Mechanisms for antibiotic tolerance and envelope remodeling in Gram-negative bacteria

革兰氏阴性菌抗生素耐受和包膜重塑的机制

• 批准号: 571867-2021
• 负责人: Tocheva, ElitzaE
• 金额: $ 1.82万
• 依托单位: University of British Columbia
• 依托单位国家: 加拿大
• 项目类别: Alliance Grants
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=761009
• 关键词: Mechanisms; antibiotic; tolerance; envelope; remodeling

This collaboration between Elitza Tocheva at the University of British Columbia and Tobias Dörr at Cornell University seeks to elucidate mechanisms of bacterial envelope morphogenesis and antibiotic tolerance while providing quality training to their research teams. The diverse Gram-negative bacteria at the center of this research display a robust ability to survive catastrophic envelope damage and the loss of their cell walls. These bacteria can compensate for cell wall deficiency until the damaging agent, i.e., a cell wall-acting antibiotic like penicillin, is removed and they can regenerate their cell walls. This phenomenon is termed "antibiotic tolerance." As the bacterial cell wall is the target of several classes of antibiotics, it is critical that we understand the mechanisms that permit these tolerant bacteria to survive cell wall-targeting antibiotics. Observing the recovery of these tolerant bacteria from a cell wall-deficient state back to a walled state also presents an opportunity to tackle the elusive yet fundamental question of how rod-shaped bacteria establish their cell shape without the template of a pre-existing cell wall. The Tocheva and Dörr groups will apply a unique and powerful combination of advanced, high-resolution cryo-electron tomography, genetics, and biochemistry to these understudied and historically difficult research questions. Genetic screens performed by the Dörr lab in V. cholerae, E. cloacae, and K. pneumoniae have identified key bacterial stress response systems and envelope biogenesis pathways that contribute to antibiotic tolerance. These studies are the source of numerous hypotheses regarding the roles of each layer in the Gram-negative bacterial envelope during cell wall degradation and regeneration that will be probed by the Tocheva lab via cryo-electron tomography and correlative fluorescent microscopy techniques. This trainee-driven project will establish Canadian expertise in both fundamental bacteriology and the emerging field of antibiotic tolerance.

不列颠哥伦比亚省大学的Elitza Tocheva和康奈尔大学的Tobias Dörr之间的合作旨在阐明细菌包膜形态发生和抗生素耐受性的机制，同时为他们的研究团队提供高质量的培训。这项研究中心的各种革兰氏阴性细菌显示出强大的能力，能够在灾难性的包膜损伤和细胞壁丧失中存活下来。这些细菌可以补偿细胞壁的缺陷，直到破坏剂，即，一种作用于细胞壁的抗生素，如青霉素，被移除，它们可以再生细胞壁。这种现象被称为“抗生素耐受性”。“由于细菌细胞壁是几类抗生素的目标，因此我们必须了解允许这些耐受细菌在细胞壁靶向抗生素中存活的机制。观察这些耐受性细菌从细胞壁缺陷状态恢复到有壁状态也提供了一个机会，可以解决杆状细菌如何在没有预先存在的细胞壁模板的情况下建立其细胞形状这一难以捉摸而又根本的问题。Tocheva和Dörr小组将采用先进的高分辨率冷冻电子断层扫描，遗传学和生物化学的独特而强大的组合来解决这些未充分研究和历史上困难的研究问题。Dörr实验室在霍乱弧菌、E. cloxacin和K.肺炎克雷伯氏菌已经鉴定了关键的细菌应激反应系统和促成抗生素耐受性的包膜生物发生途径。这些研究是关于革兰氏阴性细菌包膜中每一层在细胞壁降解和再生过程中的作用的众多假设的来源，Tocheva实验室将通过冷冻电子断层扫描和相关荧光显微镜技术进行探测。这个由受训者驱动的项目将建立加拿大在基础细菌学和抗生素耐受性新兴领域的专门知识。