Identification of Dermatophytosis Agents in Mashhad, Iran, by Using Polymerase Chain Reaction Sequencing (PCR Sequencing) Method

Abstract

Background: Dermatophytes are a group of fungi that attack keratinous tissues of the skin, hair, and nail in humans and animals, and cause infections called dermatophytosis (tinea). Since identification of pathogenic fungi at the species level is essential for the detection of the source, control and prevention, and identifying epidemiology of infection, it is necessary to use specific and sensitive diagnostic methods to identify the causes of dermatophytosis. Methods: The clinical samples (skin, nail, and hair) of patients with dermatophytosis in Mashhad City, Iran, were cultured in Mycosyl Agar culture media, and the DNA of obtained dermatophyte colonies were extracted by specific kit. The internal transcribed spacer (ITS) gene was amplified and sequenced by ITS1, ITS4 primers. Finally, the sequencing results were analyzed using SeqMan software, and were compared with the data of the global genebank. Findings: In this study, 80 dermatophyte isolates were sequenced, which included 9 dermatophyte species as 23 (28.8%) Trichophyton (T.) interdigital, 18 (22.5%) T. tunsorans, 10 (12.5%) Epidermophyton fluccosum, 10 (12.5%) of T. mentagrophytes, 8 (10%) Microsporum canis, 4 (5%) T. rubrum, 4 (5%) T. benhamiae, 2 (2.5%) Nannizzia (N.) fulvum, 1 (1.2%) N. persicolor. Conclusion: According to report the rare species of dermatophytes in this study, the use of molecular methods such as sequencing of the ITS gene can determine the diversity of dermatophytes in a region more precisely than morphological methods.

Keywords

• Dermatophytosis
• DNA sequencing
• Iran