Bacterial Interference in the oral ecology of Actinobacillus Actinomycetemcomitans and its relationship to human periodontists
Authors: J.D. Hillman, S.S. Socransky — Forsyth Dental Center, Boston, MA
Journal: Archives of Oral Biology | Published: 1982 | Vol. 27: pp. 75–77
Type: Short Communication
Summary
The plaque of 7 clinically healthy subjects was analysed for organisms inhibitory to the growth of Actinobacillus actinomycetemcomitans strain Y4 on chocolate agar medium. Ten of the 11 sites harboured such organisms, constituting a median of 5.8% of the total cultivable flora.
Four to 30% of the isolates in samples from eight sites in patients with adult periodontitis were also inhibitory to strain Y4. By contrast, 15 of the 16 plaque samples from disease sites of 6 periodontosis (juvenile periodontitis) subjects showed no inhibitors. Four of 5 healthy sites sampled from 3 of the periodontosis subjects showed inhibitors in proportions similar to plaque from healthy subjects.
The mother and 3 siblings of a subject with periodontosis lacked inhibitors in one or more plaque samples taken from their first molars.
Results Summary
| Subject Group | Median % Inhibitory Organisms |
|---|---|
| Clinically healthy subjects | 5.8% |
| Adult periodontitis — healthy sites | ~13% |
| Adult periodontitis — diseased sites | ~6% |
| Periodontosis — diseased sites | 0% |
Significance
This foundational study provides evidence that healthy individuals harbor organisms in the gingival crevice that are inhibitory to A. actinomycetemcomitans. The absence of these inhibitory organisms in periodontosis disease sites — and in family members of affected individuals — may explain both the localized pattern of tissue destruction and the familial tendency of the disease. This work helped establish the scientific basis for the use of beneficial oral streptococci as a probiotic strategy for periodontal health.
