Distribution of enzymatically pathogenic bacteria from periodontal pocket in advancing periodontitis

Production of 9 enzymatic activities of 527 strains freshly isolated from periodontal pockets in advancing periodontitis were investigated. Of these isolates, two strains showed lecithinase activity on egg yolk agar plate. Collagenase, plasmin and lipase were produced by 28 strains, 26 strains and 22 strains, respectively. Two lecithinase-producing strains were identified as Bacteroides intermedius. Nineteen strains of B. intermedius and 1 strain of Fusobacterium species produced lipase on egg yolk agar plate. All of the 28 collagenase-producing strains were B. gingivalis. B. gingivalis (20 strains) and non black-pigmented Bacteroides (6 strains) showed plasmin activity. These results indicate that Bacteroides species, mainly B. gingivalis and B. intermedius may exert an important influence on the exacerbation of the disease.