| the opportunistic human pathogenic fungus aspergillus fumigatus evades the host complement system. | the opportunistic human pathogenic fungus aspergillus fumigatus causes severe systemic infections and is a major cause of fungal infections in immunocompromised patients. a. fumigatus conidia activate the alternative pathway of the complement system. in order to assess the mechanisms by which a. fumigatus evades the activated complement system, we analyzed the binding of host complement regulators to a. fumigatus. the binding of factor h and factor h-like protein 1 (fhl-1) from human sera to a. ... | 2008 | 18039838 |
| interspecies interactions within oral microbial communities. | while reductionism has greatly advanced microbiology in the past 400 years, assembly of smaller pieces just could not explain the whole! modern microbiologists are learning "system thinking" and "holism." such an approach is changing our understanding of microbial physiology and our ability to diagnose/treat microbial infections. this review uses oral microbial communities as a focal point to describe this new trend. with the common name "dental plaque," oral microbial communities are some of th ... | 2007 | 18063722 |
| resistance of porphyromonas gingivalis atcc 33277 to direct killing by antimicrobial peptides is protease independent. | antimicrobial peptides are short, positively charged, amphipathic peptides that possess a wide spectrum of antimicrobial activity and have an important role in the host's innate immunity. lack of, or dysfunctions in, antimicrobial peptides have been correlated with infectious diseases, including periodontitis. porphyromonas gingivalis, a gram-negative anaerobe and a major pathogen associated with periodontal diseases, is resistant to antimicrobial peptides of human and nonhuman origin, a feature ... | 2008 | 18086848 |
| resistance of porphyromonas gingivalis atcc 33277 to direct killing by antimicrobial peptides is protease independent. | antimicrobial peptides are short, positively charged, amphipathic peptides that possess a wide spectrum of antimicrobial activity and have an important role in the host's innate immunity. lack of, or dysfunctions in, antimicrobial peptides have been correlated with infectious diseases, including periodontitis. porphyromonas gingivalis, a gram-negative anaerobe and a major pathogen associated with periodontal diseases, is resistant to antimicrobial peptides of human and nonhuman origin, a feature ... | 2008 | 18086848 |
| the buccale puzzle: the symbiotic nature of endogenous infections of the oral cavity. | the indigenous, 'normal', microflora causes the majority of localized infectious diseases of the oral cavity (eg, dental caries, alveolar abscesses, periodontal diseases and candidiasis). the same microflora also protects the host from exogenous pathogens by stimulating a vigorous immune response and provides colonization resistance. how can a microflora that supports health also cause endogenous oral disease? this paradoxical host-symbiont relationship will be discussed within the dynamic of sy ... | 2002 | 18159372 |
| high incidence of actinobacillus actinomycetemcomitans infection in acute coronary syndrome. | recent epidemiological studies suggest that periodontitis is an important risk factor for coronary heart disease (chd). the aim of this study was to evaluate the association between periodontitis and chd, particularly acute coronary syndrome (acs), focusing on microbiological and immunological features. twenty-eight chd patients, 15 with acs and 13 with chronic chd, were included in this study. coronary angiography, periodontal examination, and dental radiography were performed in all patients. ... | 2007 | 18160759 |
| factors and selenocysteine insertion sequence requirements for the synthesis of selenoproteins from a gram-positive anaerobe in escherichia coli. | selenoprotein synthesis in escherichia coli strictly depends on the presence of a specific selenocysteine insertion sequence (secis) following the selenocysteine-encoding uga codon of the respective mrna. it is recognized by the selenocysteine-specific elongation factor selb, leading to cotranslational insertion of selenocysteine into the nascent polypeptide chain. the synthesis of three different selenoproteins from the gram-positive anaerobe eubacterium acidaminophilum in e. coli was studied. ... | 2008 | 18165360 |
| degradation of complement 3 by streptococcal pyrogenic exotoxin b inhibits complement activation and neutrophil opsonophagocytosis. | streptococcal pyrogenic exotoxin b (spe b), a cysteine protease, is an important virulence factor in group a streptococcus (gas) infection. the inhibition of phagocytic activity by spe b may help prevent bacteria from being ingested. in this study, we examined the mechanism spe b uses to enable bacteria to resist opsonophagocytosis. using an enzyme-linked immunosorbent assay, we found that spe b-treated serum impaired the activation of the classical, the lectin, and the alternative complement pa ... | 2008 | 18174338 |
| borrelia burgdorferi uniquely regulates its motility genes and has an intricate flagellar hook-basal body structure. | borrelia burgdorferi is a flat-wave, motile spirochete that causes lyme disease. motility is provided by periplasmic flagella (pfs) located between the cell cylinder and an outer membrane sheath. the structure of these pfs, which are composed of a basal body, a hook, and a filament, is similar to the structure of flagella of other bacteria. to determine if hook formation influences flagellin gene transcription in b. burgdorferi, we inactivated the hook structural gene flge by targeted mutagenesi ... | 2008 | 18192386 |
| phylogenetic characterization and prevalence of "spirobacillus cienkowskii," a red-pigmented, spiral-shaped bacterial pathogen of freshwater daphnia species. | microscopic examination of the hemolymph from diseased daphniids in 17 lakes in southwestern michigan and five rock pools in southern finland revealed the presence of tightly coiled bacteria that bore striking similarities to the drawings of a morphologically unique pathogen, "spirobacillus cienkowskii," first described by elya metchnikoff more than 100 years ago. the uncultivated microbe was identified as a deeply branching member of the deltaproteobacteria through phylogenetic analyses of two ... | 2008 | 18192404 |
| the use of rodent models to investigate host-bacteria interactions related to periodontal diseases. | even though animal models have limitations, they are often superior to in vitro or clinical studies in addressing mechanistic questions and serve as an essential link between hypotheses and human patients. periodontal disease can be viewed as a process that involves four major stages: bacterial colonization, invasion, induction of a destructive host response in connective tissue and a repair process that reduces the extent of tissue breakdown. animal studies should be evaluated in terms of their ... | 2008 | 18199146 |
