Development of experimental sporotrichosis in normal and modified animals.

The development of experimental sporotrichosis was examined in immunologically-disturbed mice. In the case of intracutaneous inoculation, the lesion in cyclophosphamide-treated mice enlarged strikingly up to 6 days, but at 12 days it was similar in size to that in non-treated mice. The lesion in irradiated mice developed slowly up to 12 days, but thereafter it developed promptly. In nude mice, the lesion was smallest during the development of the lesion. Histological examination showed that numerous organisms were present in the lesion of nude and irradiated mice. Intraperitoneal inoculation showed that dissemination of spores were easily induced in nude mice as compared with littermate mice. These results indicate an important role of cellular immunity in the defence mechanism of sporotrichosis.