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

基本信息

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
项目类别：
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

项目摘要

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.

项目概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耐受性导致两种临床相关表型：人群增加。抗生素耐药性更难根除，需要长期抗生素治疗——这是结核病的一个标志；一些生物体已显示出抗生素耐受性，可以作为真正药物的踏脚石然而，抗生素耐受性有多种形式——从非复制性持续耐药性到耐药性。生长的表型抵抗细胞——这些细胞很可能代表不同的生理状态，由不同的分子机制。这些形式的耐受性在临床分离株中的相对普遍性。结核分枝杆菌——结核病的病因——完全未知，相对贡献也是如此我们有不同类型的体内抗生素敏感性耐受性和抗生素耐药性的发展。开发了可以测量由非复制持久性引起的相对耐受亚群的测定方法以及对一线抗结核抗生素利福平的表型耐药性不断增强，我们将使用这些检测方法。测量结核分枝杆菌临床分离株中这些不同形式耐受性的相对患病率通过转座子插入诱变和深度测序（Tnseq），代表所有主要的系统发育群体。我们将在体外和新型小鼠结核病模型中剖析耐受性的遗传要求感染，使用 B6.Sp140 -/- 小鼠，重现感染的特征，例如坏死肉芽肿我们还将确定这两种形式的利福平耐受性对 C3H/FeJ ‘Kramnik’ 小鼠的影响。选定结核分枝杆菌临床分离株中利福平耐药性的发展，并执行 Tnseq 来这些研究共同确定了耐药性的遗传因素，将进一步加深我们对分子机制的理解。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。