Virulence of black‐pigmented Bacteroides strains from periodontal pockets and other sites in experimentally induced skin lesions in mice

Abstract

The virulence of different black‐pigmented Bacteroides strains (BPB) was studied using monoinfections in an experimental animal model. Bacterial suspensions were injected subcutaneously in the back of mice. After four days the mice were killed and the induced inflammations were examined histologically. Bacteroides gingivalis strains, which are mostly isolated from subgingival plaque associated with adult destructive periodontitis. were characterized by inducing a spreading type of inflammation, mostly resulting in a gravity abscess or a phlegmonous abscess. Strains of Bacteroides melaranogenicus subspecies intermedius , isolated from gingivitis or periodontitis, always induced a localized abscess at the site of injection. Most Bacteroides asaccharolyticus strains, which are isolated from nonoral sites, caused a localized inflammation, and Bacteroides melaninogenicus subspecies melaninogenicus strains caused only minimal inflammation.