The Effects of Nisin on the Microbial Flora of the Dental Plaque of Monkeys (Macaca fascicularis)

Nisin was incorporated in a soft diet and fed to eight monkeys for five months. At the end of this period dental plaque was removed from one site in the mouths of these animals and from a similar site in eight control animals. Twelve different selective media were used for the cultivation of the bacteria in the plaque. Streptococci, Haemophilus spp. and Gram negative anaerobes were the organisms most frequently isolated. There was some evidence that streptococci constituted a lesser proportion of the flora in the nisin‐fed animals.