IADR Abstract Archives
Effect of Chlorhexidine on Exopolysaccharides of Enterococcus faecalis Biofilm
Objectives: Exopolysaccharides are an important fraction of the biofilm matrix, protecting the microbial cells from the action of antimicrobial strategies and contributing to persistent infections. The objective of this study was to investigate the effect of chlorhexidine (CHX) treatment on the exopolysaccharide composition of E. faecalis biofilms of different ages.
Methods: E. faecalis biofilms (3-day and 21-days old) were developed on hydroxyapatite discs and treated with 2% CHX for 15 and 30 minutes. Sterile water-treated biofilms served as controls. The biofilm exopolysaccharides and bacterial cells were stained with ConA conjugated-FITC and SYTO-59 respectively, and examined using confocal laser scanning microscopy (CLSM) at five randomly selected areas. The percentage of exopolysaccharides in the treated and control biofilms were calculated using a commercial software. The data were statistically analyzed using 3-way ANOVA, with the treatment, time of treatment and biofilm age as variables (p=0.05).
Results: The treatment agent (CHX vs water), duration of the treatment (15 vs 30 min) and biofilm age (3 vs 21 days) significantly influenced the exopolysaccharide composition of the biofilms (p<0.001). In the 3-days old biofilms, 2% CHX significantly reduced the exopolysaccharides content, compared to the control (p<0.01) irrespective of the treatment time. However, 2%CHX had no significant effect on the exopolysaccharide content of the 21-days old biofilms, compared to the control (p>0.05).
Conclusions: CHX was unable to eliminate the E. faecalis biofilm matrix. The results of the study highlighted that the effect of chlorhexidine on E. faecalis biofilm exopolysaccharides depended on the biofilm age.
Methods: E. faecalis biofilms (3-day and 21-days old) were developed on hydroxyapatite discs and treated with 2% CHX for 15 and 30 minutes. Sterile water-treated biofilms served as controls. The biofilm exopolysaccharides and bacterial cells were stained with ConA conjugated-FITC and SYTO-59 respectively, and examined using confocal laser scanning microscopy (CLSM) at five randomly selected areas. The percentage of exopolysaccharides in the treated and control biofilms were calculated using a commercial software. The data were statistically analyzed using 3-way ANOVA, with the treatment, time of treatment and biofilm age as variables (p=0.05).
Results: The treatment agent (CHX vs water), duration of the treatment (15 vs 30 min) and biofilm age (3 vs 21 days) significantly influenced the exopolysaccharide composition of the biofilms (p<0.001). In the 3-days old biofilms, 2% CHX significantly reduced the exopolysaccharides content, compared to the control (p<0.01) irrespective of the treatment time. However, 2%CHX had no significant effect on the exopolysaccharide content of the 21-days old biofilms, compared to the control (p>0.05).
Conclusions: CHX was unable to eliminate the E. faecalis biofilm matrix. The results of the study highlighted that the effect of chlorhexidine on E. faecalis biofilm exopolysaccharides depended on the biofilm age.
