MEDICAL MYCOLOGY JOURNAL, cilt.62, sa.1, ss.5-10, 2021 (ESCI)
Farnesol is an extracellular quorum-sensing molecule produced by Candida albicans. Farnesol is also a sesquiterpene alcohol existing in many herbal products and has various activity against fungal cells. We aimed to investigate the efficacy of farnesol alone and the contribution of farnesol on the activity of voriconazole and amphotericin B against Aspergillus clinical isolates in vitro. A total of 45 Aspergillus clinical isolates were used in this study. The MIC values of voriconazole, amphotericin B, and farnesol were determined using reference broth microdilution method. The interactions of farnesol with voriconazole and amphotericin B were investigated by the checkerboard method and evaluated based on the fractional inhibitor concentration index (FICI). The MIC ranges of farnesol, voriconazole, and amphotericin B were 1,500-6,000 mu M, 0.125-1 mu g/mL, and 0.125-0.5 mu g/mL against Aspergillus fumigatus isolates, 3,000-12,000 mu M, 0.125-0.5 mu g/mL, and 0.25-2 mu g/mL against Aspergillus flavus isolates, respectively. The most common interaction in combination tests was "no interaction," and synergistic interaction was not detected. The combinations of farnesol with voriconazole and amphotericin B had antagonistic activity against 38% and 27% of all isolates, respectively.