Inhibition of Streptococcus mutans (ATCC 25175) biofilm formation on eugenol-impregnated surgical sutures

The use of bioactive compounds as anti-infective coating on biomaterial surfaces has been studied as a tool against microbial adhesion and the establishment of biofilms. The objective of this work was to evaluate the antibacterial activity of eugenol, specifically the ability to interact with cotton suture threads for preventing adhesion and biofilm formation of Streptococcus mutans (ATCC 25175). The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of eugenol were determined according to Clinical and Laboratory Standards Institute (CLSI), which showed respective concentration values of 250 and 1000 μg/ml. In addition, eugenol displayed marked activity against to biofilm formation in 96-well polystyrene plates against several strains from the Streptococcus genus, even at lower than bacteriostatic concentrations between 15 to 250 μg/ml. Moreover, eugenol formed an effective covering on cotton-suture surfaces that inhibited cell adhesion, which decreased the S. mutans (ATCC 25175) biofilm development, according to biomass and metabolic rate, quantified by crystal violet staining and XTT reduction, respectively. This research may help to explore the eugenol molecule as an antifouling coating on surfaces, bringing a new perspective to the prevention of infections associated with biomaterials.