Anti-MRSA and Clot Lysis Activities of an Endophytic Fungus Pestalotiopsis microspora
Sandip Chowdhury1, Suvranil Ghosh2, Surendra K. Gond1*
1Department of Botany, MMV, Banaras Hindu University, Varanasi-221005, India
2Division of Molecular Medicine, Bose Institute, Kolkata, India 700054, India
There is an urgent call to search for novel natural compounds against developing multidrug-resistant microorganisms. The present work focuses on the characterization of a plant- associated fungus having bioactivity against methicillin-resistant Staphylococcus aureus (MRSA) strains. A fungal strain P31 was isolated from bark of Dillenia pentagyna plant and identified as Pestalotiopsis microspora. The fungal extract showed strong bactericidal activity by killing all treated MRSA cells within 24 hour of treatment at their respective MIC value. A scanning electron microscopic study visualized morphological damage of MRSA cells. The membrane permeability of P31 extract treated MRSA cells gradually increased which caused release of internal cytoplasmic nucleic acids, proteins and potassium ions (K+) from cells suggesting cell lysis or leakage from cells. A very low concentration of P31 extract was able to inhibit biofilm formed by MRSA cells. Thin layer chromatographic separation followed by GCMS analysis of the P31 extract revealed a number of antimicrobial compounds along with an anti-MRSA compound 2,4-di-tert-butylphenol. In addition, the P31 extract also showed in-vitro human blood clot lysis activity at various concentrations. The clot lysis activity of P31 extract was found maximum at 500 µg/mL. These findings suggest that fungal isolate P31 has potential as a source of anti-MRSA compounds useful in staph infections.