Identification of several clinical isolates of dermatophytes based on the nucleotide sequence of internal transcribed spacer 1 (ITS 1) in nuclear ribosomal DNA.

Nucleotide sequences of internal transcribed spacer 1 (ITS 1) in nuclear ribosomal DNA from seven morphologically unidentified dermatophyte isolates were determined. The sequences were compared with those of typical isolates of Trichophyton (T.) mentagrophytes var. interdigitale, T. rubrum, and Epidermophyton floccosum. Two of the isolates were classified as T. rubrum and the other five as T. mentagrophytes var. interdigitale. The results did not conflict with identifications using other molecular techniques, including random amplification of polymorphic DNA (RAPD) analysis and restriction enzyme analysis of mitochondrial DNAs. Thus, the nuclotide sequence of ITS 1 is possibly a good molecular marker for identification of these major anthropophilic dermatophyte species.