Role of ribosome modulating proteins in conferring Mycobacterium abscessus antibiotic resistance

项目摘要： 结核分枝杆菌（Mab）是一种快速生长的NTM，可引起皮肤和软组织感染 以及慢性肺损伤患者的肺部感染。它是目前世界上 耐药微生物物种，使其感染难以置信地难以治疗。 大环内酯类和氨基糖苷类阿米卡星构成抗Mab的一线治疗。疗法是 长期和低治愈率是令人遗憾的。这些抗生素的疗效差是由各种原因造成的。 暴露于药物以及宿主后，Mab中诱导的内在抗性机制 环境 最近，我们发现MabHflX，一种保守的核糖体相关的GT3，是 大环内酯-林可酰胺耐药（4）。在DMs_hflX缺失菌株中不存在HflX导致在DMs_hflX缺失菌株中不存在HflX。 70S核糖体的数量增加，表明HflX参与停滞的核糖体的解离 在抗生素存在的情况下。然而，HflX介导的抗生素抗性的详细机制，如 而且，结合在核糖体上的核糖体亚基的再循环机制仍然是未知的。在 我们的另一项研究证明了ARE-ABCF蛋白在大环内酯/林可酰胺抗性中的作用。在aim中 我们将使用遗传学、生物化学和结构方法相结合的方法来确定 HflX和ABCF介导的大环内酯类-林可酰胺类耐药的机制。 在另一项独立研究中，锌饥饿M。发现了smeglitazone 起源于核糖体冬眠，其涉及分枝杆菌蛋白Y（MPY）的结合。我们 假设低锌宿主环境将类似地导致MPY依赖性核糖体 在Mab感染期间冬眠，并赋予对氨基糖苷类包括阿米卡星的抗性。在目标2中 根据这一建议，我们将确定MabMPY在氨基糖苷类耐药中的作用， 这可能解释了观察到的本发明的体外功效和体内功效之间的不一致。 治疗（目标2）。 单克隆抗体的极端先天抗生素耐药性提供了一个独特的机会，研究 这种病原体的多重耐药机制的融合。深入了解这些 各种机制在开发新的治疗方法以治疗 单克隆抗体感染。

Project Summary: Mycobacterium abscessus (Mab) is a rapidly growing NTM causing skin and soft tissue infections and pulmonary infections in patients with chronic lung damage. It stands apart as one of the most antibiotic resistant microbial species, making its infections incredibly difficult to treat. A combination of an oral macrolide and the aminoglycoside, amikacin, comprises the frontline treatment against Mab. Therapy is prolonged and low cure rates are deplorable. The poor efficacies of these antibiotics result from various mechanisms of intrinsic resistance induced in Mab upon exposure to drugs as well as the host environment. Recently we showed that MabHflX, a conserved ribosome-associated GTPase, is required for macrolide-lincosamide resistance (4). The absence of HflX in a DMs_hflX deletion strain results in an increased population of 70S ribosomes suggesting that HflX is involved in dissociation of ribosomes stalled in the presence of antibiotics. However, the detailed mechanism of HflX-mediated antibiotic resistance, as well as the mechanisms by which antibiotic-bound ribosomal subunits are recycled remain unknown. In another study we demonstrated a role for ARE-ABCF proteins in macrolide/lincosamide resistance. In Aim 1 of this proposal we will use a combination of genetic, biochemical and structural approaches to determine the mechanisms of HflX and ABCF-mediated macrolide-lincosamide resistance. In another independent study, aminoglycoside resistance in zinc-starved M. smegmatis was found to originate from ribosome hibernation, which involves binding of mycobacterial protein Y (MPY). We hypothesize that a low-zinc host environment would similarly result in MPY-dependent ribosome hibernation during Mab infection, and confer resistance to aminoglycosides including amikacin. In Aim 2 of this proposal, we will determine the role of MabMPY in aminoglycoside resistance of which could potentially explain the observed discord between in vitro efficiency and in vivo efficacy of the current treatments (Aim 2). The extreme innate antibiotic resistance of Mab presents a unique opportunity to study the convergence of multiple resistance mechanisms in this pathogen. An in-depth understanding of these various mechanisms is critical in the development of new therapeutic approaches towards treatment of Mab infections.