Inadvertent Selection of a Pathogenic Fungus Highlights Areas of Concern in Human Clinical Practices

In studying the development of tolerance to common hospital cleaners (Oxivir(®) and CaviCide™) in clinical isolate stocks of the emerging, multidrug-resistant yeast pathogen Candida auris, we selected for a cleaner-tolerant subpopulation of a more common nosocomial pathogen, Candida glabrata. Through the purification of each species and subsequent competition and other analyses, we determined that C. glabrata is capable of readily dominating mixed populations of C. auris and C. glabrata when exposed to hospital cleaners. This result suggests that exposure to antimicrobial compounds can preferentially select for low-level, stress-tolerant fungal pathogens. These findings indicate that clinical disinfection practices could contribute to the selection of tolerant, pathogenic microbes that persist within healthcare settings.