Advances and challenges in the management of feline sporotrichosis / Avances y desafíos en el manejo de la esporotricosis felina

The domestic cat is the most susceptible host to Sporothrix infection, developing severe clinical forms. Few effective antifungal agents are available for treating feline sporotrichosis, and cases of treatment failure are common. Treatment success depends on cat health status, therapy-related factors, as well as social/economic issues, but it is mainly contingent upon the host–fungus interaction. The owner's adherence is critical and should be reinforced throughout the treatment to increase the chances of a successful outcome. The antifungal agents described for feline sporotrichosis are most often used in monotherapy regimens. Due to cases in which the treatment with itraconazole failed, the use of antifungal agents in combination should be considered to achieve synergy. The combination of itraconazole and potassium iodide represents an important option for the treatment of naïve cats presenting multiple cutaneous lesions, nasal mucosal lesions and/or respiratory signs, as well as for refractory cases. However, the therapeutic options for unsuccessfully treated cases are scarce. Therefore new options are needed, even more taking into account that there are many in vitro potential molecules not available for use in cats yet. More studies are necessary to correlate in vitro antifungal susceptibility tests results and the outcome of cats treated due to sporotrichosis. This review will briefly discuss both the antifungal drugs and treatment protocols used in cats with sporotrichosis, as well as the determinants of treatment failure. (AU)

El gato doméstico es el huésped más susceptible a la infección por Sporothrix, llegando a desarrollar formas clínicas graves. Hay pocos agentes antimicóticos efectivos disponibles para tratar la esporotricosis felina, y los casos de fracaso terapéutico son habituales. El éxito del tratamiento depende del estado de salud del gato, los factores relacionados con la terapia y los problemas sociales/económicos, pero se asocia principalmente con la interacción huésped-hongo. El cumplimiento del tratamiento por parte del propietario es fundamental y debe reforzarse durante todo el proceso para aumentar las posibilidades de éxito. Los agentes antimicóticos descritos para la esporotricosis felina se usan con mayor frecuencia en monoterapia. Debido a los casos de fallo terapéutico en el tratamiento con itraconazol se debe considerar el uso combinado de agentes antifúngicos en sinergia. La combinación de itraconazol y yoduro de potasio es una buena opción en el caso de gatos no tratados previamente y con múltiples lesiones cutáneas, en la mucosa nasal y/o con signos respiratorios, así como para casos refractarios. Sin embargo, las opciones terapéuticas para la mayoría de los casos que fracasan son escasas. Por tanto, son necesarias nuevas opciones terapéuticas, más aún cuando existen muchas moléculas potenciales in vitro, no disponibles de momento para su uso en gatos. Son necesarios más estudios que correlacionen los resultados de las pruebas de sensibilidad in vitro a los antifúngicos con aquellos del tratamiento de gatos con esporotricosis. Esta revisión discutirá brevemente los fármacos antimicóticos y los protocolos terapéuticos utilizados para tratar gatos con esporotricosis, así como los factores determinantes del fracaso del tratamiento. (AU)

Canine sporotrichosis: polyphasic taxonomy and antifungal susceptibility profiles of Sporothrix species in an endemic area in Brazil.

Sporotrichosis, a mycosis caused by pathogenic species of the genus Sporothrix, affects diverse species of mammals. Until 2007, Sporothrix schenckii was 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 of Sporothrix schenckii complex, as well as few antifungal susceptibility data available. The aim of this study was to characterize the clinical isolates of Sporothrix from 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 as S. brasiliensis and one as S. 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 of S. schenckii in dogs from Brazil, since S. brasiliensis is 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 the S. brasiliensis and S. schenckii isolates, and it is important to continuously study new canine clinical isolates from Rio de Janeiro, Brazil.

Successful Treatment of Canine Sporotrichosis with Terbinafine: Case Reports and Literature Review.

Sporotrichosis occurs worldwide, and the metropolitan region of Rio de Janeiro, Brazil, is a main endemic area, with a large number of human and animal cases in the last 19 years. This mycosis is more frequently described in cats rather than in dogs. There are a limited number of oral antifungal agents for the treatment of sporotrichosis in animals. In this context, the effectiveness of terbinafine in the treatment of sporotrichosis in humans, as well as the promising results of in vitro susceptibility tests, inspired us to use this drug in the therapy of this mycosis in dogs. We reported for the first time the use of terbinafine in the treatment of two dogs with sporotrichosis caused by Sporothrix brasiliensis. Moreover, we provided an overview of therapeutic features of canine sporotrichosis cases reported since the 1960s. One of the dogs presented the fixed cutaneous form of the disease, while the other patient presented hyperemia of the nasal mucosa and respiratory signs only. Terbinafine showed high antifungal activity in vitro against the canine Sporothrix isolates. The dogs were successfully treated with terbinafine, with remission of all clinical signs initially presented. The current reports indicate that this drug can emerge as a therapeutic option for canine sporotrichosis.