Novel antimicrobials to combat Gram-negative bacteria

项目摘要 耐药的革兰氏阴性病原体，如大肠埃希菌和肺炎克雷伯氏菌，是生命- 具有威胁性和挑战性，难以消除。令人震惊的是，他们甚至可以避免杀死最后一种粘菌素 针对这些病原体使用抗生素。虽然需要一个全面的战略，但小说的发展 抗菌药仍然是一个重要因素。这个项目的目标是发现新的抗菌剂。 这可以有效地消除耐药的革兰氏阴性病原体，这些病原体逃脱了传统的 抗生素。抗菌肽是重要的候选药物，一些(如达托霉素和格拉米丁)是 已经在临床使用了。然而，目前还不清楚如何选择有希望的抗菌剂模板 事态的发展。该项目结合了我们独特的数据库工具，为肽的发现开辟了一条新的途径 与结构生物学有关。抗菌肽数据库是建立和维护的原始资源 在私家侦探的实验室工作了十多年。为了促进我们的发展，我们建立了万能肽 分类方法，建立多肽注册标准，开发数据库过滤技术，以及 发现了多肽设计的新概念。作为令人兴奋的初步结果，我们已经确定了Verine， 它在体外杀死耐药细菌，破坏预先形成的生物膜，并在体内显示全身疗效 对粘菌素耐药克雷伯氏菌的作用与多利培南相当。值得注意的是，维林拥有一部小说 两亲性结构，与经典的两亲性螺旋结构完全不同。我们假设 威灵对耐抗生素的革兰氏阴性细菌有很强的抗药性；构效关系，ADME (吸收、分布、代谢、排泄)-毒性、药代动力学/药效学(PK/PD)研究 而在不同动物模型上的体内疗效评估将提高我们的知识并扩大其 治疗潜力。为了验证我们的假设，我们设计了以下具体目标：(1)阐明 维拉宁对革兰氏阴性杆菌的构效关系及药敏试验 体外单独或与抗生素联合应用，研究细菌反应的遗传基础；(2)调查 维拉宁和D-维拉宁的体内外毒性和药代动力学特性；(3)疗效评价 在小鼠模型中应用维拉宁对抗抗生素耐药的革兰氏阴性病原体。我们正处于一个极好的 从事这一项目的职位。我们对每个目标的初步结果支持了该项目的可行性。至 提供互补的专业知识，PI组建了一支拥有生物信息学专业知识的强大团队， 结构生物学、多肽化学、抗菌分析、作用机制、微生物学、动物模型 PK/PD、病理学、免疫学和工业抗菌剂开发。这项工程的竣工将 树立对抗抗菌素耐药性的新理念，大幅提高对抗菌素的认识 维拉宁及其类似物对各种革兰氏阴性菌的抗菌活性、PK/PD及体内药效 病原体。

Project Summary Drug-resistant Gram-negative pathogens such as Escherichia coli and Klebsiella pneumoniae are life- threatening and challenging to eliminate. It is stunning that they could avoid the killing of even colistin, the last resort antibiotic against these pathogens. While a comprehensive strategy is needed, the development of novel antimicrobials remains an important element. The objective of this project is to discover novel antimicrobials that can effectively eliminate drug-resistant Gram-negative pathogens that escape the killing of conventional antibiotics. Antimicrobial peptides are important candidates and some (e.g., daptomycin and gramicidin) are already in clinical use. However, it is not yet clear how to choose a promising template for antimicrobial developments. This project takes a new avenue to peptide discovery by combining our unique database tool with structural biology. The antimicrobial peptide database is an original resource established and maintained by the PI’s laboratory for over a decade. To facilitate our development, we have established universal peptide classification methods, set up criteria for peptide registration, developed the database filtering technology, and discovered a novel concept for peptide design. As exciting preliminary results, we have identified verine, which killed resistant bacteria, disrupted preformed biofilms in vitro and showed systemic efficacy in vivo against colistin-resistant Klebsiella comparable to doripenem. Remarkably, verine possesses a novel amphipathic structure, entirely different from the classic amphipathic helical structure. We hypothesize that verine is potent against antibiotic-resistant Gram-negative bacteria; structure-activity relationship, ADME (absorption, distribution, metabolism, excretion)-toxicity, pharmacokinetic/pharmacodynamics (PK/PD) studies and in vivo efficacy evaluation in different animal models will improve our knowledge and expand its therapeutic potential. To test our hypothesis, we have designed the following specific aims: (1) Elucidate the structure-activity relationship, test antimicrobial susceptibility of verine against Gram-negative pathogens in vitro alone or in combination with antibiotics and study the genetic basis of bacterial response; (2) Investigate the in vitro and in vivo toxicity and pharmacokinetic properties of verine and D-verine; and (3) Evaluate efficacy of verine against antibiotic-resistant Gram-negative pathogens in murine models. We are in an excellent position to pursue this project. Our preliminary results for each Aim support the feasibility of this project. To provide complementary expertise, the PI has assembled a strong team with expertise in bioinformatics, structural biology, peptide chemistry, antimicrobial assays, mechanism of action, microbiology, animal models, PK/PD, pathology, immunology, and industrial antimicrobial development. The completion of this project will foster new ideas to combat antimicrobial resistance, substantially improve our understanding of antimicrobial capability, PK/PD and in vivo efficacy of the novel peptide verine and its analog against various Gram-negative pathogens.