Related Experiment Video
Updated: Jun 17, 2026
Whole Genome Sequencing of Candida glabrata for Detection of Markers of Antifungal Drug Resistance
Published on: December 28, 2017
Screening Candida auris through a multiplex stepwise PCR algorithm directly from clinical samples of patients
Behrouz Naeimi1, Fatemeh Safari2, Kazem Ahmadikia3
1Department of Medical Laboratory Sciences, Faculty of Paramedical, Bushehr University of Medical Sciences, Bushehr, Iran.
Background:
Otomycosis is an infection of the external auditory canal caused by molds and yeasts with descending frequency. Laboratory diagnosis is usually confirmed by microscopy and culture. However, they are not specific enough to reliably differentiate the causative agents, especially for rare pathogens such as Candida auris. The purpose of the current study was to the molecular screening of C. auris species from direct clinical samples of patients with suspected otomycosis in Southern of Iran.
Materials And Methods:
A total of 221 ear aspirates collected from 221 patients with suspected otomycosis over a four-year period. All the ear aspirations were examined with pan-fungal primers, then those with a positive result was included in two separate reaction mixtures simultaneously to identify the most clinically relevant Aspergillus and Candida species. The validity of positive samples for C. auris was assessed by sequencing.
Results:
Of the 189 pan-fungal positive PCRs, 78 and 39 specimens contained Aspergillus spp. and Candida spp., respectively. Furthermore, 65 specimens showed simultaneous positive bands in both Candida and Aspergillus species-specific multiplex PCR including five samples/patients with positive result for C. auris (5/189; 2.6%). Four out of five cases with C. auris species-specific PCR were reconfirmed by sequencing, while none were positive for C. auris in culture.
Conclusion:
Unfortunately, due to high treatment failure rates of antifungal classes against C. auris species, rapid and accurate identification of patients colonised with C. auris is critical to overcome the challenge of preventing transmission. This PCR assay can be successfully applied for rapid and accurate detection of C. auris directly in patient samples and is able to differentiate C. auris from closely related Candida species.
Insights
A new PCR assay successfully detected Candida auris in 2.6% of suspected otomycosis cases in Iran. This rapid molecular method is crucial for identifying this challenging fungal pathogen, outperforming traditional cultures.
Area of Science:
- Medical Mycology
- Infectious Diseases
- Molecular Diagnostics
Background:
- Otomycosis, an external ear canal infection, is commonly caused by molds and yeasts.
- Traditional diagnostic methods like microscopy and culture lack specificity for identifying causative agents, particularly rare pathogens such as Candida auris.
- Accurate identification of Candida auris is critical due to high antifungal treatment failure rates and its potential for transmission.
Purpose of the Study:
- To perform molecular screening for Candida auris in direct clinical samples from patients with suspected otomycosis in Southern Iran.
- To evaluate a PCR-based method for the rapid and accurate detection of Candida auris.
Main Methods:
- Analysis of 221 ear aspirates from patients with suspected otomycosis over a four-year period.
- Application of pan-fungal primers followed by species-specific multiplex PCR for Aspergillus and Candida.
- Confirmation of positive Candida auris samples using DNA sequencing.
Main Results:
- Out of 189 pan-fungal positive PCRs, Aspergillus spp. and Candida spp. were identified in 78 and 39 specimens, respectively.
- Candida auris was detected in 5 out of 189 samples (2.6%) using multiplex PCR.
- Sequencing confirmed four of the five Candida auris cases, while none were identified by culture.
Conclusions:
- The developed PCR assay enables rapid and accurate detection of Candida auris directly from patient samples.
- This molecular method can differentiate Candida auris from closely related Candida species, aiding in clinical management.
- Early and precise identification of Candida auris is essential for preventing its transmission and managing infections effectively.
