Fungicidal and antibiofilm activities of 2-Bromo-N-Phenylacetamide Against Fluconazole-Resistant Candida spp.: a promising antifungal agent

Abstract

Purpose: Amides are proven to possess antimicrobial properties against both fungi and bacteria. The synthetic amide 2-bromo-N-phenylacetamide exhibits antifungal activity according to scientific literature, however, data remains scarce. Given the clinical and epidemiological importance as well as the increasing antifungal resistance in Candida spp., here we aimed to better explore the antifungal potential of 2-bromo-N-phenylacetamide against fluconazole-resistant Candida albicans, Candida glabrata, Candida parapsilosis and for the first time, against Candida tropicalis as well. Methods: Minimum Inhibitory and Minimum Fungicidal Concentrations (MIC/MFC) were established by a Broth Microdilution Technique. Mode of action was explored by Ergosterol and Sorbitol assays. For investigating the combined effect between 2-bromo-N-phenylacetamide and the standard antifungals Amphotericin B and Fluconazole a Checkerboard Technique was performed. Finally, the antibiofilm properties of 2-bromo-N-phenylacetamide were assessed by a Crystal Violet Staining Assay. Results: 2-bromo-N-phenylacetamide exhibited a fungicidal effect, MIC of 32 µg.mL-1 (87.5% of the strains) and MFC of 64 µg.mL-1 (81.25% of the strains). It also demonstrated an activity against Candida albicans mature biofilms as effective as that for Amphotericin B at all tested concentrations. When associated with Fluconazole and Amphotericin B it exerted indifferent effects. Mode of action remained unclear. Conclusion: The synthetic amide 2-bromo-N-phenylacetamide possesses a strong antifungal activity against Candida albicans, Candida tropicalis, Candida glabrata and Candida parapsilosis and an antibiofilm property against Candida albicans as effective as that exhibited for Amphotericin B.