Establishing the Genetic Basis of Altered Drug Responses in Mycobacterium tuberculosis

摘要 高水平的耐药性使结核病患者面临更高的治疗失败风险。 然而，患者也无法治疗明显对药物敏感的菌株，即使在 依从性受到良好监控的临床试验环境。我们假设几十年来 药物暴露选择了药物介导性改变的细菌菌株 常规耐药性检测无法确定的清除情况，以及这些 变化会损害患者的结果。在之前的工作中，我们发现了突变 以常规方法无法识别的方式改变细菌的药物敏感性 临床耐药检测，但通过检测细菌药物反应发现 类寄主环境条件下的时间依赖性杀灭试验。我们假设 这些突变容易导致治疗失败，即使它们也会加速 出现高水平的耐药性。为了检验这一假设，我们建议检验 突变与耐药性和临床治疗失败相关的假说 在抗生素存在的情况下，队列改变了结核分枝杆菌的存活。为此，我们将构建 和表型：携带在我们的 与耐药或治疗失败相关的临床菌株分析。我们 将检验与耐药性相关的突变和突变的假设 在感染的小鼠模型中，与治疗失败相关的导致治疗失败。 最后，因为许多与耐药性相关的突变似乎会导致多药耐药 耐受性方面，我们将评估其对新抗生素和小剂量抗生素疗效的影响 结核分枝杆菌后期开发中的分子。

Summary High-level drug resistance puts TB patients at increased risk of treatment failure. However, patients also fail treatment with apparently drug susceptible strains even in clinical trial settings where compliance is well monitored. We postulate that decades of drug exposure have selected for bacterial strains that have alterations in drug-mediated clearance that are not identified by conventional drug resistance testing and that these changes put compromise patient outcomes. In previous work, we identified mutations that alter bacterial drug susceptibility in ways that are not identified by conventional clinical resistance testing but are revealed by assaying bacterial drug responses using time-dependent killing assays under host-like environmental conditions. We hypothesize that these mutations predispose to treatment failure even as they also accelerate the emergence of high-level drug resistance. To test this hypothesis, we propose to test the hypothesis that mutations associated with resistance and treatment failure in clinical cohorts alter Mtb survival in the presence of antibiotics. For this aim, we will construct and phenotype a barcoded library of isogenic strains carrying mutations identified in our analyses of clinical strains as associated with drug resistance or treatment failure. We will test the hypothesis that the drug resistance-associated mutations and mutations associated with treatment failure cause treatment failure in a mouse model of infection. Finally, because many resistance associated mutations appear to cause multidrug tolerance, we will assess their effects on the efficacy of new antibiotics and small molecules in late stage development for Mtb.