scholarly journals Polymicrobial synergy stimulates Porphyromonas gingivalis survival and gingipain expression in a multi-species subgingival community

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Julia R. Davies ◽  
Trupti Kad ◽  
Jessica Neilands ◽  
Bertil Kinnby ◽  
Zdenka Prgomet ◽  
...  
Keyword(s):  
Proteolytic Activity ◽  
Porphyromonas Gingivalis ◽  
Fusobacterium Nucleatum ◽  
Extracellular Proteins ◽  
Nutrient Broth ◽  
Periodontal Pocket ◽  
Wild Type ◽  
Culture Techniques ◽  
Community Growth ◽  
Coated Surfaces

Abstract Background Dysbiosis in subgingival microbial communities, resulting from increased inflammatory transudate from the gingival tissues, is an important factor in initiation and development of periodontitis. Dysbiotic communities are characterized by increased numbers of bacteria that exploit the serum-like transudate for nutrients, giving rise to a proteolytic community phenotype. Here we investigate the contribution of interactions between members of a sub-gingival community to survival and development of virulence in a serum environment—modelling that in the subgingival pocket. Methods Growth and proteolytic activity of three Porphyromonas gingivalis strains in nutrient broth or a serum environment were assessed using A600 and a fluorescent protease substrate, respectively. Adherence of P. gingivalis strains to serum-coated surfaces was studied with confocal microscopy and 2D-gel electrophoresis of bacterial supernatants used to investigate extracellular proteins. A model multi-species sub-gingival community containing Fusobacterium nucleatum, Streptococcus constellatus, Parvimonas micra with wild type or isogenic mutants of P. gingivalis was then created and growth and proteolytic activity in serum assessed as above. Community composition over time was monitored using culture techniques and qPCR. Results The P. gingivalis strains showed different growth rates in nutrient broth related to the level of proteolytic activity (largely gingipains) in the cultures. Despite being able to adhere to serum-coated surfaces, none of the strains was able to grow alone in a serum environment. Together in the subgingival consortium however, all the included species were able to grow in the serum environment and the community adopted a proteolytic phenotype. Inclusion of P. gingivalis strains lacking gingipains in the consortium revealed that community growth was facilitated by Rgp gingipain from P. gingivalis. Conclusions In the multi-species consortium, growth was facilitated by the wild-type and Rgp-expressing strains of P. gingivalis, suggesting that Rgp is involved in delivery of nutrients to the whole community through degradation of complex protein substrates in serum. Whereas they are constitutively expressed by P. gingivalis in nutrient broth, gingipain expression in the model periodontal pocket environment (serum) appeared to be orchestrated through signaling to P. gingivalis from other members of the community, a phenomenon which then promoted growth of the whole community.

Polymicrobial Synergy Stimulates Porphyromonas Gingivalis Survival And Gingipain Expression In A Multispecies Subgingival Community

2021 ◽  
Author(s):  
Julia R. Davies ◽  
Trupti Kad ◽  
Jessica Neilands ◽  
Bertil Kinnby ◽  
Zdenka Prgomet ◽  
...  
Keyword(s):  
Proteolytic Activity ◽  
Fusobacterium Nucleatum ◽  
Extracellular Proteins ◽  
Periodontal Pocket ◽  
Wild Type ◽  
Culture Techniques ◽  
Survival And Development ◽  
Protease Substrate ◽  
2D Gel ◽  
Coated Surfaces

