Convergent evolution on RBA1 regulates Candidozyma auris host adaptation

Abstract

Candidozyma auris is an emerging healthcare-associated fungal pathogen, increasingly isolated from clinical outbreaks, with a high propensity to colonize patients and the medical environment. Here, we leveraged C. auris isolates from multi-facility clinical outbreaks to identify genomic patho-adaptations promoting persistence and dissemination in the healthcare environment. Genomic and phylogenetic analyses revealed loss-of-function mutations in the uncharacterized C. auris transcription factor gene RBA1 to have independently emerged multiple times within these outbreaks. We demonstrate loss of RBA1 increases C. auris adhesion to plastic and human keratinocytes, enhances biofilm formation, and exacerbates fungal burden in a mouse model of catheter-associated urinary tract infection. Finally, we uncover mutations in RBA1 have emerged during multiple C. auris outbreaks across the globe, and that RBA1 mutant lineages are present among large ongoing clinical outbreaks. These results reveal loss-of-function mutations in C. auris RBA1 as a novel and clinically relevant genetic determinant of enhanced outbreak characteristics.