| the genome of pelotomaculum thermopropionicum reveals niche-associated evolution in anaerobic microbiota. | the anaerobic biodegradation of organic matter is accomplished by sequential syntrophic catabolism by microbes in different niches. pelotomaculum thermopropionicum is a representative syntrophic bacterium that catalyzes the intermediate bottleneck step in the anaerobic-biodegradation process, whereby volatile fatty acids (vfas) and alcohols produced by upstream fermenting bacteria are converted to acetate, hydrogen, and carbon dioxide (substrates for downstream methanogenic archaea). to reveal g ... | 2008 | 18218977 |
| three unique groups of spirochetes isolated from digital dermatitis lesions in uk cattle. | bovine digital dermatitis (bdd) is a severe infectious cause of lameness which has spread through dairy cattle populations worldwide, causing serious welfare and agricultural problems. spirochetes are the main organisms implicated and have previously proven difficult to isolate. this study aimed to isolate and characterise the range of spirochetes associated with bdd in the uk. twenty-three spirochete isolates were obtained from 30 bdd lesions, which by 16s rrna gene and flab2 gene analysis clus ... | 2008 | 18243592 |
| novel ultrastructures of treponema primitia and their implications for motility. | members of the bacterial phylum spirochaetes are generally helical cells propelled by periplasmic flagella. the spirochete treponema primitia is interesting because of its mutualistic role in the termite gut, where it is believed to cooperate with protozoa that break down cellulose and produce h(2) as a by-product. here we report the ultrastructure of t. primitia as obtained by electron cryotomography of intact, frozen-hydrated cells. several previously unrecognized external structures were reve ... | 2008 | 18248579 |
| heavy metal tolerance in stenotrophomonas maltophilia. | stenotrophomonas maltophilia is an aerobic, non-fermentative gram-negative bacterium widespread in the environment. s. maltophilia sm777 exhibits innate resistance to multiple antimicrobial agents. furthermore, this bacterium tolerates high levels (0.1 to 50 mm) of various toxic metals, such as cd, pb, co, zn, hg, ag, selenite, tellurite and uranyl. s. maltophilia sm777 was able to grow in the presence of 50 mm selenite and 25 mm tellurite and to reduce them to elemental selenium (se(0)) and tel ... | 2008 | 18253487 |
| heterologous expression of the treponema pallidum laminin-binding adhesin tp0751 in the culturable spirochete treponema phagedenis. | treponema pallidum subsp. pallidum, the causative agent of syphilis, is an unculturable, genetically intractable bacterium. here we report the use of the shuttle vector pkmr4pemcs for the expression of a previously identified t. pallidum laminin-binding adhesin, tp0751, in the nonadherent, culturable spirochete treponema phagedenis. heterologous expression of tp0751 in t. phagedenis was confirmed via reverse transcriptase pcr analysis with tp0751 gene-specific primers and immunofluorescence anal ... | 2008 | 18263731 |
| genome sequence of the saprophyte leptospira biflexa provides insights into the evolution of leptospira and the pathogenesis of leptospirosis. | leptospira biflexa is a free-living saprophytic spirochete present in aquatic environments. we determined the genome sequence of l. biflexa, making it the first saprophytic leptospira to be sequenced. the l. biflexa genome has 3,590 protein-coding genes distributed across three circular replicons: the major 3,604 chromosome, a smaller 278-kb replicon that also carries essential genes, and a third 74-kb replicon. comparative sequence analysis provides evidence that l. biflexa is an excellent mode ... | 2008 | 18270594 |
| transcriptional regulation of nad metabolism in bacteria: genomic reconstruction of niar (yrxa) regulon. | a comparative genomic approach was used to reconstruct transcriptional regulation of nad biosynthesis in bacteria containing orthologs of bacillus subtilis gene yrxa, a previously identified niacin-responsive repressor of nad de novo synthesis. members of yrxa family (re-named here niar) are broadly conserved in the bacillus/clostridium group and in the deeply branching fusobacteria and thermotogales lineages. we analyzed upstream regions of genes associated with nad biosynthesis to identify can ... | 2008 | 18276644 |
| human serum antibodies recognize treponema denticola msp and prtp protease complex proteins. | treponema denticola outer membrane proteins are postulated to have key roles in microbe-host interactions in periodontitis. because there are no reports of in vivo expression of these putative virulence factors, we examined several t. denticola strains to determine whether sera from human subjects recognized specific t. denticola outer membrane proteins. | 2008 | 18279185 |
| increased interleukin-18 in gingival crevicular fluid from periodontitis patients. | this study aimed to measure the levels of interleukin-18 (il-18) in inflamed shallow sites and inflamed deep sites in patients with periodontitis and to compare the data with results from inflamed shallow sites in patients with gingivitis. a secondary aim was to examine the composition of the subgingival microbiota in the sampled sites. | 2008 | 18279187 |
| etiological analysis of initial colonization of periodontal pathogens in oral cavity. | it is unclear when the initial colonization by periodontal pathogens occurs in the oral cavity. therefore, we report here the association between specific age groups and the time when the initial colonization by periodontal pathogens occurs in the oral cavity in such groups. findings are based on an epidemiological analysis of the prevalence of five periodontal pathogens in the oral cavities of a wide range of age populations, from newborn to elderly, who were randomly selected in a geographic r ... | 2008 | 18287326 |
| colonization pattern of periodontal bacteria in japanese children and their mothers. | the purpose of this study was to determine the time of infection by anaerobic gram-negative rods associated with periodontal disease, and to clarify their transmission from mother to child. | 2008 | 18302616 |
| microbial changes in patients with acute periodontal abscess after treatment detected by padotest. | to investigate changes in bacterial counts in subgingival plaque from patients with acute periodontal abscess by iai-padotest. | 2008 | 18302679 |
| treponema denticola msp-deduced peptide conjugate, p34bsa, promotes rhoa-dependent actin stress fiber formation independent of its internalization by fibroblasts. | p34(bsa), a bsa conjugate of a synthetic 10-mer peptide deduced from treponema denticola major outer sheath protein (msp), stabilizes actin filaments in fibroblasts and retards cell motility. we reported previously that it is internalized by cells, binds and bundles actin filaments in vitro, and activates rhoa; yet, its site and mechanism of action were not defined. we have assessed p34(bsa)'s modes of interaction with and signaling to fibroblasts. at 4 degrees c, p34(bsa) was not internalized, ... | 2008 | 18330900 |
