Differential utilization of proteins in saliva from caries-active and caries-free subjects as growth substrates by plaque-forming streptococci.

Mixed or parotid saliva from caries-active individuals consistently supported better growth of Streptococcus mutans (type c) than that from caries-free individuals. Electrophoretic studies revealed that certain proteins in caries-active salivas were susceptible to microbial attack, but similar proteins in caries-free salivas were refractory.