Gram-positive bacteria as an antigen topically applied into gingival sulcus of immunized rat accelerates periodontal destruction

J Periodontal Res. 2013 Aug;48(4):420-7. doi: 10.1111/jre.12021. Epub 2012 Nov 8.


Background and objective: Periodontitis is generally accepted to relate to gram-negative bacteria, and the host defense system influences its onset and progression. However, little is known about the relation between gram-positive bacteria and periodontitis. In this study, we topically applied gram-positive and gram-negative bacterial suspensions to the gingival sulcus in rats after immunization, and then histopathologically examined their influence on periodontal destruction.

Materials and methods: Rats previously immunized with heat-treated and sonicated Staphylococcus aureus or Aggregatibacter actinomycetemcomitans were used as immunized groups. The non-immunized group received only sterile phosphate-buffered saline. In each animal, S. aureus or A. actinomycetemcomitans suspension was applied topically to the palatal gingival sulcus of first molars every 24 h for 10 d. Blood samples were collected and the serum level of anti-S. aureus or anti-A. actinomycetemcomitans immunoglobulin G (IgG) antibodies was determined by enzyme-linked immunosorbent assay. The first molar regions were resected and observed histopathologically. Osteoclasts were stained with tartrate-resistant acid phosphatase (TRAP). The formation of immune complexes was confirmed by immunohistological staining of C1qB.

Results: Serum levels of anti-S. aureus and anti-A. actinomycetemcomitans IgG antibodies in the immunized groups were significantly higher than those in the non-immunized groups were. The loss of attachment, increase in apical migration of the junctional epithelium, and decreases in alveolar bone level and number of TRAP-positive multinuclear cells in each immunized group were significantly greater than in each non-immunized group. The presence of C1qB was observed in the junctional epithelium and adjacent connective tissue in the immunized groups.

Conclusions: Heat-treated and sonicated S. aureus and A. actinomycetemcomitans induced attachment loss in rats immunized with their suspensions. Our results suggest that not only gram-negative but also gram-positive bacteria are able to induce periodontal destruction.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acid Phosphatase / analysis
  • Administration, Topical
  • Aggregatibacter actinomycetemcomitans / immunology
  • Alveolar Bone Loss / immunology
  • Alveolar Bone Loss / microbiology
  • Animals
  • Antibodies, Bacterial / blood
  • Antigen-Antibody Complex / analysis
  • Antigens, Bacterial / administration & dosage
  • Antigens, Bacterial / immunology*
  • Biomarkers / analysis
  • Connective Tissue / immunology
  • Connective Tissue / microbiology
  • Epithelial Attachment / immunology
  • Epithelial Attachment / microbiology
  • Gingiva / immunology*
  • Hyaluronan Receptors / analysis
  • Immunization
  • Immunoglobulin G / blood
  • Isoenzymes / analysis
  • Male
  • Mitochondrial Proteins
  • Molar / microbiology
  • Osteoclasts / immunology
  • Osteoclasts / microbiology
  • Periodontal Attachment Loss / immunology
  • Periodontal Attachment Loss / microbiology
  • Periodontitis / immunology
  • Periodontitis / microbiology*
  • Rats
  • Rats, Inbred Lew
  • Specific Pathogen-Free Organisms
  • Staphylococcus aureus / immunology*
  • Tartrate-Resistant Acid Phosphatase


  • Antibodies, Bacterial
  • Antigen-Antibody Complex
  • Antigens, Bacterial
  • Biomarkers
  • C1qbp protein, rat
  • Hyaluronan Receptors
  • Immunoglobulin G
  • Isoenzymes
  • Mitochondrial Proteins
  • Acid Phosphatase
  • Tartrate-Resistant Acid Phosphatase