Effect of Starting Time for Administration of a Bacteriolytic Enzyme from Streptomyces globisporus on the Rate of Caries Inhibition in Hamsters

It has recently been reported in our laboratory that a bacterilytic enzyme derived from Streptomyces globisporus strain 1829 significantly inhibited experimental dental caries in hamsters when added to the diet at 0.1% (w/w). The purpose of the present investigation was to determine the effects of starting time to the enzyme administration on experimental caries. A NIH (U.S.A.) strain of male golden hamsters weighing around 41 gr. at 30 days of age were inoculated orally with Brain Heart Infusion broth cultures of streptomycinr-esistant strain of S. mutansAHT-R and fed cariogenic diet #2000. The bacteriolytic enzyme was added to the diet at a 0.2% (w/w) level. Enzyme administration started two days before 1st inoculation with strain AHT-R, and on the 5th and the 12th day after the inoculation. After rearing under these conditions for 35 days, the animals were sacrificed and the extent of dental plaque, caries and alveolar bone loss of the molar dentition were estimated. When the hamsters were fed the diet #2000 without the enzyme, dental plaque and caries of the molars developed without the loss of alveolar bone. By addition of the bacteriolytic enzyme to the diet at 0.2%, the plaque formation was reduced, and the caries development was naturally inhibited with statistical significance. The earlier the starting of enzyme administration, the greater the inhibition of dental caries. The intake of diet and gain of body weight of the animals during the experimental period were not influenced by the enzyme in the diet.