The streptococcal flora of the tongue of the monkey Macaca fascicularis.

The major streptococcal biotypes in the 8 monkeys investigated resembled Streptococcus sanguis and Streptococcus mitior with Streptococcus salivarius forming only 5 to 6 per cent of the total colony count and being isolated from only 4 monkeys. The predominant tongue streptococci were not isolated from the dental plaque. Similarly, Streptococcus mutans, present in large numbers in the plaque of monkeys fed sucrose-rich diets, was isolated from the tongue of only 2 animals and formed only 2.4 per cent of the total colony count. Changing from a starch-based maintenance diet to sucrose-rich diets did not significantly alter the tongue flora except that the proportion of typical Strep. sanguis was significantly reduced. The oral streptococcal flora of monkeys is similar in distribution to that found in the human mouth.