Background and Objective: Porphyromonas gingivalis lipopolysaccharide (LPS) is a ligand for cell surface toll-like receptors (TLR), TLR2 and TLR4 while stimulation of either leads to cardioprotection. We hypothesized that: (1) pretreatment with P. gingivalis LPS at appropriate concentrations would i...

E. coli lipopolysaccharide (LPS) induces cytokine and adhesion molecule expression via the toll-like receptor 4 (TLR4) signaling complex in human endothelial cells. In the present study, we investigated the mechanism by which Porphyromonas gingivalis LPS antagonizes E. coli LPS-dependent activation ...

Colonization of the gingival crevice by black-pigmented Porphyromonas or Prevotella spp. (BP/P), including Porphyromonas gingivalis (formerly Bacteroides gingivalis) and Prevotella intermedia (formerly Bacteroides intermedius), is thought to be an important ecological event which may result in the d...

Objective: Although the exact reason is not known, encapsulated gram-negative Porphyromonas gingivalis strains are more virulent than non-encapsulated strains. Since difference in virulence properties may be due to difference in cytokine production following recognition of the bacteria or their products by the host inflammatory cells, we compared cytokine production following stimulation with bacteria or lipopolysaccharides (LPS) of a non-encapsulated and an encapsulated P. gingivalis strain (K^- and K1). Design: Tumour necrosis factor-alpha (TNF-@a) production following stimulation of the cell-line Mono Mac 6 with bacteria or LPS of both P. gingivalis strains was determined using flow cytometry. Furthermore, we investigated the effects of the two P. gingivalis strains or their LPS on TNF-...

Ethnopharmacological relevanceAcanthopanax senticosus (Rupr. & Maxim.) Harms (AS) has been used as a traditional medicine for the treatment of hypertension, rheumatism, ischemic heart disease, diabetes, and hepatitis in East Asia. This herb has been reported to possess anti-cancer, anti-diabetes, and anti-inflammatory properties. Aim of the studyTo examine the anti-inflammatory activity of AS extract (ASE) and its mechanism of action in Porphyromonas gingivalis lipopolysaccharide (P. gingivalis LPS)-stimulated macrophages. Materials and methodsP. gingivalis LPS was used to induce an inflammatory response in the murine macrophage cell line RAW 264.7. Pro-inflammatory cytokines were measured by using an enzyme-linked immunosorbent assay. We used western blot assays and real-time quan...

Porphyromonas gingivalis, Treponema denticola, and Tannerella forsythia are periodontal pathogens associated with the etiology of adult periodontitis as polymicrobial infections. Recent studies demonstrated that oral infection with P. gingivalis induces both periodontal disease and atherosclerosis i...

Lipopolysaccharide (LPS) from Porphyromonas gingivalis, an oral Gram-negative bacterium, acts as a virulence factor for periodontal disease. Although P. gingivalis LPS does not induce proinflammatory cytokines as strongly as Escherichia coli LPS, it is still able to exploit negative Toll-like receptor (TLR) regulatory pathways and facilitate pathogen persistence. Recent reports suggest that microRNAs (miRNAs) are also involved in the regulation of TLR signaling. Here, we demonstrate that P. gingivalis LPS strongly induces miRNA-146a expression in THP-1 cells and THP-1-derived macrophages. However, the inhibition or overexpression of miR-146a, through the transfection of a specific inhibitor or precursor, respectively, had little effect on cytokine production in macrophages stimulated with P. gingivalis LPS. Moreover, the expression of interleukin-1 associated-kinase-1 (IRAK-1) and tumor-necrosis factor (TNF) receptor-associated factor-6 (TRAF6), potential target molecules of miR-146a, were not affected by the stimulation with P. gingivalis LPS. Because TLR signaling induces various negative regulators, these results call into question the role of miR-146a in cells stimulated with TLR ligands. PMID:22480686

To characterize the roles of Porphyromonas gingivalis and its components in disease processes, we investigated the cytokine profiles induced by live P. gingivalis, its lipopolysaccharide (LPS), and its major fimbrial protein, fimbrillin (FimA). A cytokine antibody array revealed that human monocyte-derived macrophages were induced to produce chemokines (e.g., monocyte chemoattractant protein 1, macrophage inflammatory protein 1beta [MIP-1beta], and MIP-3alpha) as early as 1 h after exposure to P. gingivalis, with production declining after 24 h of exposure. As expected, an extensive repertoire of inflammatory mediators increased subsequent to infection, most predominantly tumor necrosis factor alpha (TNF-alpha), interleukin 1beta (IL-1beta), IL-6, IL-10, and granulocyte-macrophage colony-stimulating factor. The induction of cytokines by P. gingivalis was not triggered simply by bacterial cell surface components, since purified P. gingivalis LPS and FimA induced similar patterns of cytokines, while the pattern of cytokines induced by live P. gingivalis was significantly different, indicating that the host defense system senses live bacteria differently than it does the cell surface components LPS and FimA. To further understand the mechanisms by which live P. gingivalis and its components exert their effects, we used a high-throughput immunoblot screening approach (Becton-Dickinson PowerBlot) to analyze intracellular proteins involved in P. gingivalis infection in human macrophages. Exposure of human macrophages to either live P. gingivalis, its LPS, or its FimA protein led to the up-regulation of 12, 8, and 10 proteins and the down-regulation of 15, 8, and 17 proteins, respectively. The expression of proteins involved in gene transcription (e.g., monocyte enhancer factor 2D [MEF2D], signal transducer and activator of transcription 1 [STAT1], STAT3, STAT6, and IL enhancer binding factors [ILF3]), of protein kinases (e.g., mitogen-activated protein kinase 3 [MAPK3], MAP3K8, double-stranded RNA-activated protein kinase [PRKR], and MAP2K4), and of proteins involved in immune responses (e.g., TNF super family member 6 [TNFSF6] and interferon-induced protein with tetratricopeptide repeat 4 [IFIT4]), apoptosis (e.g., genes associated with retinoid interferon-induced mortality 19 [GRIM19]), and other fundamental cellular processes (e.g., clathrin heavy-chain polypeptide, culreticulin, and Ras-associated protein RAB27A) was found to be modulated differentially by P. gingivalis, LPS, and FimA. These differential changes are interpreted as preferential signal pathway activation in host immune/inflammatory responses to P. gingivalis infection. PMID:16428770

Abstract in spanish El objetivo de este trabajo fue mejorar un método estándar para la purificación de lipopolisacárido (LPS) de Porphyromonas gingivalis libre de polisacáridos usando una estrategia de extracción, digestión enzimática y cromatografía de alta resolución. La bacteria P. gingivalis se cultivó en condiciones de anaerobiosis y se hizo extracción de las membranas con el método de fenol-agua. Luego de una digestión enzimática (DNAsa, RNAsa y proteasa) se separó el e (more) xtracto por filtración por gel con Sephacryl S-200. La muestra purificada se caracterizó por electroforesis en gel de acrilamida con tinción de plata y por el método Purpald se detecto el ácido 2-ceto-3-desoxioctu-losónico (KDO). Se obtuvo una preparación libre de ácidos nucleicos, proteínas y polisacáridos. La separación por cromatografía fue de alta resolución al permitir la obtención de dos picos con diferentes componentes. El protocolo de purificación nos permitió obtener LPS de P. gingivalis con alto grado de pureza, el cual podría ser usado en próximos ensayos para evaluar su función en ensayos in vitro e in vivo; así como iniciar la obtención de LPS de otras bacterias periodontopáticas, con el fin de investigar la asociación de enfermedad periodontal con enfermedades cardiovasculares. Abstract in english The aim of this work was to improve a standard methodology to purify Porphyromonas gingivalis lipopolysaccharide (LPS) using a protocol of extraction, enzymatic digestion and high resolution chromatography. P. gingivalis bacteria was cultured in anaerobiosis, their membranes were extracted using the phenol-water method, then subjected to DNAse, RNAse and protease digestion and finally, the extract was separated by chromatography using Sephacryl S-200. The purified extract (more) was characterized by silver staining after polyacrylamide gel electrophoresis and 2-keto-3-deoxioctanoic acid (KDO) was detected using the Purpald?s method. A preparation free of nucleic acid-, protein-or polysaccharides was obtained. The chromatographic separation showed high resolution since there was two discrete peaks with different components. The purification protocol allowed us to obtain a highly purified P. gingivalis LPS which could be used in future tests to evaluate its behavior in vitro and in vivo and elucidate its function, as well as to obtain LPS from other periodontopatic bacteria to address the association of periodontal disease with cardiovascular diseases.

One of the predominant polymicrobial infections of humans is expressed clinically as periodontal disease. Porphyromonas gingivalis, Treponema denticola, and Tannerella forsythia have been strongly implicated as members of a pathogenic consortium in the etiology of adult periodontitis. In this study ...

Aqueous extracts from 8 plants used for tooth-cleaning in Nigeria were tested for their ability to inhibit the growth of five periodontopathic bacteria, Porphyromonas gingivalis, Prevotella intermedia, Fusobacterium nucleatum, Eikenella corrodens and Campylobacter rectus. Extracts of all the plants ...

Tobacco smoking is a significant risk factor for periodontal diseases. Nicotine, one of the most studied constituents in cigarette smoke, is thought to modify immune responses. Dendritic cells (DCs), which are key mediators between innate and adaptive immunity, stimulate naive T cells to differentiate to effector T-cell subsets that may be actively involved in the immunopathogenesis of periodontal diseases. In this study, we evaluated the effects of nicotine and lipopolysaccharide (LPS) from Porphyromonas gingivalis, alone and in combination, on the functions of human monocyte-derived DCs to elucidate the mechanism of tissue destruction of smoking-associated periodontal diseases. P. gingivalis LPS-stimulated DCs differentiated with nicotine (NiDCs) induced lower T-cell proliferation and human leukocyte antigen (HLA)-DR expression, but elevated expression of programmed cell death ligand 1. Additionally, NiDCs impaired interferon-? production but maintained interleukin (IL)-5 and IL-10 production in co-cultured T cells. Furthermore, NiDCs produced lower levels of proinflammatory cytokines compared with DCs differentiated in the absence of nicotine. Interestingly, NiDCs preferentially produced the T helper 2 (Th2)-type chemokines macrophage chemotactic protein-1 and macrophage-derived chemokine. These results suggest that the presence of nicotine during differentiation of DCs modulates the immunoregulatory functions of P. gingivalis LPS-stimulated DCs. PMID:22984998

Black-pigmented anaerobic bacteria, such as Porphyromonas gingivalis and Prevotella intermedia, are amongst the predominant bacteria in periodontal pockets and have been implicated in periodontal diseases. To elucidate the roles of gingival keratinocytes, which are the first cells encountered by oral bacteria in periodontal diseases, human gingival keratinocytes in primary culture were stimulated with cell-surface components of P gingivalis and Pr. intermedia. A glycoprotein fraction from Pr. intermedia (PGP) clearly augmented the release of interleukin-8, granulocyte colony-stimulating factor and granulocyte-macrophage colony-stimulating factor, as determined by enzyme-linked immunosorbent assay. This PGP also induced expression of intercellular adhesion molecule-1 (ICAM-1), as determined by flow cytometry. The augmentation of mRNA expression for these molecules was also confirmed by reverse transcription PCR. In contrast, lipopolysaccharide (LPS) from Pr. intermedia and Escherichia coli was completely inactive in these assays. LPS fraction and purified fimbriae from P gingivalis exhibited weak activities. Cytokine production and ICAM-1 expression by gingival keratinocytes might cause accumulation and activation of neutrophils in the epithelium and, therefore, may be involved in the initiation and development of inflammation in periodontal tissues. PMID:11800468

ABSTRACT: BACKGROUND: Periodontitis, the most prevalent chronic inflammatory disease, has been related to cardiovascular diseases. Autophagy provides a mechanism for the turnover of cellular organelles and proteins through a lysosome-dependent degradation pathway. The aim of this research was to study the role of autophagy in peripheral blood mononuclear cells from patients with periodontitis and gingival fibroblasts treated with a lipopolysaccharide of Porphyromonas gingivalis. Autophagy-dependent mechanisms have been proposed in the pathogenesis of inflammatory disorders and in other diseases related to periodontitis, such as cardiovascular disease and diabetes. Thus it is important to study the role of autophagy in the pathophysiology of periodontitis. METHODS: Peripheral blood mononuclear cells from patients with periodontitis (n = 38) and without periodontitis (n = 20) were used to study autophagy. To investigate the mechanism of autophagy, we evaluated the influence of a lipopolysaccharide from P. gingivalis in human gingival fibroblasts, and autophagy was monitored morphologically and biochemically. Autophagosomes were observed by immunofluorescence and electron microscopy. RESULTS: We found increased levels of autophagy gene expression and high levels of mitochondrial reactive oxygen species production in peripheral blood mononuclear cells from patients with periodontitis compared with controls. A significantly positive correlation between both was observed. In human gingival fibroblasts treated with lipopolysaccharide from P. gingivalis, there was an increase of protein and transcript of autophagy-related protein 12 (ATG12) and microtubule-associated protein 1 light chain 3 alpha LC3. A reduction of mitochondrial reactive oxygen species induced a decrease in autophagy whereas inhibition of autophagy in infected cells increased apoptosis, showing the protective role of autophagy. CONCLUSION: Results from the present study suggest that autophagy is an important and shared mechanism in other conditions related to inflammation or alterations of the immune system, such as periodontitis. PMID:23075094

Summary Periodontitis is an inflammatory bone disease caused by Gram-negative anaerobic bacteria. Osteoclast differentiation is regulated by the balance between receptor activator of nuclear factor kappa B ligand (RANKL) and osteoprotegerin (OPG). The purpose of this study was to examine the mechanism of OPG production in human gingival fibroblasts (HGF) stimulated by lipopolysaccharide (LPS) from periodontopathic bacteria. The expressions of Toll-like receptor 2 (TLR-2) and TLR-4 in HGF were examined using flow-cytometry. HGF were stimulated with whole cell extracts or LPS from Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis with or without polymyxin B, a LPS inhibitor. In addition, HGF were stimulated with LPS, prostaglandin E2 (PGE2), various agonists of PGE receptors ...

Background: Collinin is a secondary plant metabolite belonging to the class of geranyloxycoumarins. We explored the potential beneficial impact of collinin on periodontal health by investigating its effect on Porphyromonas gingivalis, LPS-induced inflammatory response of macrophages, and osteoclastogenesis. Methods: Collinin was synthesized from pyrogallol and propiolic acid. A microdilution assay was used to determine antibacterial activity of collinin. The effect of collinin on collagenase activity of P. gingivalis was determined using fluorescent collagen. Macrophages were treated with collinin prior to being stimulated with lipopolysaccharide (LPS). The secretion of interleukin 6, chemokine (C-C motif) ligand 5 and prostaglandin E(2) was assessed by enzyme-linked immunosorbent assays (ELISA). The inhibitory effect of collinin on differentiation of human pre-osteoclastic cells was assessed by tartrate-resistant acid phosphatase (TRAP) staining, while the secretion of matrix metalloproteinase-9 (MMP-9) was measured by ELISA. Bone resorption activity was investigated by using a human bone plate coupled with an immunoassay that detected the release of collagen fragments. Results: Collinin inhibited the growth of P. gingivalis. The effect was more pronounced under iron-restricted conditions. Collinin dose-dependently inhibited the degradation of type I collagen by P. gingivalis. It was also a potent inhibitor of the LPS-induced inflammatory response in macrophages and completely inhibited receptor activator of nuclear factor kappa-B ligand-dependent osteoclast differentiation and MMP-9 secretion. Lastly, collinin affected bone degradation mediated by mature osteoclasts by significantly decreasing the release of collagen helical peptides. Conclusion: Although clinical trials are required, data from these in vitro analyses support the potential of collinin as a therapeutic agent for treating inflammatory periodontitis associated with bone destruction. PMID:22897650

Numerous studies have suggested an association between periodontal disease and atherosclerosis. Porphyromonas gingivalis has been thought to be one of triggers of atherosclerosis because P. gingivalis DNA is detected in atheromatous plaques. In this study, we assessed the effect of P. gingivalis on endothelial cells to elucidate the mechanisms in P. gingivalis-accelerated atherosclerosis. Our results showed that P. gingivalis infection significantly increased the production of interleukin-8 and monocyte chemoattractant protein-1 in human umbilical vein endothelial cells (HUVEC) compared with cells without bacteria. In addition, P. gingivalis challenge upregulated the expression levels of intercellular adhesion molecule-1, vascular cell adhesion molecule-1, and E-selectin in HUVEC at both the mRNA and protein levels. These results suggest that P. gingivalis stimulation induces increases in inflammatory cytokines and adhesion molecules in endothelial cells that in turn lead to the development of atheromatous plaques.   

Porphyromonas gingivalis is a Gram-negative, anaerobic bacterium involved in periodontitis and peri-implantitis that can invade and survive inside host cells in vitro. P. gingivalis can invade human gingival fibroblasts (GF), but no data are available about the role of P. gingivalis? capsule in GF invasion. In the current study, we aimed to determine the ability of three strains of P. gingivalis (encapsulated wild type W83, non-encapsulated HG91 and the non-encapsulated insertional isogenic knockout mutant of W83, ?EpsC) to invade GF and the ability of internalized P. gingivalis to survive in vitro antibiotic treatment. The ability of P. gingivalis strains to invade GF was tested using an antibiotic protection assay at multiplicity of infection (MOI) 100 and 1000. The survival of internali...

Porphyromonas gingivalis is a major pathogen in adult periodontitis. Fimbriae play an important role in the initial interaction between the bacteria and the host. Our earlier studies suggested that the oligosaccharide moiety of lactoferrin is involved in the interaction with fimbriae. Porphyromonas gingivalis fimbriae bound strongly to albumin-fucosylamide (albumin-1-amido-1-deoxy-L-fucose) and to a lesser extent to albumin-N-acetyl-D-galactosamine (albumin-p-aminophenyl-N-acetyl-?-D-galactosaminide, but failed to bind bovine serum albumin. In this study we explored the glycan array to determine the carbohydrate-binding specificity of P. gingivalis fimbriae. Purified fimbriae bind to glycans which have a Lewis(x), Gal?1-4(Fuc?1-3) GlcNAc? structure in common. Interestingly, all glycans have a terminal fucose moiety and if fucose is removed, the fimbriae fail to bind. This is the first study that suggests that fucose is important for P. gingivalis fimbriae binding. PMID:22577836

We isolated oral bacteria that coexisted with Porphyromonas gingivalis in a hamster periodontitis model. As predominant bacteria in the periodontitis site, Collinsella-reltaed strains, Eubacterium-reltaed strains, Streptococcus suis-related strains, and Veillonella parvula-reltaed strains were detected. In addition, Actinomyces, Bacteroides, and P. gingivalis were also isolated predominantly. The results suggest that the bacterial composition of the periodontitis site in hamsters is complex, as in human periodontitis.   

Summary Porphyromonas gingivalis has been implicated as a major pathogen associated with chronic periodontitis. To extend our knowledge of post-translational protein glycosylation in P.--gingivalis, a proteomic analysis involving two-dimensional polyacrylamide gel electrophoresis combined with carbohydrate staining and mass spectrometry was performed. Four novel glycoproteins, PGN0743, PGN0876, PGN1513 and PGN0729, in P.gingivalis ATCC 33277 were identified. These four identified glycoproteins possess a range of biochemical activities and cellular localization. PGN0743 contains a sequence motif identifying it as a FKBP-type cis-trans isomerase, which has activity usually associated with chaperone functions. PGN0876 and PGN1513 contain tetratricopeptide repeat domains that mediate protein-p...

Abstract Aim: Identification of anti-adhesive plant extracts against cell surface binding of Porphyromonas gingivalis and underlying mechanisms; investigation of potential cytoprotective effects of anti-adhesive extract on KB cells. Materials and Methods: Polyphenol-enriched extract, fully characterized concerning flavan-3-ols and oligomeric proanthocyanidins, from Myrothamnus flabellifolia (MF), traditionally used for periodontitis, was tested for inhibition of P. gingivalis-mediated adhesion to KB cells by flow cytometry, for influence on gingipain activity (protease assay), haemagglutination and by microarray analysis for effects on bacterial transcriptome. The influence of MF on P. gingivalis-induced cytokine gene expression was monitored by RT-PCR and IL-6 titres by ELISA. Results: MF...

Oral Diseases (2012) 18, 586-594 Objective:- To assess the effect of two oral bacteria Streptococcus sanguinis and Porphyromonas gingivalis upon platelet aggregation. Materials and Methods:- Streptococcus sanguinis, P.gingivalis, S.sanguniis-+-P.gingivalis were added to platelet-rich plasma and platelet aggregation measured using a platelet aggregometer. Platelets were passed through a flow chamber with S.sanguinis, P.gingivalis or a biofilm of S.sanguinis and P.gingivalis coated with saliva. Platelet adhesion to the chamber was observed under a fluorescence microscope for 15-min. The positive control was platelets treated with adrenaline; the negative control was platelets treated with phosphate-buffered saline. Results:- The mean ( s.e.) aggregation magnitude of S.sanguinis and P.gingiva...

Porphyromonas gingivalis cysteine proteinases (gingipains) have been associated with virulence in destructive periodontitis, a disease process variously considered to represent an unregulated stimulation of either T helper type 1 (Th1)- or Th2-type cells. Critical in maintaining Th1 activity is the ...

