Candidozyma auris (Candida auris) as a harbinger of novel fungal pathogens

Carla Elektra Schuh , Chaitanya S. Gokhale 

Mammals are protected from fungal pathogens by two evolutionary pillars: adaptive immunity and elevated body temperature. Anthropogenic climate change is eroding this thermal barrier, while a concurrent decline in human basal body temperature accelerates convergence from both directions. The emergence of Candidozyma auris (Candida auris), a thermotolerant, multidrug-resistant pathogen that arose independently as genetically distinct clades on multiple continents, may exemplify the consequences. Unlike its closest environmental relatives, which grow poorly at mammalian temperatures, C. auris thrives at 37 ◦C, tolerates up to 47 ◦C, persists on hospital surfaces, resists all three major antifungal classes, and causes invasive infections with 30–60% mortality. Its near-simultaneous, independent emergence implicates shared selective pressures, potentially rooted in global environmental change, rather than clonal spread. Here, we review the evolutionary biology, ecology, and clinical significance of C. auris within a framework of climate-driven pathogen emergence, evaluating current hypotheses for its origin and the molecular mechanisms underlying its thermotolerance and virulence. C. auris may represent only the first of many fungal species adapting to breach mammalian thermal defences, making predictive frameworks for anticipating fungal disease emergence an urgent priority.