Esporotricose óssea em gato causada por Sporothrix brasiliensis

Background: Sporotrichosis is a deep cutaneous mycosis caused by the Sporothrix species complex, dimorphic fungi of which at least five are of clinical importance: S. brasiliensis, S. globosa, S. luriei, S. mexicana, and S. schenckii sensu stricto. The disease affects humans and animals, especially cats, which can manifest a wide spectrum of clinical sings, from cutaneous-lymphatic involvement to disseminated form. Infection usually results from direct inoculation of the fungus into skin. Zoonotic transmission is associated with scratching or biting of sick cats. The aim of this work was to report an atypical case of bone sporotrichosis in a cat.Case: A 5-year-old, male, neutered, mongrel and indoor cat was present at the Veterinary Clinic Hospital, Federal University of Rio Grande do Sul (HCV-UFRGS), Porto Alegre, Brazil, with lameness and increased volume in the left hindlimb. The animal had been treated intermittently with itraconazole during the last three years due to another cutaneous lesion which was recurrent and undiagnosed. A firm and painful mass was found in tarsal region of left hindlimb, that had approximately 5 cm in diameter. Radiographic examination of the left tibial-tarsal joint revealed bone lysis in the fifth metatarsal calcaneus, in addition to periosteum proliferation in calcaneus, tibio-tarsal subluxation, presence of osteophytes in tarsal bones and increase in soft tissue volume. Histopathological analysis of the biopsied tissue showed piogranulomatous inflammation. No yeast-like structures were observed in cytopathological exam. Tissue fragments were plated and Sporothrix sp. complex growth in mycological culture (Sabouraud Cycloheximide Chloramphenicol Agar). Physiological tests (growth rate at different temperatures and assimilation of sucrose and raffinose) were conducted for the differentiation of the species of complex. Molecular identification was performed using panfungal primers (ITS3-F / ITS4-R). The diagnosis of bone sporotrichosis caused by Sporothrix brasiliensis was based on clinical signs, mycological (confirmed by isolation and identification in culture medium) and molecular methods. Treatment was based on excision of the limb associated with oral administration of itraconazole and silymarin for two months. Unfortunately, three months later new nodules were seen at the abdomen and biopsy samples were positive in a new fungal culture for Sporothrix sp. Oral treatment was then restarted for four months. The cat is now