Immunological studies on Pityrosporum genus and Malassezia furfur.

The antigenicity of Malassezia furfur from patients with tinea versicolor and 3 species of Pityrosporum was investigated using the antiserum against P. orbiculare. The Ouchterlony gel diffusion test revealed a considerable similarity between the antigenicities of P. orbiculare and P. ovale, and little similarity between P. orbiculare andP. canis. Similar results were obtained by immunofluorescence staining with the FITC-labeled P. orbiculare antiserum. Hyphae and round spores of M. furfur in the scales and biopsy specimens from the lesions in patients with tinea versicolor revealed specific fluorescence much the same as seen in cases of P. orbiculare or P. ovale. The FITC-labeled antiserum absorbed with P. orbiculare or P. ovale failed to give a positive reaction with hyphae and round spores of M. furfur. These findings suggest a similar antigenicity among P. orbiculare, P. ovale and M. furfur.