scholarly journals Porphyromonas gingivalis HmuY and Streptococcus gordonii GAPDH—Novel Heme Acquisition Strategy in the Oral Microbiome

2020 ◽  
Vol 21 (11) ◽  
pp. 4150 ◽  
Author(s):  
Paulina Ślęzak ◽  
Michał Śmiga ◽  
John W. Smalley ◽  
Klaudia Siemińska ◽  
Teresa Olczak
Keyword(s):  
Porphyromonas Gingivalis ◽  
Wild Type Strain ◽  
Periodontal Diseases ◽  
Oral Bacteria ◽  
Oral Microbiome ◽  
Prevotella Intermedia ◽  
Streptococcus Gordonii ◽  
Wild Type ◽  
Heme Acquisition ◽  
Acquisition Strategy

The oral cavity of healthy individuals is inhabited by commensals, with species of Streptococcus being the most abundant and prevalent in sites not affected by periodontal diseases. The development of chronic periodontitis is linked with the environmental shift in the oral microbiome, leading to the domination of periodontopathogens. Structure-function studies showed that Streptococcus gordonii employs a “moonlighting” protein glyceraldehyde-3-phosphate dehydrogenase (SgGAPDH) to bind heme, thus forming a heme reservoir for exchange with other proteins. Secreted or surface-associated SgGAPDH coordinates Fe(III)heme using His43. Hemophore-like heme-binding proteins of Porphyromonas gingivalis (HmuY), Prevotella intermedia (PinO) and Tannerella forsythia (Tfo) sequester heme complexed to SgGAPDH. Co-culturing of P. gingivalis with S. gordonii results in increased hmuY gene expression, indicating that HmuY might be required for efficient inter-bacterial interactions. In contrast to the ΔhmuY mutant strain, the wild type strain acquires heme and forms deeper biofilm structures on blood agar plates pre-grown with S. gordonii. Therefore, our novel paradigm of heme acquisition used by P. gingivalis appears to extend to co-infections with other oral bacteria and offers a mechanism for the ability of periodontopathogens to obtain sufficient heme in the host environment. Importantly, P. gingivalis is advantaged in terms of acquiring heme, which is vital for its growth survival and virulence.

scholarly journals Formation of Methyl Mercaptan froml-Methionine by Porphyromonas gingivalis

2000 ◽  
Vol 68 (12) ◽  
pp. 6912-6916 ◽  
Author(s):  
Mamiko Yoshimura ◽  
Yoshio Nakano ◽  
Yoshihisa Yamashita ◽  
Takahiko Oho ◽  
Toshiyuki Saito ◽  
...  
Keyword(s):  
Porphyromonas Gingivalis ◽  
Wild Type Strain ◽  
Marked Decrease ◽  
Oral Bacteria ◽  
Methyl Mercaptan ◽  
Wild Type ◽  
Oral Malodor ◽  
Gene Encoding ◽  
Degradation Activity

ABSTRACT Methyl mercaptan production by oral bacteria is thought to be one of the main causes of oral malodor. We examined the ability of periodontopathic Porphyromonas gingivalis to produce methyl mercaptan from l-methionine and found that the invasive strains W83 and W50 produced large amounts of methyl mercaptan. We cloned and sequenced the mgl gene encodingl-methionine-α-deamino-γ-mercaptomethane-lyase (METase) from P. gingivalis W83. The structural mgl gene consisted of 1,200 bp and encoded a 43.3-kDa protein. To examine the role of methyl mercaptan in the pathogenesis ofP. gingivalis, a METase-deficient mutant of P. gingivalis W83 was constructed. The methionine degradation activity and virulence of the mutant (M1217) and the parent strain (W83) in mice were compared. M1217 showed a marked decrease in the formation of methyl mercaptan from l-methionine and decreased virulence compared with the wild-type strain W83. These results suggest that methyl mercaptan not only is one of the sources of oral malodor, but may also play a role in the pathogenicity of 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 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.

scholarly journals Sialidase and Sialoglycoproteases Can Modulate Virulence in Porphyromonas gingivalis

