Candida auris colonization or infection in the ear of four patients with chronic otitis externa: A case series and literature review

Abstract

Background and Purpose: Candida auris, a globally emerging multidrug-resistant pathogen, was first isolated from the external ear canal of a Japanese patient. Subsequently, most cases were reported from invasive or non-ear infections; however, in Iran, an increasing number of otologic infections have been reported as the dominant clinical form of C. auris infections. Materials and Methods: This study described the clinical features, microbiological findings, and outcome of four C. auris otomycotic cases that had been identified during a previous large-scale survey performed by the authors on 1,029 patients/specimens in a single center. It is accompanied by a literature review of C. auris cases reported from Iran up to 2023. Results: Six culture-proven C. auris cases were reported, of which four belonged to clade V and two to clade I. Three culture-negative, polymerase chain reaction-identified cases were also documented. The clinical profile of the infection in Iran showed a distribution of C. auris clades distinct from those of other countries, where other clades and other clinical forms, like candidemia, are predominated. No case of candidemia was noted. Although fluconazole resistance was documented in 50 of the isolates, no resistance to echinocandins or amphotericin B was noted. Conclusion: This review highlighted the following notable points: (a) C. auris infection is a challenging condition which is usually misdiagnosed or diagnosed untimely; (b) the clinical table and cladal distribution of C. auris in Iran is different from those of other countries; (c) cases with C. auris may provide negative culture, underscoring the importance of using specific direct polymerase chain reaction to rule out or confirm C. auris, particularly in cases with chronic otomycosis; (d) ongoing patient follow-up and antifungal susceptibility testing in patients who do not respond to antifungal drug are recommended; (e) reliance on non-specific, insensitive, and time-consuming approaches, such as culture, may not only postpone the detection, but also lead to misidentification of C. auris in settings where molds are predominated. © 2026 Mazandaran University of Medical Sciences. All rights reserved.