Bacterial Cell Wall Composition and the Influence of Antibiotics

项目总结 几乎每一种抗生素都出现了耐药性，这突显了引入新的抗生素的迫切需要 治疗和了解抗生素的作用模式，以帮助指导新的抗菌药的开发 对抗药性生物体有效。金黄色葡萄球菌和肠杆菌克雷伯氏菌 肺炎、鲍曼不动杆菌、铜绿假单胞菌和粪肠球菌被归类 作为ESKAPE的病原体，是全世界医院获得性感染的主要原因。其中 这些耐甲氧西林金黄色葡萄球菌是抗生素耐药死亡的主要原因。 在美国的感染。此外，这些病原体形成生物膜和周围细胞的倾向 与反复和慢性感染有关，导致肺炎、心内膜炎、菌血症和败血症。 生物膜由生长缓慢的细菌细胞组成，周围有保护性的细胞外基质，而持久性 细胞是一种休眠的、高度耐受抗生素的细菌，可以在宿主体内存活。在世界范围内，结核病是 第二大常见死因，仅次于艾滋病毒/艾滋病死亡，由分枝杆菌引起 肺结核。在美国，非结核分枝杆菌(NTM)引起的呼吸道感染正在增加， 在慢性肺病患者和患有慢性肺部疾病的患者中显著流行。的治疗方法 NTM是复杂的，与结核病的治疗相似，需要长期的联合药物治疗，因为单一治疗是 与抗药性高度相关。我们已经启动了一项抗生素的发现和作用模式活动 旨在开发针对这些严重传染病的新疗法的计划。在这 在提出的项目中，我们利用我们最近成功地设计了一种新的万古霉素衍生物，万古霉素-D- 八精氨酸(V-R8)结合物，可根除革兰氏阳性生物膜和周围细胞，并减少 体内致病机制。我们建议发现关于V-R8的S独特的动作模式的新发现， 与主要的高价值疗法相比，这些疗法现在是最后的药物，例如奥立万新，对其 开发和临床潜力，并启发新一代抗菌药物的产生。这项研究 设计综合了跨学科的化学和生物化学专业知识和观点；机械的 生物化学；以及固态核磁共振方法的集成，以测量整个细胞的成分变化 并确定V-R8和可能的多个结合位点之间的距离。此外，我们将推出一项 新的实验性固态核磁共振平台使我们能够评估分枝杆菌的药物作用模式。 该平台将广泛应用于复杂分枝杆菌细胞壁的研究，并将 这里专门针对询问CPZEN-45的活性，CPZEN-45是一种令人兴奋的治疗候选药物 结核分枝杆菌和非结核杆菌的治疗。

PROJECT SUMMARY The emergence of resistance to almost every antibiotic underscores the urgent need to introduce new therapeutics and to understand antibiotic modes of action to help guide the development of new antimicrobials effective against drug-resistant organisms. S. aureus together with Enterobacter species, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterococcus faecium, are categorized as the ESKAPE pathogens and are predominant causes of hospital-acquired infection worldwide. Among these, methicillin-resistant Staphylococcus aureus is the leading cause of mortality from antibiotic-resistant infections in the United States. Moreover, the propensity of these pathogens to form biofilms and persister cells is linked to recurrent and chronic infections leading to pneumonia, endocarditis, bacteremia, and sepsis. Biofilms consist of slow-growing bacterial cells surrounded by a protective extracellular matrix, while persister cells are dormant, highly antibiotic-tolerant bacteria that can persist in the host. Worldwide, tuberculosis is the second most common cause of death, following deaths from HIV/AIDS, and is caused by Mycobacterium tuberculosis. In the U.S., respiratory infections from non-tuberculosis mycobacteria (NTM) are increasing, notably prevalent among CF patients and individuals suffering from chronic lung disease. The treatment for NTM is complex, similar to that for TB, and requires prolonged combination drug therapy as monotherapy is highly associated with drug resistance. We have initiated an antibiotic discovery and mode-of-action activity program directed at the development of new therapeutics for these serious infectious diseases. In this proposed project, we leverage our recent success in designing a new vancomycin derivative, a vancomycin-D- octaarginine (V-r8) conjugate, that eradicates Gram-positive biofilm and persister cells and reduces pathogenesis in vivo. We propose to uncover new discoveries regarding V-r8’s unique mode of action, as compared to major high-value therapeutics that are now the drugs of last resort, e.g. oritavancin, towards its development and clinical potential and to inspire the generation of new antibacterial agents. The research design integrates interdisciplinary chemical and biochemical expertise and perspectives; mechanistic biochemistry; and integration of solid-state NMR approaches to measure compositional changes in whole cells and to determine distances between V-r8 and possible multiple binding sites. Furthermore, we will launch a new experimental solid-state NMR platform to enable us to evaluate drug modes of action in mycobacteria. This platform will be broadly applicable to investigations of complex mycobacterial cell walls and will be specifically directed here to interrogate the activity of CPZEN-45, an exciting therapeutic candidate for the treatment of both Mycobacterium tuberculosis and NTM.