Abstract Background Dysbiosis in subgingival microbial communities, resulting from increased inflammatory transudate from the gingival tissues, is an important factor in initiation and development of periodontitis. Dysbiotic communities are characterized by increased numbers of bacteria that exploit the serum-like transudate for nutrients, giving rise to a proteolytic community phenotype. Here we investigate the contribution of interactions between members of a sub-gingival community to survival and development of virulence in a serum environment - modelling that in the subgingival pocket. Methods Growth and proteolytic activity of three P. gingivalis strains in nutrient-rich broth or a serum environment were assessed using A600 and a fluorescent protease substrate, respectively. Adherence of P. gingivalis strains to serum-coated surfaces was studied with confocal microscopy and 2D-gel electrophoresis of bacterial supernatants used to investigate extracellular proteins. A model multi-species sub-gingival community containing Fusobacterium nucleatum, Streptococcus constellatus, Parvimonas micra with wild type or isogenic mutants was then created and growth and proteolytic activity in serum assessed as above. Community composition over time was monitored using culture techniques and qPCR. Results The P. gingivalis strains showed different growth rates in nutrient-rich broth related to the level of proteolytic activity (largely gingipains) in the cultures. Despite being able to adhere to serum-coated surfaces, none of the strains was able to grow alone in a serum environment. In the subgingival consortium however, all the included species were able to grow in the serum environment and the community adopted a proteolytic phenotype. Inclusion of P. gingivalis strains lacking gingipains in the consortium revealed that the ability of the community to grow was largely due to Rgp gingipain. Conclusions In the multi-species consortium, growth was facilitated by the wild-type and Rgp-expressing strains of P. gingivalis, suggesting that Rgp is involved in delivery of nutrients to the whole community through degradation of complex serum substrates. Whereas they are constitutively expressed by P. gingivalis in nutrient-rich broth, gingipain expression in the model periodontal pocket environment (serum) appears to be orchestrated through signaling to P. gingivalis from other members of the community, a phenomenon which can then promote growth of the whole community.

scholarly journals The vimE Gene Downstream of vimA Is Independently Expressed and Is Involved in Modulating Proteolytic Activity in Porphyromonas gingivalis W83

2004 ◽  
Vol 72 (10) ◽  
pp. 5555-5564 ◽  
Author(s):  
Elaine Vanterpool ◽  
Francis Roy ◽  
Hansel M. Fletcher
Keyword(s):  
Proteolytic Activity ◽  
Porphyromonas Gingivalis ◽  
Protease Activity ◽  
Catalytic Domain ◽  
Immunoblot Analysis ◽  
Extracellular Protein ◽  
Transcriptional Unit ◽  
Wild Type ◽  
Defective Mutant

ABSTRACT Regulation/activation of the Porphyromonas gingivalis gingipains is poorly understood. A unique 1.3-kb open reading frame downstream of the bcp-recA-vimA transcriptional unit was cloned, insertionally inactivated with the ermF-ermAM antibiotic resistance cassette, and used to create a defective mutant by allelic exchange. In contrast to the wild-type W83 strain, the growth rate of the mutant strain (designated FLL93) was reduced, and when plated on Brucella blood agar it was nonpigmented and nonhemolytic. Arginine- and lysine-specific gingipain activities were reduced by approximately 90 and 85%, respectively, relative to activities of the parent strain. These activities were unaffected by the culture's growth phase, in contrast to the vimA-defective mutant P. gingivalis FLL92, which has increased proteolytic activity in stationary phase. Expression of the rgpA, rgpB, and kgp gingipain genes was unaltered in P. gingivalis FLL93 compared to that of the wild-type strain. Further, in extracellular protein fractions a 64-kDa band was identified that was immunoreactive with the RgpB-specific proenzyme antibodies. Active-site labeling with dansyl-glutamyl-glycyl-arginyl chloromethyl ketone or immunoblot analysis showed no detectable protein band representing the gingipain catalytic domain. In vitro protease activity could be slightly induced by a urea denaturation-renaturation cycle in an extracellular protein fraction, in contrast to the vimA-defective mutant P. gingivalis FLL92. Expression of flanking genes, including recA, vimA, and Pg0792, was unaltered by the mutation. Taken together, these results suggest that the vimA downstream gene, designated vimE (for virulence-modulating gene E), is involved in the regulation of protease activity in P. gingivalis.

Antibacterial Activity of Silver-Hydroxyapatite/Titania Nanocomposite Coating on Titanium against Oral Bacteria

2007 ◽  
Vol 330-332 ◽  
pp. 455-458 ◽  
Author(s):  
An Chun Mo ◽  
Wei Xu ◽  
Su Qin Xian ◽  
Yu Bao Li ◽  
Shi Bai
Keyword(s):  
Antibacterial Activity ◽  
Streptococcus Mutans ◽  
Porphyromonas Gingivalis ◽  
Nanocomposite Coating ◽  
Oral Bacteria ◽  
Tio2 Coating ◽  
Prevotella Intermedia ◽  
Anaerobic Incubation ◽  
Coating Method ◽  
Coated Surfaces

