Diabetes and Immunosuppression Drive Distinct Patterns of Candidozyma auris Skin Colonization and Dissemination in Mice

Abstract

Candidozyma auris is an emerging, multidrug-resistant (MDR) fungal pathogen that persistently colonizes human skin and disproportionately causes invasive infections in patients with metabolic or immune dysfunction. Despite strong epidemiological links to diabetes and immunosuppression, how these host conditions shape skin colonization, immune defense, and dissemination remain poorly defined. Here, we establish complementary murine model of C. auris skin colonization under immunocompetent, immunosuppressed, and diabetic ketoacidosis (DKA) conditions. DKA mice exhibited significantly increased skin fungal burden, impaired clearance, and frequent systemic dissemination. Notably, DKA permitted dissemination despite preserved granulocyte and neutrophil recruitment to the skin, indicating a functional rather than quantitative defect in innate immunity. Consistent with this, phagocytes from DKA mice displayed impaired antifungal activity characterized by reduced phagocytosis and killing despite elevated reactive oxygen species production. Hyperglycemic and ketone-rich conditions (BHB) remodel the C. auris cell wall, reducing mannan, increasing chitin, and upregulating adhesins, thereby enhancing adhesion and inflammatory activation while impairing neutrophil killing. Together, these findings reveal host metabolic dysfunction as a primary driver of persistent C. auris skin colonization and dissemination, identify qualitative defects in innate antifungal immunity as a key determinant of invasive risk and highlight metabolic condition as a critical target for infection prevention strategies. Short SummaryThis study establishes the first physiologically relevant murine model of Candidozyma auris skin colonization under diabetic ketoacidosis and immunosuppression, revealing distinct immune dysfunction and systemic dissemination that can inform targeted antifungal strategies.