Isolation of Peptococci and Peptostreptococci in Developing Human Dental Plaque by Maintaining Continuous Anaerobiosis

Abstract

Plaque samples of 2, 5, 7 and 12 days were obtained under complete anaerobiosis with a special technique from the labial surfaces of the upper incisor teeth of six subjects. the samples were primarily assayed for their content of grampositive bacteria; actinomyces, eubacteria, lactobacilli, corynrbacteria, nocardia, propionibacteria, peptococci, peptostreptococci, and streptococci. At day 2 streptococci, corynebacteria and nocardia predominated, but after 5 days also anaerobic gram-positive cocci and rods were found. 15 strains of these cultivable gram-positive anaerobic cocci were investigated further with regard to morphology, biochemical reactions and fermentation products. Seven of these organisms resembled Peptostrepto-coccus intermedius and four of these strains were probably Peptostreptococcus anaerobius. One appeared to belong to Peptococcus magnus and the remaining strains could be considered as Peptococcus variabilis.