Abstract:
Biosynthesis is a green method for the synthesis of silver nanoparticles (AgNPs). This
study aimed to assess the antifungal activity of two silver nanoparticle solutions, synthesized using
beech bark extract (BBE) and acetate and nitrate silver salts (AgNP Acetate BBE and AgNP Nitrate
BBE), their influence on biofilm production, their potential synergistic effects with fluconazole, on
different Candida spp., and their influence on virulence factors of C. albicans (germ tube production,
gene expression for ALS3, SAP2, HSP70). Both the AgNP BBEs presented different minimum
inhibitory concentrations for all the studied Candida spp., but biofilm production was inhibited
only for C. albicans and C. guilliermondii. The growth rates of all the studied Candida spp. were
inhibited in the presence of both AgNP BBEs, except for C. auris. Synergistic activity was observed
for C. parapsilosis and C. guilliermondii, for different combinations of fluconazole with both the AgNP
BBEs. The germ tube production of C. albicans was slightly inhibited by the AgNP BBEs. Only AgNP
Acetate BBE was able to down-regulate the expression of SAP2. Overall, we can conclude that, even
if more studies are necessary, AgNPs synthesized with beech bark extract might be an interesting
alternative to classic antifungal treatments.
