Pathogenic factors especially enzymatic activities of obligate anaerobes in odontogenic infection

Predominant bacteria isolated from 21 cases of odontogenic infection were identified and examined for β-lactanlase, DNase, hyaluronidase, chondroitin sulfatase, lipase, lecithinase, collagenase, trypsin, chymotrypsin and plasmin activities.Pus was aspirated, immediately inserted into RTF under a stream of anaerobic gas, sealed tightly with a butyl gum stopper and transferred to the laboratory. The sample was serially diluted and smeared on blood agar plates in duplicate. One plate was incubated anaerobically for 7 days and another aerobically for 4-7 days.Bacteria were isolated in all cases and the standard number of isolates was 9.2×108 CFU/ml.Anaerobic bacteria predominated in 20 of the 21 cases yielding positive culture.In anaerobic bacteria, gram negative rods were predominant, especially species of Bacteroides (45.6%) were isolated from 20 of the 21 cases, followed by species of Peptostreptococcus (23.8%) and Streptococcus (9.0%).B.intermedius (18.8%), Ps.productus (7.6%), Ps.micros (5.3%), S.mitior (4.4%) and B.gingivalis (4.3%) were identified as major constituents.All cases contained various bacteria producing different enzymes at high percentages. Enzymes most often detected included β-lactamase (100%), DNase (87.5%), hyalurcnidase and chondroitin sulfatase (81.3%), lipase (81.0%), lecithinase (71.4%) and collagenase (68.8%).B.iltermedius was predominant as β-lactamase, DNase, hyaluronidase, chondroitin sulfatase, lipase, and lecithinase producer.While, B.gingivalis was predominant as collagenase, trypsin chymotrypsin and plasmin producer.These results indicate that hydrolyticenzyme-active B.interrrtedius and B.gingitalis may exert important influences upon the exacerbation of odontogenic infection.