Antibacterial effect of chalcogenoesters on planktonic cells and biofilms of Streptococcus mutans and Streptococcus parasanguinis

The purpose of this work was to evaluate the antibacterial and antibiofilm activity of five chalcogenoesters synthetics on oral bacteria, Streptococcus mutans, and Streptococcus parasanguinis. Five chalcogenoesters were synthesized, purified by chromatography in silica gel and its chemical structure determined by nuclear magnetic resonance. Antibacterial assays were performed using the microdilution methodology. The antibiofilm activity of chalcogenoesters was determined on biofilm formation and preformed biofilms by biofilm mass quantification (by crystal violet staining) and colony forming unit enumeration. Moreover, biofilms were also analyzed by scanning electron microscopy. In general, it was observed that the chalcogenolesters showed antibacterial activity against Streptococcus mutans and Streptococcus parasanguinis. Regarding biofilm formation and preformed biofilm, all compounds reduced efficiently the biofilm mass and of viable cells of Streptococcus parasanguinis and Streptococcus mutans biofilms. However, Streptococcus mutans biofilms showed greater resistance to action of chalcogenolesters. Scanning electron microscopy examination confirmed the results, showing a reduction of the extracellular polymeric substance and number of cells in biofilm. Our result indicated that the chalcogenoesters tested here can be considered as promising molecules for prevention and control of oral biofilms formed by Streptococcus mutans and Streptococcus parasanguinis.