| a novel treponema pallidum antigen, tp0136, is an outer membrane protein that binds human fibronectin. | the antigenicity, structural location, and function of the predicted lipoprotein tp0136 of treponema pallidum subsp. pallidum were investigated based on previous screening studies indicating that anti-tp0136 antibodies are present in the sera of syphilis patients and experimentally infected rabbits. recombinant tp0136 (rtp0136) protein was purified and shown to be strongly antigenic during human and experimental rabbit infection. the tp0136 protein was exposed on the surface of the bacterial out ... | 2008 | 18332212 |
| mutl homologs in restriction-modification systems and the origin of eukaryotic morc atpases. | the provenance and biochemical roles of eukaryotic morc proteins have remained poorly understood since the discovery of their prototype morc1, which is required for meiotic nuclear division in animals. the morc family contains a combination of a gyrase, histidine kinase, and mutl (ghkl) and s5 domains that together constitute a catalytically active atpase module. we identify the prokaryotic morcs and establish that the morc family belongs to a larger radiation of several families of ghkl protein ... | 2008 | 18346280 |
| oxyr is involved in coordinate regulation of expression of fima and sod genes in porphyromonas gingivalis. | survival of porphyromonas gingivalis in the constantly changing oral environment depends on its ability to alter gene expression. we demonstrate here that p. gingivalis activates superoxide dismutase expression in response to oxidative stress and represses expression of fima, a subunit of major fimbriae. coordinated expression of fima and sod is regulated by the redox-sensing transcription factor oxyr. mutations in the oxyr gene result in a decreased expression of sod and in an elevated expressi ... | 2008 | 18355277 |
| treponema denticola lipooligosaccharide activates gingival fibroblasts and upregulates inflammatory mediator production. | in response to bacterial challenges, fibroblasts, a major constituent of gingival connective tissue, can produce immunoregulatory cytokines and proteolytic enzymes that may contribute to tissue destruction and the progression of periodontitis, a chronic inflammatory disease affecting tooth-supporting tissues, including alveolar bone. the spirochete treponema denticola is a major etiological agent of periodontitis and can invade oral tissues. the aim of the present study was to investigate the in ... | 2008 | 18366071 |
| estimating the extent of horizontal gene transfer in metagenomic sequences. | although the extent of horizontal gene transfer (hgt) in complete genomes has been widely studied, its influence in the evolution of natural communities of prokaryotes remains unknown. the availability of metagenomic sequences allows us to address the study of global patterns of prokaryotic evolution in samples from natural communities. however, the methods that have been commonly used for the study of hgt are not suitable for metagenomic samples. therefore it is important to develop new methods ... | 2008 | 18366724 |
| site-specific development of periodontal disease is associated with increased levels of porphyromonas gingivalis, treponema denticola, and tannerella forsythia in subgingival plaque. | porphyromonas gingivalis, treponema denticola, and tannerella forsythia (previously t. forsythensis), which are regarded as the principal periodontopathogenic bacteria, exist as a consortium in subgingival biofilms. we aimed to examine quantitative relationships between p. gingivalis, t. denticola, and t. forsythia in subgingival biofilms and the relationship between the quantity and prevalence of these three bacteria and site-specific periodontal health. | 2008 | 18380560 |
| absence of alphavbeta6 integrin is linked to initiation and progression of periodontal disease. | integrin alphavbeta6 is generally not expressed in adult epithelia but is induced in wound healing, cancer, and certain fibrotic disorders. despite this generalized absence, we observed that alphavbeta6 integrin is constitutively expressed in the healthy junctional epithelium linking the gingiva to tooth enamel. moreover, expression of alphavbeta6 integrin was down-regulated in human periodontal disease, a common medical condition causing tooth loss and also contributing to the development of ca ... | 2008 | 18385522 |
| occurrence of herpes simplex virus 1 and three periodontal bacteria in patients with chronic periodontitis and necrotic pulp. | viral and bacterial associations appear to be implicated in the development of periodontal infections. little information is available describing the periodontopathic agents in root canals with necrotic pulp. in this study, the occurrence and the combinations among herpes simplex virus type 1 (hsv-1) and dialister pneumosintes, tannerella forsythia, and treponema denticola in patients with chronic periodontitis and necrotic pulp were evaluated. clinical samples from healthy subjects and patients ... | 2008 | 18389006 |
| highly conserved surface proteins of oral spirochetes as adhesins and potent inducers of proinflammatory and osteoclastogenic factors. | oral spirochetes include enormously heterogeneous treponema species, and some have been implicated in the etiology of periodontitis. in this study, we characterized highly conserved surface proteins in four representative oral spirochetes (treponema denticola, t. lecithinolyticum, t. maltophilum, and t. socranskii subsp. socranskii) that are homologs of t. pallidum tp92, with opsonophagocytic potential and protective capacity against syphilis. tp92 homologs of oral spirochetes had predicted sign ... | 2008 | 18390996 |
| bleeding on probing differentially relates to bacterial profiles: the oral infections and vascular disease epidemiology study. | various bacterial species are differentially prevalent in periodontal health, gingivitis or periodontitis. we tested the independent associations between three bacterial groupings and gingival inflammation in an epidemiological study. | 2008 | 18400025 |
| effect of glucose on treponema denticola cell behavior. | treponema denticola inhabits the oral subgingival environment and is part of a proteolytic benzoyl-dl-arginine-naphthylamide-positive 'red complex' associated with active periodontal disease. spirochetes have a unique form of chemotactic motility that may contribute to their virulence. chemotaxis is essential for efficient nutrient-directed translocation. | 2008 | 18402610 |
| the role of released atp in killing candida albicans and other extracellular microbial pathogens by cationic peptides. | a unifying theme common to the action of many cationic peptides that display lethal activities against microbial pathogens is their specific action at microbial membranes that results in selective loss of ions and small nucleotides-chiefly atp. one model cationic peptide that induces non-lytic release of atp from the fungal pathogen candida albicans is salivary histatin 5 (hst 5). the major characteristic of hst 5-induced atp release is that it occurs rapidly while cells are still metabolically ... | 2007 | 18404422 |
