Within a decade after its first description, the multidrug-resistant yeast Candida auris has emerged globally as a nosocomial pathogen causing difficult to control outbreaks. This, together with the alarmingly high mortality rate of up to 66% associated with C. auris candidemia, calls for a better understanding of its virulence traits and routes of transmission. Unlike other clinically relevant Candida species, C. auris seems to have the unique ability to be easily transmitted between patients. Although initially thought to express fewer virulence traits than Candida albicans, recent genomic insights suggest C. auris to possess these traits to a much more similar extent. This review highlights the virulence traits C. auris expresses to attack the host, defend itself against antimicrobial agents and to persist within the healthcare environment.

Non-albicans Candida species are emerging in the nosocomial environment, with the multidrug-resistant species Candida auris being the most notorious example. Consequently, rapid and accurate species identification has become essential. The objective of this study was to evaluate five commercially available chromogenic media for the presumptive identification of C. auris. Two novel chromogenic formulations, CHROMagarTM Candida Plus (Chromagar) and HiCromeTM C. auris MDR Selective Agar (HiMedia), and three reference media, CandiSelectTM (Bio-Rad), CHROMagarTM Candida (Chromagar), and ChromaticTM Candida (Liofilchem) were inoculated with a collection of 9 genetically diverse C. auris strains and 35 strains from closely related comparator species. After 48h of incubation the media were evaluated for their ability to detect and identify C. auris. All media had the same limitations in the differentiation of the more common species Candida dubliniensis and Candida glabrata. Only on CHROMagarTM Candida Plus, C. auris colonies developed a species-specific coloration. Nevertheless, the closely related pathogenic species Candida pseudohaemulonii and Candida vulturna developed a similar appearance as C. auris on this medium. CHROMagarTM Candida Plus showed to be superior in the detection and identification of C. auris, with 100% inclusivity for C. auris compared to 0% and 33% for the reference media and HiCromeTM C. auris MDR Selective agar, respectively. Although C. vulturna and C. pseudohaemulonii can cause false positives, CHROMagarTM Candida Plus showed to be a valuable addition to the plethora of mostly molecular methods for C. auris detection and identification.

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