Evaluating Antimicrobial Compounds from Coral-Associated Pseudovibrio Bacteria

描述（由申请人提供）：由于微生物对常规抗生素的耐药性增加以及新药不足，因此新型抗生素的研究与人类健康直接相关（1，2）。珊瑚礁是海洋生态系统中最具生物多样性的生物，也是新型抗生素的来源，但由于疾病，气候变化和污染，它们受到威胁。由于海洋细菌可以产生化学上与陆地细菌不同的化合物（4），因此必须对珊瑚及其潜在抗生素中未知的微生物多样性进行分类和表征。这项工作的主要目标是表征与珊瑚相关的海洋细菌的抗生素，并研究抗生素对病原体生理的功能作用。第一个目的是确定从美洲拟柳珊瑚表面粘多糖层（SML）分离的细菌的抗微生物活性，该粘多糖层是丰富多样的微生物群落的富碳栖息地（5）。SML选择具有抗微生物活性的共生细菌，可以通过检测病原微生物来保护珊瑚宿主（6，7）。我们将使用琼脂覆盖抗微生物测定法来确定美洲假单胞菌的SML相关细菌对与人类和珊瑚相关的七种微生物的抗微生物生产。第二个目标是专门针对NIAID/NIH的使命的药物发现，通过识别和表征抗菌化合物从广谱抗菌珊瑚分离，并调查其遗传生物活性的潜力与分子技术。抗生素化合物将使用色谱法（例如，HPLC）、质谱（例如，LC-MS）和光谱（NMR）技术。将进行分子技术以确定已知产生生物活性化合物的基因的存在。第三个目标将通过与抗菌珊瑚分离物共培养的代谢特征来分析抗生素对珊瑚病原体的作用的可能机制。我们将利用代谢组学来分析弧菌病原体在存在抗微生物珊瑚分离物时的细胞内变化，重点是代谢变化（例如，DNA、RNA、蛋白质合成）。相关性-世界卫生报告将微生物抗生素耐药性归类为对公共卫生的主要威胁，由于新抗生素药物的开发研究减少，这种情况有所增加（8）。该项目旨在通过表征潜在的新型抗生素及其对微生物病原体生理学的功能来满足这一需求。

DESCRIPTION (provided by applicant): The search for novel antibiotics is of direct human health relevance because of the increase in microbial resistance to conventional antibiotics and a deficit in new drugs (1, 2). Coral reefs are the most biodiverse of marine ecosystems and a source of novel antibiotics, but they are threatened due to disease, climate change, and pollution (3). Since marine bacteria can produce compounds that are chemically distinct from their terrestrial counterparts (4), it is imperative to catalog and characterize the unknown microbial diversity in corals and their potential antibiotics. The main objectives of this work are to characterize antibiotics from marine bacteria associated with a coral, and to study the functional role of the antibiotic insult on a pathogen's physiology. The first aim will ascertain the antimicrobial activity of bacteria isolated from Pseudopterogorgia americana surface mucopolysaccharide layer (SML), which is a carbon-rich habitat for an abundant and diverse microbial community (5). The SML selects for symbiotic bacteria with antimicrobial activity that may protect the coral host by detemng pathogenic microorganisms (6, 7). We will use an agar- overlay antimicrobial assay to determine the antimicrobial production of P. americana's SML-associated bacteria against seven microorganisms relevant to human and corals. The second aim specifically targets NIAID/NIH's mission for drug discovery by identifying and characterizing antimicrobial compounds from a broad-spectrum antimicrobial coral isolate, and surveying its genetic bioactive potential with molecular techniques. Antibiotic compound(s) will be purified and structurally characterized using chromatographic (e.g., HPLC), mass spectrometric (e.g., LC-MS), and spectroscopic (NMR) techniques. Molecular techniques will be performed to determine presence of genes known to produce bioactive compounds. The third aim will analyze a possible mechanism of antibiotic action against a coral pathogen through metabolic profile characterization of its co-culture with the antimicrobial coral isolate. We will utilize metabolomics to analyze the intracellular changes of a Vibrio pathogen when in presence of an antimicrobial coral isolate, focusing on metabolic changes (e.g., DNA, RNA, protein synthesis) using NMR analysis. Relevance- The World Health Report categorized microbial antibiotic resistance as a major threat to public health, which is augmented due to the diminished developmental research for new antibiotic drugs (8). This project seeks to meet this demand by characterizing potentially novel antibiotic(s) and their function on a microbial pathogen's physiology.