| antibody levels to single bacteria or in combination evaluated against myocardial infarction. | evidence is accumulating that oral bacteria are associated with myocardial infarctions (mi). we were interested in studying the differences in the association between single bacteria or bacteria in combination and the relation to c-reactive protein (crp). | 2008 | 18410396 |
| genome-wide subcellular localization of putative outer membrane and extracellular proteins in leptospira interrogans serovar lai genome using bioinformatics approaches. | in bacterial pathogens, both cell surface-exposed outer membrane proteins and proteins secreted into the extracellular environment play crucial roles in host-pathogen interaction and pathogenesis. considerable efforts have been made to identify outer membrane (om) and extracellular (ex) proteins produced by leptospira interrogans, which may be used as novel targets for the development of infection markers and leptospirosis vaccines. | 2008 | 18423054 |
| microbial analysis of canals of root-filled teeth with periapical lesions using polymerase chain reaction. | the objective of the present study was to investigate the presence of nine bacterial species in root-filled teeth associated with periapical lesions using a polymerase chain reaction analysis and to correlate these species with clinical features of the cases. dna was extracted from 45 canal samples of root-filled teeth with periapical lesions. a pcr assay using species-specific primers of 16s rdna and the downstream intergenic spacer region was used for microbial detection. enterococcus faecalis ... | 2008 | 18436030 |
| the prevalence of periodontopathogenic bacteria in saliva is linked to periodontal health status and oral malodour. | this study investigated whether an improvement in periodontal health resulted in changes in the prevalence of periodontopathogenic bacteria in saliva and tongue coatings and a reduction in volatile sulfur compounds (vscs: h(2)s and ch(3)sh) linked to oral malodour. the subjects were 35 patients who visited the breath odour clinic of kyushu dental college, japan. their mean age was 51.2+/-18.3 years (mean+/-sd). a clinical examination performed at baseline and 2 months after periodontal treatment ... | 2008 | 18436598 |
| detection of treponema denticola in root canal systems in primary and secondary endodontic infections. a correlation with clinical symptoms. | the aim of the study was to investigate the presence of treponema denticola in primary and secondary root-infected canal systems with periapical pathology and correlations with clinical signs and symptoms. | 2008 | 18437843 |
| a variable gene in a conserved region of the helicobacter pylori genome: isotopic gene replacement or rapid evolution? | the present study concerns the identification of a novel coding sequence in a region of the helicobacter pylori genome, located between jhp1069/hp1141 and jhp1071/hp1143 according to the numbering of the j99 and 26,695 reference strains, respectively, and spanning three different coding dna sequences (cdss). the cdss located at the centre of this locus were highly polymorphic, as determined by the analysis of 24 european isolates, 3 asian, and 3 african isolates. phylogenetic and molecular evolu ... | 2008 | 18442984 |
| comparative analysis of putative periodontopathic bacteria by multiplex polymerase chain reaction. | the polymerase chain reaction (pcr) has been applied for the rapid and specific detection of periodontopathic bacteria in subgingival plaque and is potentially of clinical benefit in the diagnosis and treatment of periodontitis subjects. however, several technical points need to be modified before the conventional pcr detection system can be used by clinicians. | 2008 | 18447853 |
| effects of age and oral disease on systemic inflammatory and immune parameters in nonhuman primates. | this report evaluated systemic inflammatory and immune biomarkers in a cohort of macaca mulatta (rhesus monkeys) maintained as a large family social unit, including an age range from <1 year to >24 years. we hypothesized that the systemic host responses would be affected by the age, gender, and clinical oral presentation of the population, each contributing to inflammatory and immune responses that would reflect chronic oral infections. the results demonstrated that the prevalence and severity o ... | 2008 | 18448617 |
| ability of oral bacteria to induce tissue-destructive molecules from human neutrophils. | the induction of tissue-destructive molecules from neutrophils by periodontopathic bacteria has been suggested as one of the mechanisms of periodontal destruction. the aim of this study was to determine whether the ability to stimulate neutrophils is an authentic characteristic of periodontopathic bacteria. | 2008 | 18449962 |
| reca mediated spontaneous deletions of the icaadbc operon of clinical staphylococcus epidermidis isolates: a new mechanism of phenotypic variations. | phenotypic variation of staphylococcus epidermidis involving the slime related ica operon results in heterogeneity in surface characteristics of individual bacteria in axenic cultures. five clinical s. epidermidis isolates demonstrated phenotypic variation, i.e. both black and red colonies on congo red agar. black colonies displayed bi-modal electrophoretic mobility distributions at ph 2, but such phenotypic variation was absent in red colonies of the same strain as well as in control strains wi ... | 2008 | 18454346 |
| photodynamic therapy as adjunct to non-surgical periodontal treatment in patients on periodontal maintenance: a randomized controlled clinical trial. | recent preclinical and clinical data have suggested the potential benefit of photodynamic therapy (pdt) in the treatment of periodontitis. however, currently, there are very limited data from controlled clinical trials evaluating the effect of pdt in the treatment of periodontitis. the aim of the present study was to evaluate the clinical and microbiological effects of the adjunctive use of pdt in non-surgical periodontal treatment in patients receiving supportive periodontal therapy. twenty-fou ... | 2009 | 18465191 |
| native cellular architecture of treponema denticola revealed by cryo-electron tomography. | using cryo-electron tomography, we are developing a refined description of native cellular structures in the pathogenic spirochete treponema denticola. tightly organized bundles of periplasmic flagella were readily observed in intact plunge-frozen cells. the periplasmic space was measured in both wild-type and aflagellate strains, and found to widen by less than the diameter of flagella when the latter are present. this suggests that a structural change occurs in the peptidoglycan layer to accom ... | 2008 | 18468917 |
