Abstract:
The world is on the verge of an antimicrobial crisis. Disease-causing Enterobacteriaceae, namely Escherichia coli and Klebsiella pneumoniae are becoming increasingly resistant to therapeutics and the world needs new antibiotics to treat these resistant infections. New Zealand has immense biodiversity with over 6,000 reported fungal species and another 15,000 yet to be discovered. The International Collection of Microorganisms from Plants (ICMP) contains over 10,000 fungal species that have not been screened for their antibiotic potential. In 2002, Bode and colleagues described a novel method for screening called One Strain Many Compounds (OSMAC), based on the finding that microorganisms produce unique compounds when subjected to different environments. I have developed a derivative of this method, called Many Strains Some Conditions (MASSOC) which allows for the screening of multiple strains while retaining the testing variables vital to the success of OSMAC, including media type, age of fungus and light-conditions. Using this method, I screened 40 ICMP isolates from which we identified three unique compounds. Two of these compounds are novel sesquiterpenoids made by ICMP 17554 (Hypochnicium vellereum), a native wood-rot fungus, when it was cultured on Potato Dextrose Agar. The other compound is a novel macrolide made by ICMP 16864 (Xylariales order) when cultured on Oatmeal Agar. While I did not identify any ideal conditions to screen all fungi under, I did observe some general trends which can be used in a high -throughput screening program, to improve the chances of identifying fungi secreting antibacterial compounds . These include using Oatmeal Agar as a culture media, and testing fungi when they are at 50% radial growth size. My findings support my hypothesis that New Zealand fungi are an ideal source of new antibiotic compounds. Using my results will allow the screening method to be further developed to reduce costs and labour, while retaining the benefits of the MASSOC approach.
