MOLECULAR IDENTIFICATION OF DERMATOPHYTES AMONG CLINICAL ISOLATES

Aim: This study aimed to identification of dermatophyte species in clinical isolates by both classical and molecular methods, using universal primers for amplification of ITS gene. In addition, identification at a species level was carried out by using PCR-restriction fragment length polymorphism (RFLP) technique. Methodology and Results:In the present study, out of 220 suspected patients (157 females and 63 males) with dermatophytosis were identified by the supervision of specialized dermatologist in the derma unit of the General hospital in Kalar district/Sulaimania provinceIraq during the period from middle of November 2014 to the end of June 2015. Samples were collected from patients included hair fragments, skin scraping and nail clipping which transferred to the research laboratory of Biology Department at Faculty of Education University of Garmian, where they immediately examined. Based on the conventional laboratory methods, 80 clinical isolates of dermatophytes showed positive culture which belonging to three genera (Trichophyton, Microsporum and Epidermophyton) and 13 species, , Trichophyton rubrum (downy and granular types) was the most common species 35% followed by T.mentagrophytes 17.5%, M.canis 10% and T.tonsurans 7.5%. Other species T. soudanese; T.interdigitale; T. terrestre represented 5% of dermatophytes while T.concentricum; T.schoenleinii; T.verucosum; Microsporum audouinii; M.gypsium and Epidermophyton flocosum conistitute 2.5%. Molecular identification of dermatophytes was carried by using the primers ITS1 and ITS4 to amplify the internal transcript spacer (ITS) region of ITS1 5.8S ITS2 in rDNA gene, later the species identification was made by digestion of amplified ITS regions by BstN1 restriction enzyme in restriction fragment length polymorphism (PCR-RFLP) to produce distinct band patterns. Conclusions: Survey of dermatophytes showed that PCR-RFLP is a rapid and easy method for dermatophytes identification; therefore we suggest using the PCR-RFLP corresponding to the conventional laboratory identification including macroscopic and microscopic examination.