Tissue-Destructive Products of Gingival Bacteria From Nonspecific Gingivitis

pREVIOUS work' demonstrated the presence of tissue-destructive agents in cell-free extracts of gingival bacteria. Extracts of one of these tissuedestructive agents, which occurred somewhat irregularly, gave a histamine-like reaction on injection in rabbit skin. Another, which was consistently present in extracts prepared from inflamed gingiva, was a spreading factor (hyaluronidase). That such a spreading factor could play a part in producing gingivitis was supported by the demonstration that topical applications of hyaluronidase on human gingiva produced tissue changes similar to those found in gingivitis. The idea that hyaluronidase is important in gingival destruction is supported by histologic studies which show that the amorphous ground substance in the gingival connective tissue contains hyaluronic acid and that this is removed in local inflammatory areas. Evidence of the existence of two tissue-destructive agents suggested that other such agents could be identified in bacteria-free preparations of gingival bacteria. That an enzyme acting on the chondroitin sulfate might be present is suggested by the observations2-4 that chondroitin sulfate disappears in areas of gingival inflammation; the likelihood that a collagenase might be involved is suggested by the progressive destruction of collagen fibers in advanced gingivitis.5 Therefore, it was decided to prepare bacteria-free filtrates from bacterial deposits from the gingivae of individuals with gingivitis and normal gingiva, to test them for activity against hyaluronic acid, chondroitin sulfuric acid, and collagen, and also to look for further evidence of the presence of histamine and, if possible, to determine whether the occurrence of these different agents were in any way interrelated. In addition, extracts of pure cultures of several microorganisms isolated from the human gingival pocket were tested for activity against the substrates listed. The work on gingival filtrates and bacterial cultures will be reported in separate sections.