Canine sporotrichosis: polyphasic taxonomy and antifungal susceptibility profiles ofSporothrixspecies in an endemic area in Brazil

Sporotrichosis, a mycosis caused by pathogenic species of the genusSporothrix, affects diverse species of mammals. Until 2007,Sporothrix schenckiiwas considered the unique etiologic agent of sporotrichosis. Canine sporotrichosis is a poorly reported disease, and the majority of cases are from Rio de Janeiro, Brazil. There are scarce studies on the characterization of canine isolates ofSporothrix schenckiicomplex, as well as few antifungal susceptibility data available. The aim of this study was to characterize the clinical isolates ofSporothrixfrom dogs from Brazil at species level and evaluate their antifungal susceptibility profile. Polyphasic taxonomy was used to characterization at species level (morphological, phenotypical characteristics, and molecular identification). Antifungal susceptibility profiles (amphotericin B, itraconazole, ketoconazole, posaconazole, and terbinafine) were determined using the Clinical and Laboratory Standards Institute broth microdilution method (M38-A2). According to phenotypic identification and molecular analysis, 46 isolates included in this study were identified asS. brasiliensisand one asS. schenckii. Amphotericin B presented the highest minimum inhibitory concentration values, and the other drugs showed effective in vitro antifungal activity. This is the first report ofS. schenckiiin dogs from Brazil, sinceS. brasiliensisis the only species that has been described in canine isolates from Rio de Janeiro to date. Nevertheless, no differences were observed in the antifungal susceptibility profiles between theS. brasiliensisandS. schenckiiisolates, and it is important to continuously study new canine clinical isolates from Rio de Janeiro, Brazil.