Octenidine effectively reduces Candida auris colonisation on human skin.

Candidozyma (formerly Candida) auris (C. auris), a WHO critical priority pathogen known for its multi-drug resistance and strong skin tropism, is posing a significant health threat. This study evaluates the efficacy of commercial octenidine-based antiseptics in reducing C. auris colonisation on intact and wounded human skin. Using an established ex vivo human skin model to simulate clinical settings, skin samples from healthy donors were exposed to planktonic C. auris cells. Six hours post-contamination, two ready-to-use octenidine-based antiseptics were applied, and fungal colonisation was assessed after 18 h via periodic acid-Schiff staining, bright field and scanning electron microscopy and colony forming unit quantification. In vitro biofilm assays with various C. auris strains, including drug resistant ones, were performed to determine the antifungal effects of octenidine formulations. Results showed that octenidine-based antiseptics significantly reduced C. auris viability on intact and wounded human skin, and also demonstrated a nearly complete eradication across tested strains in vitro. These findings highlight the potential of octenidine-based products in reducing C. auris colonisation, supporting infection prevention and control strategies in healthcare settings and enhancing patient safety.