万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-03-01 至 2025-02-28
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10592979
• 关键词: Animal Model; Animals; Antibiotic Resistance; Antibiotic Therapy; Antibiotic susceptibility; Antibiotics; Antitubercular Agents; Antitubercular Antibiotics; Bacteria; Biological Assay; Cells; Clinical; DNA-Directed RNA Polymerase; Development; Drug Tolerance; Drug resistance; Drug resistance in tuberculosis; Evolution; Exhibits; Fluorescence; Genes; Genetic; Genus Mycobacterium; In Vitro; Infection; Insertional Mutagenesis; Maps; Measures; Mediating; Methods; Molecular; Mouse Strains; Mus; Mutagenesis; Mutation; Mycobacterium tuberculosis; Necrosis; Organism; Outcome; Pathway interactions; Patients; Pharmaceutical Preparations; Pharmacotherapy; Phenotype; Phylogenetic Analysis; Physiological; Population; Population Sizes; Predisposition; Prevalence; Regimen; Resistance; Resistance development; Rifampicin resistance; Rifampin; Testing; Time; Treatment Protocols; Treatment outcome; Tuberculosis; Variant; Vertebral column; antibiotic tolerance; bactericide; clinically relevant; deep sequencing; drug resistance development; forward genetics; genetic resistance; in vivo; mouse model; novel; pathogen; small molecule; trait; tuberculosis drugs; tuberculosis treatment

PROJECT SUMMARY Antibiotic tolerance describes differential susceptibility of an isogenic bacterial population to bactericidal antibiotics. Antibiotic tolerance contributes to two clinically relevant phenotypes: populations with increased antibiotic tolerance are harder to eradicate and need prolonged antibiotic therapy – a hallmark of tuberculosis; and antibiotic tolerance has been shown in some organisms to act as a stepping stone to bona fide drug- resistance. However, there are many forms of antibiotic tolerance – ranging from non-replicating persisters to growing phenotypic resister cells – and these most likely represent diverse physiological states, mediated by distinct molecular mechanisms. The relative prevalence of these forms of tolerance in clinical isolates of Mycobacterium tuberculosis – the cause of tuberculosis – is completely unknown, as is the relative contribution of distinct types of tolerance to in vivo antibiotic susceptibility and development of antibiotic resistance. We have developed assays that can measure the relative tolerant subpopulation caused by non-replicating persistence and growing phenotypic resistance to the first-line anti-TB antibiotic rifampicin. Using these assays, we will measure the relative prevalence of these distinct forms of tolerance in clinical isolates of M. tuberculosis representing all major phylogenetic groups. By transposon insertion mutagenesis and deep-sequencing (Tnseq), we will dissect the genetic requirements for tolerance both in vitro and in a novel murine model of tuberculosis infection, using B6.Sp140 -/- mice that recapitulate the hallmarks of infection such as necrotic granulomata of C3H/FeJ ‘Kramnik’ mice. We will also determine the contribution of these two forms of rifampicin tolerance to the development of rifampicin-resistance in select clinical isolates of M. tuberculosis, and perform Tnseq to identify genetic contributors to resistance. Together, these studies will further our understanding of the molecular mechanisms of distinct forms of rifampicin tolerance in clinical strains of tuberculosis, and their relevance to the development of genetic resistance.

项目摘要 抗生素耐受性描述了同基因细菌群体对杀菌剂的不同敏感性。 抗生素抗生素耐受性导致两种临床相关表型： 抗生素耐药性难以根除，需要长期的抗生素治疗-这是结核病的一个标志; 抗生素耐受性在某些生物体中被证明是真正药物的垫脚石， 阻力然而，有许多形式的抗生素耐受性-从非复制持久性， 生长表型抵抗细胞-这些最有可能代表不同的生理状态，介导的 不同的分子机制。这些形式的耐受性在临床分离株中的相对流行率 结核分枝杆菌-结核病的原因-是完全未知的，因为是相对贡献 对体内抗生素敏感性的不同类型的耐受性和抗生素耐药性的发展。我们有 开发了可以测量非复制持久性引起的相对耐受亚群的测定方法 对一线抗结核抗生素利福平的表型耐药性不断增加。使用这些分析，我们将 测量这些不同形式的耐受性在M临床分离株中的相对流行率。结核 代表了所有主要的系统发育群。通过转座子插入诱变和深度测序（Tnseq）， 我们将在体外和一种新的结核病小鼠模型中剖析耐受性的遗传要求。 感染，使用B6.Sp140 -/-小鼠，其重现了感染的标志，例如 C3 H/FeJ 'Kramnik'小鼠。我们还将确定这两种形式的利福平耐受性对 利福平耐药性的发展，在选择临床分离的M。结核病，并执行Tnseq， 确定耐药性的遗传因素。总之，这些研究将进一步加深我们对分子生物学的理解。 结核病临床菌株中不同形式利福平耐受的机制及其与 遗传抗性的发展。