| a genome-wide proteome array reveals a limited set of immunogens in natural infections of humans and white-footed mice with borrelia burgdorferi. | humans and other animals with lyme borreliosis produce antibodies to a number of components of the agent borrelia burgdorferi, but a full accounting of the immunogens during natural infections has not been achieved. employing a protein array produced in vitro from 1,292 dna fragments representing approximately 80% of the genome, we compared the antibody reactivities of sera from patients with early or later lyme borreliosis to the antibody reactivities of sera from controls. overall, approximate ... | 2008 | 18474646 |
| interaction of porphyromonas gingivalis with oral streptococci requires a motif that resembles the eukaryotic nuclear receptor box protein-protein interaction domain. | porphyromonas gingivalis initially colonizes the oral cavity by interacting with organisms in supragingival plaque, such as the oralis group of oral streptococci. this interaction involves the association of the streptococcal antigen i/ii with the minor fimbrial antigen (mfa1) of p. gingivalis. our previous studies showed that a peptide (bar) derived from antigen i/ii inhibits p. gingivalis adherence and subsequent biofilm formation on streptococcal substrates. in addition, screening a combinato ... | 2008 | 18474648 |
| assessment of the microbiota in root canals of human primary teeth by checkerboard dna-dna hybridization. | the purpose of this study was to evaluate in vivo the prevalence of microorganisms in root canals of human primary teeth, by checkerboard dna-dna hybridization. | 2007 | 18477431 |
| complete genome sequence of treponema pallidum ssp. pallidum strain ss14 determined with oligonucleotide arrays. | syphilis spirochete treponema pallidum ssp. pallidum remains the enigmatic pathogen, since no virulence factors have been identified and the pathogenesis of the disease is poorly understood. increasing rates of new syphilis cases per year have been observed recently. | 2008 | 18482458 |
| a 52-kda leucyl aminopeptidase from treponema denticola is a cysteinylglycinase that mediates the second step of glutathione metabolism. | the metabolism of glutathione by the periodontal pathogen treponema denticola produces hydrogen sulfide, which may play a role in the host tissue destruction seen in periodontitis. h2s production in this organism has been proposed to occur via a three enzyme pathway, gamma-glutamyltransferase, cysteinylglycinase (cgase), and cystalysin. in this study, we describe the purification and characterization of t. denticola cgase. standard approaches were used to purify a 52-kda cgase activity from t. d ... | 2008 | 18482986 |
| implication of an outer surface lipoprotein in adhesion of bifidobacterium bifidum to caco-2 cells. | we found that the human intestinal isolate bifidobacterium bifidum mimbb75 strongly adhered to caco-2 cells. proteinase k and lithium chloride treatments showed that proteins play a key role in mimbb75 adhesion to caco-2 cells. by studying the cell wall-associated proteins, we identified a surface protein, which we labeled bopa. we purified the protein chromatographically and found that it functioned as an adhesion promoter on caco-2 cells. in silico analysis of the gene coding for this protein ... | 2008 | 18539800 |
| an interleukin-1beta (il-1beta) single-nucleotide polymorphism at position 3954 and red complex periodontopathogens independently and additively modulate the levels of il-1beta in diseased periodontal tissues. | inflammatory cytokines such as interleukin-1beta (il-1beta) are involved in the pathogenesis of periodontal diseases. a high individual variation in the levels of il-1beta 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-1beta promoter single-nucleotide po ... | 2008 | 18541658 |
| invasive differences among porphyromonas gingivalis strains from healthy and diseased periodontal sites. | the purpose of this study was to determine any difference between porphyromonas gingivalis isolates from periodontally healthy sites as compared to those from diseased sites with respect to the ability to invade host cells. | 2008 | 18544120 |
| pcr-based identification of selected pathogens associated with endodontic infections in deciduous and permanent teeth. | the aim of the present study was to evaluate the presence of the selected pathogens in samples from deciduous and permanent tooth root canals by using pcr method and to determine the association of these organisms with clinical symptoms. | 2008 | 18547832 |
| genetic analysis of spirochete flagellin proteins and their involvement in motility, filament assembly, and flagellar morphology. | the filaments of spirochete periplasmic flagella (pfs) have a unique structure and protein composition. in most spirochetes, the pfs consist of a core of at least three related proteins (flab1, flab2, and flab3) and a sheath of flaa protein. the functions of these filament proteins remain unknown. in this study, we used a multidisciplinary approach to examine the role of these proteins in determining the composition, shape, and stiffness of the pfs and how these proteins impact motility by using ... | 2008 | 18556797 |
| [relationship between herpesviruses and periodontal pathogenic bacteria in subgingival plaque]. | to evaluate the prevalence rates of human cytomegalovirus(hcmv) and epstein-barr virus-1(ebv-1) in subgingival plaque and analyze the relationship between herpesviruses, periodontal pathogenic bacteria and periodontal clinical parameters in chinese patients with aggressive periodontitis(agp). | 2008 | 18560463 |
| evidence of multiple treponema phylotypes involved in bovine digital dermatitis as shown by 16s rrna gene analysis and fluorescence in situ hybridization. | the etiopathogenesis of the skin disease digital dermatitis (dd), an important cause of lameness in cattle, remains uncertain. microscopically, the disease appears to be polymicrobial, with spirochetes as the predominant bacteria. the objective of this study was to identify the main part of the bacteria involved in dd lesions of cattle by using culture-independent molecular methods. ten different phylotypes of treponema were identified either by 16s rrna gene sequencing of bacteria from dd lesio ... | 2008 | 18562583 |
| rapid and simple detection of eight major periodontal pathogens by the loop-mediated isothermal amplification method. | loop-mediated isothermal amplification (lamp) was applied to develop a rapid and simple detection system for eight periodontal pathogens: aggregatibacter (actinobacillus) actinomycetemcomitans, campylobacter rectus, eikenella corrodens, fusobacterium nucleatum, porphyromonas gingivalis, prevotella intermedia, treponema denticola and tannerella forsythia. primers were designed from the 16s ribosomal rna gene for each pathogen, and the lamp amplified the targets specifically and efficiently under ... | 2008 | 18565108 |