Porphyromonas gingivalis is a gram-negative, obligate anaerobe strongly associated with chronic adult periodontitis. A previous study has demonstrated that this organism requires superoxide dismutase (SOD) for its modest aerotolerance. In this study, we have constructed a mutant deficient in SOD act...

  A perilla seed (Perilla frutescens Britton var. japonica Hara) extract was examined for its antimicrobial activity against oral cariogenic streptococci and periodontopathic Porphyromonas gingivalis. Luteolin, one of the components of perilla seed, showed the strongest antimicrobial effect among the phenolic compounds. According to our results, perilla seed may be the source of an antimicrobial agent that could prevent dental caries and periodontal diseases.   

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 me...

A chemically defined medium, OMIZ (Oral Microbiology and Immunology, Zürich)-W1 was developed. Medium OMIZ-W1 supports the long-term proliferation of a wide range of oral anaerobes, including representative strains of four Treponema species and Porphyromonas gingivalis. High concentrations of ascorb...

BACKGROUND/PURPOSE: Epigenetic alterations such as DNA methylation and histone acetylation are described as changes in the pattern of gene expression not involving the DNA sequence. Lipopolysaccharide (LPS) derived from Porphyromonas gingivalis has been shown to inhibit osteoblastic cell differentiation. We examined whether DNA hypermethylation was involved in the inhibitory effect of LPS on osteoblastic differentiation of fibroblasts derived from human periodontal ligament (HPDL). METHODS: The HPDL cells were incubated with LPS derived from P. gingivalis at a concentration of 10 ?g/ml for 24 h. The cells were treated with DNA methyltransferase inhibitor 5-Aza-2'-deoxycytidine (5Aza). Untreated cells were used as a control. Cell viability was determined using cell proliferation reagent. DNA methyltransferase (DNMT1) and runt-related transcription factor 2 (RUNX2) mRNAs were evaluated by quantitative polymerase chain reaction (RT-PCR). Analysis of RUNX2 DNA methylation was performed using quantitative methylation-specific PCR. RESULTS: The expression level of RUNX2 was significantly lower in the cells stimulated with LPS than the controls. The presence of 5Aza increased the expression of RUNX2 in cells stimulated with LPS. The expression levels of DNMT1 mRNA in the cells stimulated with LPS were significantly higher than in the control. The presence of 5Aza completely abolished the upregulated expression of DNMT1 in cells stimulated with LPS. The methylation of DNA at 0.1 kb and -1.9 kb in the cells stimulated with LPS was significantly higher than the control. CONCLUSION: The results indicate that DNA hypermethylation may be involved in the inhibitory effect of LPS on osteoblastic differentiation in HPDL. PMID:23010540

The purpose of our study was to examine if lipopolysaccharide (LPS) from Porphyromonas gingivalis (P.g.) modifies the vasomotor responses to Endothelin-1 (ET-1) and Sarafotoxin 6c (S6c) in rat coronary arteries. The arteries were studied directly or following organ culture for 24 h in absence and presence of 2.5EU/ml LPS. The contractile responses of coronary arteries were investigated by using the selective ETB receptor agonist S6c (1 pM-0.3 µM) and ET-1 (1 pM-0.3 µM). The functional studies demonstrated an augmented contractile response only to S6c in isolated rat coronary arteries after organ culture (with or without LPS). These contractile responses by S6c were blocked by the selective ETB receptor antagonist BQ788 in both vessel groups. The augmented contractile response to S6c was supported by immunohistochemistry, where a significant increase in fluorescence intensity for ETB receptors in smooth muscle cells was observed after organ culture. The presence of LPS in the culture medium significantly increased the sensitivity of endothelium-intact coronary artery to S6c as compared to endothelium-denuded segments. Our results showed a significant increase in both ETB receptor protein levels and S6c-induced maximal contraction in coronary arteries upon 24 h of organ culture, which was further sensitized by LPS.

Jeong E, Lee J-Y, Kim S-J, Choi J. Predominant immunoreactivity of Porphyromonas gingivalis heat shock protein in autoimmune diseases. J Periodont Res 2012; 47: 811-816. © 2012 John Wiley & Sons A/S Background and Objective:? Autoimmune diseases, including atherosclerosis, diabetes mellitus and rheumatoid arthritis, can be triggered and aggravated by the pathogen-driven antigenic peptide from Porphyromonas gingivalis HSP60. P. gingivalis is the major pathogen of chronic periodontitis, which is a global epidemic prevalent in two-thirds of the adult population. The monoclonal antibody raised against peptide 19 (Pep19: TLVVNRLRGSLKICAVKAPG) from P. gingivalis HSP60 was polyreactive to the human homolog. The aim of this study was to determine if Pep19 from P. gingivalis HSP60 manifests itself as a predominant antigen in infection-triggered autoimmune diseases. Material and Methods:? Pep19 from P. gingivalis HSP60, Mycobacterium tuberculosis HSP60 and Chlamydia pneumoniae HSP60 was synthesized for comparative recognition by the sera from patients with atherosclerosis, type 2 diabetes and rheumatoid arthritis, all with ongoing periodontal disease, and by the sera of a control group of patients with periodontal disease but with no history of atherosclerosis, type 2 diabetes or rheumatoid arthritis. Results:? Of the Pep19 peptides from P. gingivalis HSP60, M. tuberculosis HSP60 and C. pneumoniae HSP60, Pep19 from P. gingivalis HSP60 was the peptide epitope predominantly and most consistently recognized by the serum samples of the four disease groups (chronic periodontitis, atherosclerosis, type 2 diabetes mellitus and rheumatoid arthritis). Conclusion:? Seroreactivity to Pep19 of P. gingivalis HSP60, an oral pathogen, was predominant in patients with autoimmune disease with ongoing periodontal disease. PMID:22812430

Summary Porphyromonas gingivalis, Treponema denticola, and Tannerella forsythia are consistently associated with adult periodontitis. This study sought to document the host transcriptome to a P.gingivalis, T.denticola, and T.forsythia challenge as a polymicrobial infection using a murine calvarial model of acute inflammation and bone resorption. Mice were infected with P.gingivalis, T.denticola, and T.forsythia over the calvaria, after which the soft tissues and calvarial bones were excised. A Murine GeneChip array analysis of transcript profiles showed that 6997 genes were differentially expressed in calvarial bones (P-P.gingivalis, T.denticola, or T.forsythia. To our knowledge, this is the first definition of the polymicrobially induced transcriptome in calvarial bone and soft tissue in ...

Porphyromonas gingivalis, one of the major pathogen associated with periodontitis, is a highly proteolytic bacterial species. Production of proteases is a common microbial virulence factor that enables the destruction of host tissues and evasion from host defense mechanisms. Antimicrobial peptides are important effector molecules of the innate immune system with a broad range of antimicrobial and immunoregulatory activities. We and others have previously demonstrated that P. gingivalis is relatively resistant to the bactericidal activity of the human b-defensin 3 (hBD3). In this study, ability of proteases released by the pathogenic strain of P. gingivalis ATCC 49417 to degrade hBD3 and to affect the antibacterial properties of the peptide was assessed. P. gingivalis culture supernatants (...

Abstract in spanish Entre las bacterias relacionadas con la enfermedad periodontal, existen dos especies más claramente asociadas a esta enfermedad: Actinobacillus actinomycetemcomitans y Porphyromonas gingivalis. Este trabajo es una revisión bibliográfica sobre estos dos patógenos periodontales, mostrando su origen, prevalencia, distribución, transmisión y respuesta al tratamiento periodontal. Abstract in english Among the bacteria related to periodontal disease, there are two species clearly associated to this disease: Actinobacillus actinomycetemcomitans and Porphyromonas gingiva lis. This paper presents a review of the literature regarding this two periodontal pathogens, and showing their origin, prevalence, distribution, transmission and response to periodontal treatment.

In periodontitis, a common chronic inflammatory condition, gram-negative-rich bacterial biofilms trigger, in susceptible individuals, perpetuating inflammation that results in extensive tissue damage of tooth supporting structures. To delineate immune cell-dependent mechanisms whereby bacterial challenge drives persistent destructive inflammation in periodontitis and other inflammatory diseases, we studied involved tissues ex vivo and investigated host cell responses to the periodontal pathogen Porphyromonas gingivalis, in vitro. Diseased lesions were populated by abundant Th17 cells, linked to infection, chronic inflammation/autoimmunity and tissue pathology. In vitro, P. gingivalis, particularly the more virulent strain W83, stimulated myeloid antigen presenting cells (APC) to drive Th17...

Asahi Y, Noiri Y, Igarashi J, Asai H, Suga H, Ebisu S. Effects of N-acyl homoserine lactone analogues on Porphyromonas gingivalis biofilm formation. J Periodont Res 2009; doi: 10.1111/j.1600-0765.2009.01228.x Copyright 2009 John Wiley &Sons A/S Background and Objective: The gram-negative anaerobic rod Porphyromonas gingivalis in oral biofilms is a primary etiological agent of periodontal disease. Biofilm formation of various gram-negative bacteria is regulated by a quorum-sensing circuit that relies on N-acyl homoserine lactones (HSLs). Some synthetic N-acyl HSL analogues act as quorum-sensing inhibitors and suppress biofilm formation in Pseudomonas aeruginosa. Development of chemical control agents against oral biofilms is necessary, because until now, biofilms have been removed only by m...

The aim of this study was to investigate the correlation between endodontic clinical signs and symptoms and the presence of Porphyromonas gingivalis, Treponema denticola, and Tannerella forsythia or their association by nested polymerase chain reaction assay. Microbial samples were taken from 50 cases with necrotic pulp tissues in primary infections. DNA was extracted from the samples, which were analyzed for the presence of three endodontic pathogens by using species-specific primers. P gingivalis, T denticola, and T forsythia were detected in 46%, 38%, and 22% of the symptomatic cases, respectively. The bacterial complex composed by T forsythia, P gingivalis, and T denticola was found in 14% of the cases with spontaneous pain, tenderness to percussion, swelling, and pain on palpation. Th...

Summary Porphyromonas gingivalis has been associated with subgingival biofilms in adult periodontitis. However, the molecular mechanisms of its contribution to chronic gingival inflammation and loss of periodontal structural integrity remain unclear. This investigation aimed to examine changes in the host transcriptional profiles during a P. gingivalis infection using a murine calvarial model of inflammation and bone resorption. P. gingivalis FDC 381 was injected into the subcutaneous soft tissue over the calvaria of BALB/c mice for 3 days, after which the soft tissues and calvarial bones were excised. RNA was isolated from infected soft tissues and calvarial bones and was analysed for transcript profiles using Murine GeneChip arrays to provide a molecular profile of the events that occur ...

Summary The VimA protein of Porphyromonas gingivalis is a multifunctional protein involved in cell surface biogenesis. To further determine if its acetyl coenzyme A (acetyl-CoA) transfer and putative sorting functions can affect the secretome, its role in peptidoglycan biogenesis and effects on the extracellular proteins of P.gingivalis FLL92, a vimA-defective mutant, were evaluated. There were structural and compositional differences in the peptidoglycan of P.gingivalis FLL92 compared with the wild-type strain. Sixty-eight proteins were present only in the extracellular fraction of FLL92. Fifteen proteins present in the extracellular fraction of the parent strain were missing in the vimA-defective mutant. These proteins had protein sorting characteristics that included a C-terminal motif ...

Aims: Progression of diabetes-associated periodontal destruction and the roles of advanced glycation end-products (AGEs) were investigated. Materials and methods: Diabetes was induced by streptozocotin injection, and periodontitis was induced via silk ligature placement with Porphyromonas gingivalis lipopolysaccharide injection in 64 Sprague-Dawley rats for 7-21 days. The quality of alveolar bone and attachment loss was measured by micro-computed tomography and histology. Destruction profiles were evaluated by histology, histochemistry, immunohistochemistry, and quantitative assessments of inflammatory cells, expression of receptors for AGEs (RAGE), tartrate-resistant acid phosphatase (TRAP), and proliferating cell nuclear antigen (PCNA). Results: Without periodontitis induction, there was no obvious morphological change in the periodontium, although slight elevations of AGEs and RAGE levels were noted in diabetic animals. In the experimental periodontitis group, significant periodontal bone loss was noted in both diabetic and non-diabetic animals from day 7, with more progressive bone loss in diabetic animals during days 14-21. Histologically, the disruption of attachment and inflammation were observed from day 7, but subsequently subsided in non-diabetic animals. A stronger and more prolonged response with significant attachment loss was observed in diabetic animals. Stronger inflammation, attenuated and persistent resorptive activity and weaker proliferating potential were demonstrated by diabetic animals. AGE deposition and RAGE expression were noted in non-diabetic periodontitis animals, although levels were considerably elevated in the later stages in diabetic animals. Conclusion: Diabetes augments periodontal destruction by reducing the proliferating capability and activating resorptive activities. Presence of the AGE-RAGE axis without diabetes implies that it is involved in the regulation of inflammation. PMID:22554295

This study seeks to access the potential of a heat-killed recombinant Lactobacillus casei expressing 40-kDa outer membrane protein of Porphyromonas gingivalis (L. casei/40k-OMP) as a nasal vaccine against P. gingivalis infection. The 40-kDa outer membrane protein of P. gingivalis (40k-OMP) were expressed on the surface of L. casei using poly-?-glutamate symthetase A (pgsA). Nasal immunization with heat-killed L. casei/40k-OMP induced significant 40k-OMP-specific serum IgG, IgA and saliva IgA antibody responses. Antibody-forming cell analysis revealed high numbers of 40k-OMP-specific IgA antibody-forming cells in the submandibular glands of mice given heat-killed L. casei/40k-OMP. Importantly, nasal administration of heat-killed L. casei/40k-OMP resulted in the significant reduction of alveolar bone loss caused by oral infection with P. gingivalis. Because L. casei is one of major probiotic bacterias, nasal administration of heat-killed L. casei/40k-OMP should be an effective and safe mucosal vaccine for humans against P. gingivalis infection and may be an important tool for prevention of chronic periodontitis.   

ABSTRACT: BACKGROUND: Porphyromonas gingivalis is a Gram-negative anaerobic bacterium associated with periodontal disease onset and progression. Genetic tools for the manipulation of bacterial genomes allow for in-depth mechanistic studies of metabolism, physiology, interspecies and host-pathogen interactions. Analysis of the essential genes, protein-coding sequences necessary for survival of P. gingivalis by transposon mutagenesis has not previously been attempted due to the limitations of available transposon systems for the organism. We adapted a Mariner transposon system for mutagenesis of P. gingivalis and created an insertion mutant library. By analyzing the location of insertions using massively-parallel sequencing technology we used this mutant library to define genes essential for P. gingivalis survival under in vitro conditions. RESULTS: In mutagenesis experiments we identified 463 genes in P. gingivalis strain ATCC 33277 that are putatively essential for viability in vitro. Comparing the 463 P. gingivalis essential genes with previous essential gene studies, 364 of the 463 are homologues to essential genes in other species; 339 are shared with more than one other species. Twenty-five genes are known to be essential in P. gingivalis and B. thetaiotaomicron only. Significant enrichment of essential genes within Cluster of Orthologous Groups 'D' (cell division), 'I' (lipid transport and metabolism) and 'J' (translation/ribosome) were identified. Previously, the P. gingivalis core genome was shown to encode 1,476 proteins out of a possible 1,909; 434 of 463 essential genes are contained within the core genome. Thus, for the species P. gingivalis twenty-two, seventy-seven and twenty-three percent of the genome respectively are devoted to essential, core and accessory functions. CONCLUSIONS: A Mariner transposon system can be adapted to create mutant libraries in P. gingivalis amenable to analysis by next-generation sequencing technologies. In silico analysis of genes essential for in vitro growth demonstrates that although the majority are homologous across bacterial species as a whole, species and strain-specific subsets are apparent. Understanding the putative essential genes of P. gingivalis will provide insights into metabolic pathways and niche adaptations as well as clinical therapeutic strategies. PMID:23114059

Porphyromonas gingivalis, the causative agent of adult periodontitis, must maintain nitric oxide (NO) homeostasis and surmount nitric oxide stress from host immune responses or other oral bacteria to survive in the periodontal pocket. To determine the involvement of a putative hydroxylamine reductase (PG0893) and a putative nitrite reductase-related protein (PG2213) in P. gingivalis W83 NO stress resistance, genes encoding those proteins were inactivated by allelic exchange mutagenesis. The isogenic mutants P. gingivalis FLL455 (PG0893ermF) and FLL456 (PG2213ermF) were black pigmented and showed growth rates and gingipain and hemolytic activities similar to those of the wild-type strain. P. gingivalis FLL455 was more sensitive to NO than the wild type. Complementation of P. gingivalis FLL455 with the wild-type gene restored the level of NO sensitivity to a level similar to that of the parent strain. P. gingivalis FLL455 and FLL456 showed sensitivity to oxidative stress similar to that of the wild-type strain. DNA microarray analysis showed that PG0893 and PG2213 were upregulated 1.4- and 2-fold, respectively, in cells exposed to NO. In addition, 178 genes were upregulated and 201 genes downregulated more than 2-fold. The majority of these modulated genes were hypothetical or of unknown function. PG1181, predicted to encode a transcriptional regulator, was upregulated 76-fold. Transcriptome in silico analysis of the microarray data showed major metabolomic variations in key pathways. Collectively, these findings indicate that PG0893 and several other genes may play an important role in P. gingivalis NO stress resistance. PMID:22247513

Abstract in spanish Antecedentes: La investigación de la microflora subgingival en pacientes diabéticos tipo 2 con periodontitis ha presentado resultados contradictorios. Objetivo: Determinar la presencia de Porphyromonas gingivalis, Tannerella forshytia, Treponema denticola y Aggregatibacter actinomycetemcomitans, en el biofilm subgingival de pacientes diabéticos tipo 2 y relacionarlo con el grado de control metabólico. Método: Estudio descriptivo transversal, en el cual se analizaron (more) 23 pacientes diabéticos derivados consecutivamente del Policlínico de Especialidades de la Universidad de los Andes. Previo consentimiento informado, se realizó un examen clínico periodontal que incluyó mediciones de profundidad al sondaje, nivel de inserción clínica y sangrado gingival. Fueron clasificados según severidad de periodontitis y control metabólico de la diabetes determinado por un promedio de 3 exámenes de hemoglobina glicosilada. La detección microbiológica se realizó mediante la técnica de reacción en cadena de la polimerasa. Resultados: En el grupo de pacientes estudiados, Treponema denticola y Tannerella forsythia fueron las bacterias más prevalentes (65.2%), seguida por Porphyromonas gingivalis (17.3%) y Aggregatibacter actinomycetemcomitans (13%). Los pacientes con peor control glicémico tuvieron una mayor presencia de Treponema denticola, Tannerella forsythia, Porphyromonas gingivalis y Agreggatibacter actinomycetemcomitans y un aumento en el índice de sangrado al sondaje. Conclusiones: En el grupo de pacientes diabéticos estudiado, las bacterias más prevalentes fueron Treponema denticola y Tannerella forsythia. Los pacientes diabéticos tipo 2 con moderado y mal control glicémico presentaron mayor presencia de los microorganismos estudiados, comparado con los grupos con mejores niveles de control glicémico. Abstract in english Background: The investigation of subgingival microflora in type 2 diabetic patients with periodontitis presented conflicting results. Aim: To determine the presence of Porphyromonas gingivalis, Tannerella forshytia, Treponema denticola and Aggregatibacter actinomycetemcomitans in subgingival biofilm of patients with diabetes type 2 and to relate it to the degree of metabolic control. Method: A descriptive study, which analyzed 23 diabetic patients consecutively referred f (more) rom the Internal Medicine Unit of Medicine Faculty at Universidad de los Andes was conducted. After obtaining an informed consent from the patients a clinical examination that included measurements of periodontal pocket depth, clinical attachment level and gingival bleeding was performed. The patients were classified according to the severity of periodontitis and metabolic control of diabetes as determined by an average of 3 of glycosylated haemoglobin tests. Microbial technique was performed by chain reaction of polymerase. Results: In the group of patients examined the most prevalent bacteria were, Treponema denticola and Tannerella forsythia (65.2%), followed by Porphyromonas gingivalis (17.3%) and Aggregatibacter actinomycetemcomitans (13%). Patients with poor glycemic control had a greater presence of Treponema denticola, Tannerella forsythia, Porphyromonas gingivalis and Agreggatibacter actinomycetemcomitans and an increase in the rate of bleeding on probing. Conclusions: In the group of diabetic patients studied, the most prevalent bacteria were Treponema denticola and Tannerella forsythia. Type 2 diabetic patients with moderate and poor glycemic control had a higher presence of these microorganisms, compared to groups with higher levels of glycemic control.

Abstract Enteromorpha linza, a green alga, has been recognized as a potential source of natural antimicrobial and antifungal compounds. We previously reported that an E. linza extract strongly inhibited the growth of Prevotella intermedia and Porphyromonas gingivalis. The principal objective of this study was to evaluate the clinical effect of a mouth rinse containing the E. linza extract on gingivitis disease, as measured by the plaque index (PI), gingival index (GI), and bleeding on probing (BOP), and on two bacterial strains (P. intermedia and P. gingivalis), in comparison with Listerine? (Listerine-Korea, Seoul, Korea), which was used as a positive control. In total, 55 subjects were recruited into active participation in this clinical study. The PI, GI, BOP, and bacterial strains were...