2011 ◽  
Vol 79 (7) ◽  
pp. 2779-2791 ◽  
Author(s):  
Wilson Aruni ◽  
Elaine Vanterpool ◽  
Devon Osbourne ◽  
Francis Roy ◽  
Arun Muthiah ◽  
...  
Keyword(s):  
Porphyromonas Gingivalis ◽  
Type Strain ◽  
Wild Type Strain ◽  
Wild Type ◽  
Content Type ◽  
Sialidase Activity ◽  
Catalytic Domains ◽  
Virulence Regulation ◽  
Isogenic Mutants ◽  
Related Proteins

ABSTRACTThePorphyromonas gingivalisrecombinant VimA can interact with the gingipains and several other proteins, including a sialidase. Sialylation can be involved in protein maturation; however, its role in virulence regulation inP. gingivalisis unknown. The three sialidase-related proteins inP. gingivalisshowed the characteristic sialidase Asp signature motif (SXDXGXTW) and other unique domains. To evaluate the roles of the associated genes, randomly chosenP. gingivalisisogenic mutants created by allelic exchange and designated FLL401 (PG0778::ermF), FLL402 (PG1724::ermF), and FLL403 (PG0352::ermF-ermAM) were characterized. Similar to the wild-type strain, FLL402 and FLL403 displayed a black-pigmented phenotype in contrast to FLL401, which was not black pigmented. Sialidase activity inP. gingivalisFLL401 was reduced by approximately 70% in comparison to those in FLL402 and FLL403, which were reduced by approximately 42% and 5%, respectively. Although there were no changes in the expression of the gingipain genes, their activities were reduced by 60 to 90% in all the isogenic mutants compared to that for the wild type. Immunoreactive bands representing the catalytic domains for RgpA, RgpB, and Kgp were present in FLL402 and FLL403 but were missing in FLL401. While adhesion was decreased, the capacity for invasion of epithelial cells by the isogenic mutants was increased by 11 to 16% over that of the wild-type strain. Isogenic mutants defective inPG0778andPG0352were more sensitive to hydrogen peroxide than the wild type. Taken together, these results suggest that theP. gingivalissialidase activity may be involved in regulating gingipain activity and other virulence factors and may be important in the pathogenesis of this organism.

scholarly journals Inhibitory Effects of Lactoferrin on Growth and Biofilm Formation of Porphyromonas gingivalis and Prevotella intermedia

2009 ◽  
Vol 53 (8) ◽  
pp. 3308-3316 ◽  
Author(s):  
Hiroyuki Wakabayashi ◽  
Koji Yamauchi ◽  
Tetsuo Kobayashi ◽  
Tomoko Yaeshima ◽  
Keiji Iwatsuki ◽  
...  
Keyword(s):  
Porphyromonas Gingivalis ◽  
Biofilm Formation ◽  
Periodontal Diseases ◽  
Antimicrobial Protein ◽  
Antibiofilm Activity ◽  
Prevotella Intermedia ◽  
Periodontopathic Bacteria ◽  
Oral Pathogens ◽  
In Vitro Effects

ABSTRACT Lactoferrin (LF) is an iron-binding antimicrobial protein present in saliva and gingival crevicular fluids, and it is possibly associated with host defense against oral pathogens, including periodontopathic bacteria. In the present study, we evaluated the in vitro effects of LF-related agents on the growth and biofilm formation of two periodontopathic bacteria, Porphyromonas gingivalis and Prevotella intermedia, which reside as biofilms in the subgingival plaque. The planktonic growth of P. gingivalis and P. intermedia was suppressed for up to 5 h by incubation with ≥130 μg/ml of human LF (hLF), iron-free and iron-saturated bovine LF (apo-bLF and holo-bLF, respectively), and ≥6 μg/ml of bLF-derived antimicrobial peptide lactoferricin B (LFcin B); but those effects were weak after 8 h. The biofilm formation of P. gingivalis and P. intermedia over 24 h was effectively inhibited by lower concentrations (≥8 μg/ml) of various iron-bound forms (the apo, native, and holo forms) of bLF and hLF but not LFcin B. A preformed biofilm of P. gingivalis and P. intermedia was also reduced by incubation with various iron-bound bLFs, hLF, and LFcin B for 5 h. In an examination of the effectiveness of native bLF when it was used in combination with four antibiotics, it was found that treatment with ciprofloxacin, clarithromycin, and minocycline in combination with native bLF for 24 h reduced the amount of a preformed biofilm of P. gingivalis compared with the level of reduction achieved with each agent alone. These results demonstrate the antibiofilm activity of LF with lower iron dependency against P. gingivalis and P. intermedia and the potential usefulness of LF for the prevention and treatment of periodontal diseases and as adjunct therapy for periodontal diseases.

