Metabolic cooperativity between Porphyromonas gingivalis and Treponema denticola

Abstract

Background: Porphyromonas gingivalis and Treponema denticola are proteolytic periodontopathogens that co-localize in polymicrobial subgingival plaque biofilms, display in vitro growth symbiosis and synergistic virulence in animal models of disease. These symbioses are underpinned by a range of metabolic interactions including cooperative hydrolysis of glycine-containing peptides to produce free glycine, which T. denticola uses as a major energy and carbon source. Objective: To characterize the P. gingivalis gene products essential for these interactions. Methods: The P. gingivalis transcriptome exposed to cell-free T. denticola conditioned medium was determined using RNA-seq. P. gingivalis proteases potentially involved in hydrolysis of glycine-containing peptides were identified using a bioinformatics approach. Results: One hundred and thirty-twogenes displayed differential expression, with the pattern of gene expression consistent with succinate cross-feeding from T. denticola to P. gingivalis and metabolic shifts in the P. gingivalis folate-mediated one carbon superpathway. Interestingly, no P. gingivalis proteases were significantly up-regulated. Three P. gingivalis proteases were identified as candidates and inactivated to determine their role in the release of free glycine. P. gingivalis PG0753 and PG1788 but not PG1605 are involved in the hydrolysis of glycine-containing peptides, making free glycine available for T. denticola utilization. Conclusion: Collectively these metabolic interactions help to partition resources and engage synergistic interactions between these two species.

Inhibitory effect of a gel paste containing surface pre-reacted glass-ionomer (S-PRG) filler on the cariogenicity of Streptococcus mutans

“…S-PRG filler also had an inhibitory effect on Streptococcus oralis and Streptococcus gordonii 33 , and may inhibit sugar metabolism by oral streptococci. In contrast, Porphyromonas gingivalis , a major Gram-negative periodontopathic bacterium, is unable to metabolize sugar and uses protease activity to degrade proteins as energy sources 34 , 35 . S-PRG filler can inhibit the protease activity of P. gingivalis 36 .…”

A quantitative framework reveals traditional laboratory growth is a highly accurate model of human oral infection

“…Thus, we compared P. gingivalis gene expression in the 12 periodontitis samples to 122 transcriptomes of wild-type P. gingivalis collected during growth in experimental model systems (Table 2 and Dataset S2C). A total of 117 of these transcriptomes were from in vitro culture from 12 publications, mostly from growth in rich media under laboratory conditions (17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29). Of these transcriptomes, 85 were from monoculture and 32 from pairwise coculture with either Streptococcus gordonii, Acinetobacter baumannii, or Candida albicans.…”

Association between Vitamin D Receptor Gene Polymorphisms and Periodontal Bacteria: A Clinical Pilot Study

“…They are involved in the formation of dental plaque and some species contribute to the development of caries [ 62 , 63 ]. Many of these are pathogens, such as the Porphyromonas gingivalis , which is an anaerobic Gram-negative bacterium that can cause various diseases such as periodontitis, abscesses, and endocarditis, and T. denticola , which is a Gram-negative, obligate anaerobic causing periodontitis [ 64 , 65 , 66 ]. Studies have shown that cotinine (a substance found in cigarette smoke) can interfere with P. gingivalis ability to bind and invade epithelial cells [ 67 , 68 , 69 ].…”