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新的广谱抗生素，对关键的人类病原体起作用。未得到满足的需求对革兰氏阴性病原体的需求尤其迫切，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。根据上一次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。新生物公司拥有一项专有技术，能够应对这一挑战。我们正在从一种以前无法获得的来源--未培养的真菌中获得新的抗菌剂。在第一阶段，我们开发了一种捕捉器，用于特定捕获和生长未培养的真菌。许多抗菌剂，包括β-内酰胺类和头孢菌素类，都来自这类微生物的可培养代表。诱捕器由两层无菌琼脂组成，夹在插入土壤的半透膜之间。真菌产生菌丝，使它们能够穿过膜上的小孔进入捕捉器，进入琼脂上层，形成纯粹的菌落。许多最初在原地生长的未培养物种随后能够在标准实验室条件下体外生长。第一阶段的目标是使用诱捕法收集200种真菌，筛选它们的抗微生物活性，并对其中25种进行去复制。我们实现了这些里程碑，并从一种未培养的真菌中发现了一种新型的广谱抗菌剂Novo15，这种真菌与已知生物只有遥远的亲缘关系。在第二阶段，我们将在金黄色葡萄球菌和肺炎克雷伯菌肺部感染的体外生物检测和动物模型中验证第一阶段中发现的化合物。此外，我们还将从诱捕器中分离和筛选另外250,000个真菌菌株(目标1)，通过体外生物学测试验证潜在的线索并确定有希望的化合物的结构(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药。在该计划的下一阶段，这些药物将被开发成药物。 公共卫生相关性：公众越来越关注现有抗生素跟上微生物耐药性演变的步伐的能力；在社区和医院感染的情况下自然获得的抗生素，以及在生物恐怖制剂的情况下可能经过改造的抗生素。解决这个问题的一个办法是开发新的抗生素。这个项目的目的是使用我们的新技术来识别对常规和生物防御病原体具有广谱活性的新类别的抗生素。

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.