This study was focused on evaluating the bactericidal and anti-adhesive efficacy of silver-hydroxyapatite/ titania nanocomposites (nAg-HA/TiO2) coating on titanium against oral bacteria. Porphyromonas gingivalis, Prevotella intermedia and Fusohacterium nucleatum and Streptococcus mutans were used. Antibacterial activity of nAg-HA/TiO2 coating was investigated quantitatively using film applicator coating method and titanium plates incubated with bacteria were prepared for SEM to observe the adherence of oral bacteria. The viability of each type of bacteria on the antibacterial film was suppressed to about 10% after anaerobic incubation for 3 hours. Image of SEM demonstrated that bacteria on sandblasting surfaces were relatively confluent whilst on coated surfaces fewer bacteria were observed. Adherence of bacteria on nAg-HA / TiO2-coated surfaces compared with uncoated surfaces was remarkably decreased.

scholarly journals Abrogation of Neuraminidase Reduces Biofilm Formation, Capsule Biosynthesis, and Virulence of Porphyromonas gingivalis

2011 ◽  
Vol 80 (1) ◽  
pp. 3-13 ◽  
Author(s):  
Chen Li ◽  
Kurniyati ◽  
Bo Hu ◽  
Jiang Bian ◽  
Jianlan Sun ◽  
...  
Keyword(s):  
Porphyromonas Gingivalis ◽  
Biofilm Formation ◽  
Adult Population ◽  
Transcriptional Analysis ◽  
Wild Type ◽  
Content Type ◽  
Multiple Organs ◽  
Biochemical Analyses

ABSTRACTThe oral bacteriumPorphyromonas gingivalisis a key etiological agent of human periodontitis, a prevalent chronic disease that affects up to 80% of the adult population worldwide.P. gingivalisexhibits neuraminidase activity. However, the enzyme responsible for this activity, its biochemical features, and its role in the physiology and virulence ofP. gingivalisremain elusive. In this report, we found thatP. gingivalisencodes a neuraminidase, PG0352 (SiaPg). Transcriptional analysis showed thatPG0352is monocistronic and is regulated by a sigma70-like promoter. Biochemical analyses demonstrated that SiaPgis an exo-α-neuraminidase that cleaves glycosidic-linked sialic acids. Cryoelectron microscopy and tomography analyses revealed that thePG0352deletion mutant (ΔPG352) failed to produce an intact capsule layer. Compared to the wild type,in vitrostudies showed that ΔPG352 formed less biofilm and was less resistant to killing by the host complement.In vivostudies showed that while the wild type caused a spreading type of infection that affected multiple organs and all infected mice were killed, ΔPG352 only caused localized infection and all animals survived. Taken together, these results demonstrate that SiaPgis an important virulence factor that contributes to the biofilm formation, capsule biosynthesis, and pathogenicity ofP. gingivalis, and it can potentially serve as a new target for developing therapeutic agents againstP. gingivalisinfection.

scholarly journals Lipopolysaccharides of Fusobacterium nucleatum and Porphyromonas gingivalis increase RANKL-expressing neutrophils in air pouches of mice

2021 ◽  
Vol 37 (1) ◽  
Author(s):  
Ae Ri Kim ◽  
Yun Kyong Lim ◽  
Joong-Ki Kook ◽  
Eun-Jung Bak ◽  
Yun-Jung Yoo
Keyword(s):  
Flow Cytometry ◽  
Porphyromonas Gingivalis ◽  
Osteoclast Differentiation ◽  
Fusobacterium Nucleatum ◽  
Pathological Changes ◽  
Air Pouch ◽  
E Coli ◽  
Differentiation Factor ◽  
Osteoclast Differentiation Factor

