Prevalence of different streptococci species in the oral cavity of children and adolescents

Streptococci species were isolated, identified and counted in 262 saliva samples collected from 131 children and adolescents from a public school nursery at the city of Jaboticabal, SP. Four Streptococci species harboring oral samples were identified biochemically, as Streptococcus salivarius, Streptococcus mutans, Streptococcus rattus, Streptococcus sobrinus, and streptococci of the mitis group. The mean Streptococcus counts obtained were 1.0 x 109 CFU/ml saliva for the 3 to 5 year age range, 1.5 x 109 CFU/mL saliva for the 6 to 8 year age range, and 2.0 x 109 CFU/mL saliva for the 12 to 14 year age range. The prevalence of Streptococci in saliva were: S. salivarius (89.31%), S. mutans (73.28%), S. salivarius + S. mutans (44.27%) by the standard method. The tongue depressor method showed S. mutans (62.59%), S. salivarius (77.86%), S.salivarius + S. mutans (33.58%). The analysis of both techniques showed significant agreement for Streptococcus isolation.