Antimicrobial activity of endophytic fungi from medicinal plants Mammea americana (Calophyllaceae) and Moringa oleifera (Moringaceae)

Introduction: Infectious diseases are the main cause of deaths in the world, antimicrobial resistance is a global problem, and therefore, research of new sources of potentially effective antimicrobial agents, of natural origin is convenient. Objective: To evaluate the antimicrobial activity of endophytic fungi of M. americana and M. oleifera in S. aureus (ATCC (R) 29213 (TM)) S. aureus (resistant strain USb003), E. coli (ATCC (R) 25922 (TM)) and E. coli (resistant strain USb007). 25922 (TM)). Materials and methods: Endophytic fungi, leaves, seeds and stems of the two plants under study were isolated. Their antimicrobial activity was evaluated through the formation of sensitivity haloes by dual tests in vitro and through tests with crude ethanolic extracts from the endophytes, to which they were evaluated minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC). and cytotoxicity. Results: Three ethanolic extracts of Penicillium sp., Cladosporium (001) and Cladosporium (002), showed greater inhibition halos in sensitive and resistant strains of E. coli and S. aureus. The MIC, CBM found, were statistically significant (P <= 0.05), compared with the control of gentamicin, the cytotoxicity tests CC50>1000 showed that endophytic fungi have bactericidal characteristics without causing any damage. Conclusion: There is a source of active secondary metabolites with antimicrobial and non-toxic properties in the endophytic fungi of M. oleifera and M. americana; these findings are important to continue with chemical identification of the compounds, and research on the mechanisms of action, highlighting that the isolation of endophytes in these plants is scarce or unknown.