AbstractIncreases of neutrophils and osteoclasts are pathological changes of periodontitis. RANKL is an osteoclast differentiation factor. The effect of periodontopathogen LPS on RANKL-expressing neutrophils has not been clarified yet. We evaluated numerical changes of RANKL-expressing neutrophils in air pouches of mice injected with LPSs of Fusobacterium nucleatum and Porphyromonas gingivalis. Mice with air pouches were assigned into saline (C)-, E. coli LPS- (Ec LPS)-, F. nucleatum LPS (Fn LPS)-, P. gingivalis LPS (Pg LPS)-, and Fn LPS and Pg LPS (Fn + Pg LPS)-injected groups. CD11b+Ly6G+ neutrophils and CD11b+Ly6G+RANKL+ neutrophils in blood and air pouch exudates were determined by flow cytometry. In blood, compared to the C group, the Fn LPS group showed increases of CD11b+Ly6G+ neutrophils and CD11b+Ly6G+RANKL+ neutrophils whereas the Pg LPS group showed no significant differences. These increases in the Fn LPS group were not different to those in the Ec LPS group. In exudates, Fn LPS and Pg LPS groups showed increases of CD11b+Ly6G+ neutrophils and CD11b+Ly6G+RANKL+ neutrophils compared to the C group. Increased levels in the Fn LPS group were not different to those in the Ec LPS group, but Pg LPS group was lower than those in the Ec LPS group. In blood and exudates, the Fn + Pg LPS group showed no difference in levels of these neutrophils compared to the Ec LPS group. LPSs of F. nucleatum and P. gingivalis increased RANKL-expressing neutrophils although the degrees of increases were different. These suggest that periodontopathogen LPS can act as a stimulant to increase RANKL-expressing neutrophils.

scholarly journals Dynamic oligopeptide acquisition by the RagAB transporter from Porphyromonas gingivalis

2019 ◽  
Author(s):  
Mariusz Madej ◽  
Joshua B. R. White ◽  
Zuzanna Nowakowska ◽  
Shaun Rawson ◽  
Carsten Scavenius ◽  
...  
Keyword(s):  
Porphyromonas Gingivalis ◽  
Direct Evidence ◽  
Inflammatory Diseases ◽  
Extracellular Proteins ◽  
Substrate Selectivity ◽  
Binding Studies ◽  
Uptake Mechanism ◽  
X Ray ◽  
Cryo Electron Microscopy ◽  
Binding Surface

AbstractPorphyromonas gingivalis, an asaccharolytic Bacteroidetes, is a keystone pathogen in human periodontitis that may also contribute to the development of other chronic inflammatory diseases, such as rheumatoid arthritis, cardiovascular disease and Alzheimer’s disease. P. gingivalis utilizes protease-generated peptides derived from extracellular proteins for growth, but how those peptides enter the cell is not clear. Here we identify RagAB as the outer membrane importer for peptides. X-ray crystal structures show that the transporter forms a dimeric RagA2B2 complex with the RagB substrate binding surface-anchored lipoprotein forming a closed lid on the TonB-dependent transporter RagA. Cryo-electron microscopy structures reveal the opening of the RagB lid and thus provide direct evidence for a “pedal bin” nutrient uptake mechanism. Together with mutagenesis, peptide binding studies and RagAB peptidomics, our work identifies RagAB as a dynamic OM oligopeptide acquisition machine with considerable substrate selectivity that is essential for the efficient utilisation of proteinaceous nutrients by P. gingivalis.

scholarly journals Erratum to: Bactericidal effect of visible light in the presence of erythrosine on Porphyromonas gingivalis and Fusobacterium nucleatum compared with diode laser, an in vitro study

LASER THERAPY ◽  
2014 ◽  
Vol 23 (4) ◽  
pp. 263-271 ◽  
Author(s):  
Ghanbari Habiboallah ◽  
Zakeri Mahdi ◽  
Naderi Nasab Mahbobeh ◽  
Zareian Jahromi Mina ◽  
Faghihi Sina ◽  
...  
Keyword(s):  
Visible Light ◽  
Diode Laser ◽  
Porphyromonas Gingivalis ◽  
In Vitro Study ◽  
Fusobacterium Nucleatum ◽  
Bactericidal Effect ◽  
Vitro Study

scholarly journals Mutational Analysis of Ocriplasmin to Reduce Proteolytic and Autolytic Activity in Pichia pastoris

2020 ◽  
Vol 22 (1) ◽  
Author(s):  
Roghayyeh Baghban ◽  
Safar Farajnia ◽  
Younes Ghasemi ◽  
Reyhaneh Hoseinpoor ◽  
Azam Safary ◽  
...  
Keyword(s):  
Pichia Pastoris ◽  
Proteolytic Activity ◽  
Mutational Analysis ◽  
Expression System ◽  
Catalytic Efficiency ◽  
Site Directed Mutagenesis ◽  
Wild Type ◽  
Vitreomacular Adhesion ◽  
Autolytic Activity