Abstract in english The aim of this study was to evaluate the ability of the BANA Test to detect different levels of Porphyromonas gingivalis, Treponema denticola and Tannerella forsythia or their combinations in subgingival samples at the initial diagnosis and after periodontal therapy. Periodontal sites with probing depths between 5-7 mm and clinical attachment level between 5-10 mm, from 53 subjects with chronic periodontitis, were sampled in four periods: initial diagnosis (T0), immediat (more) ely (T1), 45 (T2) and 60 days (T3) after scaling and root planing. BANA Test and Checkerboard DNA-DNA hybridization identified red complex species in the subgingival biofilm. In all experimental periods, the highest frequencies of score 2 (Checkerboard DNA-DNA hybridization) for P. gingivalis, T. denticola and T. forsythia were observed when strong enzymatic activity (BANA) was present (p

Abstract Generalized aggressive periodontitis (GAgP) is an inflammatory condition resulting in destruction of tooth-supporting tissues. We examined the production of IL-1b, IL-6, tumour necrosis factor (TNF)-a, IL-12 and IL-10 in cultures of peripheral mononuclear cells (MNC) from 10 patients with GAgP and 10 controls stimulated with periodontal pathogens or a control antigen, tetanus toxoid (TT) in the presence of autologous serum. The pathogens used were Porphyromonas gingivalis, Prevotella intermedia and Fusobacterium nucleatum, either as type strains or bacteria isolated from the participants' inherent oral flora. The P. gingivalis -induced production of IL-6 was approximately 2.5-fold higher in patients with GAgP than in healthy controls (P < 0.05), while the corresponding TNF-a produ...

Abstract Objective: To evaluate the potential of 980-nm gallium aluminum arsenide (GaAlAs) and 1064-nm neodymium-doped yttrium aluminum garnet (Nd:YAG) lasers to reduce bacteria after irradiation of implant surfaces contaminated with Enterococcus faecalis and Porphyromonas gingivalis and on irradiated implant surface morphology. Background: Despite the frequency of implant success, some implant loss is related to peri-implantitis because of difficulty in eliminating the biofilm. Methods: Implants (3.75???13?mm) with machined surfaces, surfaces sand blasted with titanium oxide (TiO2), and sand-blasted and acid-etched surfaces were exposed to P. gingivalis and E. faecalis cultures and irradiated with 980-nm GaAlAs or 1064-nm Nd:YAG lasers. After laser treatments, the number of remaining colo...

Aloe vera is a medicinal plant with anti-inflammatory, antimicrobial, antidiabetic and immune-boosting properties. In the present study we investigated the inhibitory activities of Aloe vera gel on some cariogenic (Streptococcus mutans), periodontopathic (Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis) and an opportunistic periodontopathogen (Bacteroides fragilis) isolated from patients with dental caries and periodontal diseases. Twenty isolates of each of these bacteria were investigated for their sensitivity to Aloe vera gel using the disk diffusion and microdilution methods. S. mutans was the species most sensitive to Aloe vera gel with a MIC of 12.5 µg/ml, while A. actinomycetemcomitans, P. gingivalis, and B. fragilis were less sensitive, with a MIC of 25-50 µg/ml (P Aloe vera gel at optimum concentration could be used as an antiseptic for prevention of dental caries and periodontal diseases. PMID:22466882

Objective: Predicting the progression of periodontitis would allow for targeted supportive periodontal therapy. The purpose of this study was to determine the usefulness of salivary biomarkers for predicting the progression of periodontitis. Design: Eighty-five chronic periodontitis patients were enrolled in an 18-month longitudinal study. Amongst them, 57 experienced progression of periodontitis, indicated at the end of the 18 months by at least one site with >3mm loss of attachment compared with baseline. We determined the levels of aspartate aminotransferase, alanine aminotransferase (ALT), lactate dehydrogenase, alkaline phosphatase and free haemoglobin as biomarkers, as well as the counts of Porphyromonas gingivalis, Prevotella intermedia and Tannerella forsythia, which represented th...

Three kinds of interactions occur between ginseng botanicals and microorganisms: a) spoilage of the botanical by various fungi (e.g., Aspergillus, Penicillium, Alternaria, and Eurotium species) and bacteria; b) transformation of ginsenosides into more bioactive forms by bacteria such as Intrasporangium sp. GS603, Microbacterium sp. GS514, Caulobacter leidyia, Bifidobacterium sp. Int57, Bifidobacterium sp. SJ32, Fusobacterium sp. and Bacteroides sp., and moulds (e.g., Aspergillus niger, Fusarium sacchari, Paecilomyces bainier sp. 229, Rhizopus stolonifer, Myrothecium verrucaria and Acremonium strictum); and c) inhibition of certain bacteria (Propionibacterium acnes, Porphyromonas gingivalis, Staphylococcus aureus, Pseudomonas aeruginosa), fungi (Candida albicans, Aspergillus fumigatus, Fusa...

The purpose of this study was to examine the effects of catecholamines on in vitro growth of a range of bacterial species, including anaerobes. Bacteria tested included: Porphyromonas gingivalis, Bacteriodes fragilis, Shigella boydii, Shigella sonnie, Enterobacter Sp, and Salmonella choleraesuis. The results of the current study indicated that supplementation of bacterial cultures in minimal medium with norepinephrine or epinephrine did not result in increased growth of bacteria. Positive controls involving treatment of Escherichia coli with catecholamines did result in increased growth of that bacterial species. The results of the present study extend previous observations that showed differential capability of catecholamines to enhance bacterial growth in vitro.

Abstract Coaggregation assays were performed to investigate interactions between oral Bifidobacterium adolescentis and other oral bacterial species. Bifidobacterium adolescentis OLB6410 isolated from the saliva of healthy humans did not coaggregate with Actinomyces naeslundii JCM8350, Streptococcus mitis OLS3293, Streptococcus sanguinis JCM5708, Veillonella parvula ATCC17745 or Porphyromonas gingivalis OB7124, but it did coaggregate with Fusobacterium nucleatum JCM8532. Subsequent examination of biofilm formation on saliva-coated hydroxyapatite discs using FISH revealed that B. adolescentis OLB6410 could not directly adhere to the coated discs. It did, however, adhere to biofilms of A. naeslundii, V. parvula, and F. nucleatum, although it did not coaggregate with A. naeslundii nor with V. ...

Objectives: The aims of this study were to evaluate periodontal conditions and identify the presence of Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis and Tannerella forsythia, and four different species of Candida (C. albicans, C. dubliniensis, C. glabrata and C. tropicalis) in periodontal pockets and furcation sites of insulin-dependent type 2 diabetic and non-diabetic patients with generalised chronic periodontitis. Design: Clinical parameters, including oral status assessed using plaque index, gingival index, probing depth, gingival recession and clinical attachment level and systemic conditions with fasting glucose level or glycosylated haemoglobin were measured in diabetic and non-diabetic patients with chronic periodontitis. Samples of subgingival biofilm were obtai...

Abstract Purpose: Prevention of peri-implantitis is essential for the success of implant rehabilitation. Infection by periodontopathic bacteria is a major cause of peri-implantitis. The aim of the present study was to identify the source of peri-implant colonization by periodontopathic bacteria. Materials and Methods: Twenty-one patients with implants were enrolled in the study. Subgingival plaque samples from the adjacent, occluding, and contralateral natural teeth were collected prior to second-stage surgery. Samples from implant sulci were then obtained 2 weeks later. Detection of periodontopathic bacteria was performed by the polymerase chain reaction. Results: The detection rates for Aggregatibacter actinomycetemcomitans, Prevotella intermedia, Porphyromonas gingivalis, Treponema dent...

BackgroundChronic inflammation in periodontal disease has been suggested as a potential risk factor in Alzheimer's disease (AD). The purpose of this study was to examine serum antibody levels to bacteria of periodontal disease in participants who eventually converted to AD compared with the antibody levels in control subjects. MethodsSerum samples from 158 participants in the Biologically Resilient Adults in Neurological Studies research program at the University of Kentucky were analyzed for immunoglobulin G antibody levels to seven oral bacteria associated with periodontitis, including Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Campylobacter rectus, Treponema denticola, Fusobacterium nucleatum, Tannerella forsythia, and Prevotella intermedia. All 158 participants we...

Casarin RCV, Del Peloso Ribeiro E, Mariano FS, Nociti FH Jr, Casati MZ, Goncalves RB. Levels of Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, inflammatory cytokines and species-specific immunoglobulin G in generalized aggressive and chronic periodontitis. J Periodont Res 2010; 45: 635-642. Copyright 2010 John Wiley &Sons A/S Background and Objective: Aggressive periodontitis pathogenesis still is not completely understood in the literature regarding the relationship between microbial and inflammatory aspects. So this study aimed to compare microbial and inflammatory patterns in the gingival crevicular fluid of generalized aggressive and chronic periodontitis patients. Material and Methods: Forty aggressive and 28 chronic periodontitis patients were selected. Biofilm and ...

A new study finds significant associations between antibodies for multiple oral bacteria and the risk of pancreatic cancer, adding support for the emerging idea that the ostensibly distant medical conditions are related. The study of blood samples from more than 800 European adults, published in the journal Gut, found that high antibody levels for one of the more infectious periodontal bacterium strains of Porphyromonas gingivalis were associated with a two-fold risk for pancreatic cancer. The study was co-led by researchers from Brown University and Harvard University.

Introduction Clinical/microbiological studies have consistently revealed the persistence of some bacteria after conventional root canal debridement. Although this was originally attributed to the complexity of the root canal anatomy and the difficulty of delivering antibacterial agents effectively, it has emerged that the biofilm encasement of bacterial cells may confer a further mechanism of resistance. The purpose of this study was to investigate the relative disruption and bactericidal effects of root canal irrigants on single- and dual-species biofilms of root canal isolates. Methods Biofilms of Streptococcus sanguinis, Enterococcus faecalis, Fusobacterium nucleatum, and Porphyromonas gingivalis were grown on nitrocellulose membranes for 72 hours and immersed in NaOCl, EDTA, chlorhexid...

International Journal of Paediatric Dentistry 2012; 22: 116-124 Background.- Intracanal medication is important for endodontic treatment success as it eliminates microorganisms that persist after biomechanical preparation. Aim.- To evaluate the effect of two intracanal medications against Porphyromonas gingivalis and Enterococcus faecalis in the root canals of human primary teeth with necrotic pulp with and without furcal/periapical lesion, using quantitative real-time polymerase chain reaction (qRT-PCR). Design.- Thirty-two teeth with necrotic pulp were used. Twelve teeth did not present lesion, and 20 teeth presented radiographically visible furca/periapical lesion. Microbiological samples were collected after coronal access and biomechanical preparation. The teeth were medicated with ca...

RgpA and Kgp gingipains are non-covalent complexes of endoprotease catalytic and hemagglutinin-adhesin domains on the surface of Porphyromonas gingivalis. A motif conserved in each domain has been suggested to function as an oligomerization motif. We tested this hypothesis by mutating motif residues to hexahistidine or insertion of hexahistidine tag to disrupt the motif within the Kgp catalytic domain. All modifications led to the secretion of entire Kgp activity into the growth media, predominantly in a form without functional His-tag. This confirmed the role of the conserved motif in correct posttranslational proteolytic processing and assembly of the multidomain complexes

Abstract in portuguese Neste estudo, a presença de patógenos periodontais, Porphyromonas gingivalis, Prevotella intermedia, Tannerella forsythensis, Fusobacterium nucleatum, Dialister pneumosintes, Actinobacillus actinomycetemcomitans, Campylobacter rectus, Eikenella corrodens e Treponema denticola foi determinada por PCR, em amostras subgengivais de 40 cães com (25) e sem (15) doença periodontal. Os produtos amplificados pelo PCR para cada espécie bacteriana mostraram amplicons específic (more) os. Dos 25 cães apresentando doença periodontal, P. gingivalis foi detectado em 16 amostras (64%), C. rectus em 9 (36%), A. actinomycetemcomitans em 6 (24%), P. intermedia em 5 (20%), T. forsythensis em 5 (20%), F. nucleatum em 4 (16%) e E. corrodens em 3 (12%). Em nenhuma amostra clínica periodontal foi observada a presença de T. denticola ou D. pneumosintes. Adicionalmente, P. gingivalis foi detectado em apenas um (6,66%) cão saudável, sem raça definida. Nossos resultados mostram que esses microrganismos estão presentes na microbiota periodontal de cães com periodontitis, e isto torna importante a avaliação do papel que esses microrganismos periodontais desempenham na periodontite de animais domésticos, particularmente cães, em termos ecológicos e terapêuticos, desde que esses cães podem adquirir esses periodontopatógenos de seus respectivos proprietários. Abstract in english In this study, the presence of putative periodontal organisms, Porphyromonas gingivalis, Prevotella intermedia, Tannerella forsythensis, Fusobacterium nucleatum,Dialister pneumosintes,Actinobacillus actinomycetemcomitans,Campylobacter rectus,Eikenella corrodens and Treponema denticola were examined from subgingival samples of 40 dogs of different breeds with (25) and without (15) periodontitis, by using the PCR method. The PCR products of each species showed specific ampl (more) icons. Of the 25 dogs with periodontitis, P. gingivalis was detected in 16 (64%) samples, C. rectus in 9 (36%), A. actinomycetemcomitans in 6 (24%), P. intermedia in 5 (20%), T. forsythensis in 5 (20%), F. nucleatum in 4 (16%) and E. corrodens in 3 (12%). T. denticola and D. pneumosintes were not detected in clinical samples from dogs with periodontitis. Moreover, P. gingivalis was detected only in one (6.66%) crossbred dog without periodontitis. Our results show that these microorganisms are present in periodontal microbiota of dogs with periodontitits, and it is important to evaluate the role of these putative periodontal microorganisms play in the periodontitis in household pets particularly, dogs in ecologic and therapeutic terms, since these animals might acquire these periodontopahogens from their respective owners.

Abstract in spanish La enfermedad periodontal debe considerarse un proceso infeccioso bacteriano crónico. En su etiología, no hay una única especie bacteriana implicada, sino que podríamos considerarla como una infección polimicrobiana en la que estarían implicados diversos microorganismos. Las bacterias que se han asociado más directamente con la enfermedad periodontal son Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Bacteroides forsythus y T (more) reponema denticola. Los parámetros farmacodinámicos de los antibióticos son muy útiles a la hora de seleccionar pautas posológicas. El aumento de resistencias producido en muchos periodontopatógenos en los últimos años ha relegado a algunos antibióticos a un segundo plano. Entre la gran variedad de antibióticos utilizados, se han obtenido buenas respuestas terapéuticas con amoxicilina/ácido clavulánico, metronidazol, clindamicina, doxiciclina y las combinaciones de metronidazol más amoxicilina y metronidazol más amoxicili-na/ácido clavulánico. Abstract in english Periodontal disease must be considered a chronic bacterial infection. It does not appear to one single bacterial species that is uniquely involved. Rather, periodontal disease seems to be a polymicrobial infection involving several organisms. The bacteria most often associated with periodontal disease are Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Bacteroides forsythus y Treponema denticola. Pharmacodynamics parameters are very (more) useful to select dosing regimens. The increase in prevalence of resistance occurred in some periodontopathogens in the last years has pushed some antibiotics into the background. Positive responses have been reported with amoxicillin/clavulanate, metronidazole, clindamycin, doxycycline and the combination therapy metronidazole plus amoxicillin and metronidazole plus amoxicillin/clavulanate.

Abstract in spanish Fundamento: en Latinoamérica se ha estudiado muy poco la asociación entre Aggregatibacter actinomycetemcomitans y microorganismos del complejo rojo con los parámetros clínicos de pacientes con periodontitis crónica. Objetivo: identificar la presencia de Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis y Tanerella forsythia en pacientes con periodontitis crónica, y establecer su asociación con parámetros clínicos y hábito de fumar. Método: se exam (more) inaron los parámetros clínicos (profundidad de bolsa, nivel de inserción, sangrado al sondaje, índice de placa y supuración) y la presencia de periodontopatógenosen 76 pacientes con periodontitis crónica en Medellín, Colombia. Las muestras subgingivales se procesaron mediante cultivo. Para determinar las diferencias de las variables clínicas y el hábito de fumar con la presencia o ausencia de periodontopatógenos se utilizaron pruebas de chi cuadrado y U de Mann-Whitney (P Abstract in english Background: the association between Aggregatibacter actinomycetemcomitans and red complex microorganisms with clinical parameters of patients with chronic periodontitis has been studied very little in Latin America. Objective: to identify the presence of Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis and Tanerella forsythia in patients with chronic periodontitis, and establish their association with clinical parameters and smoking. Method: we examined cli (more) nical parameters (probing depth, attachment level, bleeding on probing, suppuration and plaque index) and the presence of periodontal pathogens in 76 patients with chronic periodontitis in Medellín, Colombia. Subgingival samples were processed by culture. Chi square and Mann-Whitney test were used to determine differences in clinical variables and smoking in the presence or absence of periodontal pathogens (P

Phosphate-based glasses (PBGs) are excellent controlled delivery agents for antibacterial ions such as silver and gallium. The aim of this study was to assess the potential utility of novel PBGs combining both gallium and silver for use in periodontal therapy. To this end, an in vitro biofilm model with the putative periodontal pathogen, Porphyromonas gingivalis, and an initial colonizer, Streptococcus gordonii, was established. The effect of increasing calcium content in gallium-silver-doped PBG on the susceptibility of P. gingivalis was examined. A decrease in degradation rates (30.34, 25.19, 21.40 ?g mm(-2) h(-1)) with increasing PBG calciumcontent (10, 11, 12 mol.% respectively) was observed, correlating well with gallium and silver ion release and antimicrobial activity against planktonic P. gingivalis (approximately 5.4log(10) colony-forming units (CFU) reduction after 24h by the C10 glass compared with controls) and S. gordonii (total growth inhibition after 32h by C10, C11 and C12 glasses compared with controls). The most potent PBG (C10) was evaluated for its ability to inhibit the biofilm growth of P. gingivalis in a newly established constant-depth film fermentor model. The simultaneous release of silver and gallium from the glass reduced P. gingivalis biofilm growth with a maximum effect (1.92log(10) CFU reduction) after 168 h. Given the emergence of antibiotic-resistant bacteria and dearth of new antibiotics in development, the glasses, especially C10, would offer effective alternatives to antibiotics or may complement current therapies through controlled, localized delivery of gallium and silver ions at infected sites in the oral cavity. PMID:22314314

Enteromorpha linza, a green alga, has been recognized as a potential source of natural antimicrobial and antifungal compounds. We previously reported that an E. linza extract strongly inhibited the growth of Prevotella intermedia and Porphyromonas gingivalis. The principal objective of this study was to evaluate the clinical effect of a mouth rinse containing the E. linza extract on gingivitis disease, as measured by the plaque index (PI), gingival index (GI), and bleeding on probing (BOP), and on two bacterial strains (P. intermedia and P. gingivalis), in comparison with Listerine(®) (Listerine-Korea, Seoul, Korea), which was used as a positive control. In total, 55 subjects were recruited into active participation in this clinical study. The PI, GI, BOP, and bacterial strains were then evaluated over a test period of 6 weeks. After 1, 2, 4, and 6 weeks, the same clinical indices were recorded, and the levels of P. intermedia and P. gingivalis were quantified via real-time polymerase chain reaction. At the end of the study, the group using the mouth rinse containing the E. linza extract evidenced significant reductions in the clinical indices (PI, GI, and BOP) and P. gingivalis compared with baseline values. Moreover, E. linza extract containing mouth rinse produced effects similar to those of Listerine. Overall, these results indicate that a mouth rinse containing E. linza extract significantly reduces plaque, improves the condition of gingival tissues, and reduces bleeding. Additionally, E. linza extract mouth rinse significantly inhibits P. gingivalis and P. intermedia. Thus, this clinical study demonstrated that the twice-daily use of an E. linza extract mouth rinse can inhibit and prevent gingivitis. PMID:22145775

Fifty-seven species of common seaweed from the Coast of Korea were screened for antimicrobial (i.e. inhibition of Prevotella intermedia and Porphyromonas gingivalis growth) activity. As a source of bioactive compounds, seaweeds can produce many secondary metabolites with a variety of activities. Using the agar diffusion method, only 17 species (29.8%) showed inhibitory activity. Of these, methanol extracts of Enteromorpha linza, Sargassum sagamianum, and Ulva pertusa showed strong inhibitory effects against both P. intermedia and P. gingivalis. The MIC values of E. linza, S. sagamianum, and U. pertusa extracts against P. intermedia were 625, 78 and 625 microg ml(-1) and those against P. gingivalis were 312, 156 and 625 microg ml(-1), respectively. When these three species' extracts were separated into five fractions according to their polarity, the main active agents were determined to be phenolic compounds. We then compared the antimicrobial activities of these phenolic compounds against various periodontal pathogens using a MIC test. Phenolic compound containing extracts at concentrations of 10 to 100 microg ml(-1) showed a moderate to significant inhibitory effect on collagenase 1,2 and 3 activity. PMID:23033653

Porphyromonas gingivalis is a Gram-negative bacterium associated with the development of periodontitis. The evolutionary success of this pathogen results directly from the presence of numerous virulence factors, including a peptidylarginine deiminase (PPAD), an enzyme, which converts arginine to citrulline in proteins and peptides. Such posttranslational modification is thought to affect the function of many different signaling molecules. Taking into account the importance of tissue remodeling and repair mechanisms for periodontal homeostasis, which are orchestrated by ligands of the epidermal growth factor receptor (EGFR), we investigated the ability of PPAD to distort cross-talk between the epithelium and the EGF signaling pathway. We found that EGF preincubation with purified recombinant PPAD, or a wild-type strain of P. gingivalis, but not with a PPAD-deficient isogenic-mutant, efficiently hindered the ability of the growth factor to stimulate epidermal cell proliferation and migration. In addition, PPAD abrogated EGFR-EGF interaction-dependent stimulation of expression of Suppressor of Cytokine Signaling 3 (SOCS3) and Interferon Regulatory Factor 1 (IRF-1). Biochemical analysis clearly showed that the PPAD-exerted effects on EGF activities were solely due to deimination of the C-terminal arginine. Interestingly, citrullination of two internal Arg residues with human endogenous peptidylarginine deiminases did not alter EFG function, arguing that the C-terminal arginine is essential for EGF biological activity. Cumulatively, these data suggest that PPAD-activity-abrogating EGF function in gingival pockets may at least partially contribute to tissue damage and delayed healing within P. gingivalis-infected periodontia.

