Histoplasma capsulatum in planktonic and biofilm forms: in vitro susceptibility to amphotericin B, itraconazole and farnesol.

This study aimed to evaluate the in vitro susceptibility of H. capsulatum var. capsulatum to the antifungal agents itraconazole and amphotericin B and farnesol, alone and combined, as well as to determine the in vitro antifungal activity of these compounds against biofilms of this pathogen. The results show that farnesol has antifungal activity against H. capsulatum in the yeast and filamentous phases, with MIC values ranging from 0.0078 to 0.00312 µM. A synergistic effect (FICI ≤ 0.5) between itraconazole and farnesol was found against 100% and 83.3% of the isolates in yeast and mycelial forms, respectively, while synergism between amphotericin B and farnesol was only observed against 37.5% and 44.4% of the isolates in yeast and filamentous forms, respectively. Afterwards, the antifungal drugs and farnesol alone and the combination of itraconazole and farnesol were tested against mature biofilms of H. capsulatum, through XTT metabolic assay, and the isolated antifungal drugs showed lower antibiofilm activity, when compared to farnesol alone and farnesol combined with itraconazole. PMID: 25657300 [PubMed - as supplied by publisher]
Source: Journal of Medical Microbiology - Category: Microbiology Authors: Tags: J Med Microbiol Source Type: research