Modelo invertebrado Tenebrio molitor para a avaliação da virulência de espécies clínicas e ambientais de fungos patogênicos do gênero Sporothrix

Abstract

Sporotrichosis is a zoonotic subcutaneous mycosis, which has the feline as the main host. Due to the rapid spread by traumatic inoculation, this disease represents a serious public health problem. This mycosis is caused by thermodimorphic fungal species of the genus Sporothrix, in particular by 7 species that are divided into a clinical clade (those that commonly cause sporotrichosis) and an environmental clade (accidental pathogenic species). Due to this range of possible etiologic agents of sporotrichosis, the understanding of the different virulence profiles and response to antifungal agents is essential for a rapid and accurate treatment. Thus, alternative models to the murine, more practical and easily reproducible, are attractive for comparative studies of virulence profiles. In this work, larvae of the Coleoptera species Tenebrio molitor were used as an experimental inoculation model for the clinical and environmental clade of pathogenic Sporothrix species, proving to be an efficient and reproducible alternative model. Higher survival rates were observed for larvae infected with conidia of clinical species and lower for larvae infected with conidia of environmental species. Through histopathology, it was possible to identify the dimorphism of the fungus in the larval tissue, the same process that occurs in the mammalian host. The results of CFU's recoveries indicate that the species of the clinical clade are more familiar with the parasitic environment, by propagating better in the larval tissue and keeping the host alive for longer.