Frequency Distribution of Keratinophilic Dermatophyte Fungi from the Soil of Different Zones in Isfahan Using Morphological and Molecular Methods

BACKGROUND: Dermatophytes are one of the most important etiologic agents of cutaneous infections in humans and animals. The present study aimed to study the frequency distribution of keratinophilic dermatophyte fungi using conventional and molecular methods in soil of Isfahan city. MATERIALS AND METHODS: In this study, 200 soil samples were randomly selected in three northern, southern, and central parts of Isfahan using hair-baiting technique. The fungi were identified by morphology based on macroscopic and microscopic characteristics of fungi. Furthermore, the sequencing of ITS1-5.8S-ITS2 region of the ribosomal DNA of the 60 randomly isolated fungi was investigated. RESULTS: The results of conventional method showed that from a total of 371 fungal colonies, the highest amount of detected colonies was in the central zone (151, 40.26%). Furthermore, in all three areas, the most common detected dermatophyte was Microsporum gypseum (38.3%). The results of the molecular analysis showed that M. gypseum identified by the morphology method was Nannizzia fulva, and also, Chrysosporium sp. with the frequency of 30% in morphology method was the second dominated fungus including Chrysosporium keratinophilum (42.6%) and Chrysosporium shanxiense (21.4%) which confirmed by sequencing method. CONCLUSION: The results showed that keratinophilic dermatophyte fungi including Nannizzia fulva, Chrysosporium sp., and Trichophyton mentagrophytes are found in the children playgrounds in Isfahan. Therefore, health-care officials should pay more attention to these hygienic issues. C. shanxiense, which is found here for the first time in Iran, has been reported only from China.