Porphyromonas gingivalis: keeping the pathos out of the biont

Abstract

The primary goal of the human microbiome initiative has been to increase our understanding of the structure and function of our indigenous microbiota and their effects on human health and predisposition to disease. Because of its clinical importance and accessibility for in vivo study, the oral biofilm is one of the best-understood microbial communities associated with the human body. Studies have shown that there is a succession of select microbial interactions that directs the maturation of a defined community structure, generating the formation of dental plaque. Although the initiating factors that lead to disease development are not clearly defined, in many individuals there is a fundamental shift from a health-associated biofilm community to one that is pathogenic in nature and a central player in the pathogenic potential of this community is the presence of Porphyromonas gingivalis. This anaerobic bacterium is a natural member of the oral microbiome, yet it can become highly destructive (termed pathobiont) and proliferate to high cell numbers in periodontal lesions, which is attributed to its arsenal of specialized virulence factors. Hence, this organism is regarded as a primary etiologic agent of periodontal disease progression. In this review, we summarize some of the latest information regarding what is known about its role in periodontitis, including pathogenic potential as well as ecological and nutritional parameters that may shift this commensal to a virulent state. We also discuss parallels between the development of pathogenic biofilms and the human cellular communities that lead to cancer, specifically we frame our viewpoint in the context of ‘wounds that fail to heal’.

Functional Analysis of Porphyromonas gingivalis W83 CRISPR-Cas Systems

“…To date, however, no phages able to infect P. gingivalis have been identified, and this species has no known naturally occurring plasmids (48,49). Hence, the main function of this system remains unconfirmed.…”

Changes in lipopolysaccharide profile of Porphyromonas gingivalis clinical isolates correlate with changes in colony morphology and polymyxin B resistance

“…gingivalis can cause dysbiosis, inducing a microbial shift that leads to periodontitis [9,17]. Furthermore, P. gingivalis was the most frequent bacteria isolated from chronic periodontitis patients and has been related to disease progression [13,43].…”

Porphyromonas gingivalis infection in gestational diabetes mellitus and survival in tobacco smokers.

“…As per PSD model, periodontitis is believed to be initiated by synergistic and dysbiotic microbial communities [21]. Dysbiosis is characterized by the relative abundance of pathobionts, commensals of the biofilm that under certain conditions can cause pathology [22,23], compared to commensals in the biofilm. The results of human clinical studies are in agreement with the observations identified in animal models regarding the PSD model.…”

“…In response to a change in pH or temperature, P. gingivalis alters the biophysical properties of its membrane lipids [22]. Despite being anaerobe, P. gingivalis is microaerotolerant.…”

“…gingivalis is related not only to its physiological state but also to its interactions with other oral microflora [22].…”