| differential gender effects of a reduced-calorie diet on systemic inflammatory and immune parameters in nonhuman primates. | dietary manipulation, including caloric restriction, has been shown to impact host response capabilities significantly, particularly in association with aging. this investigation compared systemic inflammatory and immune-response molecules in rhesus monkeys (macaca mulatta). | 2008 | 18565132 |
| distribution of 10 periodontal bacterial species in children and adolescents over a 7-year period. | there is scant information available regarding the distribution of periodontal bacterial species in children and adolescents over an extended period. the purpose of this study was to compare bacterial profiles in the same individuals over a period of 7 years. | 2008 | 18565147 |
| a porphyromonas gingivalis tyrosine phosphatase is a multifunctional regulator of virulence attributes. | low molecular weight tyrosine phosphatases (lmwtp) are widespread in prokaryotes; however, understanding of the signalling cascades controlled by these enzymes is still emerging. porphyromonas gingivalis, an opportunistic oral pathogen, expresses a lmwtp, ltp1, that is differentially regulated in biofilm communities. here we characterize the enzymatic activity of ltp1 and, through the use of mutants that lack ltp1 or expresses catalytically defective ltp1, show that tyrosine phosphatase activity ... | 2008 | 18573179 |
| analysis of neutrophil-derived antimicrobial peptides in gingival crevicular fluid suggests importance of cathelicidin ll-37 in the innate immune response against periodontogenic bacteria. | during periodontitis, an innate immune response to bacterial challenge is primarily mediated by neutrophils. we compared neutrophilic content and the level of neutrophil-derived antimicrobial peptides in gingival crevicular fluid (gcf) in two clinical forms of severe periodontitis. | 2008 | 18582333 |
| relationship of porphyromonas gingivalis with glycemic level in patients with type 2 diabetes following periodontal treatment. | the aim of this study was to assess the relationship between serum glycemic levels and subgingival microbial profile alteration following periodontal treatment in patients with type 2 diabetes mellitus. | 2008 | 18582336 |
| periodontal status of patients with dentin dysplasia type i: report of three cases within a family. | dentin dysplasia type i (ddi) is a rare hereditary disturbance of dentin formation. it is characterized by clinically normal-appearing crowns; obliteration of pulp chambers; and short, blunted and malformed roots that are commonly associated with periodontal attachment loss (pal). in this context, we report three cases within a family with similar clinical and radiographic features of ddi but with differing microbiologic and periodontal conditions. | 2008 | 18597615 |
| borrelia burgdorferi vlse antigenic variation is not mediated by reca. | reca is a key protein linking genetic recombination to dna replication and repair in bacteria. previous functional characterization of borrelia burgdorferi reca indicated that the protein is mainly involved in genetic recombination rather than dna repair. genetic recombination may play a role in b. burgdorferi persistence by generation of antigenic variation. we report here the isolation of a reca null mutant in an infectious b. burgdorferi strain. comparison of the in vitro growth characteristi ... | 2008 | 18606826 |
| an engineered folded plp-bound monomer of treponema denticola cystalysin reveals the effect of the dimeric structure on the catalytic properties of the enzyme. | cystalysin, a dimeric pyridoxal 5'-phosphate (plp)-dependent lyase, is a virulence factor of the human oral pathogen treponema denticola. guided by bioinformatic analysis, two interfacial residues (leu57 and leu62) and an active site residue (tyr64*), hydrogen-bonded with the plp phosphate group of the neighboring subunit, have been mutated. the wild-type and the l57a, l62a, y64*a, l57a/l62a, l57a/y64*a, l57a/l62a/y64*a mutants, all having a c-terminal histidine tag, have been constructed, expre ... | 2009 | 18618696 |
| analysis of a growth-phase-regulated two-component regulatory system in the periodontal pathogen treponema denticola. | nothing is currently known regarding the global regulatory networks of treponema denticola and other oral spirochetes. in this report, we assess the properties and potential phosphotransfer capability of a putative two-component regulatory system (tcs) of t. denticola that is formed by the products of open reading frames tde0032 (a sensor kinase) and tde0033 (a response regulator), henceforth designated atcs and atcr, respectively. using pcr and dna sequence analyses, atcs and atcr were demonstr ... | 2008 | 18621891 |
| analysis of proteinase-activated receptor 2 and tlr4 signal transduction: a novel paradigm for receptor cooperativity. | proteinase-activated receptor 2 (par2), a seven-transmembrane g protein-coupled receptor, is activated at inflammatory sites by proteolytic cleavage of its extracellular n terminus by trypsin-like enzymes, exposing a tethered, receptor-activating ligand. synthetic agonist peptides (ap) that share the tethered ligand sequence also activate par2, often measured by ca2+ release. par2 contributes to inflammation through activation of nf-kappab-regulated genes; however, the mechanism by which this oc ... | 2008 | 18622013 |
| microorganisms in root canal-treated teeth from a german population. | posttreatment apical periodontitis is usually associated with persistent or secondary intraradicular infection. this study evaluated the presence and relative levels of 28 bacterial taxa in treated root canals of teeth with posttreatment apical periodontitis from german patients using 16s ribosomal rna (rrna) gene probes in a reverse-capture checkerboard hybridization assay. species-specific polymerase chain reaction (pcr) was also performed to detect enterococcus faecalis and candida albicans. ... | 2008 | 18634922 |
| cdp-alcohol hydrolase, a very efficient activity of the 5'-nucleotidase/udp-sugar hydrolase encoded by the usha gene of yersinia intermedia and escherichia coli. | nucleoside 5'-diphosphate-x hydrolases are interesting enzymes to study due to their varied activities and structure-function relationships and the roles they play in the disposal, assimilation, and modulation of the effects of their substrates. few of these enzymes with a preference for cdp-alcohols are known. in yersinia intermedia suspensions prepared from cultures on columbia agar with 5% sheep blood, we found a cdp-alcohol hydrolase liberated to triton x-100-containing medium. growth at 25 ... | 2008 | 18641143 |
| treatment outcomes of dental flossing in twins: molecular analysis of the interproximal microflora. | the purpose of this study was to assess the effects of dental flossing on the microbial composition of interproximal plaque samples in matched twins. | 2008 | 18672992 |
