Diagnostic Performance of Direct PCR Assay for Candida auris Detection: A Comparison of Liquid Amies Transport Medium and Fungal Enrichment Broth.

BACKGROUND

Candida auris has rapidly spread worldwide, representing a significant global health threat. Rapid diagnostic testing is essential for C. auris infection control. This study aimed to assess the diagnostic performance of a direct polymerase chain reaction (PCR) assay compared with culture. The liquid Amies transport medium (Copan ESwab; Copan, Italy) and fungal enrichment broth were compared to determine the optimal media for the direct PCR assay.

METHODS

The diagnostic performance of the cobas omni Utility Channel Reagent Kit (Roche Diagnostics, Germany)-based direct PCR assay and culture was assessed against clinical outcomes. Sixty skin swab specimens were prospectively collected from intensive care unit patients at a university hospital in Korea. Each sample was tested in parallel using the Copan ESwab and Sabouraud dextrose (SD) broth.

RESULTS

The direct PCR assay showed a sensitivity of 92.0%-96.0% and specificity of 85.7%-97.1% compared with a sensitivity of 76.0%-80.0% and specificity of 100% for culture across both media. For the direct PCR assay, the Copan ESwab showed a higher specificity, positive predictive value, and kappa value but lower sensitivity and negative predictive value than the SD broth. The discordant direct PCR assay-positive/reference standard-negative and PCR assay-positive/culture-negative cases showed significantly higher cycle threshold values than the concordant cases (p < 0.05).

CONCLUSION

The direct PCR assay using the Copan ESwab showed high sensitivity for the detection of C. auris in clinical skin swab specimens. This approach may be useful for screening, although further validation in larger multicenter studies is needed.