Silver Nanoparticles: A Promising Antifungal Agent against the Growth and Biofilm Formation of the Emergent Candida auris

Abstract

Candida auris is a globally-emerging pathogen that is correlated to nosocomial infections and high mortality rates, causing major outbreaks in hospitals and serious public health concerns worldwide. This study investigated the antifungal activity of silver nanoparticles (AgNPs) on clinical isolates of C. auris. A total of eight clinical isolates were collected from blood, urine, ear swab, and groin. C. auris was confirmed by MALDI-TOF MS, and gene sequencing. All isolates confirmed as C. auris were subjected to antimicrobial agents, including amphotericin B, fluconazole, caspofungin, voriconazole, micafungin, and flucytosine. A serial dilution of a silver nanoparticles solution was prepared to test antifungal susceptibility testing under planktonic conditions. Moreover, an antibiofilm activity assay was determined using a colony-forming assay and a cell viability assay by a live–dead yeast kit. Significant antifungal and antibiofilm activity of AgNPs was detected against all isolates; MIC was <6.25 μg/mL, the range of MFC was from 6.25 to 12.5 μg/mL for all isolates, and the highest value of IC50 was 3.2 μg/mL. Silver nanomaterials could represent a possible antimicrobial agent to prevent outbreaks caused by C. auris infections.