Adhesion of Porphyromonas gingivalis serotypes to pocket epithelium.

Porphyromonas gingivalis, a key pathogen in periodontitis, is able to adhere to and invade the pocket epithelium. Different capsular antigens of P. gingivalis have been identified (K-serotyping). These P. gingivalis capsular types show differences in adhesion capacity to human cell lines or to cells cultured on a feeder layer or stromal equivalent. The adhesion capacity of different P. gingivalis serotypes (6 capsular types and non-encapsulated strains) was compared on in vitro cultured epithelial monolayers from periodontal pockets of patients with periodontitis. The degree of adherence of P. gingivalis was evaluated by both culture and fluorescence microscopy. Non-encapsulated strains adhered significantly more than their capsulated variants. Capsule type 4 (K-4) adhered slightly better than the remaining K-types. This study indicates that the presence and type of capsule have a significant influence on the initial adhesion of P. gingivalis to human periodontal pocket epithelial cells.