COAGGREGATION OF ORAL LACTOBACILLI WITH STREPTOCOCCI FROM THE ORAL CAVITY

The ability of oral lactobacilli to coaggregate with streptococci and actinomycetes was investigated. Of the 7 species of lactobacilli studi ed, only two were capable of coaggregation and the coaggregation was r estricted to streptococci. Lactobacillus salivarius strains (2/4) coag gregated with Streptococcus salivarius, Streptococcus gordonii, Strept ococcus crista and tufted Streptococcus sanguis II strains. Lactobacil lus fermentum (2/3) coaggregated with S. gordonii and S. sanguis. The coaggregation between L. salivarius and S. salivarius, S. gordonii or tufted S. sanguis 11 strains was mediated by a protein on the surface of the lactobacilli and was not inhibited by lactose. The coaggregatio n between L. fermentum and the streptococci was mediated by protein on the surface of the streptococci and was inhibited by lactose.