Abstract:

Sporotrichosis is a subcutaneous mycosis caused by pathogenic fungi of the genus Sporothrix. Sporothrix schenckii infections have a worldwide distribution; the Brazilian outbreak is caused by S. brasiliensis while, in China, S. globosa transmitted through the sapronotic route became an epidemic among farmers. Sporothrix inoculation is required for infection and often occurs through a cutaneous trauma caused by plant thorns and wood splinters, popularly known as Gardner’s disease, or by cat scratching/biting. This last route of infection became important in Brazil since the mid-90’s outbreak, leading up to the currently hyperendemic neglected zoonosis in this country, along with recent evidence of a potential spreading to South America. In fact, S. brasiliensis is highly pathogenic, and cats show a unique interaction with this fungus, possibly determined by its high susceptibility, displaying severe disease forms which require prolonged antifungal administration. Frequently, domestic felines are refractory to itraconazole, the main azole used in the sporotrichosis treatment, with reports of relapse and treatment abandonment. As in other fungal infections, the immune system plays a central role in the pathogenesis of sporotrichosis. In cats the most unfavorable prognosis presents due to indiscriminate spread of Sporothrix yeasts, maintaining the high fungal load on the lesions and increasing the zoonotic potential of this host, thus resulting in severe clinical conditions. This suggests that in addition to the virulence of the fungus, feline immunity may contribute to the poor ability to control Sporothrix multiplication. The different types of host immune response to Sporothrix virulence factors were both in vitro and in vivo studied, mainly in murine and human models. Nonetheless, very little is known about the immune response of cats against Sporothrix, motivating our group to mobilize efforts and to describe a novel protocol of S. schenckii and S. brasiliensis in vitro exposure to domestic feline PBMCs. Such new method will provide a unique opportunity to investigate Sporothrix-cat interaction and, therefore, open doors for the future discovery of new ways to better treat feline sporotrichosis, a major Public Health concern. Indeed, recently, we described the coinfection of domestic felines residing in hyperendemic sporotrichosis areas by more than one S. brasiliensis isolates. These show disparate phenotypic parameters such as cytokine levels after PBMC interaction and different responses to antifungal agents. Likewise, it is quite possible that cat coinfection by this species represents a common occurrence with potential clinical implications. In this lecture we will present and discuss our main research data focusing on the “One Health approach” and its key concepts for better facing and future coping with this relevant fungal disease.

Biography:

Associate Professor at the Department of Microbiology and Parasitology at Fluminense Federal University, Rio de Janeiro, Brazil. Advises masters, doctoral and post-doctoral students in three Graduate Programs (Microbiology and Parasitology, Veterinary Medicine and Science and Biotechnology). Leader of the Research Group Center for Microorganisms’ Investigation, coordinates the homonymous laboratory. Ad hoc reviewer of high-impact journals and a consultant member of international funding agencies. Member of the “Working Group on Sporotrichosis” of the International Society for Human and Animal Mycoses (ISHAM). Leading subjects of investigation are the pathogen-host interaction, molecular and serologycal diagnostic methods and the molecular epidemiology of infectious and parasitic agents, especially Sporothrix spp. and Plasmodium vivax.

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