In this study, we demonstrated that the 40-kDa outer membrane protein of Porphyromonas gingivalis (40k-OMP) sublingually administered with a cDNA vector plasmid encoding Flt3 ligand (pFL) elicited a protective immune response. Sublingual immunization of mice with 40k-OMP plus pFL induced significant serum IgG and IgA, as well as salivary IgA, antibody responses that were comparable to those induced by 40k-OMP plus cholera toxin as adjuvant. When the subclasses of 40k-OMP-specific IgG were evaluated, sublingual immunization with 40k-OMP plus pFL induced both IgG1 and IgG2a antibody responses. Sublingual delivery of pFL resulted in FL expression in submandibular glands, but not in other oral tissues. Furthermore, marked increases in FL protein occurred in saliva and serum, and the frequencies of both CD11c(+)CD11b(+) and CD11c(+)CD8alpha(+) dendritic cells with up-regulated expression of CD80, CD86 and CD40 molecules significantly increased in submandibular lymph nodes and spleen. Importantly, the mice given sublingual 40k-OMP plus pFL showed a significant reduction of alveolar bone loss caused by oral infection with P. gingivalis. These findings suggest that sublingual administration of 40k-OMP with pFL acts as an effective and safe mucosal vaccine against oral P. gingivalis infection, and may be a useful tool in the prevention of chronic periodontitis. PMID:19852927

OBJECTIVES: Modifications of titanium (Ti) implant surfaces have a significant effect on early biofilm formation and the outcome of implant procedures. The aim of this study was to examine the role of plasma proteins and electrostatic forces in the adhesion mechanism of oral bacteria to modified Ti surfaces. MATERIALS AND METHODS: Ti discs with three different types of surface modifications, machined, acid-etched, and acid-etched and blasted, were examined for adhesion of oral bacteria: Streptococcus mutans, Porphyromonas gingivalis, and Fusobacterium nucleatum. Following pretreatment of the Ti with ion rich solutions or coating by human serum albumin or fibronectin, bacterial adhesion was examined by scanning electron microscopy and assessed quantitatively by DNA analysis. Ti coating by proteins as well as bacterial adhesion and their interrelationships were further investigated through confocal scanning laser microscopy. RESULTS: Acid-etched and blasted Ti surfaces exhibited significantly higher amounts of bacteria adhesion than the other two surfaces. Calcium was found to serve as a bridging agent in the adhesion process of S. mutans and F. nucleatum to Ti surfaces. Although albumin coating of the Ti reduced the adhesion of S. mutans to all surfaces, it had no influence on the adhesion of P. gingivalis or F. nucleatum. Coating the Ti with fibronectin enhanced P. gingivalis and F. nucleatum adhesion. CONCLUSIONS: Bacterial adhesion to Ti surfaces is roughness-dependent, and the adhesion mechanism is influenced by ions and proteins of the initial coating derived from the blood. PMID:22150723

We analyzed the distribution of 6 periodontal bacteria (Porphyromonas gingivalis, Prevotella nigrescens, Prevotella intermedia, Eikenella corrodens, Actinobacillus actinomycetemcomitans and Capnocytophaga sputigena) in dental plaque materials from 227 children (3-6 years old). The plaque materials were collected from all erupted teeth sites using a sterile toothbrush. Chromosomal DNA was extracted from each plaque sample, followed by a polymerase chain reaction with species-specific sets of primers. Standard strains of 6 bacteria were used as controls. Total detection rate of P.gingivalis, P.nigrescens, P.intermedia, E.corrodens, A.actinomycetemcomitans and C.sputigena were 5.3%, 47.1%, 8.4%, 83.7%, 83.3% and 81.1%, respectively. E.corrodens, C.sputigena and A.actinomycetemcomitans were very frequently detected at all ages. On the other hand, P.gingivalis and P.intermedia were detected less frequently. Detection rate of P.nigrescens, E.corrodens and C.sputigena increased with age. The average detection number for each age group increased with age (2.63, 2.98, 3.43 and 3.45 for age 3, 4, 5 and 6, respectively). The number of bacterial species in the plaque materials increased with age as well. Our results indicate that P.nigrescens, E.corrodens, A.actinomycetemcomitans and C.sputigena are established quite early in childhood, these bacteria increase with age in the oral cavity.   

BACKGROUND AND OBJECTIVES: One of the major disadvantages of DNA-based microbial diagnostics is their inability to differentiate DNA between viable and dead microorganisms, which could be important when studying etiologically relevant pathogens. The aim of this investigation was to optimize a method for the selective detection and quantification of only viable Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis cells by combining quantitative real-time polymerase chain reaction (qPCR) and propidium monoazide (PMA). MATERIAL AND METHODS: Three different concentrations of PMA (10, 50 or 100 ?m) were added to suspensions of 10(6)  (CFU)/mL of viable/dead A. actinomycetemcomitans and P. gingivalis cells. After DNA isolation, qPCR was carried out using specific primers and probes for the tested bacteria. PMA was further tested with different mixtures containing varying ratios of viable and dead cells. The efficacy of PMA to detect viable/dead cells was tested by analysis of variance. RESULTS: For these specific bacterial pathogens, 100 ?m PMA resulted in a significant reduction of qPCR amplification with dead cells (10(6)  CFU/mL), while with viable cells no significant inhibition was detected. PMA was also effective in detecting selectively viable cells by qPCR detection, when mixtures of varying ratios of viable and dead bacteria were used. CONCLUSIONS: This study demonstrated the efficiency of PMA for differentiating viable and dead A. actinomycetemcomitans and P. gingivalis cells. This method of PMA-qPCR may be useful for monitoring new antimicrobial strategies and for assessing the pathogenic potential of A. actinomycetemcomitans and P. gingivalis in different oral conditions when using molecular diagnostic methods. PMID:22957816

The 5S ribosomal ribonucleic acid (rRNA) sequences were determined for Bacteroides fragilis, Bacteroides thetaiotaomicron, Bacteroides capillosus, Bacteroides veroralis, Porphyromonas gingivalis, Anaerorhabdus furcosus, Fusobacterium nucleatum, Fusobacterium mortiferum, and Fusobacterium varium. A dendrogram constructed by a clustering algorithm from these sequences, which were aligned with all other hitherto known eubacterial 5S rRNA sequences, showed differences as well as similarities with respect to results derived from 16S rRNA analyses. In the 5S rRNA dendrogram, Bacteroides clustered together with Cytophaga and Fusobacterium, as in 16S rRNA analyses. Intraphylum relationships deduced from 5S rRNAs suggested that Bacteroides is specifically related to Cytophaga rather than to Fusobacterium, as was suggested by 16S rRNA analyses. Previous taxonomic considerations concerning the genus Bacteroides, based on biochemical and physiological data, were confirmed by the 5S rRNA sequence analysis.

AbstractObjective To examine the relationship of Porphyromonas gingivalis to the presence of autoantibodies in individuals at risk of rheumatoid arthritis (RA). Methods Study participants included the following: 1) a cohort enriched in subjects with HLA-DR4 and 2) subjects at risk of RA by virtue of having a first-degree relative with RA. None of the study subjects satisfied the American College of Rheumatology 1987 classification criteria for RA. Autoantibodies measured included anti-citrullinated protein antibody (ACPA; by second-generation anti-cyclic citrullinated peptide antibody enzyme-linked immunosorbent assay [ELISA]) and rheumatoid factor (RF; by nephelometry or ELISA for IgA, IgM, or IgG isotype). Individuals were considered autoantibody positive (n = 113) if they had -1 RA-rela...

Iodine complexes with ethyl cellulose (EC) and hydroxypropyl cellulose (HPC) were prepared by immersing polymer powder in aqueous solutions of iodine. These complexes were incorporated in a mucoadhesive tablet for potential use as antimicrobial agent for treating oral infections. The release profile of iodine from the adhesive tablets was determined and the antimicrobial activity was assessed by diffusion assays using Candida albicans and Porphyromonas gingivalis cultures. Iodine was readily absorbed up to 35%w/w in the polymers. A differential scanning colorimeter (DSC) scan revealed a correlation between the endotherm peak of the complexes and the iodine content in the polymer complex. The tablets exhibited marked antifungal and antibacterial activities against the fungal/bacterial strai...

Objective The aim of this study was to determine the profiles of periodontopathogenic bacteria in a Chinese population using quantitative real-time polymerase chain reaction (qRT-PCR). Materials and methods Twenty-four periodontally healthy Chinese subjects and 60 patients with chronic periodontitis (CP) were enrolled in this cross-sectional study. qRT-PCR was used to quantify Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum, Porphyromonas gingivalis, and Prevotella intermedia as well as total bacterial counts from 252 samples collected from the saliva, supragingival plaque, and subgingival plaque of all 84 subjects. Results The detection frequency of A. actinomycetemcomitans was less than 50%. F. nucleatum was detected in all subjects and CP patients had higher bacterial loa...

Huth KC, Quirling M, Lenzke S, Paschos E, Kamereck K, Brand K, Hickel R, Ilie N. Effectiveness of ozone against periodontal pathogenic microorganisms. - Eur J Oral Sci 2011; 119: 204-210. 2011 Eur J Oral Sci Ozone has been proposed as an adjunct antiseptic in periodontitis therapy. The aim of this study was to investigate the antimicrobial effectiveness of gaseous/aqueous ozone, in comparison with that of the established antiseptic chlorhexidine digluconate (CHX), against periodontal microorganisms. Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia, and Parvimonas micra in planktonic or biofilm cultures were exposed, for 1-min, to gaseous ozone, aqueous ozone, CHX, or phosphate-buffered saline (control). None of the agents was able to substantially reduc...

Summary Periodontitis is an infectious process characterized by inflammation affecting the supporting structures of the teeth. Porphyromonas gingivalis is a major oral bacterial species implicated in the pathogenesis of periodontitis. Processing of interleukin (IL)-1 family cytokines is regulated by an intracellular innate immune response system, known as the NALP3 [nacht domain-, leucine-rich repeat-, and pyrin domain (PYD)-containing protein 3] inflammasome complex. The aim of the present study was to investigate by quantitative real-time polymerase chain reaction (PCR) the mRNA expression of NALP3, its effector molecule apoptosis associated speck-like protein (ASC), its putative antagonist NLRP2 (NLR family, PYD-containing protein 2), IL-1b and IL-18 (i) in gingival tissues from patient...

Resin coating materials have been used for composite resin or provisional restoration in order to prevent plaque accumulation on their surfaces. However, it is not clear whether the coating materials influence attachment of periodontal bacteria. Therefore, we investigated the effect of resin coating materials on the attachment of Porphyromonas gingivalis (Pg). The polymerized auto cure resin plates were coated with two resin coating materials. To estimate the Pg attachment, each plate was immersed in brain heart infusion medium containing Pg. The quantity of bacteria attached on each plate was evaluated by crystal violet quantification. Morphological change of Pg was recorded using scanning electron microscopy. Both coating groups presented significantly lower Pg attachment compared to the control. The Pg shapes on the plates with resin coating materials were similar to the non-treated control plates. The resin coating materials clearly prevent Pg attachment on the polymerized auto cure resin plate.   

A gene from the periodontal organism Porphyromonas gingivalis has been identified as encoding a DNA methylase. The gene, referred to as pgiIM, has been sequenced and found to contain a reading frame of 864 basepairs. The putative amino acid sequence of the encoded methylase was 288 amino acids, and shared 47% and 31% homology with the Streptococcus pneumoniae DpnII and E. coli Dam methylases, respectively. The activity and specificity of the pgi methylase (M.PgiI) was confirmed by cloning the gene into a dam- strain of E. coli (JM110) and performing a restriction analysis on the isolated DNA with enzymes whose activities depended upon the methylation state of the DNA. The data indicated that M.PgiI, like DpnII and Dam, methylated the adenine residue within the sequence 5'-GATC-3'. PMID:1870972

The protein family (Pfam) PF04536 is a broadly conserved domain family of unknown function (DUF477), with more than 1,350 members in prokaryotic and eukaryotic proteins. High-quality NMR structures of the N-terminal domain comprising residues 41?180 of the 684-residue protein CG2496 from Corynebacterium glutamicum and the N-terminal domain comprising residues 35?182 of the 435-residue protein PG0361 from Porphyromonas gingivalis both exhibit an ?/? fold comprised of a four-stranded ?-sheet, three ?-helices packed against one side of the sheet, and a fourth ?-helix attached to the other side. In spite of low sequence similarity (18%) assessed by structure-based sequence alignment, the two structures are globally quite similar. However, moderate structural differences are observed for the re...

Diabetes-driven cardiovascular diseases represent a high challenge for developed countries. Periodontal disease is strictly linked to the aforementioned diseases, due to its Gram negative-driven inflammation. Thus, we investigated the effects of periodontal disease on arterial pressure during the development of diabetes in mice. To this aim, C57BL/6 female mice were colonized with pathogens of periodontal tissue (Porphyromonas gingivalis, Prevotella intermedia and Fusobacterium nucleatum) for 1month, whereas another group of mice did not undergo the colonization. Subsequently, all mice were fed a high-fat carbohydrate-free diet for 3months. Then, arterial pressure was measured in vivo and a tomodensitometric analysis of mandibles was realized as well. Our results show increased mandibular ...

Rheumatoid arthritis is an autoimmune disease characterized by the production of two known antibodies - rheumatoid factor and anti-citrullinated peptide antibody (ACPA) - against common autoantigens that are widely expressed within and outside the joints. The interactions between genes and environment are crucial in all stages of the disease, involving namely genes from major histocompatibility complex locus, and antigens such as tobacco or microbes (e.g. Porphyromonas gingivalis). T and B cells are activated as soon as the earliest phases of the disease, rheumatoid arthritis appearing as a Th1 and Th17 disease. Inflammatory cytokines have a considerable importance in the hierarchy of the processes involved in RA. The joint destruction seen in RA is caused not only by cytokine imbalances, ...

To examine the effects of titanium (Ti) coated with biomimetic diamond-like carbon (DLC) on osteoclast differentiation and bacterial biofilm formation, RAW264.7 cells and Porphyromonas gingivalis (P. g) were grown on Ti disks without DLC (control), or with DLC (DLC-treated). Real-time quantitative reverse transcriptase-polymerase chain reaction analysis showed that TRAP and cathepsin K mRNA levels in RAW264.7 cultured on DLC?treated Ti disks with soluble receptor activators for NF-?B ligand (sRANKL) were significantly lower than those of control Ti disks. Similarly, DLC-treated Ti decreased the expression of NFATc1 protein in sRANKL-stimulated RAW264.7 cells. Futher, reduced P. g biofilm formation was observed on DLC?treated disks as compared with the biofilm on control Ti disks. These results, taken together, suggested that DLC altered osteoclast differentiation and biofilm formation of P.g, which could promise long-term success of implant therapy.   

The role of Th1 and Th2 cytokines in the pathogenesis of aggressive periodontitis has not been previously examined. The aim of this study was to analyse the expression and production of IL-2, IFN-?, IL-4 and IL-13 in CD4+ cells from the peripheral blood of patients with aggressive periodontitis (AgP) and periodontally healthy controls. Gene expression was analysed in inactivated and activated CD4+ cells by real-time PCR. Cells were activated for 4, 8 and 24 h with anti-CD3/CD28 antibody, phytohemagglutinin (PHA), and Porphyromonas gingivalis (P.g.) outer membrane protein (OMP). Protein levels were measured in supernatants of activated CD4+ cells by bead-based immunoassay (CBA). Statistics were performed using U test (p?p?=?0.05), and IFN-? and IL-2 expressions were increased in activated C...

Maltose-binding protein (MBP) produced by Escherichia coli acts as an adjuvant when fused to various antigens. In this study, the antigenic region of hemagglutinin A of Porphyromonas gingivalis with a molecular mass of 25 kDa (25k-hagA) was fused to MBP (25k-hagA-MBP) and the efficacy of the resulting fusion protein as a nasal vaccine was assessed. While nasal immunization with 25k-hagA induced no antibody responses, 25k-hagA-MBP elicited high serum IgG, IgA, and secretory IgA anti-25k-hagA antibodies in the saliva. When 25k-hagA-MBP was co-administered with an established mucosal adjuvant, cholera toxin, 25k-hagA-specific serum IgG and salivary IgA antibody responses were not further elevated. Interestingly, 25k-hagA mixed with MBP failed to induce 25k-hagA-specific antibody responses. These findings suggest that MBP must be fused to the target antigen for induction of antigen-specific antibody responses and that nasal administration of 25k-hagA-MBP may be an effective mucosal vaccine for the prevention of P. gingivalis infection.   

Anti-adhesive compounds are potential prophylactic tools in alternative treatment regimes against bacterial infection, as bacterial adhesion is commonly mediated by carbohydrate-protein interactions between surface adhesions of microorganisms and the host cell. The use of exogenous polyvalent, high-molecular carbohydrates and tannin-like plant-derived compounds should antagonize the adhesive interaction. A range of carbohydrates and carbohydrate- and proanthocyanidin-enriched plant extracts were screened for potential anti-adhesive effects against Helicobacter pylori, Campylobacter jejuni, Porphyromonas gingivalis and Candida albicans in different in-situ assays on primary tissue. The adhesion of H. pylori on human stomach tissue was effectively blocked by glucuronic acid-enriched polysaccharides from immature okra fruits (Abelmoschus esculentus). These compounds also had strong in-vitro effects against C. jejuni (inhibition up to 80%), but were ineffective in an in-vivo study in infected chicken broilers due to metabolism in the gastrointestinal system. Polysaccharides from Glycyrrhizia glabra, also enriched with glucuronic acid, showed strong anti-adhesive properties against H. pylori and P. gingivalis (inhibition 60-70%). Pelargonium sidoides extract, containing mainly polymeric proanthocyanidins, was effective against H. pylori in a dose-dependent manner. Due to the multifunctional adhesive strategy of C. albicans, no effective compounds were detected against this yeast. Structure-activity relationships are presented and the potential in-vivo use of carbohydrate-based anti-adhesives is discussed. PMID:17637170

Periodontitis is initiated by accumulation of microbial plaque and activation of gingival inflammation through overexpression of matrix metalloproteinases (MMPs), leading to tissue destruction. Natural MMP inhibitors may be developed as therapeutic agents against periodontitis. In this study, panduratin A, a natural bioactive compound isolated from Kaempferia pandurata ROXB., was used to test its in vitro inhibitory activity against MMP-9 secretion from Porphyromonas gingivalis supernatant-induced human oral epidermoid carcinoma KB cells. Gelatin zymography, Western blot and RT-PCR analyses were performed to evaluate MMP-9 expression. The gelatin zymograms revealed that the main gelatinase secreted by P. gingivalis supernatant-induced KB cells migrated at 92 kDa, representing MMP-9. MMP-9 protein and mRNA levels were significantly decreased after panduratin A treatment (p<0.05). In contrast, panduratin A had no effect on tissue inhibitor of metalloproteinases (TIMP)-1 and TIMP-2 mRNA. Panduratin A also suppressed urokinase type plasminogen activator (uPA) mRNA expression. These results suggest that panduratin A could potentially prevent periodontal inflammation by decreasing the levels of MMP-9 protein and mRNA.   

