Molecular identification of Candida auris by PCR amplification of species-specific GPI protein-encoding genes

Area of Science:

• Clinical Microbiology
• Infectious Diseases
• Molecular Diagnostics

Background:

• Candida auris is an emerging multidrug-resistant yeast causing severe invasive infections.
• Its high hospital transmission rate and frequent misidentification pose significant diagnostic challenges.
• Accurate and rapid detection is crucial for effective patient management and infection control.

Purpose of the Study:

• To develop and validate a rapid, reliable, and cost-effective PCR assay for the specific identification of Candida auris.
• To address the limitations of current diagnostic methods, such as MALDI-TOF MS, in accurately identifying C. auris.

Main Methods:

• Design of PCR primers targeting unique GPI protein-encoding genes specific to C. auris.
• Verification of primer specificity against 19 different Candida species, including closely related ones.
• Validation of the PCR assay using clinical isolates from a Spanish hospital outbreak and international sources, including blind negative controls.

Main Results:

• The PCR assay demonstrated high specificity and efficacy in identifying 112 C. auris isolates from a Spanish outbreak.
• The method correctly identified 27 diverse C. auris isolates from various international locations.
• The assay outperformed MALDI-TOF MS, which failed to reliably identify 20% of the outbreak isolates.

Conclusions:

• A novel PCR assay based on unique GPI protein-encoding genes provides accurate and rapid identification of Candida auris.
• This method enhances diagnostic robustness by employing dual primer pairs, mitigating risks of false negatives.
• The developed PCR assay is a valuable tool for clinical settings, offering an easy, low-cost solution for C. auris detection.