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

Danielly Corrêa-Moreira,Orazio Romeo,Rodrigo C Menezes,Manoel M E Oliveira,Cintia M Borba

doi:10.3390/pathogens10121647

Danielly Corrêa-Moreira, Orazio Romeo + Show 3 more

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https://doi.org/10.3390/pathogens10121647

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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.

Highlights

The Sporothrix genus is composed of about 60 species distributed worldwide in the tropical and subtropical regions, being commonly saprophytes
Our research group is a pioneer in studying the infection of mice inoculated simultaneously with isolates of seven clinically important Sporothrix species in vivo and exploring the infection with S. schenckii sensu stricto and S. brasiliensis in a chemically immunosuppressed murine model [24]
It was possible to observe different biological behaviors among the isolates investigated and establish a ranking of “aggressiveness”, in which the pathogenic S. schenckii sensu stricto isolate, followed by S. mexicana isolate and, surprisingly, S. pallida isolate, the last two, species grouped in the environmental clade, were able to cause more expressive clinical and anatomopathological changes in mice infected with them

Summary

Introduction

The Sporothrix genus is composed of about 60 species distributed worldwide in the tropical and subtropical regions, being commonly saprophytes. Sporotrichosis is a worldwide subcutaneous mycosis endemic in Latin America [11] and hyperendemic in the metropolitan region of Rio de Janeiro state, Brazil, where the largest number of cases in the world occurred (over 5000 cases in humans and 4000 cases in animals since 1998) In this region, the main form of transmission is zoonotic rather than the classical transmission (through contaminated plants, wood, or soil), and the main species involved in human and animal cases is S. brasiliensis [12,13]. 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). We reinforce the hypothesis that the pathogenicity of Sporothrix is related to the species of this fungus, and shows variation between different isolates of the same species

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