Agents of Otomycosis in Manisa Region, Turkey, 1995-2011

Otomycosis, which is otitis externa caused by fungi, is common throughout the world especially in tropical and subtropical countries. However, the epidemiologic data about the etiologic agents of otomycosis in Turkey is limited. The aim of this retrospective study was to evaluate the agents of otomycosis in patients living at Manisa region (located at western Anatolia of Turkey). A total of 2279 cases [1465 male, 813 female; age range 1-87 (mean: 41.7) years] who were clinically prediagnosed as otomycosis at Celal Bayar University Hospital, between February 1995 and July 2011, were included in the study. External ear swab samples from patients with suspicion of otomycosis have been evaluated by routine mycological methods. Identification of mold-like fungi was based on colony morphology and microscopic examination of fungal structure, whereas germ tube test, growth characteristics on cornmeal-Tween 80 agar and API 20C AUX (bio-Merieux, France) system were used for the identification of yeast-like fungi. Of the samples, 28% (638/2279) were found positive by direct microscopy and 24% (544/2279) by culture methods. Among culture-positive cases the isolation rates of mold-like and yeast-like fungi were 66% (359/544) and 34% (185/544), respectively. The number of distribution of the molds were as follows; Aspergillus niger (180), Aspergillus fumigatus (95), Aspergillus terreus (32), Aspergillus flavus (23), Aspergillus spp. (14), Penicillium spp. (13), Trichophyton spp. (T.rubrum 1, T.mentagrophytes 1); while this distribution was as follows for the yeasts; Candida tropicalis (97), Candida albicans (39), Candida parapsilosis (21), Candida glabrata (19), Candida kefyr (4), C.guilliermondii (2), Candida krusei (1), Geotrichum candidum (1) and Trichosporon capitatum (1). It was notable that 96% (344/359) of mold-like fungi were Aspergillus spp., and 99% (183/185) of yeast-like fungi were Candida spp. The results of this study indicated that the most frequent agents of otomycosis were non-dermatophyte species such as Aspergillus, followed by Candida. Dermatophytes were isolated in a small number of otomycosis cases. These data will provide support to the establishment of antifungal therapy guidelines for otomycosis.