Comparison of Two Commercially Available qPCR Kits for the Detection of Candida auris

Abstract

<i>Candida auris</i> is an emerging pathogen with resistance to many commonly used antifungal agents. Infections with <i>C. auris</i> require rapid and reliable detection methods to initiate successful medical treatment and contain hospital outbreaks. Conventional identification methods are prone to errors and can lead to misidentifications. PCR-based assays, in turn, can provide reliable results with low turnaround times. However, only limited data are available on the performance of commercially available assays for <i>C. auris</i> detection. In the present study, the two commercially available PCR assays <i>Auris</i>ID (OLM, Newcastle Upon Tyne, UK) and Fungiplex <i>Candida Auris</i> RUO Real-Time PCR (Bruker, Bremen, Germany) were challenged with 29 <i>C. auris</i> isolates from all five clades and eight other <i>Candida</i> species as controls. <i>Auris</i>ID reliably detected <i>C. auris</i> with a limit of detection (LoD) of 1 genome copies/reaction. However, false positive results were obtained with high DNA amounts of the closely related species <i>C. haemulonii, C. duobushaemulonii</i> and <i>C. pseudohaemulonii</i>. The Fungiplex <i>Candida Auris</i> RUO Real-Time PCR kit detected <i>C. auris</i> with an LoD of 9 copies/reaction. No false positive results were obtained with this assay. In addition, <i>C. auris</i> could also be detected in human blood samples spiked with pure fungal cultures by both kits. In summary, both kits could detect <i>C. auris</i>-DNA at low DNA concentrations but differed slightly in their limits of detection and specificity.