Mycobacterial single cell drug susceptibility

描述（由申请人提供）：一些细菌在抗生素治疗中存活的能力是治疗传染病的一个严重问题。对于人类结核病（TB）的病原体结核分枝杆菌（Mtb）来说尤其如此。尽管采用了积极和长期的抗生素化疗来治疗结核病，但全球结核病死亡率仍在上升。治疗失败的原因之一是，即使在药物敏感的疾病中，相当数量的细菌也能在抗生素治疗中存活下来。我打算研究分枝杆菌的这种表型耐受性现象，通常被称为持久性。由于表型耐受性需要观察单个细胞而不是群体，因此对表型耐受性的了解很少，而且很难研究。在这里，我提出了一种基于荧光生物传感器和延时显微镜的新方法来验证我的假设，即细菌的生理状态在单细胞水平上预先决定了抗生素的敏感性，并且这种状态可以响应内源性和外源性刺激而波动。这些结果将深入了解分枝杆菌表型耐受性的潜在机制，从而导致未来的工作将侧重于制定更快治疗结核病感染的新策略。

DESCRIPTION (provided by applicant): The ability of some bacteria to survive antibiotic treatment is a serious problem for the treatment of infectious diseases. This is especially true fo the pathogen Mycobacterium tuberculosis (Mtb), the causative agent of human tuberculosis (TB). Global TB mortality rates are increasing, despite the aggressive and lengthy antibiotic chemotherapy used to treat the disease. One of the reasons for failed treatment is that even in drug susceptible disease a considerable population of bacteria can survive antibiotic therapy. I intend to study this phenomenon of phenotypic tolerance, often referred to as persistence, in mycobacteria. Phenotypic tolerance is poorly understood and difficult to study since it requires looking at individual cells rather than populations. Here, I propose a novel method based on fluorescent biosensors and time-lapse microscopy to test my hypothesis that bacterial physiological state predetermines antibiotic susceptibility on a single-cell level and that this stte can fluctuate in response to endogenous and exogenous stimuli. The results will give insight into the mechanisms underlying phenotypic tolerance in mycobacteria, leading to future work that will focus on developing new strategies for treating TB infections more rapidly.