Selective antifungal activity of silver nanoparticles: A comparative study between Candida tropicalis and Saccharomyces boulardii

In this study, the antifungal activity of AgNPs was tested against C. tropicalis (pathogen fungi) and S. boulardii (probiotic). The effectiveness of the AgNPs was assessed by comparing their antifungal activity with a triazole antifungal drug fluconazole and amphotericin B. The AgNPs have a polygonal-like shape (average size of 35 ± 15 nm) with 1.2% wt. of metallic silver stabilized with 18.8% wt. of polyvinylpyrrolidone (PVP) in 80% wt. of distilled water. The results revealed that 35 μg/mL of fluconazole inhibits 55–60% of both fungal cell growth. As for amphotericin B, 5 μg/mL is sufficient to inhibit more than 95% of both fungal cells. For AgNPs, 25 μg/mL was needed to inhibit 90% of the C. tropicalis cell growth, but remarkably, 50% of the S. boulardii cell population remains viable, which can potentiate cell reproduction. Our results could initiate the development of AgNPs possessing selective specificity against pathogenic fungal species.