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.

项目摘要抗生素耐受性描述了等生细菌对细菌的差异敏感性抗生素。抗生素耐受性有助于两种临床相关的表型：种群增加抗生素耐受性更难放射素，需要长时间的抗生素治疗 - 结核病的标志；在某些生物体中已经显示出抗生素耐受性作为真正的垫脚石来实现真正的药物 - 反抗。但是，有多种形式的抗生素耐受性 - 从非复制的持久到增长的表型转化细胞 - 这些很可能代表潜水的物理状态，由不同的分子机制。这些形式的公差形式在临床分离株中的相对患病率结核分枝杆菌 - 结核病的原因 - 完全未知，相对贡献也是如此对体内抗生素易感性的不同类型的耐受性和抗生素耐药性的发展。我们有开发的测定方法，可以测量非复制持久性引起的相对耐受亚群以及对一线抗TB抗生素利福平的表型耐药性的增长。使用这些测定法，我们将测量结核分枝杆菌临床分离株中这些不同形式的耐受性的相对普遍性代表所有主要的系统发育群体。通过转座子插入诱变和深层后续（TNSEQ），我们将在体外和新型结核病模型中阐述对耐受性的遗传要求感染，使用B6.SP140 - / - 小鼠，概括了感染的标志，例如坏死性肉芽肿 C3H/fej'Kramnik'小鼠。我们还将确定这两种形式的利福平耐受性的贡献在结核分枝杆菌的某些临床分离株中的利福平耐药性的发展，并执行TNSEQ 确定抗药性的遗传因素。总之，这些研究将进一步我们对分子的理解结核病临床菌株中不同形式的利福平耐受性的机制及其与遗传抗性的发展。