Abstract
The effect of a bacteriocin (mutacin) produced by Streptococcums utans strain C3603 (serotype c) on experimental dental caries in rats infected with S. mutans MT8148R (serotype c) was examined. Significant inhibition of caries development in rats was observed when mutacin was administered both in the drinking water and in the diet at a high level of concentration (100 μg/ml and 1,000 μg/g respectively). However, the inhibition rate was not as high as expected from the concentration of the administered mutacin, and in addition, mutacin administration in drinking water had little effect on the colonization of infected S. mutans, accumulation of plaque or caries incidence in rats receiving a low concentration mutacin diet. The results of the present experiment suggest that the antimicrobial activity of mutacin must have been reduced in the oral cavity of rats.
