Subgingival colonization by Porphyromonas gingivalis

Porphyromonas gingivalis, a gram-negative anaerobe, is a major causative ag ent in the initiation and progression of severe forms of periodontal diseas e. In order to cause periodontal disease, P, gingivalis must colonize the s ubgingival region, a process that involves several distinct steps and multi ple gene products. The organism must first navigate within the oral fluids in order to reach the hard or soft tissues of the mouth. Retention and grow th of bacteria on these surfaces is facilitated by a repertoire of adhesins including fimbriae, hemagglutinins and proteinases. Once established subgi ngivally, P. gingivalis cells participate in intercellular communication ne tworks with other oral prokaryotic cells and with eukaryotic cells. The est ablishment of these multiple interactive interfaces can lead to biofilm for mation, invasion of root dentin and internalization within gingival epithel ial cells. The resulting bacterial and host cellular locations, products an d fate contribute to the success of P. gingivalis in colonizing the periodo ntal region.