BackgroundSporotrichosis is a neglected zoonosis caused by pathogenic fungi belonging to the Sporothrix schenckii complex. In Rio de Janeiro state, this disease reached an epidemic status with over 4700 domestic felines and around 4000 humans affected since the mid-90s. The present study evaluated clinical and epidemiological aspects and also the frequency of colonization and infection by these fungi in healthy cats and among those with suspicious cutaneous lesions, inhabiting four Rio de Janeiro state distinct areas.ResultsThree hundred and seventy-one cats were included in two groups: 175 healthy cats [CRG] and 196 cats showing lesions suggesting sporotrichosis [SSG]. Mycological diagnosis allowed SSG animals to be divided in positive [104 cats; +SG] and negative [92 cats; -SG] groups. Nails, oral mucosa and lesions swabs were submitted to culture and potential colonies were subculture for micromorphologycal analysis, dimorphism and molecular tests. In the CRG, only one cat was colonized in the oral cavity [0.57%]; in the -SG group, four animals showed colonization of the nail and/or oral cavity [4.3%]; while the highest frequency of colonization [39.4%] was observed in the +SG. All molecularly typed isolates were identified as S. brasiliensis.ConclusionThe results obtained here indicate that healthy cats have a minor role in sporotrichosis transmission within the state of Rio de Janeiro. Conversely, a higher participation of diseased feline in sporotrichosis transmission was evidenced, especially by the colonization of their oral cavity. Sporothrix brasiliensis equally affects and colonizes animals from distinct Rio de Janeiro state areas. Thus, we hypothesize that sporotrichosis is a uniform endemic throughout the state, whose transmission depends mainly on the contact with cats with sporotrichosis. Since Rio de Janeiro displays a world unique epidemic model of the disease, not fully understood, data on the infected and non-infected animals can be of major importance for future strategies of sporotrichosis prevention and control. Finally, considering the importance of the current concept of “one health”, the experience here observed can be helpful for distinct epizootias and/or zoonosis.

INTRODUÇÃO: O estado do Rio de Janeiro vem passando por uma epidemia de esporotricose, considerada doença negligenciada, de transmissão zoonótica pelo felino doméstico (Felis catus). Apesar do isolamento de fungos do complexo Sporothrix schenckii em cultura micológica ser o padrão-ouro no diagnóstico, a citopatologia por imprint das lesões é rotineiramente utilizada na prática da clínica veterinária. OBJETIVO: Avaliar o desempenho da citopatologia como método diagnóstico da esporotricose em gatos com suspeita dessa micose, provenientes de diferentes áreas geográficas do estado do Rio de Janeiro, Brasil. MATERIAIS E MÉTODOS: Após avaliação clínica, o swab do exsudato e lâminas via imprint da lesão foram coletados de 196 felinos domésticos, com posterior semeadura em Ágar Sabouraud Dextrose e Mycosel e coloração das lâminas por Panótico Rápido. RESULTADOS: Dos 196 animais, 102 (52,0%) foram diagnosticados com esporotricose. Para 50,0% da população, os resultados da cultura e da citopatologia foram discordantes (p < 0,0001; χ² = 32,960), com a cultura micológica mais sensível (95,2%) que a citopatologia (52,6%). Para os animais tratados com dosagem de itraconazol ≥ 100 mg/dia, foi observada uma significante redução no desempenho diagnóstico da citopatologia (p = 0,0136). Contudo, o mesmo não foi verificado em relação ao tempo de tratamento ou às demais dosagens (p > 0,05). CONCLUSÃO: A dosagem de itraconazol ≥ 100 mg/dia, independente da duração do tratamento, reduz a sensibilidade diagnóstica da citopatologia. Tal resultado representa um alerta para o uso dessa ferramenta como recurso único para a confirmação diagnóstica da esporotricose felina na rotina da clínica veterinária.

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Sporotrichosis zoonotic transmission by cats has obtained hyperendemic magnitude in Rio de Janeiro, Brazil. Atypical cases, relapses, and reinfections as well as reduced diagnostic sensitivity of conventional methods have been reported. Previously, the anti-SsCBF enzyme-linked immunosorbent assay (ELISA) test was shown to be useful as a diagnostic tool for human sporotrichosis. Effective diagnosis and treatment are critical to interrupt the chain of transmission of this major pathogen in Brazilian Public Health. To evaluate its applicability for feline sporotrichosis diagnosis and/or therapeutic follow-up, 15 domestic cats from Rio de Janeiro were clinically and laboratory monitored by cytopathology, culture, Sporothrix genotyping, and anti-SsCBF IgG levels. Subsequently, animals were divided into satisfactory and non-satisfactory therapeutic responders. Averages of antibody serum levels obtained for diagnosis (first consultation) compared with the levels found after follow-up (last consultation) were significantly different in both groups (p = 0.0002 and p = 0.038, respectively). We conclude that the SsCBF ELISA test can predict feline sporotrichosis therapeutic responses even for animals with distinct clinical evolutions.

Recently, the well-known geographically wide distribution of sporotrichosis in Brazil, combined with the difficulties of effective domestic feline treatment, has emphasized the pressing need for new therapeutic alternatives. This work considers a range of synthetic derivatives as potential antifungals against Sporothrix brasiliensis isolated from cats from the hyperendemic Brazilian region. Six S. brasiliensis isolates from the sporotrichotic lesions of itraconazole responsive or non-responsive domestic cats were studied. The minimum inhibitory concentrations (MICs) of three novel hydrazone derivatives and eleven novel quinone derivatives were determined using the broth microdilution method (M38-A2). In silico tests were also used to predict the pharmacological profile and toxicity parameters of these synthetic derivatives. MICs and MFCs ranged from 1 to >128 µg/mL. The ADMET computational analysis failed to detect toxicity while a good pharmacological predictive profile, with parameters similar to itraconazole, was obtained. Three hydrazone derivatives were particularly promising candidates as antifungal agents against itraconazole-resistant S. brasiliensis from the Brazilian hyperendemic region. Since sporotrichosis is a neglected zoonosis currently spreading in Latin America, particularly in Brazil, the present data can contribute to its future control by alternative antifungal drug design against S. brasiliensis, the most virulent and prevalent species of the hyperendemic context.