Understanding the Evolutionary Origins and Molecular Mechanisms of Antimicrobial Peptide Resistance

了解抗菌肽耐药性的进化起源和分子机制

• 批准号: BB/M029255/1
• 负责人: Susanne Gebhard
• 金额: $ 52.95万
• 依托单位: University of Bath
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2016
• 资助国家: 英国
• 起止时间: 2016 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FM029255%2F1
• 关键词: Understanding; Evolutionary; Origins; Molecular; Mechanisms

The global increase in antibiotic resistance has made it difficult to treat bacterial infections, and mortality from infectious disease is rising at an alarming rate. Each year 700,000 people die from resistant bacteria such as MRSA, and some bacteria are now resistant to all available drugs. In 2014, the World Health Organisation issued its first Global Report on Antimicrobial Resistance, urging governments world-wide to join forces in tackling this health emergency. One goal is to identify new antimicrobials, but no new major class of antibiotics has been developed in 30 years. Current studies are exploring antimicrobial peptides (AMPs) for clinical use. AMPs target an essential bacterial structure (the cell wall), which cannot be easily changed by mutation, and are thus considered as "safe" regarding resistance. The same assumption was made with the introduction of vancomycin in the late 1950's, but transfer of resistance genes from environmental bacteria has resulted in one of the current "superbugs", Vancomycin Resistant Entercocci (VRE). Resistance against AMPs in environmental bacteria already exists, and many human pathogens, e.g. Staphylococci, contain related genes. To prevent a similar development as was seen for vancomycin, it is therefore imperative that we understand these AMP resistance systems and use the findings to devise strategies to counteract them. One innovative approach is to block the pathway by which bacteria detect the antibiotic and activate their resistance. A drug that interferes with this process would restore the efficacy of the antibiotic, providing a long-term solution. Similar treatments are already used in cancer therapy, but not yet to tackle antibiotic resistance.In recent years, a new type of AMP resistance has been identified in many Gram-positive bacteria, incl. human pathogens like S. aureus. These so-called Bce-like systems consist of a transporter that presumably removes the antibiotic from the cell, and a regulatory system that controls production of the transporter. Their key feature is that the transporter acts as an AMP sensor and controls the regulatory system and thus indirectly itself. Two aspects make these systems highly relevant for detailed exploration: (i) they share a conserved domain with other resistance transporters found in nearly all bacteria; (ii) their unique regulatory pathway presents a prime drug target for blocking resistance. Because pathogenic bacteria are difficult to handle, we will use the closely related bacitracin resistance Bce system of Bacillus subtilis as our experimental model.Our first aim is to determine how these systems evolved, in order to understand their relationship to other resistance systems. Bce-like transporters contain a domain, called FtsX, we expect to be important for resistance and which can be found in many disease-causing bacteria. We will use computational and experimental methods to determine the function of this domain. This will provide information on Bce-like systems as well as on the other transporters possessing an FtsX domain.The second aim addresses the question how the transporter controls the regulatory system. We will use molecular biology techniques to find out where the proteins interact, and how information is passed from the transporter to the regulatory system. Blocking this pathway will prevent activation of resistance, and we will provide the information needed to explore it as a novel drug target.The first step of the resistance pathway is detection of AMPs by the cell, yet it is unknown how Bce-like transporters accomplish this. In our third aim, we will use protein biochemistry methods to study AMP binding. Knowledge of how a drug is bound will allow the design of modifications that prevent detection and thus resistance.Our project will provide detailed understanding of AMP resistance by Bce-like systems and identify important processes to explore as drug targets in combatting resistance.

