Canine dermatophytosis caused by an anthropophilic species: molecular and phenotypical characterization of Trichophyton tonsurans.

Abstract

Microsporum canis is the most common species isolated from canine and feline dermatophytosis in the world. However, this study reports a rare case of canine dermatophytosis caused by the anthropophilic dermatophyte Trichophyton tonsurans in the city of Fortaleza, Ceará, Brazil. The fungal characterization was performed by classical mycological examination and by genotypical analysis using the restriction enzymes Sau3A, RsaI, DdeI and EcoRI. The phenotypical characteristics were compatible with T. tonsurans. The results obtained in the genotypical analysis were similar to the digestion pattern of the ITS sequences for T. tonsurans strains. In addition, an antifungal susceptibility test was performed with griseofulvin, ketoconazole and itraconazole. The MICs were 0.5 microg ml(-1) for griseofulvin, 0.25 microg ml(-1) for ketoconazole and 1 microg ml(-1) for itraconazole. This study emphasizes the adaptability of anthropophilic fungi such as T. tonsurans to animal conditions.