We have shown previously that gingipains from Porphyromonas gingivalis W83 can induce cell detachment, cell adhesion molecule (CAM) cleavage, and apoptosis in endothelial cells; however, the specific roles of the individual gingipains are unclear. Using purified gingipains, we determined that each of the gingipains can cleave CAMs to varying degrees with differing kinetics. Kgp and HRgpA work together to quickly detach endothelial cells. Interestingly, in the absence of active caspases, both gingipain-active W83 extracts and purified HRgpA and RgpB induce apoptotic morphology, suggesting that the gingipains can induce both caspase-dependent and caspase-independent apoptosis. Using z-VAD-FMK to inhibit Kgp activity and leupeptin to inhibit Rgp activity in gingipain-active W83 extracts, we investigated the relative significance of the synergistic role of the gingipains. z-VAD-FMK or leupeptin delayed, but did not inhibit, cell detachment induced by gingipain-active W83 extracts or purified gingipains. There was partial cleavage of N-cadherin and cleavage of VE-cadherin was not inhibited. Degradation of integrin beta1 was inhibited only in the presence of z-VAD-FMK. These results further clarify the role P. gingivalis plays in tissue destruction occurring in the periodontal pocket. PMID:16988242

Garlic has been used medicinally throughout human history. Allicin is considered the most therapeutic constituent of garlic. This study tested the antimicrobial activity of garlic allicin on oral pathogens associated with dental caries and periodontitis. Allicin was found effective against all the tested bacteria. The broth dilution method revealed that planktonic growth of the cariogenic, gram-positive species Streptococcus mutans, S. sobrinus, and Actinomyces oris was inhibited by an allicin concentration of 600 ?g/mL or higher. Planktonic growth of the tested gram-negative periopathogenic species Aggregatibacter actinomycetemcomitans and Fusobacterium nucleatum was inhibited by a minimum allicin concentration of 300 ?g/mL. Porphyromonas gingivalis, an anaerobic, gram-negative pathogen and the bacterium most associated with chronic periodontitis, demonstrated the lowest sensitivity to allicin (2,400 ?g/mL). Gel zymography and the synthetic chromogenic substrate N(?)-benzoyl-L-arginine 4-nitroanilide hydrochloride demonstrated that allicin inhibits the proteases of P. gingivalis, including the arginine and lysine gingipains known as major virulence factors of this organism. A gingipain-inactivated mutant demonstrated high sensitivity to allicin (allicin. Live/dead staining followed by analysis with confocal laser scanning microscopy revealed that allicin was bactericidal to S. mutans grown in mature biofilms. However, this bactericidal effect was reduced as biofilm depth increased. In conclusion, these results support the traditional medicinal use of garlic and suggest the use of allicin for alleviating dental diseases. PMID:21548800

Periodontitis is an infectious process characterized by inflammation affecting the supporting structures of the teeth. Porphyromonas gingivalis is a major oral bacterial species implicated in the pathogenesis of periodontitis. Processing of interleukin (IL)-1 family cytokines is regulated by an intracellular innate immune response system, known as the NALP3 [nacht domain-, leucine-rich repeat-, and pyrin domain (PYD)-containing protein 3] inflammasome complex. The aim of the present study was to investigate by quantitative real-time polymerase chain reaction (PCR) the mRNA expression of NALP3, its effector molecule apoptosis associated speck-like protein (ASC), its putative antagonist NLRP2 (NLR family, PYD-containing protein 2), IL-1? and IL-18 (i) in gingival tissues from patients with gingivitis (n = 10), chronic periodontitis (n = 18), generalized aggressive periodontitis (n = 20), as well as in healthy subjects (n = 20), (ii) in vitro in a human monocytic cell line (Mono-Mac-6), in response to P. gingivalis challenge for 6 h. The clinical data indicate that NALP3 and NLRP2, but not ASC, are expressed at significantly higher levels in the three forms of inflammatory periodontal disease compared to health. Furthermore, a positive correlation was revealed between NALP3 and IL-1? or IL-18 expression levels in these tissues. The in vitro data demonstrate that P. gingivalis deregulates the NALP3 inflammasome complex in Mono-Mac-6 cells by enhancing NALP3 and down-regulating NLRP2 and ASC expression. In conclusion, this study reveals a role for the NALP3 inflammasome complex in inflammatory periodontal disease, and provides a mechanistic insight to the host immune responses involved in the pathogenesis of the disease by demonstrating the modulation of this cytokine-signalling pathway by bacterial challenge. PMID:16367933

The rapid rise in bacterial drug resistance coupled with the low number of novel antimicrobial compounds in the discovery pipeline has led to a critical situation requiring the expedient discovery and characterization of new antimicrobial drug targets. Enzymes in the bacterial fatty acid synthesis pathway, FAS-II, are distinct from their mammalian counterparts, FAS-I, in terms of both structure and mechanism. As such, they represent attractive targets for the design of novel antimicrobial compounds. Enoyl-acyl carrier protein reductase II, FabK, is a key, rate-limiting enzyme in the FAS-II pathway for several bacterial pathogens. The organism, Porphyromonas gingivalis, is a causative agent of chronic periodontitis that affects up to 25% of the US population and incurs a high national burden in terms of cost of treatment. P. gingivalis expresses FabK as the sole enoyl reductase enzyme in its FAS-II cycle, which makes this a particularly appealing target with potential for selective antimicrobial therapy. Herein we report the molecular cloning, expression, purification and characterization of the FabK enzyme from P. gingivalis, only the second organism from which this enzyme has been isolated. Characterization studies have shown that the enzyme is a flavoprotein, the reaction dependent upon FMN and NADPH and proceeding via a Ping-Pong Bi-Bi mechanism to reduce the enoyl substrate. A sensitive assay measuring the fluorescence decrease of NADPH as it is converted to NADP{sup +} during the reaction has been optimized for high-throughput screening. Finally, protein crystallization conditions have been identified which led to protein crystals that diffract x-rays to high resolution.

OBJECTIVES: The aim of this study was to determine whether measurements of volatile sulfur compounds (VSCs) are useful to predict colonization of periodontopathic bacteria. For this purpose, we assessed the relationships among distributions of 4 species of periodontopathic bacteria in tongue coating and dental plaque, oral conditions including VSC concentration in mouth air, and smoking habit of periodontal healthy young subjects. METHODS: The subjects were 108 young adults (mean age, 23.5±2.56 years) without clinical periodontal pockets. Information regarding smoking habit was obtained by interview. After VSC concentration in mouth, air was measured with a portable sulfide monitor (Halimeter(®)), non-stimulated saliva flow and dental caries status were assessed, and tongue coating and dental plaque samples were collected from the subjects. The tongue coating samples were weighed to determine the amount. The colonization of Porphyromonas gingivalis, Tannerella forsythia, Prevotella intermedia, and Treponema denticola in both tongue coating and plaque samples was investigated using species-specific polymerase chain reaction assays. RESULTS: Significant relationships were observed between the colonization of periodontopathic bacteria in tongue coating and plaque samples, especially that of P. gingivalis. VSC concentration showed the most significant association with colonization of P. gingivalis in both tongue coating and dental plaque. Logistic regression analysis demonstrated that the adjusted partial correlation coefficient [Exp(B)] values for VSC concentration with the colonization of P. gingivalis, P. intermedia, and T. denticola in dental plaque were 135, 35.4 and 10.4, respectively. In addition, smoking habit was also shown to be a significant variable in regression models [Exp(B)=6.19, 8.92 and 2.53, respectively]. Therefore, receiver operating characteristic analysis was performed to predict the colonization of periodontal bacteria in dental plaque in the subjects divided by smoking habit. Based on our results, we found cut-off values that indicated likelihood ratios (LR) within the efficient range for positive findings in both groups. CONCLUSION: The present results demonstrated that measurement of VSC concentration in mouth air is a useful method to predict the presence of colonization of some periodontopathic bacteria in dental plaque. PMID:23107050

Porphyromonas gulae is a gram-negative black-pigmented anaerobe which is known to be a pathogen for periodontitis in dogs. Approximately 41kDa filamentous appendages on the cell surface (FimA) encoded by the fimA gene are regarded as important factors associated with periodontitis. The fimA genotype was classified into two major types and strains in type B were shown to be more virulent than those in type A. In the present study, we characterized a strain with a novel fimA genotype and designated it as type C. The putative amino acid sequence was shown to be similar to the genotype IV fimA of Porphyromonas gingivalis, a major pathogen of human periodontitis. Analyses using an oral squamous cell carcinoma cell line derived from tongue primary lesions revealed that the type C strain inhibited proliferation and scratch closure more than genotype A and B strains. In addition, experiments using a mouse abscess model demonstrated that the type C strain could induce much higher systemic inflammation when compared with strains of the other genotypes. Furthermore, molecular analyses of oral swab specimens collected from dogs demonstrated that the detection frequencies of P. gulae and the genotype C in the periodontitis group were significantly higher than those in the periodontally healthy group. These results suggest that FimA of P. gulae is diverse with the virulence of genotype C strains the highest and that molecular identification of genotype C P. gulae could be a possible useful marker for identifying dogs at high risk of developing periodontitis. PMID:22877518

The polymicrobial nature of periodontal diseases is reflected by the diversity of phylotypes detected in subgingival plaque and the finding that consortia of suspected pathogens rather than single species are associated with disease development. A number of these microorganisms have been demonstrated in vitro to interact and enhance biofilm integration, survival or even pathogenic features. To examine the in vivo relevance of these proposed interactions, we extended the spatial arrangement analysis tool of the software daime (digital image analysis in microbial ecology). This modification enabled the quantitative analysis of microbial co-localization in images of subgingival biofilm species, where the biomass was confined to fractions of the whole-image area, a situation common for medical samples. Selected representatives of the disease-associated red and orange complexes that were previously suggested to interact with each other in vitro (Tannerella forsythia with Fusobacterium nucleatum and Porphyromonas gingivalis with Prevotella intermedia) were chosen for analysis and labeled with specific fluorescent probes via fluorescence in situ hybridization. Pair cross-correlation analysis of in vivo grown biofilms revealed tight clustering of F. nucleatum/periodonticum and T. forsythia at short distances (up to 6 µm) with a pronounced peak at 1.5 µm. While these results confirmed previous in vitro observations for F. nucleatum and T. forsythia, random spatial distribution was detected between P. gingivalis and P. intermedia in the in vivo samples. In conclusion, we successfully employed spatial arrangement analysis on the single cell level in clinically relevant medical samples and demonstrated the utility of this approach for the in vivo validation of in vitro observations by analyzing statistically relevant numbers of different patients. More importantly, the culture-independent nature of this approach enables similar quantitative analyses for "as-yet-uncultured" phylotypes which cannot be characterized in vitro. PMID:22655057

In periodontitis lesions with interproximal craters, periodontal flap surgery with osseous recontouring allows more apical positioning of the soft periodontal tissue than flap surgery without osseous recontouring. The present study determined the clinical and microbiologic responses to periodontal surgery with and without osseous recontouring in adult periodontitis lesions with interproximal craters. In 7 osseous surgery patients, osteoplasty and ostectomy were performed from the lingual/palatal aspect to eliminate interproximal osseous defects and to partly mimic the original alveolar bony transition to neighboring teeth. In 7 nonosseous surgery patients, the surgical flap was adapted to the preexisting osseous level. Clinical monitoring included periodontal probing depth, Plaque Index, gingival bleeding index, and radiographic examination. Samples of the subgingival microbiota were examined. In sites treated with osseous surgery, mean pocket depth was 5.5 mm at baseline, 1.9 mm at 1 month, 2.0 mm at 3 months, and 2.1 mm at 6 months. In sites not receiving osseous recontouring surgery, the corresponding pocket depths were 5.9 mm, 3.1 mm, 3.8 mm, and 4.1 mm. At baseline in the osseous surgery group, Actinobacillus actinomycetemcomitans was recovered from one patient and Porphyromonas gingivalis from 5 patients; posttreatment, these microbiota were not detected in any patient. In the nonosseous surgery group, the presence of A actinomycetemcomitans increased posttreatment, and levels of P gingivalis remained essentially unchanged after therapy. This study suggests that in patients not receiving adjunctive antibiotic therapy, apically positioned flap surgery with osseous recontouring is more effective than apically positioned flap surgery without osseous recontouring in reducing periodontal pocket depth and levels of major periodontal pathogens. PMID:11203584

Inflammatory cytokines such as interleukin-1? (IL-1?) are involved in the pathogenesis of periodontal diseases. A high individual variation in the levels of IL-1? mRNA has been verified, which is possibly determined by genetic polymorphisms and/or by the presence of periodontopathogens such as Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, and Aggregatibacter actinomycetemcomitans. In this study, we investigated the role of an IL-1? promoter single-nucleotide polymorphism at position 3954 [IL-1?(3954) SNP] and the presence of the periodontopathogens in the determination of the IL-1? levels in the periodontal tissues of nonsmoking chronic periodontitis (CP) patients (n = 117) and control (C) subjects (n = 175) and the possible correlations with the clinical parameters of the disease. IL-1?(3954) SNP was investigated by restriction fragment length polymorphism, while the IL-1? levels and the presence of the periodontopathogens were determined by real-time PCR. Similar frequencies of IL-1?(3954) SNP were found in the C and CP groups, in spite of a trend toward a higher incidence of T alleles in the CP group. The IL-1?(3954) SNP CT and TT genotypes, as well as P. gingivalis, T. forsythia, and T. denticola, were associated with higher IL-1? levels and with higher values of the clinical parameters of disease severity. Concomitant analyses demonstrate that IL-1?(3954) and the red complex periodontopathogens were found to independently and additively modulate the levels of IL-1? in periodontal tissues. Similarly, the concurrent presence of both factors was associated with increased scores of disease severity. IL-1?(3954) genotypes and red complex periodontopathogens, individually and additively, modulate the levels of IL-1? in the diseased tissues of nonsmoking CP patients and, consequently, are potentially involved in the determination of the disease outcome.

The aim of this study was to use the fluorescence in situ hybridization (FISH) technique to test the hypothesis of qualitative and quantitative differences of 8 periodontopathogens between pregnant and non-pregnant women. This cross-sectional study included 20 pregnant women in their second trimester of pregnancy and 20 non-pregnant women. Probing depth, bleeding on probing, clinical attachment level, and presence of calculus were recorded. Subgingival plaque samples were collected and the FISH technique identified the presence and numbers of Aggregatibacter actinomycetemcomitans, Tannerella forsythia, Campylobacter rectus, Porphyromonas gingivalis, Treponema denticola, Fusobacterium nucleatum, Prevotella intermedia and Prevotella nigrescens. The Mann-Whitney U-test was applied to compare the data between the two groups. The mean age, ethnicity, marital status, education, and economic level in both groups were similar. The clinical parameters showed no significant differences between pregnant and non-pregnant women. The numbers of subgingival periodontopathogens were not found to be significantly different between groups, despite the higher mean counts of P. intermedia in pregnant women. Colonization patterns of the different bacteria most commonly associated with periodontal disease were not different in the subgingival plaque of pregnant and non-pregnant women. PMID:23018230

Periodontitis is a bacterial disease that can be treated with systemic antibiotics. The aim of this study was to establish the antibiotic susceptibility profiles of five periodontal pathogens to six commonly used antibiotics in periodontics. A total of 247 periodontal bacterial isolates were tested for susceptibility to the six antibiotics using the Etest method. MIC(50) and MIC(90) values (minimum inhibitory concentrations for 50% and 90% of the organisms, respectively) were calculated. Both European Committee on Antimicrobial Susceptibility Testing (EUCAST) and Clinical and Laboratory Standards Institute (CLSI) breakpoints were used in the study to interpret results. ?-Lactamase production was tested when amoxicillin resistance was found. MIC(90) values of the anaerobic bacteria were all well below breakpoint values, except for three isolates of Prevotella intermedia and one isolate of Fusobacterium nucleatum that were resistant to amoxicillin (CLSI breakpoints); these isolates were ?-lactamase-positive. Two isolates of the capnophilic Aggregatibacter actinomycetemcomitans appeared to be amoxicillin-resistant but failed to show ?-lactamase activity. Comparison with a previous study from The Netherlands showed minor differences in susceptibility profiles, but the MIC(90) values of A. actinomycetemcomitans for amoxicillin, clindamycin, azithromycin and tetracycline were higher. Geographical differences in the susceptibility profiles of Porphyromonas gingivalis and A. actinomycetemcomitans between European countries were noted. Comparison of European susceptibility profiles with that of a South American country (Colombia) revealed a much higher resistance in the latter. Owing to these differences in susceptibility profiles, it is of concern to regularly perform surveillance studies on antibiotic resistance. PMID:22890195

High-molecular-weight arginine- and lysine-specific (Kgp) gingipains are essential virulence factors expressed by the oral pathogen Porphyromonas gingivalis. Haemagglutinin/adhesin (HA) regions of these proteases have been implicated in targeting catalytic domains to biological substrates and in other adhesive functions. We now report the crystal structure of the K3 adhesin domain/module of Kgp, which folds into the distinct ?-jelly roll sandwich topology previously observed for K2. A conserved structural feature of K3, previously observed in the Kgp K2 module, is the half-way point anchoring of the surface exposed loops via an arginine residue found in otherwise highly variable sequences. Small-angle X-ray scattering data for the recombinant construct K1K2K3 confirmed a structure comprising a tandem repeat of three homologous modules, K1, K2 and K3 while also indicating an unusual 'y'-shape arrangement of the modules connected by variable linker sequences. Only the K2 and K3 modules and a K1K2 construct were observed to be potently haemolytic. K2, K3 and the K1K2 construct showed preferential recognition of haem-albumin over albumin whereas only low affinity binding was detected for K1 and the K1K2K3 construct. The data indicate replication of some biological functions over the three adhesin domains of Kgp while other functions are restricted. PMID:21812842

The objective of this paper is to evaluate the effects of oil drops containing Lactobacillus salivarius WB21 on periodontal health and oral microbiota producing volatile sulfur compounds (VSCs). For this study, 42 subjects were randomly assigned to receive oil samples containing L. salivarius WB21 or a placebo for two weeks. Oral assessment and saliva collection were performed on days 1 and 15. Bacterial analysis was performed using the real-time polymerase chain reaction and terminal restriction fragment length polymorphism (T-RFLP). In both the experimental and placebo groups, the average probing depth, number of periodontal pockets, and the percentage of bleeding on probing (BOP) decreased while stimulated salivary flow increased on day 15. BOP was reduced in the experimental group compared with the placebo group (P = 0.010). In the experimental group, total bacterial numbers decreased, and the number of L. salivarius increased. The number of Prevotella intermedia, which is correlated with hydrogen sulfide concentration in mouth air, increased in the placebo group and did not change in the experimental group. T-RFLP analysis found that the peak area proportions representing Porphyromonas gingivalis, P. intermedia, Tannerella forsythensis, and Fusobacterium nucleatum decreased in the experimental group, although there was no significant change in the bacterial composition. Thus we observed oil drops containing L. salivarius WB21 improved BOP and inhibited the reproduction of total and VSC-producing periodontopathic bacteria compared with the placebo group, but also showed the limit of its efficacy in controlling VSCs producing and periodontal pathogens. PMID:22368259

OBJECTIVE: Solobacterium moorei is a Gram positive bacterium that has been specifically associated with halitosis. The aim of this study was to characterize volatile sulfur compound (VSC) production by S. moorei. METHODS: S. moorei was either grown or incubated in the presence of various supplements prior to determining VSC production with a Halimeter sulfide monitor. The effect of exogenous proteases or glycosidase inhibitors on VSC production by S. moorei was examined. RESULTS: We first showed that S. moorei can convert cysteine into hydrogen sulfide. The capacity of S. moorei to produce VSCs from serum, saliva, and mucin was dependent on the presence of an exogenous source of proteases such as pancreatic trypsin or Porphyromonas gingivalis gingipains. VSC production from mucin was inhibited by the presence of a ?-galactosidase inhibitor, thus suggesting that deglycosylation of mucin by S. moorei is critical for VSC production. CONCLUSION: Our study suggests that S. moorei can be a major source of malodorous compounds in halitosis by producing VSCs through a process involving the ?-galactosidase activity of the bacterium and an exogenous source of proteases. PMID:23088790

Rheumatoid arthritis is an autoimmune disease characterized by the production of two known antibodies - rheumatoid factor and anti-citrullinated peptide antibody (ACPA) - against common autoantigens that are widely expressed within and outside the joints. The interactions between genes and environment are crucial in all stages of the disease, involving namely genes from major histocompatibility complex locus, and antigens such as tobacco or microbes (e.g. Porphyromonas gingivalis). T and B cells are activated as soon as the earliest phases of the disease, rheumatoid arthritis appearing as a Th1 and Th17 disease. Inflammatory cytokines have a considerable importance in the hierarchy of the processes involved in RA. The joint destruction seen in RA is caused not only by cytokine imbalances, but also by specific effects of the Wnt system and osteoprotegerin on osteoclasts and by matrix production dysregulation responsible for cartilage damage. Both innate and adaptative immunity demonstrated their respective cornerstone position in rheumatoid arthritis, since targeted treatments has been efficiently developed against TNF-?, IL-6 receptor, IL-1?, CD20 B cells and T-cell/Dendritic cell interactions. PMID:22704962

