Isolating novel fungi for antibiotic discovery

描述（由申请人提供）：该项目的目标是发现和开发针对重要人类病原体的新型广谱抗生素。革兰氏阴性病原体的需求未得到满足的情况尤其严重，在革兰氏阴性病原体中，我们正在迅速耗尽治疗假单胞菌、不动杆菌、伯克霍尔德氏菌、克雷伯氏菌和肠杆菌等多重耐药物种的选择。这是一个具有挑战性的目标，因为最后一类新型广谱抗生素是在40年前发现的。根据上次ICAAC会议对这一重要主题的审查，目前在全球药物发现管道中没有广谱线索。抗菌药物发现进展的主要障碍是缺乏新化合物的来源。NovoBiotic拥有能够应对这一挑战的专有技术。我们正在从以前无法获得的来源——未经培养的真菌中获得新的抗菌剂。在第一阶段，我们开发了一种专门捕获和生长未培养真菌的陷阱。许多抗菌剂，包括？-内酰胺类和头孢菌素类来源于这类微生物的可培养代表。诱捕器由两层无菌琼脂夹在插入土壤的半透膜之间组成。真菌产生菌丝，使它们能够通过膜上的孔进入陷阱，进入琼脂的上层，形成纯粹的菌落。许多未培养的物种最初在原地生长，然后能够在标准实验室条件下在体外生长。第一阶段的目的是利用诱捕法收集200种真菌，筛选它们的抗菌活性，并对其中的25种进行去复制。我们实现了这些里程碑，并发现了一种新的广谱抗菌剂，Novo15，来自一种与已知生物只有远亲关系的未经培养的真菌。在第二阶段，我们将在体外生物试验和金黄色葡萄球菌和肺炎克雷伯菌肺部感染的动物模型中验证第一阶段发现的化合物。此外，我们将从陷阱中分离和筛选另外250,000株真菌菌株（目标1），使用体外生物试验验证潜在的线索，确定有前途的化合物的结构（目标2），并对10种新化合物进行动物试验（目标3）。第二阶段的最终结果将是2-3种经过验证的新型广谱抗菌剂。这些将在下一阶段被开发成药物。

DESCRIPTION (provided by applicant): The goal of this project is to discover and develop novel broad-spectrum antibiotics acting against critically important human pathogens. The unmet need is especially acute for Gram-negative pathogens, where we are rapidly running out of options for treating multidrug resistant species of Pseudomonas, Acinetobacter, Burkholderia, Klebsiella and Enterobacter. This is a challenging goal, since the last novel class of broad-spectrum antibiotics was discovered 40 years ago. Currently, there are no broad-spectrum leads in the global pipeline of drug discovery, according to the review of this important subject at the last ICAAC meeting. The main barrier to progress in antimicrobial drug discovery is the lack of sources for novel compounds. NovoBiotic has a proprietary technology capable of meeting this challenge. We are obtaining new antimicrobials from a previously inaccessible source - uncultured fungi. In Phase I, we developed a trap for specific capture and growth of uncultured fungi. Many antimicrobials, including ?-lactams and cephalosporins derive from culturable representatives of this group of microorganisms. The trap consists of two layers of sterile agar sandwiched between semi-permeable membranes that is inserted into soil. Fungi produce hyphae which enable them to penetrate into the trap through the pores in the membrane, into the upper layer of agar and form pure colonies. Many uncultured species that initially grow in situ are then capable of growing under standard laboratory conditions in vitro. The aims of Phase I were to assemble a collection of 200 fungi using the trap method, screen them for antimicrobial activity and dereplicate 25 of them. We achieved these milestones and discovered a novel broad- spectrum antimicrobial, Novo15, from an uncultured fungus only distantly related to known organisms. In Phase II we will validate the compounds discovered in Phase I in in vitro biological assays and animal models of S. aureus and K. pneumonia pulmonary infection. Also, we will isolate and screen an additional 250,000 fungal strains from the trap (Aim 1), validate potential leads using in vitro biological tests and determine the structure of promising compounds (Aim 2), and perform animal tests on 10 novel compounds (Aim 3). The end result of Phase II will be 2-3 validated, novel broad-spectrum antimicrobials. These will be developed into drugs in the next phase of the program. PUBLIC HEALTH RELEVANCE: There is increasing public health concern about the ability of currently available antibiotics to keep pace with evolving microbial resistance; naturally acquired in the case of community and hospital based infections, and potentially engineered in the case of bioterror agents. One solution to this problem is the development of new antibiotics. The purpose of this project is to use our new technology to identify new classes of antibiotics with broad-spectrum activity against both conventional and biodefense pathogens.