Molecular identification and epidemiology aspects of dermatophytosis in Tehran, Iran

Dermatophytes are the most common fungal agents causing superficial skin infections in worldwide. Species identification of these fungi is important for therapeutic and epidemiological apects. The purpose of this study was identification and epidemiology of dermatophytosis in patients referring to medical mycology laboratory of Razi hospital in Tehran, during 2014. In this study, 610 clinical specimens were collected from patients with suspected dermatophytosis. Direct microscopy and culture examinations were performed for all samples. DNA was extracted from fungal colony using phenol chloroform. Then ITS1-5.8s-ITS2 region of ribosomal DNA (rDNA) was amplified by the universal fungal primers ITS1 and ITS4 and digested with enzymes mva1. In the present study, 236 subjects (38.6%) were positive for dermatophytosis. Among the patients, 64.8% were male and 35.2% female. The most frequent dermatophytes isolated were Trichophyton interdigitale (40.3%), Trichophyton rubrum (22.9%) and Trichophyton tonsurans (18.7%) respectivly. Also 58 samples were improperly diagnosed by morphological method, they were re-identified as Trichophyton interdigitale and Trichophyton rubrum by using PCR-RFLP. The survey showed that PCR-RFLP is a rapid and reliable method for discrimination of dermatophytes. We suggest using of PCR-RFLP as a valuable method along with morphological examination for diagnostic dermatophytes particularly in clinical and epidemiological settings.