Localization of Porphyromonas gingivalis-carrying Fimbriae in situ in Human Periodontal Pockets

Abstract

Fimbriae, which are involved in adherence, constitute an important pathogenic factor of Porphyromonas gingivalis. In vivo, however, the distribution of P. gingivalis-carrying fimbriae is unknown. The localization of P. gingivalis-carrying fimbriae was examined in situ. From 19 patients with severe periodontitis and P. gingivalis, we obtained 20 teeth with periodontal tissue attached, with and without immunolocalized fimbriae. Eleven teeth were subjected to light microscopy, 9 to electron microscopy. In 6 of the 11 samples examined, we detected positive reactions with an anti-P. gingivalis-fimbriae serum, located in the cementum-attached plaque area in the deep pocket zones. In the so-called 'plaque-free zones', P. gingivalis-carrying fimbriae were immunocytochemically observed to reside in contact with the dental cuticle in 6 of the 9 samples examined. These findings suggest that P. gingivalis-carrying fimbriae are strongly related to adherence to the root surface at the bottoms of human periodontal pockets.

Fimbrial Proteins of Porphyromonas gingivalis Mediate In Vivo Virulence and Exploit TLR2 and Complement Receptor 3 to Persist in Macrophages

“…P. gingivalis fimbriae are adhesive filamentous appendages that are required for virulence in rodent models of periodontitis or atherosclerosis (5,8). In humans, fimbriated P. gingivalis is readily detected in periodontal pockets by immunogold labeling with specific anti-fimbrial Ab (9) and is more frequently found in deep periodontal pockets or in sites with severe periodontal attachment loss than nonfimbriated strains (10). These studies suggest a strong association between the expression of fimbriae and periodontal tissue destruction in humans.…”

Identification and Localization of Extraradicular Biofilm-Forming Bacteria Associated with Refractory Endodontic Pathogens

“…Recently, P. gingivalis cells adhering to the root surface were detected at the bottom of human periodontal pockets (11,14,15), and it has been suggested that P. gingivalis plays a role as an early colonizer in biofilm formation under most anaerobic conditions. It is proposed that P. gingivalis, observed in close contact with the root surface (Fig.…”

“…Five selected teeth and two root tips were carefully fixed in 4% paraformaldehyde and 0.1% glutaraldehyde for 12 h at 4°C and decalcified for 10 days at 4°C with stirring in 10% formic acid-sodium citrate (pH 2.2); 8-m-thick serial frozen sections were prepared. Some of the sections were stained by the Brown and Brenn-modified Gram staining procedure, while others were subjected to the alkaline phosphatase-conjugated streptavidin-biotin method (13)(14)(15). The results of both staining methods were observed under a light microscope (Optiphot-2; Nikon, Tokyo, Japan).…”

Porphyromonas gingivalis Genes Involved in Community Development with Streptococcus gordonii

“…It should be noted that our interbacterial community model represents a prelude to biofilm formation and that other transcriptional changes in P. gingivalis are likely to occur during different stages of the development of mature heterotypic biofilms. In addition, P. gingivalis sequenced strain W83 is deficient in biofilm formation, possibly due to impaired production of both the long and short fimbriae (32,33,52). Hence, for this study we employed strain ATCC 33277, which produces both fimbrial types, has been used as a model biofilm organism (21,23,55), and is pathogenic in the rat model of periodontitis (20,34).…”