A culture medium for simultaneous counts of Streptococcus mutans and lactobacilli in saliva.

The use of a single culture medium that allows the isolation and counts of both Streptococcus mutans and lactobacilli could be of great value in microbiological diagnosis, control and evaluation of prevention programs that are nowadays employed in Odontology. To date there is no method that allows the simultaneous counts of lactobacilli and S. mutans in oral samples using a single culture medium. A single culture medium would allow for a more exact diagnosis of cariogenic risk and activity and a reduction in costs and processing time. We here in propose the selective-differential LAPTg 7% sucrose medium to differentiate oral streptococci and lactobacilli according to colony morphology and dextran production. The choice of this medium was the result of testing culture media such as MRS Agar, Elliker Agar and modified LAPTg Agar.