Effects of antibodies on adherence and cell-associated glucan production by Streptococcus mutans cells.

Studies reported here show that hyperimmune rabbit serums can have profound inhibitory effects on adherence of S mutans to smooth surfaces and that this reduction in adherence is correlated with the reduction of CAG. The latter was measured by an assay developed in our laboratory that estimates CAG production by measuring the uptake of 14C glucose-labeled sucrose into components which can be extracted by dilute alkali. This is a direct demonstration of the effect of antibody on a metabolic function of S mutans that is important in virulence. The direct correlation bewteen inhibition of CAG production, and inhibition of adherence by an antibody, suggests that the inhibition of adherence is brought about by reduction of CAG synthesis. Further studies reported here show that the inhibition of adherence and of CAG synthesis is much more effective in homologous antiserums as compared to heterologous antiserums. These results point to the need for in vivo experiments to test the effects of vaccines on colonization by heterologous as well as homologous S mutans strains.