Antifungal and antibacterial metabolites from a French poplar type propolis

Abstract

During this study, the in vitro antifungal and antibacterial activities of different extracts (aqueous and organic) obtained from a French propolis batch were evaluated. Antifungal activity was evaluated by broth microdilution on three pathogenic strains: Candida albicans, C. glabrata, and Aspergillus fumigatus. Antibacterial activity was assayed using agar dilution method on 36 Gram-negative and Gram-positive strains including Staphylococcus aureus. Organic extracts showed a significant antifungal activity against C. albicans and C. glabrata (MIC 80 between 16 and 31 μg/mL) but only a weak activity towards A. fumigatus (MIC 80 = 250 μg/mL). DCM based extracts exhibited a selective Gram-positive antibacterial activity, especially against S. aureus (SA) and several of its methicillin-resistant (MRSA) and methicillin-susceptible (MSSA) strains (MIC 100 30-97 μg/mL). A new and active derivative of catechin was also identified whereas a synergistic antimicrobial effect was noticed during this study.