Intragingival Occurrence of Actinobacillus actinomycetemcomitans and Bacteroides gingivalis in Active Destructive Periodontal Lesions

Abstract

A total of six active and six nonactive sites from six untreated periodontitis patients were examined for intragingival presence of Actinobacillus actinomycetemcomitans and Bacteroides gingivalis. The active destructive periodontal disease was determined by the "tolerance method." The method of immunoperoxidase was used in the identification of intragingival microorganisms in active and nonactive periodontal sites. Light microscopic sections of gingival tissues consecutive to those with gram stain, revealing presence of bacteria (substantiated by electron microscopy), were stained with peroxidase-labeled antibodies against A. actinomycetemcomitans and B. gingivalis. B. gingivalis was found to be significantly elevated in the connective tissue of active sites when compared to nonactive sites. A statistically significant border-line difference was found between active and nonactive sites in the connective tissue invaded by A. actinomycetemcomitans. Our findings plus the well established periodontopathic potential of A. actinomycetemcomitans and B. gingivalis support the concept that these bacteria are important invasive pathogenic agents in periodontitis.

Gingipains ofPorphyromonas gingivalisModulate Leukocyte Adhesion Molecule Expression Induced in Human Endothelial Cells by Ligation of CD99

“…The data support the view that the NF-B signaling cascade is a component in the CD99-mediated adhesion response. In recent years gingipains have been associated with the ability to destroy epithelial barriers and infiltrate vascularized periodontal tissues (3,17,34). In line with these findings, the results of the present study support a role for gingipains in down-regulation of CD99 expressed on endothelial junctions.…”

“…Among periodontopathogens, most evidence points to a pathogenic role for Porphyromonas gingivalis, which is more frequently detected in active lesions of periodontitis than in healthy or gingivitis sites (37,38). Previous studies have shown that P. gingivalis may penetrate the epithelial barrier surrounding the gingival sulcus and invade endothelial cells (3,17,34). Virulence of P. gingivalis is associated with the proteolytic enzymes expressed by this gram-negative anaerobic bacterium (21,24).…”

Functional Implication of the Hydrolysis of Platelet Endothelial Cell Adhesion Molecule 1 (CD31) by Gingipains ofPorphyromonas gingivalisfor the Pathology of Periodontal Disease

“…Further, P. gingivalis has been observed within gingival tissues in vivo (55), whereas tissue penetration and destruction by P. gingivalis have been demonstrated in vitro (1). These results indicated that P. gingivalis may invade deeper structures of the connective tissue.…”

The Hemoglobin Receptor Protein ofPorphyromonas gingivalisInhibits Receptor Activator NF-κB Ligand-Induced Osteoclastogenesis from Bone Marrow Macrophages

“…Among them, the gram-negative anaerobic bacterium Porphyromonas gingivalis has been implicated to be one of the major etiological agents of chronic adult periodontitis. P. gingivalis colonizes in periodontal pockets and spreads into deeper tissues, including connective and bone tissues (11,14,21,22,25,40,47). The bacterium possesses a number of virulence factors, such as fimbriae, lipopolysaccharide (LPS), and cysteine proteinases named gingipains (11,21).…”