| development of a transposon mutagenesis system in the oral spirochete treponema denticola. | here, we report successful transposon mutagenesis in the oral spirochete treponema denticola. a modified himar1 transposon, including a new antibiotic selection cassette for t. denticola, generated mutations affecting cell division, transport, and chemotaxis, among other processes. this random mutagenesis system should facilitate research on the biology and pathogenesis of this spirochete, which is associated with human periodontal diseases. | 2008 | 18723655 |
| clinical and microbiological benefits of systemic metronidazole and amoxicillin in the treatment of smokers with chronic periodontitis: a randomized placebo-controlled study. | the aim of this study was to evaluate the clinical and microbiological effects of scaling and root planing (srp) alone or combined with metronidazole (mtz) or with mtz and amoxicillin (amx) in the treatment of smokers with chronic periodontitis. | 2008 | 18727657 |
| treponema denticola tror is a manganese- and iron-dependent transcriptional repressor. | treponema denticola harbours a genetic locus with significant homology to most of the previously characterized treponema pallidum tro operon. within this locus are five genes (troabcdr) encoding for the components of an atp-binding cassette cation-transport system (troabcd) and a dtxr-like transcriptional regulator (tror). in addition, a sigma(70)-like promoter and an 18 bp region of dyad symmetry were identified upstream of the troa start codon. this putative operator sequence demonstrated simi ... | 2008 | 18761626 |
| importance of tlr2 in early innate immune response to acute pulmonary infection with porphyromonas gingivalis in mice. | the periodontal pathogen porphyromonas gingivalis is implicated in certain systemic diseases including atherosclerosis and aspiration pneumonia. this organism induces innate responses predominantly through tlr2, which also mediates its ability to induce experimental periodontitis and accelerate atherosclerosis. using a validated mouse model of intratracheal challenge, we investigated the role of tlr2 in the control of p. gingivalis acute pulmonary infection. tlr2-deficient mice elicited reduced ... | 2008 | 18768871 |
| laboratory maintenance of treponema denticola. | this unit describes the methods, media, and equipment necessary for routine laboratory culture and handling of the anaerobic oral spirochete treponema denticola. topics discussed include nutrient requirements, recommended media formulations, and expected growth kinetics, as well as methods and equipment necessary to maintain anaerobic conditions. an additional protocol on isolation of t. denticola from clinical samples is included. | 2005 | 18770551 |
| genetic manipulation of treponema denticola. | the oral anaerobic spirochete, treponema denticola, has been implicated in the etiology of human periodontal diseases; however, the molecular basis for the virulence of these organisms is still unclear. potential pathogenic factors expressed by t. denticola have recently begun to be identified through the development of gene transfer approaches in this organism following electroporetic transformation. several antibiotic resistance markers have been developed for use in the construction of monosp ... | 2005 | 18770552 |
| photodynamic therapy as an adjunct to non-surgical periodontal treatment: a randomized, controlled clinical trial. | recent preclinical and clinical data have suggested a potential benefit of photodynamic therapy (pdt) in the treatment of periodontitis. however, there are very limited data from controlled clinical trials evaluating the effect of pdt in the treatment of periodontitis. the aim of this study was to evaluate the clinical and microbiologic effects of the adjunctive use of pdt to non-surgical periodontal treatment. | 2008 | 18771363 |
| identification of a methioninase inhibitor, myrsinoic acid b, from myrsine seguinii lév., and its inhibitory activities. | a methioninase inhibitor from myrsine seguinii was purified and identified as myrsinoic acid b. its inhibitory activities as to crude methioninase from periodontal bacteria such as fusobacterium nucleatum, porphyromonas gingivalis, and treponema denticola were determined. the ic50 values were 10.5, 82.4, and 30.3 microm respectively. | 2008 | 18776663 |
| the genome of borrelia recurrentis, the agent of deadly louse-borne relapsing fever, is a degraded subset of tick-borne borrelia duttonii. | in an effort to understand how a tick-borne pathogen adapts to the body louse, we sequenced and compared the genomes of the recurrent fever agents borrelia recurrentis and b. duttonii. the 1,242,163-1,574,910-bp fragmented genomes of b. recurrentis and b. duttonii contain a unique 23-kb linear plasmid. this linear plasmid exhibits a large polyt track within the promoter region of an intact variable large protein gene and a telomere resolvase that is unique to borrelia. the genome content is char ... | 2008 | 18787695 |
| composition of supra- and subgingival biofilm of subjects with healthy and diseased implants. | the purpose of this study was to compare the microbial composition of supra- and subgingival biofilm in subjects with and without peri-implantitis. | 2008 | 18828812 |
| the chronicles of porphyromonas gingivalis: the microbium, the human oral epithelium and their interplay. | the microbiota of the human oral mucosa consists of a myriad of bacterial species that normally exist in commensal harmony with the host. porphyromonas gingivalis, an aetiological agent in severe forms of periodontitis (a chronic inflammatory disease), is a prominent component of the oral microbiome and a successful colonizer of the oral epithelium. this gram-negative anaerobe can also exist within the host epithelium without the existence of overt disease. gingival epithelial cells, the outer l ... | 2008 | 18832296 |
| binding of complement inhibitor c4b-binding protein contributes to serum resistance of porphyromonas gingivalis. | the periodontal pathogen porphyromonas gingivalis is highly resistant to the bactericidal activity of human complement, which is present in the gingival crevicular fluid at 70% of serum concentration. all thirteen clinical and laboratory p. gingivalis strains tested were able to capture the human complement inhibitor c4b-binding protein (c4bp), which may contribute to their serum resistance. accordingly, in serum deficient of c4bp, it was found that significantly more terminal complement compone ... | 2008 | 18832711 |
| periodontal bacterial profiles in pregnant women: response to treatment and associations with birth outcomes in the obstetrics and periodontal therapy (opt) study. | a recent clinical trial (obstetrics and periodontal therapy [opt] study) demonstrated that periodontal therapy during pregnancy improved periodontal outcomes but failed to impact preterm birth. the present study evaluated seven target bacteria, aggregatibacter actinomycetemcomitans (previously actinobacillus actinomycetemcomitans), porphyromonas gingivalis, treponema denticola, tannerella forsythia (previously t. forsythensis), prevotella intermedia, campylobacter rectus, and fusobacterium nucle ... | 2008 | 18834241 |
