Inhibition and Removal of Mature Mixed-Bacteria Biofilms on Voice Prostheses by Sodium Selenite

PURPOSE: Biofilms on voice prostheses are important factors shortening their service life. Sodium selenite has been used to prevent and treat various diseases. Whether sodium selenite can inhibit and remove mature biofilms on voice prostheses is still unknown. METHODS: To verify the effects of sodium selenite on mature mixed-bacteria biofilms (Staphylococcus aureus, Candida albicans, and Streptococcus faecalis) on voice prostheses, we used quantitative and qualitative methods, eg, real-time fluorescence quantitative PCR, crystal violet staining, 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide) (XTT) reduction assays, and scanning electron microscopy, to measure the effects of sodium selenite on the number of bacterial colonies, biofilm formation ability, metabolic activity, and ultrastructure in a model of mature mixed-bacteria biofilms on voice prostheses and validated the effects in vitro on mature biofilms on voice prostheses from patients. RESULTS: When exploring the possible mechanism of biofilm inhibition and removal by sodium selenite, we found that it significantly inhibited and removed biofilms on voice prostheses and effectively destroyed the spatial structure of the biofilms. The inhibition and removal effects became more significant with increasing sodium selenite concentrations. CONCLUSION: We demonstrated that sodium selenite can inhibit and remove biofilms of mature mixed strains on voice prostheses, providing a novel basis for treating patients’ voice prosthesis biofilms.