Characterization and mating reactions of clinical isolates of trychophyton mentagrophytes and T. Rubrum which produce a diffusible brownish pigment

This paper reports on the factors required for pigment production and on the mating type of 6 clinical isolates of Trichophyton which produce a diffusible brownish pigment. Three isolates were identified as T. mentagrophytes and three as T. rubrum. Pigment was produced in the presence of L-phenylalanine or L-tyrosine but no pigment or growth occurred in the presence of quinic or shikimic acids. The T. mentagrophytes isolates reacted as A(+) mating type and the T. rubrum as a(-) when paired with Arthroderma simii A(+) and a(-) tester strains.