Isolating novel fungi for antibiotic discovery

DESCRIPTION (provided by applicant): The long term goal of this project, is to develop novel antibiotics active against clinically important multi-drug- resistant (MDR) bacterial pathogens such as methicillin resistant Staphylococcus aureus (MRSA), and highly drug resistant Gram negative pathogens like Pseudomonas auruginosa. The goal of obtaining novel antibiotics will be achieved by employing a newly developed method (the 'fungal trap") to isolate and grow previously uncultured microfungi as a source of new antibiotic molecules. The majority of antibiotics in use today were discovered from environmental microorganisms, including microfungi. However, known microbe-derived antibiotics were discovered from only a very small fraction (<1%) of the diverse microorganisms that are culturable using standard techniques. Microfungi are a source of numerous valuable drugs used to treat diseases such as, bacterial infections (e.g. cephalosporins), fungal infections (e.g. candins), hypercholesterolemia (statins), and inflammatory diseases (e.g. cyclosporin). The world-wide market for antibiotics exceeds $20 billion. Sorely needed antibiotics active against MDR pathogens have the potential to yield a substantial market opportunity. In this Phase I project, we will evaluate and implement the "fungal-trap" method for isolating difficult to culture environmental microfungi, and we will generate a proof-of-principle that microfungi cultured using this method will produce antibiotic activities. Data derived from this project will provide the basis for phase II in which we will continue to develop our newly discovered lead antibiotics. Specific aims of the project: Aim 1. To evaluate the fungal trap method for culturing microfungi, we will isolate 200 nonredundant fungal isolates using fungal traps and 50 fungal isolates using standard plating methods. We will compare 18s rDNA sequences of isolates derived from fungal traps and Petri plates. Aim 2. To identify antibiotic activities, we will perform a pilot screen for antibiotic production by fungal isolates derived from fungal traps: we will screen 200 fungal trap derived isolates for antibiotic activity, and prioritize 50 validated antibiotic-producing isolates for further analysis. Aim 3. To identify novel lead antibiotics, we will analyze the active components from 25 high priority fungal- trap derived isolates and compare them against known antibiotics.