Skin commensal Micrococcus luteus Induces β-defensin-14 in keratinocytes and Enhances IL-17F Responses to Reduce Candida auris Colonization

Candida auris is a major multidrug-resistant fungal pathogen that predominantly colonizes human skin, leading to nosocomial transmission and outbreaks of systemic infections. Recent evidence suggests that C. auris co-colonizes with bacteria in the skin. However, the role of skin bacteria in the C. auris colonization is unclear. In this study, we investigated the role of Micrococcus luteus, a human skin commensal bacterium, on C. auris colonization of the skin. We identified that M. luteus pre-treatment in keratinocytes and mouse skin significantly reduces C. auris colonization. Mechanistically, we found that M. luteus induced {beta}-defensin-14, a host antimicrobial peptide in skin keratinocytes, and enhanced IL-17F responses in T cells and innate lymphoid cells, thereby reducing C. auris skin colonization. These findings revealed potential microbiome-based therapeutics for the prevention and treatment of C. auris skin colonization and subsequent invasive infections in humans.