scholarly journals Role of Arg-Gingipain A in Virulence of Porphyromonas gingivalis

1998 ◽  
Vol 66 (3) ◽  
pp. 1159-1166 ◽  
Author(s):  
Masayuki Tokuda ◽  
Thonthi Karunakaran ◽  
Margaret Duncan ◽  
Nobushiro Hamada ◽  
Howard Kuramitsu
Keyword(s):  
Porphyromonas Gingivalis ◽  
Wild Type Strain ◽  
Type I Collagen ◽  
Northern Blotting ◽  
Type I ◽  
Wild Type ◽  
Self Aggregation ◽  
Wild Type Parent ◽  
Rat Tail

ABSTRACT In order to access the role of the Porphyromonas gingivalis Arg-gingipain proteases in the virulence of this organism, a mutant defective in the rgpA gene was constructed in strain 381. This mutant, MT10, displayed only 40% of the Arg-specific cysteine protease activity of the wild-type strain. In addition, MT10, as well as the recently characterized protease mutant G-102, which is defective in the rgpB gene, displayed reduced self-aggregation, hemagglutination, and the ability to bind to immobilized type I collagen compared to levels of the wild-type parent. However, unlike mutant G-102, the rgpA mutant displayed increased binding to epithelial cells relative to that of the parental organism. Mutant MT10 also did not express detectable levels of the FimA protein as assessed by both Western and Northern blotting or fimbriae visible by electron microscopy of the cells. Furthermore, the ability of MT10 to degrade rat tail collagen fibers when it was cultured at 37°C was markedly attenuated compared to that of strain 381. These results suggest that Arg-gingipain A may play a significant role in the pathogenicity of P. gingivalis by altering the colonization and toxic properties of the organism.

scholarly journals Intracellular Porphyromonas gingivalis Promotes the Tumorigenic Behavior of Pancreatic Carcinoma Cells

Cancers ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2331 ◽  
Author(s):  
JebaMercy Gnanasekaran ◽  
Adi Binder Gallimidi ◽  
Elias Saba ◽  
Karthikeyan Pandi ◽  
Luba Eli Berchoer ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Cancer Cells ◽  
Cell Lines ◽  
Porphyromonas Gingivalis ◽  
Xenograft Model ◽  
Oral Bacteria ◽  
Oral Microbiome ◽  
Human Pancreatic Cancer ◽  
Pancreatic Cancer Cells ◽  
Increased Risk

Porphyromonas gingivalis is a member of the dysbiotic oral microbiome associated with oral inflammation and periodontal disease. Intriguingly, epidemiological studies link P. gingivalis to an increased risk of pancreatic cancer. Given that oral bacteria are detected in human pancreatic cancer, and both mouse and human pancreata harbor microbiota, we explored the involvement of P. gingivalis in pancreatic tumorigenesis using cell lines and a xenograft model. Live P. gingivalis induced proliferation of pancreatic cancer cells; however, surprisingly, this effect was independent of Toll-like receptor 2, the innate immune receptor that is engaged in response to P. gingivalis on other cancer and immune cells, and is required for P. gingivalis to induce alveolar bone resorption. Instead, we found that P. gingivalis survives inside pancreatic cancer cells, a trait that can be enhanced in vitro and is increased by hypoxia, a central characteristic of pancreatic cancer. Increased tumor cell proliferation was related to the degree of intracellular persistence, and infection of tumor cells with P. gingivalis led to enhanced growth in vivo. To the best of our knowledge, this study is the first to demonstrate the direct effect of exposure to P. gingivalis on the tumorigenic behavior of pancreatic cancer cell lines. Our findings shed light on potential mechanisms underlying the pancreatic cancer–periodontitis link.

