Introduction: Microbial interactions are considered important in the adhesion process of pathogenic bacteria in the oral cavity. This study addressed the hypothesis that a streptococcal biofilm influences the hard tissue colonization by the periodontopathogen Aggregatibacter actinomycetemcomitans under hydrodynamic conditions.
Methods: The colonization of a green-fluorescent-protein-labelled A. actinomycetemcomitans strain on surfaces coated with a streptococcal biofilm, was monitored in real time using a confocal laser scanning microscope-mounted flow cell. Culture and quantitative polymerase chain reaction data were obtained in parallel from a Modified Robbins Device.
Results: Colonization of A. actinomycetemcomitans was inhibited by the four tested streptococci (Streptococcus sanguinis, Streptococcus cristatus, Streptococcus salivarius, and Streptococcus mitis). The most inhibiting species was S. sanguinis.
Conclusion: These results confirmed the hypothesis that some bacterial species influence A. actinomycetemcomitans colonization of hard surfaces in vitro under hydrodynamic conditions.