The effect of silver nanoparticles and nystatin on mixed biofilms of Candida glabrata and Candida albicans on acrylic

The purpose of this study was to examine the effect of silver nanoparticles (SN) and nystatin on pre-formed biofilms (single and dual species combinations of Candida glabrata and Candida albicans). Thus, adhesion and biofilm assays were performed on acrylic surface in presence of artificial saliva (AS), during 2 h and 48 h, respectively. Candida glabrata and C. albicans adhered cells were determined by counting recovered colony forming units (CFUs) on CHROMagar® Candida. In addition, crystal violet (CV) staining, as an indicator of biomass, was used to quantify biofilm formation ability. Furthermore, pre-formed biofilms were treated either with SN or nystatin and its effects on biofilms evaluated after 24 h. The results showed that both Candidia species adhered to, and formed biofilms on acrylic. Candida glabrata biofilms had significantly higher CFUs compared with biofilms of C. albicans (P<0.05). In the case of dual species biofilms, the number of CFUs for each species was equivalent to that encountered in the single species studies. SN or nystatin was able to reduce the biomass and CFUs of single and dual species biofilms (P<0.05). SN had a significantly greater reduction of C. glabrata biofilm biomass comparatively to C. albicans biofilms (P<0.05). Furthermore, nystatin was more effective in reducing the CFUs of dual species biofilms compared with single species biofilms (P