Abstract: A test kit and method is disclosed for the semi-quantitative detection of Streptococcus mutans from the oral cavity of a patient. Saliva from a patient is introduced into a diluent solution to which has been added just before the saliva a predetermined powdered amount of bacitracin. Then the diluent solution is contacted with a sterile media-coated paddle, the media-coated paddle containing the diluent and test saliva is incubated, and Streptococcus mutans in the test saliva is semi-quantitively determined by comparing the percent of colony density with a standard Streptococcus mutan colony density chart.

Abstract: A selective medium composition for the growth and detection of Actinomyces viscosus or Actinomyces naeslundii, which composition comprises: a solid medium selective to induce the growth of Actinomyces viscosus or Actinomyces naeslundii; a nutrient agent to induce the substantial growth of Actinomyces viscosus or Actinomyces naeslundii; a cadmium compound; a fluoride compound; a flavine compound; and the cadmium compound, the fluoride compound and the flavine compound all present in a concentration sufficient to inhibit the substantially full growth of interfering microorganisms, but in a concentration insufficient to inhibit the substantial growth of Actinomyces viscosus or Actinomyces naeslundii.