PURPOSE: Neutrophils have been shown to be involved in all stages of human and experimental abdominal aortic aneurysm (AAA) development. The initial processes of neutrophil rolling and trapping in the intraluminal thrombus (ILT) are mediated mainly by P-selectin expressed by activated platelets. In the present study, we propose to evaluate the beneficial effect of fucoidan, a competitive binding agent of P-selectin, on aneurysmal growth in a rat model of aortic aneurysm with neutrophil enrichment of the ILT induced by repeated episodes of weak bacteremia. METHODS: Sixty Lewis rats with experimental AAAs, developed from decellularized aortic xenografts, were divided into four groups. Two groups were used as controls: group fucoidan control (FC) was treated with 200 mg of fucoidan (F) delivered by 2 mL, 4-week osmotic pumps placed intraperitoneally before closing the abdomen, and group C received saline instead of fucoidan. Two more groups were injected weekly with Porphyromonas gingivalis (P. gingivalis [Pg]): group F+Pg received 200 mg of intraperitoneal fucoidan and group Pg received saline. AAAs were harvested after 4 weeks and peripheral blood was sampled at that time. Cell-free DNA (cf-DNA) and myeloperoxydase (MPO) antigen concentrations were determined in plasma and in AAA-conditioned media. Histology and P-selectin immunostaining were performed on AAA tissue samples. RESULTS: Comparing rats injected with Pg, those receiving fucoidan presented reduced aneurysmal diameter. Histologic analysis of AAAs showed that fucoidan reduced the ILT thickness in Pg-injected rats, with fewer trapped neutrophils, and with signs of a healing process, as observed in control group C. Immunohistological analysis revealed a substantial decrease in P-selectin immunostaining at the luminal surface of aneurysms in fucoidan-treated rats compared to the other groups, suggesting an interaction between fucoidan and P-selectin. A significant decrease in MPO concentrations in both plasma and conditioned medium was induced by fucoidan treatment in Pg-injected rats, reflecting a pacification of the ILT biological activity. This effect was associated with a reduction in neutrophil activation and apoptosis, reflected by a significant decrease in cf-DNA concentration in both plasma and conditioned medium of fucoidan-treated rats. CONCLUSIONS: Our results suggest that fucoidan has a beneficial effect on experimental aneurysmal degeneration by decreasing neutrophil activation in the ILT enhanced by weak pathogen contamination. This effect seems to be related to its interaction with P-selectin, which may decrease the trapping of neutrophils into the ILT. Fucoidan could represent a therapeutic option in AAAs to decrease the neutrophil activation involved in the degenerative process of aneurysmal expansion and rupture. PMID:23141684

Abstract in spanish Introducción Los cambios periapicales denominados lesiones, en dientes con integridad coronal completa y sin antecedentes de trauma, no presentan una etiología clara. Objetivo: Determinar la presencia de microorganismos en el tejido pulpar clarifica las causas de su muerte y el consiguiente daño a los tejidos periodontales Materiales y métodos Se seleccionaron 23 dientes, en personaas con rangos de edad entre 10 y 39 años. Las muestras se tomaron con puntas de papel (more) y limas Nº 0.8 (estériles), se transportaron en VMGA III, se procesaron en las siguientes 24 horas de tomada la muestra y se sembraron en agar brucella. Resultados: Los dientes más afectados fueron los centrales superiores 43.8%. De los 23 dientes estudiados, en 20 se observó crecimiento microbiológico. Se identificaron los siguientes microorganismos: Fusobacterium spp., 25%; Eubacterium spp., 15%; Peptostreptococcus spp., 10%; Campylobacter spp., 10%; bacilos entéricos gram negativos, 10%; Porphyromonas gingivalis, 10%; Prevotella intermedia, 5%; Eikenellia corrodens, 5%; Dialister pneumosintes, 5%; y levaduras en 5%. No hubo evidencias de crecimiento de Actinomyces actinomycetemcomitans, Tanerella forsythensis ni de estreptococo ? hemolítico. Discusión y conclusiones: El tejido pulpar sano es estéril, la lesión sobre él causa inflamación degeneración, muerte pulpar y contaminación bacteriana. Los resultados en el presente estudio determinaron claramente la presencia de micro-organismos en lesiones apicales cerradas de origen endodóntico. De igual forma se evidencia que gran parte de los microorganismos que se encontraron son considerados periodontopatógenos lo que puede igualmente sugerir manejo compartido entre tratamiento endodóntico, periodontal y farmacológico. Abstract in english Introduction: Periapical changes named as lesions, in teeth with full crown integrity and without history of trauma, do not show a clear aetiology. Objective To determine the presence of microorganisms in pulp dental tissue will clarify the cause of its death and therefore the damage to periodontal tissues. Materials and methods: From people between 10 and 39 years old, 23 teeth were selected. The samples were taken with paper points and 0.8 sterile files, and were transp (more) orted in VMGA III medium, to be processed in the following 24 hours after they were taken and sowed in Brucella-agar. Results: The most affected teeth were upper central incisors, 43.8%. From the 23 studied teeth, microbiological grow was seen on 20 teeth. The following microorganisms species were identified: Fusobacterium spp., 25%, Eubacterium spp., 15%; Peptostreptococcus spp., 10%; Campylobacter spp., 10%; gram negative enteric bacteria, 10%; Porphyromonas gingivalis, 10%; Prevotella intermedia, 5%; Eikenellia corrodens, 5%; Dialister pneumosintes, 5%; and yeasts, 5%. There was no growing evidence of Actinomyces actinomycetemcomitans, Tanerella forsythensis and Streptococcus ? hemolytic. Discussion and conclusions: Sound pulp dental tissue is sterile; an injury over it will cause its inflammation, degeneration, death and bacterial contamination. Results in the present study clearly show the presence of microorganisms in closed apical dental lesions of endodontic origin. In same manner, it was seen that a great part of microorganisms species found can be regarded as periodontal pathogens. This could suggest a management with an endodontic, a periodontic and a pharmacological combined treatment.

Abstract in spanish La utilización del láser en el ambiente odontológico está teniendo cada vez más difusión gracias al hecho que éste puede conciliar un elevado standard de confort para el paciente con la eficacia terapéutica. El presente estudio ha evaluado la eficacia bactericida de la radiación láser asociada al empleo del agua oxigenada respecto a cinco cepas bacterianas comúnmente presentes en las bolsas periodontales activas y resistentes al empleo separado del láser y del (more) agua oxigenada. Las cinco bacterias estudiadas son: Haemophilus actinomycetemcomitans, Bacteroides forsytus, Porphyromonas gingivalis, Micromonas micron y Fusobacterium nucleatum. La metodología de laboratorio utilizada preveía el siguiente protocolo: 30 ml de cada suspensión bacterianas, expuestas o no al agua oxigenada a distintas concentraciones del 0,5% o del 3%, han sido irradiadas separadamente con el láser por 5 o 10 segundos, utilizando tubos estériles "Eppendorf" de 1,5 ml. Por lo tanto ha sido comparada la actividad bactericida de solo agua oxigenada a concentraciones del 0,5% y del 3%, de solo irradiación láser y de los dos tratamientos asociados. En todos los cultivos bacterianos en examen, el empleo del agua oxigenada en concentración del 3% asociada a la exposición de la irradiación láser por 10 segundos ha llevado a la ausencia o a una marcada disminución del número de colonias bacterianas, mientras que la disminución ha sido menos evidente, o ausente, en el caso de los tratamientos utilizados separadamente. Los resultados confirman la mayor eficacia bactericida de la acción combinada de agua oxigenada y láser. Abstract in english The use of laser in the odontological field is every day more spread thanks to the fact that it manages to reach a high standard of comfort for the patient in the therapeutic efficiency. The goal of this study is to test the efficiency of a protocol that foresees the associated use of laser irradiation and hydrogen peroxide to reduce the bacterial charge of stocks commonly present in active periodontal pockets. The five bacterial stocks studied are: Haemophilus actinomyce (more) temcomitans, Bacteroides forsytus, Porphyromonas gingivalis, Micromonas micron, Fusobacterium nucleatem. The laboratory method used foresees the following protocol: 30 ml of each bacterial suspension has been exposed to hydrogen peroxide at diverse concentrations at 0.5% or at 3% and it has been irradiated separately with laser for 5 seconds or 10 seconds, using sterile 1.5 ml Eppendorf tubes. It has been compared thus the bacterial activity of the hydrogen peroxide alone at the concentrations of 0.5% and 3%, the bacterial activity of the laser irradiation alone and of the two associated treatments. In every bacterial cultivation examined the use of hydrogen peroxide at 3% concentration associated with the 10 second laser irradiation exposure led to the absence or a marked decrease of the number of bacterial colonies, while the decrease has been less evident or absent in the case of the two treatments used separately. The results confirm the higher bactericide effectiveness of the combined action of hydrogen peroxide and laser.

Background: The purpose of this single-masked, randomized, controlled clinical trial was to evaluate the effects of boric acid (B) irrigation as an adjunct to scaling and root planing (SRP) on clinical and microbiological parameters and compare with chlorhexidine (CHX) irrigation and SRP alone in chronic periodontitis patients. Methods: Forty-five systemically healthy, chronic periodontitis patients were included in this study. They were divided into 3 groups: 1) SRP+saline irrigation (C), 2) SRP+chlorhexidine irrigation (CHX) and 3) SRP+boric acid irrigation (B). To determine an ideal concentration of boric acid, a pre-clinical analysis was conducted. At baseline and 1 and 3 months after treatment, clinical measurements including plaque index (PI), gingival index (GI), probing depth (PD), clinical attachment level (CAL), bleeding on probing (BOP) were performed and subgingival plaque samples were taken. Quantitative analysis of Porphyromonas gingivalis (Pg), Tannerella forsythia (Tf) and Treponema denticola (Td) was carried out using real-time polymerase chain reaction (PCR) procedures. Results: The concentration of boric acid was 0.75% in this study. All clinical parameters showed statistically significant reduction at all time points compared to baseline in all groups (p0.05). The PD and CAL reductions for moderately deep pockets (5?PD0.05). BOP (%) was significantly lower in B group compared to CHX and C groups in first month after treatment (p0.05). Conclusion: The results of this study suggested that Boric acid could be an alternative to CHX and it might be more favorable since B was superior in whole mouth BOP, and PD and CAL reduction for moderate pockets in early time period. PMID:23121460

Fc?RIIB contains a unique immunoreceptor tyrosine-based inhibition motif (ITIM) and functions as a negative feedback regulator of leucocyte activation and antibody production. We have previously reported Fc?RIIB-nt645+25A/G gene polymorphism to be associated with prevalence and severity of periodontitis, Fc?RIIB expression level on peripheral B lymphocytes and the serum IgG level against periodontopathic bacteria. Previous studies have reported maternal periodontal disease to be associated with an increased risk for preeclampsia. Therefore, Fc?RIIB-nt645+25A/G gene polymorphism may be associated with preeclampsia by affecting immune response to periodontopathic bacteria in pregnant women. To elucidate whether Fc?RIIB-nt645+25A/G gene polymorphism has associations with preeclampsia and/or periodontitis in pregnant Japanese women, a case-control study was carried out on women with preeclampsia (n?=?13) and without preeclampsia (n?=?106). Maternal periodontal parameters and bacterial data of Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis and Prevotella intermedia in subgingival plaque were collected within 5?days of delivery. Fc?R genotypes of each woman were determined using the genomic DNA isolated from peripheral blood. Serum IgG levels specific for each bacteria were determined. There was a significant association between Fc?RIIB-nt645+25A/G polymorphism and preeclampsia (P?=?0.013). The frequency of the Fc?RIIB-nt645+25AA genotype was higher in the preeclampsia group compared with the nonpreeclampsia group (P?=?0.007). The DNA level of A. actinomycetemcomitans from subgingival plaque was shown to be higher in the preeclampsia group (P?=?0.017). In conclusion, maternal Fc?RIIB-nt645+25A/G polymorphism and subgingival DNA level of A. actinomycetemcomitans were significantly associated with the prevalence of preeclampsia in a limited number of Japanese women independently with periodontal infection. Further investigations should be performed to confirm this association in a larger population and to determine the biological process of the association. PMID:22594540

BACKGROUND: Compromised T-cell responses to periodontal pathogens may contribute to the pathogenesis of generalized aggressive periodontitis (GAgP). In this study, we attempted to characterize T-helper cell (Th1, Th2, and Th17) responses in patients with GAgP and healthy controls upon stimulation with disease-relevant pathogens. METHODS: Mononuclear cells (MNCs) from 10 white patients with GAgP and 10 white controls were stimulated with Porphyromonas gingivalis American Type Culture Collection (ATCC) 33277 (Pg), Prevotella intermedia ATCC 25611, Fusobacterium nucleatum ATCC 49256 (Fn), and similar bacteria isolated from the participants' inherent oral flora. Tetanus toxoid (TT) was used as control antigen. The resulting production of interferon-gamma (IFN-gamma) and interleukin (IL)-2, -4, -5 and -17 and the induced proliferation of CD4+ T cells were measured. RESULTS: MNCs from patients with GAgP exhibited decreased IL-2 responses to Pg and Fn. No difference was observed between patients with GAgP and controls with regard to CD4+ T-cell proliferation or the production of IFN-gamma and IL-4, -5, and -17, irrespective of whether type strains or bacteria isolated from the participants' oral cavity were used for stimulation. Moreover, similar proliferative and cytokine responses to TT were observed. Notably, smoking patients with GAgP exhibited significantly lower IFN-gamma responses to the bacteria and to TT than non-smoking patients or controls. CONCLUSIONS: The decreased IL-2 responses of patients with GAgP to Pg and Fn combined with adequate IL-2 responses to TT suggest an impaired antigen-specific T-cell reactivity with periodontal pathogens in GAgP. The decreased IFN-gamma responses of smokers within the patient group suggest that smoking may aggravate this impairment.

Abstract in english Neutrophils play an important role in periodontitis by producing nitric oxide (NO) and antimicrobial peptides, molecules with microbicidal activity via oxygen-dependent and -independent mechanisms, respectively. It is unknown whether variation in the production of antimicrobial peptides such as LL-37, human neutrophil peptides (HNP) 1-3, and NO by neutrophils influences the pathogenesis of periodontal diseases. We compared the production of these peptides and NO by lipopo (more) lysaccharide (LPS)-stimulated neutrophils isolated from healthy subjects and from patients with periodontitis. Peripheral blood neutrophils were cultured with or without Aggregatibacter actinomycetemcomitans-LPS (Aa-LPS), Porphyromonas gingivalis-LPS (Pg-LPS) and Escherichia coli-LPS (Ec-LPS). qRT-PCR was used to determine quantities of HNP 1-3 and LL-37 mRNA in neutrophils. Amounts of HNP 1-3 and LL-37 proteins in the cell culture supernatants were also determined by ELISA. In addition, NO levels in neutrophil culture supernatants were quantitated by the Griess reaction. Neutrophils from periodontitis patients cultured with Aa-LPS, Pg-LPS and Ec-LPS expressed higher HNP 1-3 mRNA than neutrophils from healthy subjects. LL-37 mRNA expression was higher in neutrophils from patients stimulated with Aa-LPS. Neutrophils from periodontitis patients produced significantly higher LL-37 protein levels than neutrophils from healthy subjects when stimulated with Pg-LPS and Ec-LPS, but no difference was observed in HNP 1-3 production. Neutrophils from periodontitis patients cultured or not with Pg-LPS and Ec-LPS produced significantly lower NO levels than neutrophils from healthy subjects. The significant differences in the production of LL-37 and NO between neutrophils from healthy and periodontitis subjects indicate that production of these molecules might influence individual susceptibility to important periodontal pathogens.

Because oral infections are common, the physician must understand the underlying etiology, pathogeny, and other variables that determine how these processes evolve in order to choose the most appropriate antibiotic drug. The special characteristics of the oral cavity determine the make-up of the microflora that lives there. Different anaerobic species belonging to the Peptostreptococcus, Prevotella, Fusobacterium, Gemella, and Porphyromonas genera are of particular interest, as are the aerobic species Streptococcus, Staphylococcus, and Corynebacterium. Each of these microorganisms occupies a different microniche within the oral cavity, and the prevailing balance is upset when conditions become modified as a result of illness or due to dental interventions such as tooth extraction or tooth scaling and polishing. Pathogenic or opportunistic bacteria (Actinomyces, Prevotella intermedia species, etc.) can develop in these conditions, as can yeasts (Candida sp., Histoplasma capsulatum), virus (herpes simplex, papilomavirus), and parasites (Entamoeba gingivalis, Trichomonas tenax). When infection occurs, the patients s immune system reacts by means of inborn immunity (non-specific) and acquired immunity (specific). Empirical treatment is administered that should be based on etiological data and on the antimicrobial sensitivity of the pathogen that is causing the infection. However, oral microflora sensitivity to different antibiotics is currently declining and there is a noticeable trend towards resistances. As a consequence of all this, the treatment of oral infections must also aim to restore the ecological balance of the oral cavity and to minimize the emergence of resistance in the microorganisms present in the mouth. Hence, epidemiological oral pathogen sensitivity studies must be conducted, fostering the administration of appropriate antibiotics at proper doses and keeping specialists abreast of the latest trends. In recent decades, oral infections comprise one of the most common pathologies in the general population, due in large part to infectious complications associated with poor oral hygiene. This in turn, translates into an increased need and demand for dental care, while at the same time, it requires that the professional accurately understand the etiological factors involved, as well as the pathogeny and different variables that determine the specificity of these kinds of infections, so as to be able to choose the appropriate antimicrobial drugs for proper treatment. PMID:15580129

Two hundred patients (100 males and 100 females) having either marginal periodontitis or gingivitis were examined for detection of E. gingivalis and T. tenax. E. gingivalis was more prevalent among patients with periodontitis particularly females, while T. tenax was not discovered entirely in both patients and control groups. PMID:1578154

Bacterial endotoxin (lipopolysaccharide) depresses cardiovascular function; however, the mediators and signaling pathways that are responsible for the negative inotropic effects of lipopolysaccharide are not fully known.

Investigators using light microscopy have identified the protozoan parasite Entamoeba gingivalis from diseased gingival pockets for nearly 100 years. The objective of the present investigation was to develop a molecular biology approach for determining the presence of E. gingivalis in both diseased gingival pockets and healthy gingival sites. For this, a previously developed conventional polymerase chain reaction (PCR) was evaluated and a real-time polymerase chain reaction assay was developed. Paper points were inserted into the base of the sulcus of both diseased gingival pockets and healthy gingival sites. DNA was extracted using the QIAamp DNA mini kit, and subsequently analyzed using conventional and real-time PCR analysis. A previously described primer set specific for the small subunit ribosomal RNA gene (SSU rDNA) of E. gingivalis was used for the conventional PCR. For the real-time PCR, a primer set was designed to amplify a 135-bp fragment inside the SSU rDNA of E. gingivalis. A conventional PCR assay detected E. gingivalis in 27% of diseased gingival pockets. The real-time PCR using a different primer set detected protozoa in 69% of diseased pocket sites. Thus, the latter technique proved more sensitive for detection of E. gingivalis. No E. gingivalis were detected in any of the healthy gingival pocket sites using either type of PCR assay. Results support a concept that the presence of E. gingivalis is associated only with diseased gingival pocket sites. The newly described methodology may also serve to provide a novel eukaryotic cell marker of disease status in gingival pockets. PMID:21400116

Abstract in spanish Objetivo: estudiar la frecuencia de Entamoeba gingivalis y Trichomonas tenax en pacientes diabéticos y la relación, de estos protozoarios, con IgA, pH y las periodontopatías. Material y método: se trabajó con 50 pacientes de ambos sexos, cuyas edades oscilaron entre 25 a 69 años, que concurrieron al servicio de Diagnóstico de la Facultad de Odontología de Rosario, Argentina. De cada paciente se obtuvo una muestra de placa y/o cálculo dental y una de saliva para l (more) a búsqueda de E. gingivalis y T. tenax por microscopía directa, cultivo y tinción tricrómica para E. gingivalis. En saliva se determinó también concentración de IgA y pH. Los resultados se analizaron estadísticamente. Resultados: de los 50 pacientes estudiados, 37 (74%) presentaron parásitos. La prevalencia de E. gingivalis fue 91% y 32% para T. tenax. Los cultivos de T. tenax aumentaron significativamente la sensibilidad diagnótica. Sin embargo para E. gingivalis, ni el cultivo ni la coloración aumentaron la sensibilidad. Las determinaciones de IgA salival y pH, en la población de pacientes parasitados, mostraron que un elevado número de los mismos presentaron rangos de valores normales. La patología bucal predominante en los individuos que presentaron parásitos fue gingivitis. Conclusión: la presencia de parásitos no está asociada con ninguna de las tres variables. Abstract in english Objective: to study the frequency of Entamoeba gingivalis and Trichomonas tenax in diabetic patients and the relation between these protozoa and IgA, pH and periodontal pathologies. Material and Method: 50 patients, both sexes, whose eges varied between 25 and 69 were investigated. They had attended the Diagnosis Service of the Faculty of Odontology, Rosario, Argentina for consultation. A sample of dental plaque and/or tartar was obtained from each patient, plus a saliva (more) sample, for the search of E. gingivalis and T. tenax, by direct optical microscopy and culture for both and trichromic stain for E. gingivalis. IgA and pH concentrations were also determined in saliva. Results were statistically analyzed. Results: out of the 50patiens studied, 37 (74%) presented parasites. The prevalence of E. gingivalis was 91%, while it was 32% for T. tenax. However, neither culture nor coloration increased E. gingivalis sensitivity. Salivary IgA and pH determinations in parasitized patients showed that many of these patients presented normal value ranges. Gingivitis was the predominant buccal pathology in parasitized individuals. Conclusion: the presence of parasites is not associated with any of the three variables.

