Evaluation of five real-time PCR assays for the detection of <i>Candidozyma auris</i> in clinical specimens

Candidozyma auris is notorious for its association with invasive infections and hospital outbreaks. Trying to prevent introduction in the hospital, settings are implementing screening procedures including the best diagnostic procedure. In the Netherlands, nucleic acid amplification testing is recommended for this purpose. In this study, we performed a head-to-head comparison of five different real-time PCR assays for the detection of C. auris. The evaluated assays include the CandidaGenius (Pathonostics), C. auris Detection Kit (Revvity), AurisID (Olm), AltoStar C. auris 1.5 (Altona), and Erasmus Medical Center (EMC) assay (lab-developed test). Analytical evaluation was conducted by assessing selectivity, analytical specificity, reproducibility, and limit of detection (LoD). Subsequently, a clinical evaluation was performed by testing 45 (spiked) clinical specimens. Additionally, all available specimens from a C. auris-colonized patient were tested. The analytical evaluation demonstrated excellent selectivity and specificity for all assays, high reproducibility for most assays, and an excellent LoD for all assays except the Revvity assay. The clinical validation showed excellent sensitivity (100%), high specificity (≥97.8%), and a LoD ranging from 0.3 to 1.8 CFU/PCR for all assays. Fourteen specimens from the colonized patient were tested, of which six, five, and three specimens tested positive using the AltoStar C. auris 1.5, EMC assay, and CandidaGenius, respectively. The results of this evaluation showed that AurisID, AltoStar C. auris 1.5, and the EMC assay performed equally well. All three assays are PCR reagent-only assays that can be easily implemented as screening PCRs to detect C. auris in clinical specimens.