DESCRIPTION (provided by applicant): The overall goal of this project is to discover novel antibiotics to combat important drug-resistant pathogens. One effective countermeasure against such pathogens is novel antibiotics, but the rate of antibiotic discovery has been in steady decline. All the more recently introduced antibiotics are derivatives of older antibiotics or resulted from revival of initially discarded compounds which were discovered decades ago such as daptomycin, linezolid, synercid and fidaxomycin. Clinically used antibiotics have traditionally been discovered by screening for active secondary metabolites of readily culturable microorganisms. This resource represents <1% of all microbial diversity in nature. The other >99% unexplored, and previously unavailable, microorganisms are arguably the single most promising resource for novel antibiotics. NovoBiotic directly addresses the bottleneck of antibiotic discovery by using unique cultivation approaches: the diffusion chamber and trap methodologies to isolate previously "uncultivable" microorganisms. This approach has resulted in 25 new compounds so far, at a rate far higher than the predicted industry standard. Several of these compounds are of principal novelty and are in development including Novo10, a DNA G-quadruplex binder, currently in development as an anti-cancer agent in collaboration with the National Cancer Institute; Novo22, a macrolactam inhibitor of cell wall biosynthesis; lassomycin, an inhibitor of the essential ClpP1P2C1 protease of M. tuberculosis; and teixobactin, a novel cell wall synthesis inhibitor. This project takes the next step and extends the technology to shallow water marine invertebrate- microbe symbioses, ubiquitously present and easily accessible in local communities. From the limited exploration conducted to date, a number of bioactive compounds with unique properties have been discovered from marine symbioses, including anti-tumor and anti-microbial compounds. There is strong evidence that it is the associated microorganisms living in association with the host invertebrates that produce the bioactive compounds. We will develop our methods to isolate novel microbial species living in association with marine invertebrates and screen these strains for antimicrobial activity. We will compare the diversity and novelty of active compounds from strains isolated from the diffusion chamber, trap and conventional plating. The end result of this Phase I project will be proof of concept of new technologies to discover antibiotics from a poorly explored source of microbial diversity: formerly "uncultivable" microbial species from marine invertebrate-microbe symbioses.

PUBLIC HEALTH RELEVANCE: It is widely recognized that new antibiotics are needed to combat drug-resistant bacterial infections. The proposed study will exploit the previously inaccessible microbial diversity of marine invertebrate symbionts to discover novel antibiotics.