Inhibition of caries in hamsters treated with staphylococcin 1580.

Littermate hamsters were infected orally with cariogenic Streptococcus mutans NS-50S and maintained on a high-sucrose diet to induce dental caries. Individual groups of animals were treated by single daily instillation of staphylococcin 1580 (100 micrograms) in the cheek pouches. Other groups were treated similarly with bacitracin (60 or 120 U) or saline. After 35 days on the caries test regimen, animals treated with staphylococcin 1580 had 49 or 60% less caries than the saline controls in two separate trials. Hamsters treated with 60 U of bacitracin had 40% less caries, while animals receiving 120 U of bacitracin had 58% less caries. Significant reductions in the oral and fecal levels of S. mutans NS-50S were also observed in the treated animals. In contrast to earlier, inconclusive experiments in which these agents were placed directly into the oral cavity, the inhibition of caries in this study is attributed to prolongation of the oral retention of these agents, with increased opportunity to interact with cariogenic microorganisms.