Unveiling the Morphostructural Plasticity of Zoonotic Sporotrichosis Fungal Strains: Possible Implications for Sporothrix brasiliensis Virulence and Pathogenicity.

Sporotrichosis is a fungal infection caused by Sporothrix species, with Sporothrix brasiliensis as a prevalent pathogen in Latin America. Despite its clinical importance, the virulence factors of S. brasiliensis and their impact on the pathogenesis of sporotrichosis are still poorly understood. This study evaluated the morphostructural plasticity of S. brasiliensis, a fungus that causes sporotrichosis. Three cell surface characteristics, namely cell surface hydrophobicity, Zeta potential, and conductance, were assessed. Biofilm formation was also analyzed, with measurements taken for biomass, extracellular matrix, and metabolic activity. In addition, other potential and poorly studied characteristics correlated with virulence such as lipid bodies, chitin, and cell size were evaluated. The results revealed that the major phenotsypic features associated with fungal virulence in the studied S. brasiliensis strains were chitin, lipid bodies, and conductance. The dendrogram clustered the strains based on their overall similarity in the production of these factors. Correlation analyses showed that hydrophobicity was strongly linked to the production of biomass and extracellular matrix, while there was a weaker association between Zeta potential and size, and lipid bodies and chitin. This study provides valuable insights into the virulence factors of S. brasiliensis and their potential role in the pathogenesis of sporotrichosis.

Cyclosporine Affects the Main Virulence Factors of Cryptococcus neoformans In Vitro.

This study aimed to investigate the effects of cyclosporine on the morphology, cell wall structure, and secretion characteristics of Cryptococcus neoformans. The minimum inhibitory concentration (MIC) of cyclosporine was found to be 2 µM (2.4 µg/mL) for the H99 strain. Yeast cells treated with cyclosporine at half the MIC showed altered morphology, including irregular shapes and elongated projections, without an effect on cell metabolism. Cyclosporine treatment resulted in an 18-fold increase in chitin and an 8-fold increase in lipid bodies, demonstrating changes in the fungal cell wall structure. Cyclosporine also reduced cell body and polysaccharide capsule diameters, with a significant reduction in urease secretion in C. neoformans cultures. Additionally, the study showed that cyclosporine increased the viscosity of secreted polysaccharides and reduced the electronegativity and conductance of cells. The findings suggest that cyclosporine has significant effects on C. neoformans morphology, cell wall structure, and secretion, which could have implications for the development of new antifungal agents.