Abstract Background Ocriplasmin (Jetrea) is using for the treatment of symptomatic vitreomacular adhesion. This enzyme undergoes rapid inactivation and limited activity duration as a result of its autolytic nature after injection within the eye. Moreover, the proteolytic activity can cause photoreceptor damage, which may result in visual impairment in more serious cases. Results The present research aimed to reduce the disadvantages of ocriplasmin using site-directed mutagenesis. To reduce the autolytic activity of ocriplasmin in the first variant, lysine 156 changed to glutamic acid and, in the second variant for the proteolytic activity reduction, alanine 59 mutated to threonine. The third variant contained both mutations. Expression of wild type and three mutant variants of ocriplasmin constructs were done in the Pichia pastoris expression system. The mutant variants were analyzed in silico and in vitro and compared to the wild type. The kinetic parameters of ocriplasmin variants showed both variants with K156E substitution were more resistant to autolytic degradation than wild-type. These variants also exhibited reduced Kcat and Vmax values. An increase in their Km values, leading to a decreased catalytic efficiency (the Kcat/Km ratio) of autolytic and mixed variants. Moreover, in the variant with A59T mutation, Kcat and Vmax values have reduced compared to wild type. The mix variants showed the most increase in Km value (almost 2-fold) as well as reduced enzymatic affinity to the substrate. Thus, the results indicated that combined mutations at the ocriplasmin sequence were more effective compared with single mutations. Conclusions The results indicated such variants represent valuable tools for the investigation of therapeutic strategies aiming at the non-surgical resolution of vitreomacular adhesion.

scholarly journals Porphyromonas gingivalis Impairs Oral Epithelial Barrier through Targeting GRHL2

2019 ◽  
Vol 98 (10) ◽  
pp. 1150-1158 ◽  
Author(s):  
W. Chen ◽  
A. Alshaikh ◽  
S. Kim ◽  
J. Kim ◽  
C. Chun ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Oral Mucosa ◽  
Porphyromonas Gingivalis ◽  
Oral Bacteria ◽  
Conditional Knockout ◽  
Epithelial Barrier ◽  
Wild Type ◽  
Oral Epithelial ◽  
Junction Proteins

Oral mucosa provides the first line of defense against a diverse array of environmental and microbial irritants by forming the barrier of epithelial cells interconnected by multiprotein tight junctions (TJ), adherens junctions, desmosomes, and gap junction complexes. Grainyhead-like 2 (GRHL2), an epithelial-specific transcription factor, may play a role in the formation of the mucosal epithelial barrier, as it regulates the expression of the junction proteins. The current study investigated the role of GRHL2 in the Porphyromonas gingivalis ( Pg)–induced impairment of epithelial barrier functions. Exposure of human oral keratinocytes (HOK-16B and OKF6 cells) to Pg or Pg-derived lipopolysaccharides ( Pg LPSs) led to rapid loss of endogenous GRHL2 and the junction proteins (e.g., zonula occludens, E-cadherin, claudins, and occludin). GRHL2 directly regulated the expression levels of the junction proteins and the epithelial permeability for small molecules (e.g., dextrans and Pg bacteria). To explore the functional role of GRHL2 in oral mucosal barrier, we used a Grhl2 conditional knockout (KO) mouse model, which allows for epithelial tissue-specific Grhl2 KO in an inducible manner. Grhl2 KO impaired the expression of the junction proteins at the junctional epithelium and increased the alveolar bone loss in the ligature-induced periodontitis model. Fluorescence in situ hybridization revealed increased epithelial penetration of oral bacteria in Grhl2 KO mice compared with the wild-type mice. Also, blood loadings of oral bacteria (e.g., Bacteroides, Bacillus, Firmicutes, β- proteobacteria, and Spirochetes) were significantly elevated in Grhl2 KO mice compared to the wild-type littermates. These data indicate that Pg bacteria may enhance paracellular penetration through oral mucosa in part by targeting the expression of GRHL2 in the oral epithelial cells, which then impairs the epithelial barrier by inhibition of junction protein expression, resulting in increased alveolar tissue destruction and systemic bacteremia.

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