Study of the effects of chitosan upon Streptococcus mutans adherence and biofilm formation

The main aim of this work was to access the potential use of high and low molecular weight chitosans as potential oral antimicrobials, particularly as antibiofilm agents. Chitosan's interference with Streptococcus mutans capability to adhere and form biofilms was assessed. Additionally the effect upon mature and polymicrobial biofilms was also evaluated. The results obtained showed that chitosan was capable of interfering with S. mutans adhesion and primary biofilm formation. This action was observed up to a week with little to none decrease in efficiency. In addition chitosan was capable of inhibiting biofilms formed by two microorganisms and was capable of acting upon mature biofilms leading to significant reductions (94%) in biofilm survival. However clear statistical differences (p < 0.05) were registered in all assays with, in most assays, HMw chitosan presenting higher efficiency than LMw chitosan. Considering this results chitosan's potential as a valid alternative to traditional antimicrobials in oral health it's evident.

► Chitosan inhibited cellular adhesion and biofilm formation.
► Chitosan reduced mature and polymicrobial biofilms.
► Chitosan presented significant antibiofilm action – up to a week.
► Chitosan was effective at sub-MIC concentrations.