Antimicrobial activities of fungi derived from the gorgonian sea fan <i>Annella</i> sp. & their metabolites

Abstract

One hundred and sixty-three fungi isolated from gorgonian sea fan <i>Annella</i> sp. were screened for antimicrobial activity against human pathogens<i>.</i> Forty-seven percents of the isolates produced antimicrobial metabolites against at least one pathogen with minimum inhibitory concentrations (MIC) ranged from 1 to 1,280 µg mL^-1. Crude extracts from 16%, 21%, 18% and 23% of the isolates inhibited standard strain of <i>Staphylococcus aureus</i>, methicillin-resistant <i>S. aureus</i>, <i>Escherichia coli</i> and <i>Pseudomonas aeruginosa</i>, respectively. Eighteen percents of the isolates displayed antifungal activity against <i>Microsporum gypseum</i> while only 3% inhibited <i>Cryptoccocus neoformans</i> and <i>Candida albicans</i>. Potential isolates were identified by morphological and molecular characteristics. Twenty-nine pure compounds isolated from ten isolates were evaluated for antimicrobial activity. Griseofulvin from <i>Nigrospora</i> sp. PSU-F13 exhibited the best activity against <i>M. gypseum</i> (MIC 2 µg mL^-1). The result indicates that sea fan-derived fungi are a potential source of antimicrobial agents.