Abstract Objective. Periodontal ligament (PDL) cells produce IL-6 upon stimulation with inflammation promoters, but the signaling pathways involved have not been characterized. This study investigates underlying mechanisms behind regulation of PDL cell IL-6 production by E. coli and P. gingivalis LPS. Materials and methods: Human PDL cells, endothelial cells and monocytes were stimulated with E. coli or P. gingivalis LPS in the presence or absence of pharmacological agents in order to disclose pathways involved in LPS signaling. Gene expression and cellular protein levels were assessed by quantitative real-time PCR and ELISA, respectively. Results. Stimulation with LPS from E. coli (1 µg/ml) for 24 h enhanced PDL cell IL-6 expression several fold, demonstrated both on transcript and protein levels, but P. gingivalis LPS (1-5 µg/ml) had no effect. TLR2 mRNA was more highly expressed than TLR4 transcript in PDL cells. Treatment with the non-selective nitric oxide synthase inhibitor L-NAME (100 µM) reduced E. coli LPS-induced PDL cell IL-6 by 30%, while neither aminoguanidine (10 µM), an inhibitor of inducible nitric oxide synthase, nor estrogen (17?-estradiol, 100 nM) influenced IL-6. Treatment with the glucocorticoid dexamethasone (1 µM) totally prevented the E. coli LPS-induced PDL cell IL-6. In endothelial cells, neither E. coli LPS nor P. gingivalis LPS promoted IL-6 production. In monocytes, serving as positive control, both E. coli and P. gingivalis LPS stimulated IL-6. Conclusions. E. coli LPS but not P. gingivalis LPS stimulates PDL cell IL-6 production through a glucocorticoid-sensitive mechanism involving nitric oxide formation, probably via endothelial nitric oxide synthase. PMID:23116357

The protozoa Entamoeba gingivalis and Trichomonas tenax together with yeasts of the genus Candida were investigated in the mouth (gums or neck of tooth) of 509 healthy or diabetic subjects. A study of the possible correlation between presence of these parasites and various local or general factors, showed that neither the sex, maxillo-facial anomalies nor smoking had any influence on parasite incidence. Entamoeba gingivalis was encountered in 85 per cent of subjects free from parodontopathy. Numerous factors influenced the presence of Trichomonas tenax: age, social status, alcohol consumption, dental condition and gingival pathology. Presence of Candida was associated with diabetes, poor buccal hygiene and dental condition. PMID:395489

The apoptotic cell death induced in D-galactosamine-sensitized mice by administration of lipopolysaccharide was characterized. Administration of lipopolysaccharide caused apoptotic cell death in livers of D-galactosamine-sensitized mice. Apoptotic cells were also detected in the kidney, thymus, sple...

The complement-requiring passive hemolysis test with Salmonella typhimurium lipopolysaccharide-coated sheep erythrocytes is more sensitive for antibodies directed against the lipopolysaccharide than is the passive hemagglutination test. The hemagglutinating and hemolyzing antibodies produced in Swis...

We describe two mouse monoclonal antibodies reactive with lipopolysaccharide derived from the J5 mutant of Escherichia coli O111:B4. These antibodies react with purified lipopolysaccharide derived from rough mutants of E. coli and Salmonella typhimurium and also with lipopolysaccharide associated wi...

The fine structure of lipopolysaccharide isolated from Thermoplasma acidophilum was examined by electron microscopy. Negative staining of the lipopolysaccharide revealed long, ribbon-like structures with some branching. The average width of the lipopolysaccharide ribbons was 5 nm. Treatment of the l...

Alzheimer's disease susceptibility genes, APP and gamma-secretase, are involved in the herpes simplex life cycle, and that of other suspect pathogens (C. pneumoniae, H. pylori, C. neoformans, B. burgdorferri, P. gingivalis) or immune defence. Such pathogens promote beta-amyloid deposition and tau ph...

A study on the presence of oral Entamoeba gingivalis and Trichomonas tenax has been carried out on calculus or dental plaque from 117 diabetic subjects. Statistical analysis of results shows no correlation between diabetes and protozoa. The same frequency was found between diabetic and normal subjects. Nevertheless, a significant relation has been found between the diabetes and the yeasts. PMID:372177

Since the pH of the gingival crevice increases from below neutrality in health to above pH 8 in disease, we decided to investigate the effect of environmental pH on the growth and enzyme activity of Bacteroides gingivalis W50. Cells were grown in a chemostat under hemin-excess conditions over a rang...

Background: Interactions between eosinophils and monocytes after lipopolysaccharide inhalation are yet to be investigated. The mechanism of eosinophil activation induced by lipopolysaccharide in the presence of monocytes was investigated. Methods: Expression of ICAM-1 and Mac-1 on eosinophils was evaluated after lipopolysaccharide stimulation in the presence of monocytes or monocyte culture supernatants. Cytokines in the supernatant of lipopolysaccharide-stimulated monocytes were measured using a cytokine array. Results: Expression of ICAM-1 and Mac-1 on eosinophils was up-regulated after lipopolysaccharide stimulation in the presence of monocytes or monocyte culture supernatant. Lipopolysaccharide induced secretion of ENA-78, GMCSF, GRO, IL-1beta, IL-6, IL-10, MCP-1, TNF-alpha and MIP-3 alpha from monocytes. The up-regulation of ICAM-1, but not Mac-1, on eosinophils was attenuated by anti-TNF-alpha neutralizing antibody. Conclusions: Monocyte-derived TNF-alpha plays an important role in the up-regulation of ICAM-I on eosinophils induced by lipopolysaccharides.   

The lipopolysaccharide structure of oil field and freshwater isolates of bacteria that reduce ferric iron, recently classified as strains of Shewanella putrefaciens, was analyzed using polyacrylamide gel electrophoresis and a lipopolysaccharide-specific silver-staining procedure. The results demonstrate that all the oil field and freshwater isolates examined exhibited the more hydrophobic R-type lipopolysaccharide, which has been found to be characteristic of Gram-negative marine bacteria. This hydrophobic lipopolysaccharide would confer an advantage on bacteria involved in hydrocarbon degradation by assisting their association with the surface of oil droplets. 15 refs., 1 fig.

The oral protozoa frequency has been studied in 300 patients consulting for oral problems. Entamoeba gingivalis has been isolated more frequently in culture than Trichomonas tenax (50.7% against 28%). The age range which showed the highest frequency in protozoa was the 30-34 year old group for the amoeba and the 45-54 year old group for the flagellae. The endemia increased progressively in relation to the OHIS index. Trichomonas tenax is three times more frequent in case of deep periodontal diseases whereas, Entamoeba gingivalis reached its highest frequency in the case of gingivitis. The pathogenic potentials of these protozoa have been discussed in the light of these correlations and some therapeutical arguments. PMID:6943141

The oral cavity is suitable for invasion of many microorganisms. Entamoeba gingivalis (E.gingivalis) and Trichomonas tenax (T.tenax) settle in the oral cavity of patients with poor oral hygiene and gingival disease. In the present study, two slide specimens were prepared from the cole region of the teeth of 46 persons for investigation of the parasites. One of the slide specimens was dried in the air while the other one put into fixative and they were stained with trichrome and Giemsa stains. The two staining methods were used for 36 samples and only Giemsa, for 10 samples. E. gingivalis was positive in 7 (19.44%) out of 36 samples stained by the trichrome stain while T. tenax was positive in one (2.17%) out of 46 samples stained by Giemsa stain. Parasitic infections were found to be positive in seven (21.2%) specimen from 33 patients with periodontal disease and in one (7.69%) specimen from 13 healthy controls. Dental policlinics are generally far from parasitology laboratories and microscopical wet mount examination can not be performed. Therefore dentists can send the specimens and have the parasites diagnosed with Giemsa and trichrome staining methods as an alternative to wet mount examination. PMID:20597052

The E. coli yrbG-lptB locus (yrbG kdsD kdsC lptC lptA lptB) encodes genes for outer membrane biogenesis, namely: kdsC and kdsD for biosynthesis of the lipopolysaccharide inner core sugar Kdo, and lptA, lptB, and lptC for lipopolysaccharide transport to the outer membrane. Three promoters (yrbGp, kds...

To begin to understand the surprising survival of macrophage-specific lipopolysaccharide-induced tumor necrosis factor alpha factor-deficient (macLITAF?/?) animals after a lethal dose of lipopolysaccharide (LPS), as reported earlier, the present follow-up study focuses on the role of LITAF in the re...

In a previous study we demonstrated that lipopolysaccharide failed to elicit nonspecific resistance in C3H/He lipopolysaccharide low-responder mice against Klebsiella infection in contrast to its activity in a closely related histocompatible high-responder subline, C3HeB/Fe. Complete restoration of ...

Intravenous injection of a small dose of lipopolysaccharide 24 h before infection with Listeria monocytogenes enhanced the resistance of mice to this organism. This protective effect of lipopolysaccharide related to the ability of nonimmune macrophages to inhibit bacterial proliferation in livers an...

Abstract in english Lipopolysaccharide induces TLR-1-8 mRNAs over-expression in corneal fibroblast. Analyzing if other TLR-ligands can do the same, we found that peptidoglycan does, but not muramyldipeptide, lipoteichoic acid and polyI:C. This suggests that the recognition of lipopolysaccharide and peptidoglycan is enough to alert these cells against microorganisms through the over-expression of the majority TLRs.

Mild alkaline hydrolysis was found to enhance the mitogenicity of lipopolysaccharide endotoxin for murine B lymphocytes. Alkaline treated lipopolysaccharide also retained its property as a polyclonal activator. Whereas this treatment reduced the lethality of endotoxin for mice, its toxicity for lymp...

The lipopolysaccharide receptors for the mutator bacteriophages Mu, MuhP1, and D108 were investigated with lipopolysaccharide mutants of Salmonella typhimurium LT2. Mu adsorbed only to mutants lacking the terminal O antigen but retaining the main chain sugars of the core; the side chain N-acetylgluc...

Four monoclonal antibodies were raised against the lipopolysaccharide of Rhizobium leguminosarum bv. phaseoli CFN42 grown in tryptone and yeast extract. Two of these antibodies reacted relatively weakly with the lipopolysaccharide of bacteroids of this strain isolated from bean nodules. Growth ex pl...

Mild acid hydrolysis of Hafnia alvei strain 2 lipopolysaccharide released no O-specific polysaccharide but instead gave a monomeric octasaccharide repeating unit with N-acetylneuraminic acid as the reducing terminus. In addition, a dimer of the octasaccharide repeating unit, and also a decasaccharide composed of a fragment of the O-specific polysaccharide chain and the core region, were obtained in minute amounts. On the basis of the sugar and methylation analyses, periodate oxidation, and {sup 1}H NMR spectroscopy of the lipopolysaccharide hydrolytic products, the biological repeating unit of the O-specific polysaccharide was shown to be a branched octasaccharide. The linkage between the O-specific polysaccharide chain and core region has also been determined and has yielded strong evidence that N-acetylneuraminic acid is an inherent lipopolysaccharide component. The lipopolysaccharide of H. alvei strain 2 is the first lipopolysaccharide reported to contain 4-substituted neuraminic acid in its O-specific polysaccharide region.

Abstract in spanish La endotoxina (lipopolisacárido) induce estados trombogénicos en el shock séptico. La agregación plaquetaria inducida por lipopolisacárido es inhibida por ticlopidina. Investigamos si ticlopidina podía modificar el efecto de la interacción lipopolisacárido - plaqueta sobre la morfología de cultivos endoteliales. Las células fueron aisladas de la microvasculatura dérmica de embriones de rata. Los cultivos fueron incubados con: lipopolisacárido; lipopolisacárid (more) o + plasma rico en plaquetas; lipopolisacárido + plasma rico en plaquetas de ratas pretratadas con ticlopidina; lipopolisacárido + solución de ticlopidina; lipopolisacárido + plasma rico en plaquetas + solución de ticlopidina; solución de ticlopidina. Se evidenció daño celular con lipopolisacárido, que se acentuó en presencia de plasma rico en plaquetas, pero con plasma rico en plaquetas procedente de ratas pretratadas con ticlopidina, estas alteraciones no estuvieron presentes. En conclusión ticlopidina suprimió las alteraciones derivadas de la interacción lipopolisacárido - plaqueta sobre el endotelio por lo que podría tener un potencial terapéutico en el shock séptico Abstract in english induced by lipopolysaccharide is inhibited by ticlopidina. We investigated if ticlopidina could modify the effect of the lipopolysaccharide -platelets interaction, on endothelial cell morphology. The endothelial cells were isolated from rat embryos dermal microvasculature. The cultures were incubated with: lipopolysaccharide; lipopolysaccharide + platelet rich plasma; lipopolysaccharide + platelet rich plasma from rats treated with ticlopidina; lipopolysaccharide + ticlop (more) idina solution; lipopolysaccharide + control platelet rich plasma + ticlopidina; ticlopidina solution. The results evidenced citoplasmatic alterations with lipopolysaccharide. This cellular damage was strengthen by platelet rich plasma; however, in the presence of platelet rich plasma from rats pretreated with ticlopidina, these changes did not become present. We concluded that ticlopidina suppresses some derived adverse effects of the lipopolysaccharide -platelet interaction on the endothelium, thus ticlopidina could have a therapeutic potential on septic shock

Isoforskolin was isolated from Coleus forskohlii native to Yunnan in China. We hypothesize that isoforskolin pretreatment attenuates acute lung injury induced by lipopolysaccharide (endotoxin). Three acute lung injury models were used: situ perfused rat lung, rat and mouse models of endotoxic shock. Additionally, lipopolysaccharide stimulated proinflammatory cytokine production was evaluated in human mononuclear leukocyte. In situ perfused rat lungs, pre-perfusion with isoforskolin (100, and 200mM) and dexamethasone (65mM, positive control) inhibited lipopolysaccharide (10 mg/L) induced increases in lung neutrophil adhesion rate, myeloperoxidase activity, lung weight Wet/Dry ratio, permeability-surface area product value, and tumor necrosis factor (TNF)-a levels. In rats, pretreatments wit...

PurposeWe determined toll-like receptor expression in normal human urothelium and functional responses in normal human urothelial cell cultures to bacterial lipopolysaccharide via toll-like receptor-4 and to flagellin via toll-like receptor-5. Materials and MethodsToll-like receptor protein expression was examined immunohistochemically. Toll-like receptor transcript expression was determined in freshly isolated urothelium, and in proliferating and differentiated normal human urothelial cultured cells. Lipopolysaccharide binding was assessed by flow cytometry. Functional responses of proliferating and differentiated normal human urothelial cells to lipopolysaccharide and flagellin were determined by interleukin-6 and 8 secretion, and transcription factor activation. Polymyxin B and siRNA we...

Abstract in spanish Para determinar la prevalencia de Entamoeba gingivalis y Trichomonas tenax en cavidad bucal, se analizaron 50 muestras de la cavidad bucal de individuos de ambos géneros que acudieron a la Clínica Integral del Adulto de la Facultad de Odontología de la Universidad del Zulia. Se dividieron en dos grupos, de 25 individuos cada uno. Grupo 1, con manifestaciones clínicas de enfermedad (enfermedad periodontal y/o caries dental) al cual se le tomaron muestras de caries dent (more) al, placa y cálculo dental y grupo 2 o control con cavidad bucal sin manifestaciones clínicas de enfermedad, al cual se le tomó muestras de saliva y placa dental. Las muestras fueron analizadas microscópicamente a través del examen directo y con coloración permanente de hematoxilina férrica. Se observó una prevalencia de protozoarios bucales de un 10%; la especie predominante fue Entamoeba gingivalis en 5 casos, seguida de Trichomonas tenax en 1 caso. El estrato de 20 a 39 años fue el más afectado con un 10% de los casos. Al realizar el análisis estadístico resultó significativo (p=0,011) para las variables parasitismo y cavidad bucal enferma. El presente estudio pone de manifiesto una baja prevalencia de los protozoarios bucales en la población estudiada. Abstract in english Fifty samples from the oral cavity of individuals of both genders who attended the Integral Adult Clinic of the Faculty of Odontology of Universidad del Zulia were analyzed to determine Entamoeba gingivalis and Trichomonas tenax prevalence. The patients were divided into two groups of 25 individuals each: Group 1, with clinical disease manifestations (periodontal disease and/or dental caries) from which we took samples from dental caries, plaque and dental calculus; and G (more) roup 2 or control, who had no clinical disease manifestations, from which we took saliva and dental plaque samples. All samples were analyzed microscopically through direct examination and with a ferric hematoxilin stain. There was a 10% prevalence of oral protozoa; the predominant species was Entamoeba gingivalis in 5 cases followed by Trichomonas tenax in 1 case. The 20-39 years age group was the most affected with 10% of cases. The statistical analysis was significant (p=0.011) for the parasitism and diseased oral cavity variables. The present study shows a low prevalence of oral cavity protozoa in the population studied.

Abstract in spanish El objetivo de la presente investigación fue estudiar los efectos de un gel de tetraciclina al 5% sobre los niveles de 3 microorganismos asociados al desarrollo de la periodontitis rápidamente progresiva (PRP). En un total de 20 pacientes con PRP se seleccionaron 5 dientes por paciente con bolsas periodontales > a 5 mm. con sangrado al sondaje periodontal en los cuales se efectuaron los siguientes tratamientos: 1. Control. 2. Aplicación de un gel de tetraciclina al 5% (more) (T). 3. Placebo (Pl). 4. Raspado y alisado radicular (RA). 5. T + RA .De forma previa, en cada sitio seleccionado, se tornaron muestras de placa subgingival con un cono de papel estéril para detectar y cuantificar la presencia de P. gingivalis , P. intermedia y A. actinomycetemcomitans, mediante el uso de sondas DNA (OMNIGENE, U.S.A.).Se dieron instrucciones de higiene oral, y se efectuó un nuevo control microbiológico a los 60 días El análisis estadístico de los resultados demostró lo siguiente: 1. Ninguno de los tratamientos redujo significativamente los niveles de A. actinomycetemcomitans. 2. Se detectó una reducción significativa de P. gingivalis en los sitios tratados con (R.A). (p Abstract in english The purpose of this investigation was to study the effects of local delivery of a tetracycline 5% gel on the levels of 3 bacteria associated to development of rapidly progressive periodontitis. In a sample of 20 patients, five teeth were selected from each patient with periodontal pockets > 5 mm and bleeding upon probing. One of the following treatments were done at each selected site: 1. Control (no treatment). 2. Local delivery of a 5% tetracycline gel. 3. Placebo gel. (more) 4. Scaling and root planing. 5. Scaling and root planing + local application of tetracycline gel. Previously, at each selected site samples of subgingival plaque were taken with sterile paper points in order to detecte and quantify the presence of P.gingivalis, P.intermedia and A. actinomycetemcomitans, by using DNA probe technology (OMNIGENE, U.S.A.). Oral hygiene instructions were given to each patient and new samples of subgingival plaque were obtained at 60 days. Statistical analysis of results showed the following 1. No significant reductions of A. actinomycetemcomitans were found with performed treatments. 2. Scaling and root planing reduced the levels of P. gingivalis (p 0.02) or when the later was combined with tetracycline (p

Ehrlichia chaffeensis is an obligately intracellular gram-negative bacterium and is the etiologic agent of human monocytic ehrlichiosis (HME). Although E. chaffeensis induces the generation of several cytokines and chemokines by leukocytes, E. chaffeensis lacks lipopolysaccharide and peptidoglycan. ...

Escherichia coli alpha-hemolysin was purified from culture supernatants by affinity chromatography, using a hemolysis-neutralizing monoclonal antibody ligand. Purified hemolysin contains several proteins and lipopolysaccharides. Thus, alpha-hemolysin exists as a macromolecular complex and may be exp...

Progress in the characterisation of Neisseria gonorrhoeae and other bacterial pathogens has suggested that immunoprophylaxis for gonorrhoea may be possible despite the well-known propensity for reinfection. Pili, outer membrane proteins, a capsular polysaccharide, and the lipopolysaccharide may be i...

Murine peritoneal macrophages were preincubated with amphotericin B (AMPH) and were then stimulated with bacterial lipopolysaccharide or streptococcal preparation (OK432). These macrophages produced a large amount of tumor necrosis factor. When administered to mice, the priming activity of amphoteri...

R-Form lipopolysaccharides of Acinetobacter calcoaceticus could be incorporated into polyacrylamide gels in an immobile form by adding it directly to the acrylamide-N,N'-methylenebisacrylamide polymerization mixture. The separation of A. calcoaceticus 69 V outer membrane proteins in these affinity gels demonstrated a specific interaction with the lipopolysaccharide ligand for one of the proteins. This protein is heat-modifiable and has an Mr of about 18,000. By incorporation of varying concentrations of lipopolysaccharide, a dissociation constant of the protein-lipopolysaccharide complex of 0.5 mM could be determined. In comparison, for another A. calcoaceticus strain, CCM 5593, a higher dissociation constant (1.0 mM)--indicative of lower affinity--was obtained. PMID:2743966

Mycobacteria produce two sets of unusual polymethylated polysaccharides, the 3-O-methylmannose polysaccharides and the 6-O-methylglucose lipopolysaccharides. Both polysaccharides localize to the cytoplasm, where they have been postulated to regulate fatty acid metabolism due to their ability to ...

The lipopolysaccharides ( LPSs ) from strains of Rhizobium leguminosarum, Rhizobium trifolii, and Rhizobium phaseoli were isolated and partially characterized by mild acid hydrolysis and by polyacrylamide gel electrophoresis. Mild acid hydrolysis results in a precipitate which can be removed by cent...

