Teleomorphs and mating types in Trichophyton mentagrophytes complex.

In the set of 132 strains of Trichophyton mentagrophytes isolated from humans (129 strains) and animals (3 strains) with dermatophytosis in Czechoslovakia, 41 strains were classified as Arthroderma benhamiae. Out of them, 40 strains were of mating type + and one strain of type -. Ten strains were A. vanbreuseghemii, including 3 strains of mating type + and 7 strains of type -. Other strains studied did not form any fertile cleistothecia during crossing. Some strains of A. benhamiae developed defective cleistothecia with rare asci or without ascospores. From conidia of two strains (T. mentagrophytes var. mentagrophytes and T.m. var. quinckeanum) two morphological variants (granular and fluffy) were cultivated. Both variants were A. benhamiae type + and pathogenic. The determination of mating types using the test of sexual stimulation with Arthroderma simii and hybridization test with the reference strains of A. benhamiae and A. vanbreuseghemii gave identical results. No relationships between the variety of anamorphous state (T. mentagrophytes var. mentagrophytes, var. granulosum, var. interdigitale, var. quinckeanum), teleomorph, mating type, localization of dermatophytosis, and pathogenicity for guinea pig were found. The reasons for unequal distribution of mating types in clinical isolates of various dermatophytes are discussed.