Genetic and physiological characteristics of oral Streptococcus intermedius

The taxonomic relationships among strains of oral Streptococcus intermedius and the related streptococci were determined by G + C mol%, DNA-DNA hydridization, phenotypical and serological tests. As to the results, group 1 strains of S. intermedius including the type strain ATCC 27335 and five isolates behaved distinctively with respect to genetic, phenotypic and serological characteristics compared with group 2 strains of S. intermedius including ATCC 31412 and two isolates. Therefore, nine strains of oral S. intermedius could be separated at least into two homology groups.