Different virulence levels of the species of Sporothrix in a murine model

Abstract

A comparative study on the experimental pathogenicity of five species of Sporothrix of clinical interest, Sporothrix albicans, Sporothrix brasiliensis, Sporothrix globosa, Sporothrix mexicana, and Sporothrix schenckii sensu stricto, was performed using an immunocompetent murine model. Two strains of each species and two levels of inoculum for each strain (2x10(7) and 2x10(4) conidia/animal) were tested by intravenous inoculation of mice (ten per group). Mortality was caused by the low inoculum of one strain of S. brasiliensis only, and the high inocula of S. brasiliensis and S. schenckii strains. Other inocula and other species tested did not kill any of the experimental animals. Tissue burden studies showed fungal spread to kidneys, lungs, spleen, brain, and testicles. S. brasiliensis was recovered extensively from all of the studied organs, and S. schenckii and S. globosa were recovered in lower amounts. Histopathological studies revealed differences in the lesions, which ranged from local inflammation with a low number of fungal cells at the injection site in mice infected with S. globosa, to massive infiltration of fungal cells in organs of those infected with S. brasiliensis. Our findings showed that S. brasiliensis and S. schenckii were the most virulent species, and suggest that lesional mechanisms could be species-specific.

Characterization of virulence profile, protein secretion and immunogenicity of differentSporothrix schenckii sensu strictoisolates compared withS. globosaandS. brasiliensisspecies

“…35 Some comparative studies were conducted correlating the route of experimental infection 32 or clinical manifestation in humans with the virulence degree of different isolates. 33,34 Recently, Arrillaga-Moncrieff et al 2,3 showed different degrees of virulence among S. schenckii s. str., S. brasiliensis and S. globosa species.…”

“…2,3 This is the first study which evaluates the protein secretion of S. brasiliensis, S. globosa and S. schenckii s. str. and connects the humoral immune response to virulence of these species.…”

“…[1][2][3][4] Some of these fungi present potential to survival in mammalian hosts being able to cause damage in multiple species of animals including humans. Since 1898 when the etiological agent of sporotrichosis, Sporothrix schenckii sensu lato (s.l.…”

Sporothrix brasiliensis produces the highest levels of oxidative stress in a murine model among the species of the Sporothrix schenckii complex

“…str.) showed marked heterogeneity in the virulence profiles studied 2,3 . Sporotrichosis has a worldwide distribution and is the most common subcutaneous fungal infection in South America 4 .…”

“…Subsequently, studies have been conducted in order to elucidate the different levels of virulence and pathogenicity demonstrated by each species 2 . According to previous studies, S. brasiliensis demonstrated the highest pathogenicity and virulence, while isolates of S. schenckii sensu stricto (s.…”