Send to

Choose Destination
See comment in PubMed Commons below
J Oral Microbiol. 2011;3. doi: 10.3402/jom.v3i0.8396. Epub 2011 Oct 17.

Identification of interspecies interactions affecting Porphyromonas gingivalis virulence phenotypes.

Author information

  • 1Division of Geographic Medicine and Infectious Diseases, Tufts Medical Center, Boston, MA, USA.



Periodontitis is recognized as a complex polymicrobial disease, however, the impact of the bacterial interactions among the 700-1,000 different species of the oral microbiota remains poorly understood. We conducted an in vitro screen for oral bacteria that mitigate selected virulence phenotypes of the important periodontal pathogen, Porphyromonas gingivalis.


We isolated and identified oral anaerobic bacteria from subgingival plaque of dental patients. When cocultured with P. gingivalis W83, specific isolates reduced the cytopathogenic effects of P. gingivalis on oral epithelial cells.


In an initial screen of 103 subgingival isolates, we identified 19 distinct strains from nine species of bacteria (including Actinomyces naeslundii, Streptococcus oralis, Streptococcus mitis, and Veilonella dispar) that protect oral epithelial cells from P. gingivalis-induced cytotoxicity. We found that some of these strains inhibited P. gingivalis growth in plate assays through the production of organic acids, whereas some decreased the gingipain activity of P. gingivalis in coculture or mixing experiments.


In summary, we identified 19 strains isolated from human subgingival plaque that interacted with P. gingivalis, resulting in mitigation of its cytotoxicity to oral epithelial cells, inhibition of growth, and/or reduction of gingipain activity. Understanding the mechanisms of interaction between bacteria in the oral microbial community may lead to the development of new probiotic agents and new strategies for interrupting the development of periodontal disease.


bacterial interactions; cytotoxicity; gingipain; oral pathogen; virulence

PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for PubMed Central
    Loading ...
    Support Center