PCR identification of Trichophyton mentagrophytes var. interdigitale and T. mentagrophytes var. mentagrophytes dermatophytes with a random primer.

Dermatophytes are a group of keratinophilic fungi falling within the genera of Epidermophyton, Microsporum and Trichophyton. The genus Trichophyton is particularly important and complex; it comprises at least 15 recognised species. In addition, there are several different variants in the species T. mentagrophytes, which occur both in man and animals. The current methods of determining T. mentagrophytes varieties may require several different culture media and time-consuming procedures, as well as specialist skills. This study used a random primer, 5'-GAGCCCGACT-3', in the arbitrarily primed polymerase chain reaction (AP-PCR) and showed that the two common T. mentagrophytes varieties (var. interdigitale and var. mentagrophytes) can be clearly identified on the basis of their characteristic DNA band patterns. The relative reproducibility, ease of use and precision of this method make the AP-PCR a valuable tool in the laboratory diagnosis of human dermatophytosis.