PCR Typing of Trichophyton Rubrum Isolates by Specific Amplification of Subrepeat Elements in Ribosomal DNA Nontranscribed Spacer

Background: trichophyton rubrum (t. rubrum) is the most common cause of dermatophytosis of skin and nail tissue. strain identification in trichophyton rubrum is important for identification of strain-related differences in infectivity potential or transmissibility and epidemiological studies. pcr typing could determine whether the original isolate is responsible for re- infection or a new strain has been acquired. methods: a minipreparation method for dna from dermatophytes was used. tandemly repetitive subelements (trs-1 & trs-2) of nts region at ribosomal dna of 23 t.rubrum isolates were amplified and the pcr products were separated by electrophoresis in 2% agarose gel (200 ma, 140 v), visualized by staining with ethidium bromide, and photographed. results: on the basis of copy number of trs-1 and trs-2, 8 out of our 23 samples were type 2 & ii, respectively. six of them were type 3 & ii, four isolates were type 1 & ii, two isolates were type 4 & ii, two isolates were type 1 & i and one isolate was type 5 & ii. conclusion: in this study, most of t. rubrum isolates were type 2 & ii, dissimilar to european studies where type 1 & ii has been the most common. the present study showed that 26.1% of iranian isolates were type 1 in contrast with a previous study which has demonstrated a much lower prevalence in asians (5%).