scholarly journals Inactivation of vimF, a Putative Glycosyltransferase Gene Downstream of vimE, Alters Glycosylation and Activation of the Gingipains in Porphyromonas gingivalis W83

2005 ◽  
Vol 73 (7) ◽  
pp. 3971-3982 ◽  
Author(s):  
Elaine Vanterpool ◽  
Francis Roy ◽  
Hansel M. Fletcher
Keyword(s):  
Porphyromonas Gingivalis ◽  
Wild Type Strain ◽  
Wild Type ◽  
Reading Frame ◽  
Allelic Exchange ◽  
Sugar Moiety ◽  
Defective Mutant ◽  
Porphyromonas Gingivalis W83 ◽  
High Molecular Weight Proteins ◽  
Group 1

ABSTRACT Regulation/activation of the Porphyromonas gingivalis gingipains is poorly understood. A 1.2-kb open reading frame, a putative glycosyltransferase, downstream of vimE, was cloned, insertionally inactivated using the ermF-ermAM antibiotic resistance cassette, and used to create a defective mutant by allelic exchange. In contrast to the wild-type W83 strain, this mutant, designated P. gingivalis FLL95, was nonpigmented and nonhemolytic when plated on Brucella blood agar. Arginine- and lysine-specific gingipain activities were reduced by approximately 97% and 96%, respectively, relative to that of the parent strain. These activities were unaffected by the growth phase, in contrast to the vimA-defective mutant P. gingivalis FLL92. Expression of the rgpA, rgpB, and kgp gingipain genes was unaffected in P. gingivalis FLL95 in comparison to the wild-type strain. In nonactive gingipain extracellular protein fractions, multiple high-molecular-weight proteins immunoreacted with gingipain-specific antibodies. The specific gingipain-associated sugar moiety recognized by monoclonal antibody 1B5 was absent in FLL95. Taken together, these results suggest that the vimE downstream gene, designated vimF (virulence modulating gene F), which is a putative glycosyltransferase group 1, is involved in the regulation of the major virulence factors of P. gingivalis.

scholarly journals Role of vimA in cell surface biogenesis in Porphyromonas gingivalis

Microbiology ◽  
2010 ◽  
Vol 156 (7) ◽  
pp. 2180-2193 ◽  
Author(s):  
Devon O. Osbourne ◽  
Wilson Aruni ◽  
Francis Roy ◽  
Christopher Perry ◽  
Lawrence Sandberg ◽  
...  
Keyword(s):  
Cell Surface ◽  
Outer Membrane ◽  
Porphyromonas Gingivalis ◽  
Type Strain ◽  
Wild Type Strain ◽  
Phenotypic Expression ◽  
Surface Proteins ◽  
Wild Type ◽  
In The Wild

The Porphyromonas gingivalis vimA gene has been previously shown to play a significant role in the biogenesis of gingipains. Further, in P. gingivalis FLL92, a vimA-defective mutant, there was increased auto-aggregation, suggesting alteration in membrane surface proteins. In order to determine the role of the VimA protein in cell surface biogenesis, the surface morphology of P. gingivalis FLL92 was further characterized. Transmission electron microscopy demonstrated abundant fimbrial appendages and a less well defined and irregular capsule in FLL92 compared with the wild-type. In addition, atomic force microscopy showed that the wild-type had a smoother surface compared with FLL92. Western blot analysis using anti-FimA antibodies showed a 41 kDa immunoreactive protein band in P. gingivalis FLL92 which was missing in the wild-type P. gingivalis W83 strain. There was increased sensitivity to globomycin and vancomycin in FLL92 compared with the wild-type. Outer membrane fractions from FLL92 had a modified lectin-binding profile. Furthermore, in contrast with the wild-type strain, nine proteins were missing from the outer membrane fraction of FLL92, while 20 proteins present in that fraction from FLL92 were missing in the wild-type strain. Taken together, these results suggest that the VimA protein affects capsular synthesis and fimbrial phenotypic expression, and plays a role in the glycosylation and anchorage of several surface proteins.

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