Actinobacillus actinomycetemcomitans attached to oral epithelial cells: stability and ultrastructural aspects

Abstract

Actinobacillus actinomycetemcomitans is considered an important pathogen in periodontal disease, especially in localized juvenile periodontitis. The bacterial mechanism of adherence to oral epithelial cells (OEC), teeth or other bacteria is the initial step in colonization and in the pathogenesis of oral infectious processes, such as gingivitis and periodontitis. The goal of this study was to evaluate the adherence and its variability, as well as ultrastructural aspects of A. actinomycetemcomitans isolates on OEC, when they were submitted to repeated subcultures. Twenty-one fresh isolates from 21 patients with periodontal disease and one reference strain were tested. All tested isolates adhered to OEC and repeated subcultures produced variations in the adhesion rates of each isolate. Furthermore, a direct correlation between high levels of adherence and the presence of large amounts of extracellular components, such as fimbriae, vesicles and extracellular amorfous material, was observed.