Insights into Candida auris dispersal cells and their impact on antifungal resistance

The emerging Candidozyma auris (formerly known as Candida auris, C. auris) has caused several outbreaks globally. While several studies explored the resistant biofilm formed by C. auris, little is known regarding the cells dispersed following biofilm formation. Herein, I investigated and characterized the cells dispersed from C. auris biofilms. Cells dispersed from biofilm developed in 96 well plate were isolated and counted. The antifungal susceptibility testing showed that the dispersed cells display similar antifungal susceptibility as the parent planktonic cells, except amphotericin B. Gene expression analysis performed by quantitative real-time PCR indicated that dispersed cells can express genes coded for antifungal resistance (ERG2, ERG6, ERG11, FKS1, CHS1, CHS2, CDR1, MDR1) more than the parent planktonic cells. It was observed that dispersed cells can acquire resistance to caspofungin faster than the parent planktonic cells once exposed to caspofungin at sub MIC level. Furthermore, biofilms formed by dispersed cells displayed significantly higher metabolic activity, as indicated by the XTT analysis. To provide more insight, I explored the expression of genes coding for biofilm initiation and maturation and the data obtained indicated that dispersed cells overexpressed ALS5 and KRE6 genes. Further, GC-MS analysis indicated that dispersed cells exhibit altered metabolic profile that enhance cells survivability under stress and nutrient limit condition. The presented study is the first to explore C. auris dispersed cells and indicated that they are not able to revert to the planktonic mode once released from the biofilm.