Clinical and Anatomopathological Evaluation of BALB/c Murine Models Infected with Isolates of Seven Pathogenic Sporothrix Species

Abstract

Background: Sporotrichosis is a subcutaneous mycosis with worldwide distribution and caused by seven pathogenic species of Sporothrix genus: S. schenckii sensu stricto, S. brasiliensis, S. globosa and S. luriei (clinical clade), and the species S. mexicana, S. pallida and S. chilensis (environmental clade). Isolates of the same species of Sporothrix may have different pathogenicities; however, few isolates of this fungus have been studied. Thus, the aim of this work was to analyze the clinical and anatomopathological changes in immunocompetent and immunosuppressed BALB/c mice infected with clinical and environmental isolates of seven different species of Sporothrix, from both clades. One human clinical isolate of S. schenckii sensu stricto, S. brasiliensis, S. globosa, S. luriei, S. mexicana and S. chilensis species and one environmental isolate of S. pallida were inoculated subcutaneously in immunocompetent mice and the same isolates of S. brasiliensis and S.schenckii sensu stricto were inoculated in immunossupressed mice. Clinical manifestations as external lesions, apathy, and alopecia were observed. At 21, 35, and 49 days after fungal inoculation, four mice from each group were weighed, euthanized and necropsied for evaluation of splenic index, recovery of fungal cells, macroscopic and histopathological analysis of livers, lungs, kidneys, and hearts. The survival assessment was observed for 50 days following inoculation. Our results demonstrated that, clinical S. schenckii isolate, followed by clinical S. mexicana, and environmental S. pallida isolates, the last two, species grouped in the environmental clade, were capable of inducing greater anatomopathological changes in mice, which was reflected in the severity of the clinical signs of these animals. Thus, we reinforce the hypothesis that the pathogenicity of Sporothrix is not only related to the species of this fungus, but also shows variation between different isolates of the same species.

Galleria mellonella Antimicrobial Peptides and Stress Management Gene Expression in Response to Deleterious Events Caused by Sporothrix brasiliensis

“…Gandra and colleagues [31] observed that by inoculating 1x10 7 Candida albicans/larvae, CFUs ranged from 1.0x10 8 to 1.0x10 12 at 6, 24, and 48 hours. These data reinforce the suitability of G. mellonella as a model of yeast infection since it differentially mirrors Candida and Sporothrix fungal loads increase, such as previously described for mammalian hosts [47,48].…”

Neutrophil Oxidative Burst Profile Is Related to a Satisfactory Response to Itraconazole and Clinical Cure in Feline Sporotrichosis

“…On the other hand, another study found a more pronounced proinflammatory profile induced by S. brasiliensis in human PBMCs in comparison to S. schenckii [ 56 ], suggesting that factors within the same species can impact their behavior upon interaction with the host. The study by Corrêa-Moreira et al [ 57 ] indicates that virulence may be related to the isolate independent of the Sporothrix species. Sporothrix virulence characteristics have not been assessed in the causative isolates from this study, but it is safe to say that evasion mechanisms of the fungus may interfere with the capacity of the feline host to cope with the infection, and it is possible that the impaired phagocytosis in cats with sporotrichosis may be related to more pathogenic isolates of Sporothrix .…”

The Mating Type (MAT) and Virulence of Sporothrix schenckii sensu stricto Isolates Maintained in Culture Collection

“…Analysis was performed following the protocols described by Corrêa-Moreira et al [19]. At each point of observation (21,35 and 49 days after inoculation), clinical signs were observed such as cutaneous lesions, alopecia and apathy in the mice.…”