Pseudomonas aeruginosa-mediated suppression of the immune response to Listeria monocytogenes was investigated in mice. Because delayed-type hypersensitivity (DTH) footpad swelling to L. monocytogenes was suppressed equally in lipopolysaccharide-responsive and -hyporesponsive mouse strains, the lipop...

The phospholipid ester-linked normal and lipopolysaccharide layer hydroxy fatty acids from microbes in a natural gas (85% methane)-stimulated soil column capable of degrading halogenated hydrocarbons were analyzed in detail by capillary column GC-MS. Microbial biomass, calculated...

Pasteurella tularensis cell wall or lipopolysaccharide (LPS), unlike Salmonella enteritidis LPS, is nontoxic for mice previously sensitized by enterotoxin B. Studies in normal mice challenged with P. tularensis 425, a strain of intermediate virulence, dem...

Abstract Platelets are reportedly causal in hepatitis. We previously showed that in mice, lipopolysaccharide (LPS) induces a reversible and macrophage-dependent hepatic platelet accumulation (HPA), including translocation of platelets into Disse spaces and their entry into hepatocytes. Conca...

Isoforskolin was isolated from Coleus forskohlii native to Yunnan in China. We hypothesize that isoforskolin pretreatment attenuates acute lung injury induced by lipopolysaccharide (endotoxin). Three acute lung injury models were used: situ perfused rat lung, rat and mouse models of endotoxic shock. Additionally, lipopolysaccharide stimulated proinflammatory cytokine production was evaluated in human mononuclear leukocyte. In situ perfused rat lungs, pre-perfusion with isoforskolin (100, and 200 ?M) and dexamethasone (65 ?M, positive control) inhibited lipopolysaccharide (10 mg/L) induced increases in lung neutrophil adhesion rate, myeloperoxidase activity, lung weight Wet/Dry ratio, permeability-surface area product value, and tumor necrosis factor (TNF)-? levels. In rats, pretreatments with isoforskolin (5, 10, and 20 mg/kg, i.p.) and dexamethasone (5mg/kg, i.p.) markedly reduced lipopolysaccharide (6 mg/kg i.v.) induced increases of karyocyte, neutrophil counts and protein content in bronchoalveolar lavage fluid, and plasma myeloperoxidase activity. Lung histopathology showed that morphologic changes induced by lipopolysaccharide were less pronounced in the isoforskolin and dexamethasone pretreated rats. In mice, 5 mg/kg isoforskolin and dexamethasone caused 100% and 80% survival, respectively, after administration of lipopolysaccharide (62.5mg/kg, i.v., 40% survival if untreated). In human mononuclear leukocyte, isoforskolin (50, 100, and 200 ?M) and dexamethasone (10 ?M) pre-incubation lowered lipopolysaccharide (2 ?g/mL) induced secretion of the cytokine TNF-?, and interleukins (IL)-1?, IL-6, and IL-8. In conclusion, pretreatment with isoforskolin attenuates lipopolysaccharide-induced acute lung injury in several models, and it is involved in down-regulation of inflammatory responses and proinflammatory cytokines TNF-?, IL-1?, IL-6, and IL-8. PMID:21272678

The lipopolysaccharides of three strains each of Rhizobium leguminosarum, R. phasecoli, and R. trifolii have been purified and partially characterized. The last step in the purification procedure is gel filtration column chromatography using Sepharose 4B with the elution buffer consisting of ethylenediaminetetraacetic acid and triethylamine. Each of the lipopolysaccharides reported in this paper elutes as a symmetrical peak in the partially included volume of this Sepharose 4B column. The ration of 2-keto-3-deoxyoctonate acid (a sugar which is characteristic of lipopolysaccharides) to hexose is constant throughout the carbohydrate-containing peaks as they elute from the Sepharose 4B. The compositions and immunodominant structures of the purified lipopolysaccharides vary as much among strains of a single Rhizobium species as among the different species of Rhizobium. There is no obvious correlation between the nodulation group to which a Rhizobium belongs and the chemical composition or immunochemistry of the Rhizobium's lipopolysaccharide. There is extensive crosslysis by phage of strains of R. trifolii, R. phaseoli, and R. leguminosarum. This suggests that the receptors for these cross-lysing phage reside either in nonlipopolysaccharide structures or in common structures within the lipopolysaccharide which are not detected by compositional or immunochemical analysis.

Objectives: Immunologic processes are involved in preterm delivery (PTD). Considering the anti-inflammatory properties of muscimol (GABA(A) agonist), the effect of this drug was evaluated in lipopolysaccharide-induced PTD in mice. Methods: PTD was induced by two intraperitoneal injections of lipopolysaccharide (35 µg/kg; n = 11), on gestational day 15 (d15). Muscimol was administered twice on d14 and twice on d15 (1?h prior to each lipopolysaccharide injection; 0.05, 0.1, 0.2?mg/kg; intraperitoneally; n = 8-12). To assess the involved mechanisms, either bicuculline (GABA(A) antagonist; 0.1 and 1 µg/kg; intraperitoneally; n = 6-7) or N(?)-nitro-l-arginine methyl ester (l-NAME; non-selective inhibitor of nitric oxide (NO) synthase enzymes; 2?mg/kg; intraperitoneally; n = 6) were administered 1?h before each muscimol administration on d14 and the first dose of muscimol on d15. Maternal plasma and amniotic fluid nitrite + nitrate levels, placental histopathologies and uterine contractions were assessed. Results: Muscimol (0.1?mg/kg) significantly decreased lipopolysaccharide-induced PTD rates from 100 to 50% and delayed delivery time from d16 to d18. Muscimol moderately increased maternal plasma and amniotic fluid nitrite + nitrate concentrations and decreased lipopolysaccharide-induced placental inflammation and surge in nitrite + nitrate levels. Contrary to bicuculline, l-NAME reversed the beneficial effects of muscimol. Muscimol did not affect myometrial contractions. Conclusions: Muscimol inhibits lipopolysaccharide-induced PTD through modulating NO release. PMID:22913283

Abstract in portuguese Realizou-se um estudo sobre a microbiota saprófita associada à doença periodontal espontânea em cães com o objetivo de identificar as bactérias anaeróbias predominantes nas lesões. Com auxílio de cureta odontológica, amostras colhidas diretamente do espaço subgengival foram semeadas em meio CDC (Central for Disease Control) para anaeróbios e incubadas, em anaerobiose, a 37°C, por sete dias. A caracterização das colônias foi realizada por meio da morfologia (more) e do teste bioquímico (Sistema API 20AÒ). Identificaram-se os seguintes gêneros: Prevotella spp., Bacteroides spp., Propionibacterium spp., Gemella spp., Actinomyces spp., Eubacterium spp. e Porphyromonas spp. Abstract in english Anaerobic bacteria associated with spontaneous periodontal disorders were studied. The samples were directly colected from the subgingival space with a odontologic curet, and they were plated in Central for Disease Control culture medium for anaerobic bacteria and incubated in anaerobic conditions at 37°C for seven days. The characterization of the colonies were done by the morphologic study and biochemical tests (API 20A). Prevotella spp., Bacteroides spp., Propionibact (more) erium spp., Actinomyces spp., Eubacterium spp., Porphyromonas spp. and Gemella spp. were identified in the samples.

Various chymotrypsin inhibitors occur in the hemolymph of silkworm larvae. Interaction of chymotrypsin inhibitor b1 (CI-b1) with Escherichia coli was examined from the viewpoint of action against invading bacteria. Injection of dead E. coli cells into larva reduced the CI-b1 content of the hemolymph, suggesting in vivo binding of CI-b1 to the outer membrane of the cell. Results from incubation of E. coli in cell-free hemolymph in the presence or absence of lipopolysaccharide indicated that CI-b1 is the only CI bound to E. coli and that it interacts with lipopolysaccharide. CI-b1 formed a complex with lipopolysaccharide in vitro; the value of the dissociation constant was relatively large. Inhibitory activity of CI-b1 changed insignificantly in mixture with lipopolysaccharide. CI-b1 affected the growth of E. coli but never worked lethally. CI-b1 is speculated to be a mediator that scavenges intruding bacteria rather than a direct anti-bacterial factor. This is the first report confirming that CI-b1 is a lipopolysaccharide binding protein.   

BackgroundSepsis is a major health threat that remains refractory to treatment. Impairment of normal cellular function due to oxidative stress is implicated in organ injury during systemic inflammatory responses. We investigated whether the new anti-oxidative drug, ETS-GS, could inhibit secretion of cytokines and mono-nitrogen oxides, thus reducing organ damage in a rat model of lipopolysaccharide-induced sepsis. Materials and MethodsLipopolysaccharide was administered intravenously to male Wistar rats in order to establish a rat model of systemic inflammation. These rats were challenged with or without intravenous ETS-GS. Mouse macrophage RAW264.7 cells were stimulated with lipopolysaccharide, with or without simultaneous ETS-GS treatment, in order to elucidate the mechanism of action. Re...

Alveolar epithelial cell death plays a crucial role in the progression of acute lung injury. We have demonstrated up-regulation of Fas expression on alveolar epithelial cells, and soluble Fas ligand secretion from inflammatory cells upon acute lung injury. Here we show that the lipopolysaccharide-stimulated human monocyte cell line THP-1 releases Fas ligand, and that conditioned medium from lipopolysaccharide-stimulated THP-1 cells induces apoptosis of the human pulmonary adenocarcinoma cell line A549. Activation of caspase-3 and -8 is associated with the apoptosis. Gene targeting on Fas in A549 cells by specific small interfering RNA impairs apoptosis induced by conditioned medium from activated THP-1, while that on Fas ligand in THP-1 cells impairs the apoptosis-inducing activity of the conditioned medium produced by lipopolysaccharide-stimulated cells. These results suggest that Fas ligand released by monocytes causes alveolar epithelial cell death through a Fas-dependent apoptotic mechanism in the development of acute lung injury.   

Abstract in english Sepsis is a systemic inflammatory response that can lead to tissue damage and death. In order to increase our understanding of sepsis, experimental models are needed that produce relevant immune and inflammatory responses during a septic event. We describe a lipopolysaccharide tolerance mouse model to characterize the cellular and molecular alterations of immune cells during sepsis. The model presents a typical lipopolysaccharide tolerance pattern in which tolerance is re (more) lated to decreased production and secretion of cytokines after a subsequent exposure to a lethal dose of lipopolysaccharide. The initial lipopolysaccharide exposure also altered the expression patterns of cytokines and was followed by an 8- and a 1.5-fold increase in the T helper 1 and 2 cell subpopulations. Behavioral data indicate a decrease in spontaneous activity and an increase in body temperature following exposure to lipopolysaccharide. In contrast, tolerant animals maintained production of reactive oxygen species and nitric oxide when terminally challenged by cecal ligation and puncture (CLP). Survival study after CLP showed protection in tolerant compared to naive animals. Spleen mass increased in tolerant animals followed by increases of B lymphocytes and subpopulation Th1 cells. An increase in the number of stem cells was found in spleen and bone marrow. We also showed that administration of spleen or bone marrow cells from tolerant to naive animals transfers the acquired resistance status. In conclusion, lipopolysaccharide tolerance is a natural reprogramming of the immune system that increases the number of immune cells, particularly T helper 1 cells, and does not reduce oxidative stress.

Abstract:- The effects of red meat consumption with and without fermentable carbohydrates on indices of large bowel health in rats were examined. Sprague-Dawley rats were fed cellulose, potato fiber, or potato-resistant starch diets containing 12% casein for 2 wk, then similar diets containing 25% cooked beef for 6 wk. After week 8, cecal and colonic microbiota composition, fermentation end-products, colon structure, and colonocyte DNA damage were analyzed. Rats fed potato fiber had lower Bacteroides-Prevotella-Porphyromonas group compared to other diet groups. Colonic Bifidobacterium spp. and/or Lactobacillus spp. were higher in potato fiber and potato-resistant starch diets than in the cellulose diet. Beneficial changes were observed in short-chain fatty acid concentrations (acetic, buty...

Abstract Aims: Purification, identification and partial characterization of bacteriocin produced by Lactobacillus paracasei HL32. It has been shown to have activity against Porphyromonas sp. Methods and Results: The purification of bacteriocin consisting of gel exclusion followed by anion exchange chromatography produced a single band upon an electrophoresis gel with a molecular weight corresponding to 56 kDa. The isolated protein contained 171 amino acids and the first 151 were sequenced. The bacteriocin contained a high percentage of cationic amino acids near the N-terminus, hydrophobic amino acids in the central region (Leu, Ile, Val, Phe, Trp and Gly) and hydrophilic residues (Ser, Asn and Gln) at the C-terminus. This structure did not match with that of previously reported bacteriocin...

Outer membrane vesicles (OMV) are used as a vaccine against Neisseria meningitidis serogroup B and are traditionally produced with detergent-extraction to remove toxic lipopolysaccharide. Engineered strains with attenuated lipopolysaccharide allowed the use of native vesicles (NOMV) with improved stability and immunogenicity. In the NOMV production process detergents are omitted and vesicle release is stimulated with EDTA extraction (a chelating agent) to enable a higher yield. Many process parameters may change the EDTA extraction efficiency, but it is unknown what the optimal ranges for these parameters are in terms of quality. The present study systematically optimized EDTA extraction and was representative for production at large-scale. Two critical process parameters were identified, ...

The viability of Gram-negative organisms is dependent on the proper placement of lipopolysaccharide (LPS) in the outer leaflet of its outer membrane. LPS is synthesized inside the cell and transported to the surface by seven essential lipopolysaccharide transport (Lpt) proteins. How these proteins cooperate to transport LPS is unknown. We show that these Lpt proteins can be found in a membrane fraction that contains inner and outer membranes and that they copurify. This constitutes the first evidence that the Lpt proteins form a transenvelope complex. We suggest that this protein bridge provides a route for LPS transport across the cell envelope. PMID:20446753

Millions of molecules of lipopolysaccharide (LPS) must be assembled on the E. coli cell surface every division. Biogenesis of LPS requires seven essential lipopolysaccharide transport (Lpt) proteins to move LPS from the inner membrane through the periplasm to the cell surface. However, no intermediate transport states have been observed. We developed methods to observe intermediate LPS molecules bound to Lpt proteins in the process of being transported in vivo. Movement of individual LPS molecules along these binding sites required multiple rounds of ATP hydrolysis in vitro, which suggests that ATP is used to push a continuous stream of LPS through a transenvelope bridge in discrete steps against a concentration gradient. PMID:23138981

A methanolic extract of dried leaves of Polygala japonica Houtt (Polygalaceae) significantly attenuated nitric oxide production in lipopolysaccharide-simulated BV2 microglia. Five anthraquinones chrysophanol (1), emodin (2), aloe-emodin (3), emodin 8-O-beta-D-glucopyranoside (4) and trihydroxy anthraquinone (5), and four flavonoids kaempferol (6), chrysoeriol (7), kaempferol 3-gentiobioside (8) and isorhamnetin (9) were isolated from the methanolic extract using bioactivity-guided fractionation. Among them, compounds 1-4, 6 and 7 showed significant inhibitory effect on lipopolysaccharide-induced nitric oxide production in BV2 microglia at the concentrations ranging from 1.0 to 100.0 microM. PMID:18825536

Modulation of intestinal microbiota by non-digestible carbohydrates may reduce inflammation in inflammatory bowel disease (IBD). The aim of the present study was to assess the effects of inulin and fructo-oligosaccharides (FOS) on intestinal microbiota and colitis in HLA-B27 transgenic rats, a well-validated rodent model for IBD. In this study, 4-week-old rats were fed 8 g/kg body weight inulin or FOS for 12 weeks, or not. Faeces were collected at 4 and 16 weeks of age; and caecal samples were collected at necropsy. The effects of inulin and FOS on chronic intestinal inflammation were assessed using a gross gut score, histology score and levels of mucosal IL-1?. Intestinal microbiota were characterised by quantitative PCR and denaturing gradient gel electrophoresis. Colitis was significantly reduced in all FOS-fed rats compared to the control diet, whereas inulin decreased chronic intestinal inflammation in only half the number of animals. Quantitative analysis of caecal microbiota demonstrated that inulin increased the numbers of total bacteria and the Bacteroides-Prevotella-Porphyromonas group, FOS increased bifidobacteria, and both fructans decreased Clostridium cluster XI. In the faecal samples, both inulin and FOS decreased total bacteria, Bacteroides-Prevotella-Porphyromonas group, and Clostridium clusters XI and XIVa. FOS increased Bifidobacterium spp., and mediated a decrease of gene copies of Enterobacteriaceae and Clostridium difficile toxin B in faeces. SCFA concentrations in the faecal and caecal samples were unaffected by the diets. In conclusion, FOS increased the abundance of Bifidobacterium spp., whereas both fructans reduced Clostridium cluster XI and C. difficile toxin gene expression, correlating with a reduction of chronic intestinal inflammation. PMID:22243836

Infection rates of parasites in the oral cavity were compared for two study areas in South Kalimantan, Indonesia. Penguiran and Sungai Baru, two adjacent villages, were considered a single study area and were inhabited by 151 individuals ranging from 2 to 70 years. Tanah Intan, the second study area, had a population of 265 persons who also ranged from 2 to 70 years. The standard of living was low in all the villages (average of 450 U.S. dollars per family per year). Teeth and gums were examined by standard diagnostic techniques. Material from infected gums was examined for parasites. Of the 373 individuals studied, 49 were infected with Entamoeba gingivalis, 1 with Entamoeba histolytica, 19 with Trichomonas tenax, and 14 with Candida sp. The infection rates in the first study area were substantially lower than in the second study area. PMID:6729983

Cyclic ADP-ribose (cADPR), a universal calcium mobilizer from intracellular stores, was recently demonstrated to stimulate proliferation of various cell types. The role of cADPR in a specific process of monocyte- and plasma-mediated activation of T-lymphocytes by lipopolysaccharide (LPS) was address...

It is thought that lipopolysaccharide (LPS) from gram-negative bacteria contributes significantly to the pathogenesis of septic shock. In vitro studies to address the mechanisms involved in this process have often investigated human monocytes or mouse macrophages, since these cells produce many of t...

Filarial nematodes harbour intracellular endosymbiotic bacteria, which have been assigned to the genus Wolbachia. These bacteria appear to play an important role in the pathogenesis of filarial diseases through their lipopolysaccharides. In view of the presence of Wolbachia endosymbionts in the body...

To examine the in vivo effects of the 15-member macrolide, azithromycin (AZM), on mucus hypersecretion, we induced hypertrophic and metaplastic changes of goblet cells in rat nasal epithelium by intranasal instillation of ovalbumin (OVA) in OVA-sensitized rats, or by intranasal lipopolysaccharides (...

Sugar coat: The nitrogen-fixing soil bacterium Bradyrhizobium sp. BTAi1 is coated with a unique lipopolysaccharide that does not induce innate immune responses in its host plant Aeschynomene indica or in different plant families. The chemical nature of the monosaccharide forming the polymer (see picture) is unprecedented in nature, which helps to avoid "harmful" recognition by its symbiotic host. PMID:22058060

The effect of human milk on B cell function was studied by using murine spleen cells stimulated with suboptimal doses of lipopolysaccharide. Cell free, defatted, filtered colostrum as well as mature breast milk showed an enhancing effect on B cell proliferation and generation of antibody secretion, ...

Lipopolysaccharide (LPS) fluorescently labeled with boron dipyrromethane (BODIPY) first binds to the plasma membrane of CD14-expressing cells and is subsequently internalized. Intracellular LPS appears in small vesicles near the cell surface and later in larger, punctate structures identified as the...

We have characterized the nitric oxide (NO) induction by CpG oligodeoxydinucleotide (CpG-ODN) and lipopolysaccharide (LPS) in an avian macrophage cell line (HD11) and evaluated roles of signal transduction pathways by using selective inhibitors. Our results indicate while CpG-ODN and LPS both stimu...

Background: Membrane-bound CD14 (mCD14) is a myeloid differentiation antigen expressed on monocytes/macrophages and neutrophils. It is a key molecule responsible for the innate recognition of bacteria by host cells and functions as an important receptor for bacterial lipopolysaccharide. This study i...

Taxol, a microtubule stabilizer with anticancer activity, mimics the actions of lipopolysaccharide (LPS) on murine macrophages in vitro. Recently, it was shown that taxol-induced macrophage activation was inhibited by the LPS antagonist Rhodobacter sphaeroides diphosphoryl lipid A (RsDPLA). To inves...

Taxol, a plant-derived antitumor agent, stabilizes microtubules. Taxol also elicits cell signals in a manner indistinguishable from bacterial lipopolysaccharide (LPS). LPS-like actions of Taxol are controlled by the lps gene and are independent of binding to the known Taxol target, ?-tubulin. Using ...

As Lewis a (Lea) and Lewis b (Leb) blood group antigens are isoforms of Lewis x (Lex) and Lewis y (Ley) and are expressed in the gastric mucosa, we evaluated whether the patterns of expression of Lex and Ley on Helicobacter pylori lipopolysaccharides reflected those of host expression of Lea and Leb...

Lewis X (Lex) antigen is expressed on the human gastric mucosa and the O-specific chain of lipopolysaccharides of Helicobacter pylori. This antigen can induce autoantibodies, which may be involved in bacterial colonization and thus deserve further investigation. Flow cytometry was used to examine th...