Anti-Sporothrix brasiliensis potential and anti-biofilm activity of Psidium guajava L. hydroacetone extract.

Sporothrix brasiliensis is the primary cause of sporotrichosis in Brazil. Reports of therapeutic failures with itraconazole treatment exist. We evaluated the antifungal activity of the hydroacetone extract of Psidium guajava in planktonic cells and biofilms of S. brasiliensis. The extract was obtained from the leaves, and high-performance liquid chromatography was performed. Broth microdilution tests were performed according to the CLSI M38. The strains were subjected to biofilm formation, and the antifungal activity of the extract against a strong producer strain was determined. The extract inhibited planktonic cells with minimum inhibitory concentrations (MICs) of ≤ 2 to 8 µg/mL. The metabolic activity of the strain with strong biofilm formation was inhibited with MICs of 16 and 32 µg/mL. The anti-Sporothrix activity of the hydroacetone extract of P. guajava serves as a basis for future studies for developing new drugs for the treatment of sporotrichosis.