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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 ...200818248579
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 ...200818253487
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 ...200818263731
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 ...200818270594
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 ...200818276644
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.200818279185
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.200818279187
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 ...200818287326
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.200818302616
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.200818302679
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, ...200818330900
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 ...200818332212
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 ...200818346280
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 ...200818355277
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 ...200818366071
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 ...200818366724
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.200818380560
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 ...200818385522
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 ...200818389006
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 ...200818390996
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.200818400025
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.200818402610
detection of treponema denticola in saliva obtained from patients with various periodontal conditions.the aim of the study was to determine the prevalence of treponema denticola in saliva of periodontally diseased and healthy patients and its relationship with the periodontal status. a 16s rrna-based polymerase chain reaction detection method was used to determine the prevalence of t. denticola in whole saliva samples from patients with chronic periodontitis (cp, n = 37), aggressive periodontitis (agp, n = 24), and healthy subjects (n = 28). the periodontal status of each subject was assessed by ...200817823835
the major outer sheath protein of treponema denticola selectively inhibits rac1 activation in murine neutrophils.treponema denticola major outer sheath protein (msp) inhibits neutrophil chemotaxis in vitro, but key regulatory mechanisms have not been identified. because the rac small gtpases regulate directional migration in response to chemoattractants, the objective was to analyse the effects of msp on formyl-methionyl-leucyl-phenylalanine (fmlp)-mediated neutrophil polarization and rac activation in murine neutrophils. msp pretreatment of neutrophils inhibited both polarization and chemotactic migration ...200817868382
salivary detection of periodontopathic bacteria in periodontally healthy children.salivary occurrence of periodontopathic bacteria is of interest especially in children as a risk indicator for the transmission, development and control of periodontal disease. we assessed the prevalence of aggregatibacter actinomycetemcomitans, porphyromonas gingivalis, tannerella forsythia, prevotella intermedia, prevotella nigrescens and treponema denticola as microbial complexes in the saliva of children with mixed dentition and healthy gingiva.200817869137
porphyromonas gingivalis hmuy and hmur: further characterization of a novel mechanism of heme utilization.porphyromonas gingivalis hmuy is a putative heme-binding lipoprotein associated with the outer membrane. it is part of an operon together with a gene encoding an outer-membrane hemin utilization receptor (hmur) and four uncharacterized genes. a similar operon organization was found in bacteroides fragilis and b. thetaiotaomicron, with the former containing an additional hmuy homologue encoded upstream of the hmur-like gene. in p. gingivalis cultured under heme-limited conditions, a approximately ...200817922109
porphyromonas gingivalis hmuy and hmur: further characterization of a novel mechanism of heme utilization.porphyromonas gingivalis hmuy is a putative heme-binding lipoprotein associated with the outer membrane. it is part of an operon together with a gene encoding an outer-membrane hemin utilization receptor (hmur) and four uncharacterized genes. a similar operon organization was found in bacteroides fragilis and b. thetaiotaomicron, with the former containing an additional hmuy homologue encoded upstream of the hmur-like gene. in p. gingivalis cultured under heme-limited conditions, a approximately ...200817922109
periodontitis may increase the risk of peripheral arterial disease.the aim of this case control study was to evaluate whether periodontitis was associated with peripheral arterial disease (pad).200817964192
toll-like receptor 2-mediated interleukin-8 expression in gingival epithelial cells by the tannerella forsythia leucine-rich repeat protein bspa.tannerella forsythia is a gram-negative anaerobe strongly associated with chronic human periodontitis. this bacterium expresses a cell surface-associated and secreted protein, designated bspa, which has been recognized as an important virulence factor. the bspa protein belongs to the leucine-rich repeat (lrr) and bacterial immunoglobulin-like protein families. bspa is, moreover, a multifunctional protein which interacts with a variety of host cells, including monocytes which appear to respond to ...200817967853