全球抗生素耐药性的增加使细菌感染的治疗变得困难，传染病的死亡率正在以惊人的速度上升。每年有70万人死于耐药性细菌，如MRSA，有些细菌现在对所有可用的药物都有耐药性。2014年，世界卫生组织发布了第一份《全球抗菌素耐药性报告》，敦促世界各国政府联合起来应对这一卫生紧急情况。目标之一是确定新的抗菌药物，但30年来没有开发出新的主要抗生素。目前的研究正在探索抗菌肽（AMP）的临床应用。抗菌肽靶向一个基本的细菌结构（细胞壁），这是不容易改变的突变，因此被认为是“安全”的耐药性。在20世纪50年代后期引入万古霉素时也做出了相同的假设，但是来自环境细菌的抗性基因的转移导致了目前的“超级细菌”之一，万古霉素抗性肠球菌（VRE）。环境细菌中已经存在对AMP的抗性，并且许多人类病原体（例如葡萄球菌）含有相关基因。为了防止类似的发展，如万古霉素，因此，我们必须了解这些AMP耐药系统，并利用这些发现来制定策略，以抵消他们。一种创新的方法是阻断细菌检测抗生素并激活其耐药性的途径。干扰这一过程的药物将恢复抗生素的功效，提供长期解决方案。近年来，在许多革兰氏阳性菌中发现了一种新型的AMP耐药性，包括革兰氏阳性菌和革兰氏阴性菌。人类病原体如S.金黄色。这些所谓的Bce样系统由一个可能将抗生素从细胞中清除的转运蛋白和一个控制转运蛋白产生的调节系统组成。其关键特征是转运蛋白作为AMP传感器并控制调节系统，从而间接控制自身。两个方面使得这些系统与详细探索高度相关：（i）它们与几乎所有细菌中发现的其他抗性转运蛋白共享保守结构域;（ii）它们独特的调控途径提供了阻断抗性的主要药物靶标。由于病原菌很难处理，我们将使用枯草芽孢杆菌的杆菌肽抗性Bce系统作为我们的实验模型，我们的首要目标是确定这些系统是如何进化的，以了解它们与其他抗性系统的关系。Bce样转运蛋白包含一个称为FtsX的结构域，我们预计它对耐药性很重要，并且可以在许多致病细菌中发现。我们将使用计算和实验的方法来确定这个域的功能。这将提供有关BCE样系统以及其他拥有FtsX结构域的转运蛋白的信息。第二个目的是解决转运蛋白如何控制调节系统的问题。我们将使用分子生物学技术来找出蛋白质相互作用的位置，以及信息如何从转运蛋白传递到调节系统。阻断这一途径将阻止耐药的激活，我们将提供探索其作为新的药物靶点所需的信息。耐药途径的第一步是细胞检测AMP，但目前尚不清楚Bce样转运蛋白如何完成这一过程。在我们的第三个目标中，我们将使用蛋白质生物化学方法来研究AMP结合。了解药物是如何结合的将允许设计的修改，防止检测，从而耐药。我们的项目将提供详细的了解AMP耐药性的Bce样系统，并确定重要的过程，探索作为药物靶点，在打击耐药性。

项目成果

The Cell Envelope Stress Response of Bacillus subtilis towards Laspartomycin C.

• DOI: 10.3390/antibiotics9110729
• 发表时间: 2020-10-23
• 期刊: Antibiotics (Basel, Switzerland)
• 作者: Diehl A;Wood TM;Gebhard S;Martin NI;Fritz G
• 通讯作者: Fritz G

From modules to networks: A systems-level analysis of the bacitracin stress response in Bacillus subtilis

从模块到网络：枯草芽孢杆菌中杆菌肽应激反应的系统级分析

• DOI: 10.1101/827469
• 发表时间: 2019
• 作者: Piepenbreier H

BceAB-type antibiotic resistance transporters appear to act by target protection of cell wall synthesis

BceAB 型抗生素抗性转运蛋白似乎通过细胞壁合成的目标保护发挥作用

• DOI: 10.1101/835702
• 发表时间: 2019
• 作者: Kobras C

Application of a Bacillus subtilis Whole-Cell Biosensor (PliaI-lux) for the Identification of Cell Wall Active Antibacterial Compounds.

应用枯草芽孢杆菌全细胞生物传感器 (PliaI-lux) 鉴定细胞壁活性抗菌化合物。

• DOI: 10.1007/978-1-0716-2855-3_13
• 发表时间: 2023
• 期刊: Methods in molecular biology (Clifton, N.J.)
• 作者: Kobras CM