Genetic diversity among Trichophyton mentagrophytes isolates using random amplified polymorphic DNA method

Trichophyton mentagrophytes is a common cosmopolitan dermatophyte species c omposed of two varieties: T. mentagrophytes var, interdigitale (anthropophi lic form) and T, mentagrophytes var, mentagrophytes (zoophilic form). We us ed a random amplified polymorphic DNA (RAPD) method to study the genetic di versity of 46 clinical isolates of the T. mentagrophytes complex collected from 38 patients with different geographical origins (Europe, Africa, South America), The T, mentagrophytes were isolated either from a unique lesion for 31 patients, including two patients living together, or from at least t wo sites for seven patients. Only one primer of lj primers tested showed DN A polymorphism in the isolates, producing 23 distinct patterns belonging to three clusters. There was no specific cluster grouping isolates from the s ame geographical origin, The same pattern is shared by all the four T, ment agrophytes var, mentagrophytes and 13 of 42 T, mentagrophytes var, interdig itale. An identity of strains responsible for several lesions in seven indi viduals suggests an homogeneous T, mentagrophytes population in the case of multiple lesions, In contrast, the dissimilarity of two strains recovered from two patients living together argues against person-to-person transmiss ion in that case, This study indicates that RAPD can be successfully applie d to show genetic diversity among T. mentagrophytes isolates.