| granulocyte chemotactic protein 2 (gcp-2/cxcl6) complements interleukin-8 in periodontal disease. | mucosal inflammatory responses are orchestrated largely by pro-inflammatory chemokines. the chemokine granulocyte chemotactic protein 2 (cxcl6) is involved in neutrophil recruitment and migration. previous studies have shown that granulocyte chemotactic protein 2 is up-regulated during mucosal inflammation (e.g. in inflammatory bowel disease), similarly to the functionally and structurally related chemokine interleukin-8. nevertheless, unlike interleukin-8, a role of granulocyte chemotactic prot ... | 2009 | 18842116 |
| tree of life based on genome context networks. | efforts in phylogenomics have greatly improved our understanding of the backbone tree of life. however, due to the systematic error in sequence data, a sequence-based phylogenomic approach leads to well-resolved but statistically significant incongruence. thus, independent test of current phylogenetic knowledge is required. here, we have devised a distance-based strategy to reconstruct a highly resolved backbone tree of life, on the basis of the genome context networks of 195 fully sequenced rep ... | 2008 | 18852873 |
| effects of caloric restriction on inflammatory periodontal disease. | dietary caloric restriction (cr) has been found to reduce systemic markers of inflammation and may attenuate the effects of chronic inflammatory conditions. the purpose of this study was to examine the effects of long-term cr on naturally occurring chronic inflammatory periodontal disease in a nonhuman primate model. | 2009 | 18929461 |
| effects of caloric restriction on inflammatory periodontal disease. | dietary caloric restriction (cr) has been found to reduce systemic markers of inflammation and may attenuate the effects of chronic inflammatory conditions. the purpose of this study was to examine the effects of long-term cr on naturally occurring chronic inflammatory periodontal disease in a nonhuman primate model. | 2009 | 18929461 |
| a novel class of modular transporters for vitamins in prokaryotes. | the specific and tightly controlled transport of numerous nutrients and metabolites across cellular membranes is crucial to all forms of life. however, many of the transporter proteins involved have yet to be identified, including the vitamin transporters in various human pathogens, whose growth depends strictly on vitamin uptake. comparative analysis of the ever-growing collection of microbial genomes coupled with experimental validation enables the discovery of such transporters. here, we used ... | 2009 | 18931129 |
| a novel class of modular transporters for vitamins in prokaryotes. | the specific and tightly controlled transport of numerous nutrients and metabolites across cellular membranes is crucial to all forms of life. however, many of the transporter proteins involved have yet to be identified, including the vitamin transporters in various human pathogens, whose growth depends strictly on vitamin uptake. comparative analysis of the ever-growing collection of microbial genomes coupled with experimental validation enables the discovery of such transporters. here, we used ... | 2009 | 18931129 |
| hprk regulates succinate-mediated catabolite repression in the gram-negative symbiont sinorhizobium meliloti. | the hprk kinase/phosphatase is a common component of the phosphotransferase system (pts) of gram-positive bacteria and regulates catabolite repression through phosphorylation/dephosphorylation of its substrate, the pts protein hpr, at a conserved serine residue. phosphorylation of hpr by hprk also affects additional phosphorylation of hpr by the pts enzyme ei at a conserved histidine residue. sinorhizobium meliloti can live as symbionts inside legume root nodules or as free-living organisms and ... | 2009 | 18931135 |
| hprk regulates succinate-mediated catabolite repression in the gram-negative symbiont sinorhizobium meliloti. | the hprk kinase/phosphatase is a common component of the phosphotransferase system (pts) of gram-positive bacteria and regulates catabolite repression through phosphorylation/dephosphorylation of its substrate, the pts protein hpr, at a conserved serine residue. phosphorylation of hpr by hprk also affects additional phosphorylation of hpr by the pts enzyme ei at a conserved histidine residue. sinorhizobium meliloti can live as symbionts inside legume root nodules or as free-living organisms and ... | 2009 | 18931135 |
| treponema denticola does not induce production of common innate immune mediators from primary gingival epithelial cells. | it has been hypothesized that the neutrophil chemoattractant interleukin-8 (il-8) forms a gradient in the oral cavity, with the highest concentration of il-8 produced closest to the bacterial biofilm. in periodontitis, this gradient is disrupted, impairing neutrophil chemotaxis to diseased sites. treponema denticola is prominently associated with periodontal disease, yet little is known about its ability to modulate the production of inflammatory mediators by epithelial cells. others have shown ... | 2008 | 18954353 |
| treponema denticola peptidoglycan induces the production of inflammatory mediators and matrix metalloproteinase 9 in macrophage-like cells. | treponema denticola is a key pathogen associated with periodontitis, a chronic inflammatory disease affecting tooth-supporting tissues. in the present study, we investigated the response of human macrophage-like cells to stimulation by peptidoglycan isolated from t. denticola. we also studied the effect of the peptidoglycan preparation on the phosphorylation state of kinases. | 2009 | 18973520 |
| factors affecting human supragingival biofilm composition. ii. tooth position. | little is known regarding the factors that affect the microbial composition of supragingival biofilms. this study was designed to test the hypothesis that tooth location affects the microbial composition of supragingival plaque beyond the effect due to plaque mass as reflected by total dna probe count. | 2009 | 18973539 |
| factors affecting human supragingival biofilm composition. ii. tooth position. | little is known regarding the factors that affect the microbial composition of supragingival biofilms. this study was designed to test the hypothesis that tooth location affects the microbial composition of supragingival plaque beyond the effect due to plaque mass as reflected by total dna probe count. | 2009 | 18973539 |
| factors affecting human supragingival biofilm composition. i. plaque mass. | little is known about the factors that affect the microbial composition of supragingival biofilms. this study was designed to examine the relationship between total dna probe counts of supragingival biofilm samples, clinical parameters and supragingival biofilm composition. | 2009 | 18973540 |