Subgingival colonization by Porphyromonas gingivalis

Abstract

Porphyromonas gingivalis, a gram-negative anaerobe, is a major causative agent in the initiation and progression of severe forms of periodontal disease. In order to cause periodontal disease, P. gingivalis must colonize the subgingival region, a process that involves several distinct steps and multiple 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 growth of bacteria on these surfaces is facilitated by a repertoire of adhesins including fimbriae, hemagglutinins and proteinases. Once established subgingivally, P. gingivalis cells participate in intercellular communication networks with other oral prokaryotic cells and with eukaryotic cells. The establishment of these multiple interactive interfaces can lead to biofilm formation, invasion of root dentin and internalization within gingival epithelial cells. The resulting bacterial and host cellular locations, products and fate contribute to the success of P. gingivalis in colonizing the periodontal region.

Adaptation of Porphyromonas gingivalis to microaerophilic conditions involves increased consumption of formate and reduced utilization of lactate

“…Although P. gingivalis grows optimally without oxygen and is found mainly in anaerobic periodontal pockets, to reach the periodontal pocket it is transferred through different sites in the oral cavity (saliva, tongue, buccal mucosa), where it is exposed to oxygen (Dahlen et al, 1992;Lamont & Jenkinson, 2000;van Steenbergen et al, 1993). Thus, it must cope with the oxidative stress resulting from oxygen exposure, and it probably employs oxygen metabolism pathways similar to those of B. fragilis (Baughn & Malamy, 2004).…”

Arginine deiminase inhibits Porphyromonas gingivalis surface attachment

“…a natural member of the human microbiota, that under certain perturbations to the host and/or microflora can cause pathology. This Gram-negative, highly proteolytic anaerobe is regarded as the primary aetiological agent of adult periodontal disease, leading to chronic inflammation and destruction of both the soft and hard tissues supporting the teeth (Choil et al, 1990;Dzink et al, 1988; Grossi et al, 1994;Lamont & Jenkinson, 2000;Moore et al, 1991). As a pathobiont, the ability to proliferate and express virulence determinants is central to its shift to pathogenicity, thus determining the mechanisms that control the emergence of its pathogenic state are of fundamental importance.…”

The nucleoid-associated protein HUβ affects global gene expression in Porphyromonas gingivalis

“…A shift in the microbial community leading to outgrowth of this anaerobe is directly linked to periodontitis, a chronic inflammatory disease that leads to destruction of the tissues supporting the gums and ultimately, exfoliation of the teeth (Choil et al, 1990;Dzink et al, 1988;Grossi et al, 1994;Lamont & Jenkinson, 2000;Moore et al, 1991). This commensal can colonize, invade and multiply within gingival epithelial cells, as well as penetrate into deeper epithelial cell layers, potentially releasing the whole organism and/or virulence factors into the bloodstream (reviewed by Yilmaz, 2008).…”