Enterococcus is a normal inhabitant of the human oral cavity, the vagina, and the gastrointestinal tract. Four isolates of Enterococcus in this study were identified as E. durans. These bacteria were characterized and the interaction of these bacteria with the important oral bacteria as like S. mutans and S. oralis was studied as follows.
1. The carbohydrate fermentation test and biochemical test showed similar results in 4 isolates.
2. The susceptibility test against erythromycin, penicillin, tobramycin, ampicillin, teicoplanin, ciprofloxacin, vancomycin, gentamicin, kanamycin, and streptomycin showed to be susceptible in all four isolates.
3. The optical density of absorbance at 550 nm was 1.405 in the culture of S. mutans in disposable cuvette, whereas being 0.855, 0.867, 0.797, and 1.083 in the combined culture of S. mutans and each E. durans.
4. The mean weight of produced artificial plaque on the wires in the beaker was 1566103 mg in culture of S. mutans only, whereas being reduced to 445 mg, 4112 mg, 347 mg, and 3812 mg in the combined culture of S. mutans and each E. durans. The viable cells were 2.0 x 109 per ml in the culture of S. mutans, wheras being 2.0 x 107 to 6.0 x 107 per ml in the combined culture of S. mutans and E. durans.
5. The viable cells were 2.1 x 108 per ml in the culture of S. oralis, whereas being 1.4 x 107 to 7.0 x 107 per ml in the combined culture of S. oralis and E. durans.
6. Plasmid of about 60 kb was isolated in three isolates of E. durans.
These results suggest that E. durans isolated from the oral cavity inhibits the replication of S. mutans and formation of artificial plaque, while inhibiting the replication of S. oralis a little.
|