Black-pigmented Bacteroides from clinically characterized periodontal sites.

Abstract

Gingival sites were clinically evaluated on the basis of gingival color and contour, pocket depth, bleeding upon probing and peercent bone loss as measured radiographically. Using anaerobic techniques, subgingival plaque collected from these sites was examined for the presence of the black‐pigmented Bacteroides (BPB). The BPB were identified by biochemical testing and Gram stain morphology. With one exception, only saccharolytic strains (B. melaninogenicus) were found at normal and gingivitis sites, while these and asaccharolytic strains (B. asaccharolyticus) were found at sites exhibiting bone loss.