Otomycosis Due to the Rare Fungi Talaromyces purpurogenus, Naganishia albida and Filobasidium magnum

Abstract

Otomycosis is a common finding in otorhinolaryngology clinics and is usually caused by species of Candida and Aspergillus, particularly black aspergilli. Meanwhile, other fungi can give rise to this infection, and the identification of these requires accurate methods. Here, we report three cases of otomycosis due to rare fungal pathogens. All the patients were young females, and manipulation of the ear canal was identified as a common potentially predisposing factor. In direct examination, filamentous fungal elements (in one case) and yeast cells (in two other cases) were seen. Culture was positive in all cases. Based on PCR-sequencing of internal transcribed spacers and beta-tubulin (for mold isolate), the isolated fungi were identified as Talaromyces purpurogenus, Naganishia albida and Filobasidium magnum. By susceptibility testing of the isolates to fluconazole, itraconazole, voriconazole and amphotericin B, the lowest minimum inhibitory concentration values were observed for amphotericin B followed by voriconazole. Patients were successfully treated by a combination of antifungals and corticosteroids with no relapse over the next year, except for the case due to F. magnum, in which, despite partial recovery, a course of relapse was reported in the 1-year follow-up call.