The Wor2 phenotypic switching regulator controls biofilm formation in Candida auris

The emerging fungal pathogen Candida auris is a serious global public health threat due to its ability to persist in healthcare environments and on human skin. Here, we report a prevalent cluster of clinical C. auris strains with enhanced biofilm formation, a contributor to environmental and skin persistence. Genomic analyses show that the clinical isolates with enhanced biofilm formation ability carry a loss-of-function mutation in the WOR2 locus, which encodes a white–opaque switching regulator in Candida species. Analysis of 13,314 published genomes revealed that 3104 strains (23.3%) harbor nonsense or frameshift mutations in WOR2, indicating frequent clinical occurrence. Deletion of WOR2 in a clinical strain markedly increased biofilm formation, whereas reintroduction of an intact WOR2 significantly attenuated biofilm development. Further analyses show that Wor2 inactivation upregulates GFC1, ALS4, and multiple biofilm-associated genes. Together, these findings reveal a key regulatory mechanism underlying biofilm development, environmental persistence, and transmission of C. auris.