Candida auris PCR for high-throughput infection control screening

Area of Science:

• Clinical microbiology
• Infectious disease diagnostics
• Molecular biology

Background:

• Candida auris is a multidrug-resistant fungus causing global healthcare-associated infections.
• Traditional culture-based screening is time-consuming and poses risks to laboratory staff.
• Rapid and accurate detection is crucial for effective infection control.

Purpose of the Study:

• To adapt and validate a real-time PCR assay for high-throughput screening of Candida auris in skin swabs.
• To establish the limit of detection, specificity, and sensitivity of the PCR assay.
• To ensure the safety of laboratory personnel by inactivating the fungus during sample processing.

Main Methods:

• Adaptation of a published real-time PCR protocol for C. auris identification.
• Analysis of primer and probe sets to determine the limit of detection (1 CFU/reaction).
• Testing of clinical skin swabs (n=100) and samples from known cases and contacts for specificity and sensitivity.
• Inactivation of C. auris using a guanidinium thiocyanate lysis buffer.

Main Results:

• The selected PCR assay demonstrated a limit of detection of 1 colony-forming unit per reaction.
• High specificity was confirmed, with no cross-reactivity observed in non-C. auris isolates or routine skin swabs.
• The PCR assay correctly identified all C. auris-positive skin swabs (n=6) and C. auris-negative surveillance swabs from contacts (n=46).
• The lysis buffer effectively rendered C. auris non-viable, ensuring laboratory safety.

Conclusions:

• A real-time PCR assay is effective for high-throughput screening of Candida auris in skin swabs.
• This molecular method provides rapid, accurate, and safe detection for infection control.
• The PCR assay is a valuable tool for managing C. auris outbreaks in healthcare settings.