ANTICARIOGENIC ACTIVITY OF GALLS OF QUERCUS INFECTORIA OLIVIER AGAINST ORAL PATHOGENS CAUSING DENTAL CARIES

In this study, attempts were made to evaluate the anti-microbial activity of the galls of Quercus infectoria Olivier against oral bacteria causing dental caries. Various solvents systems were used to screen the potential of the extract on the clinically isolated organism and reference strains; Candida albicans MTCC 183, Streptococcus mutans MTCC 497, Lactobacillus acidophilus MTCC 10307 and Staphylococcus aureus MTCC 1144 using agar-well diffusion method. This was followed by determination of minimum inhibitory concentration (MIC) by using two-fold serial microdilution methods at a concentration ranging between 0.02 mg/ml to 10 mg/ml. The MIC values against each bacterial species was found in the range of 0.16 to 0.31 mg/ml. Minimum bactericidal concentration (MBC) was obtained by subculturing microtiter wells which showed no changes in color of the indicator after incubation. Among all tested bacteria, S. aureus was the most susceptible. The clinically isolated S. mutans was further analyzed for its ability to form biofilm on the surface of seashells. The biofilm reduction percent assay in microtitre wells was used to quantitatively determine the inhibition in the presence of Q. infectoria extract. Maximum reduction was seen at 0.018 µg/ml of methanolic extract. Thus, the galls may be considered as effective phototherapeutic agents for the prevention of biofilm formation by common oral pathogens.