toll-like receptor 2-mediated interleukin-8 expression in gingival epithelial cells by the tannerella forsythia leucine-rich repeat protein bspa.tannerella forsythia is a gram-negative anaerobe strongly associated with chronic human periodontitis. this bacterium expresses a cell surface-associated and secreted protein, designated bspa, which has been recognized as an important virulence factor. the bspa protein belongs to the leucine-rich repeat (lrr) and bacterial immunoglobulin-like protein families. bspa is, moreover, a multifunctional protein which interacts with a variety of host cells, including monocytes which appear to respond to ...200817967853
novel mechanism for conditional aerobic growth of the anaerobic bacterium treponema denticola.treponema denticola, a periodontal pathogen, has recently been shown to exhibit properties of a facultative anaerobic spirochete, in contrast to its previous recognition as an obligate anaerobic bacterium. in this study, the capacity and possible mechanism of t. denticola survival and growth under aerobic conditions were investigated. factors detrimental to the growth of t. denticola atcc 33405, such as oxygen concentration and hydrogen sulfide (h(2)s) levels as well as the enzyme activities of ...200817981934
multiple phospholipid n-methyltransferases with distinct substrate specificities are encoded in bradyrhizobium japonicum.phosphatidylcholine (pc) is the major phospholipid in eukaryotic membranes. in contrast, it is found in only a few prokaryotes including members of the family rhizobiaceae. in these bacteria, pc is required for pathogenic and symbiotic plant-microbe interactions, as shown for agrobacterium tumefaciens and bradyrhizobium japonicum. at least two different phospholipid n-methyltransferases (pmta and pmtx) have been postulated to convert phosphatidylethanolamine (pe) to pc in b. japonicum by three c ...200817993534
multiple phospholipid n-methyltransferases with distinct substrate specificities are encoded in bradyrhizobium japonicum.phosphatidylcholine (pc) is the major phospholipid in eukaryotic membranes. in contrast, it is found in only a few prokaryotes including members of the family rhizobiaceae. in these bacteria, pc is required for pathogenic and symbiotic plant-microbe interactions, as shown for agrobacterium tumefaciens and bradyrhizobium japonicum. at least two different phospholipid n-methyltransferases (pmta and pmtx) have been postulated to convert phosphatidylethanolamine (pe) to pc in b. japonicum by three c ...200817993534
optimizing qpcr for the quantification of periodontal pathogens in a complex plaque biofilm.quantitative pcr (qpcr) has recently been used to quantify microorganisms in complex communities, including dental plaque biofilms. however, there is variability in the qpcr protocols being used. this study was designed to evaluate the validity of two of these variables with the intent of developing a more standardized qpcr protocol. the two variables evaluated were (1) the use of dna content versus actual cell counts to estimate bacterial numbers in mixed plaque samples and (2) the effectivenes ...200819088882
proteolytic activities of oral bacteria on prommp-9 and the effect of synthetic proteinase inhibitors.tissue reactions to bacteria lead to proinflammatory reactions involving matrix metalloproteinases (mmps). synthetic protease inhibitors may offer new possibilities to regulate bacterial proteases. we investigated proteolytic activities of certain periodontal bacteria, their effects on the latent prommp-9, and the effects of synthetic mmp inhibitors and a serine protease inhibitor pefabloc. the strains studied were porphyromonas gingivalis, prevotella intermedia, peptostreptoccus micros, prevote ...200819088890
tobacco use increases susceptibility to bacterial infection.abstract: active smokers and those exposed to secondhand smoke are at increased risk of bacterial infection. tobacco smoke exposure increases susceptibility to respiratory tract infections, including tuberculosis, pneumonia and legionnaires disease; bacterial vaginosis and sexually transmitted diseases, such as chlamydia and gonorrhoea; helicobacter pylori infection; periodontitis; meningitis; otitis media; and post-surgical and nosocomial infections. tobacco smoke compromises the anti-bacterial ...200819094204
[identification of periodontopathogen microorganisms by pcr technique].periodontitis is an inflammatory disease of the supporting tissues of teeth and is a major cause of tooth loss in adults. the onset and progression of periodontal disease is attributed to the presence of elevated levels of a consortium of pathogenic bacteria. gram negative bacteria, mainly strict anaerobes, play the major role.200819069337
identification of prophages in bacterial genomes by dinucleotide relative abundance difference.prophages are integrated viral forms in bacterial genomes that have been found to contribute to interstrain genetic variability. many virulence-associated genes are reported to be prophage encoded. present computational methods to detect prophages are either by identifying possible essential proteins such as integrases or by an extension of this technique, which involves identifying a region containing proteins similar to those occurring in prophages. these methods suffer due to the problem of l ...200718030328
the correlation between serum immunoglobulin a and immunoglobulin g levels and the presence of treponema denticola in human periapical lesions.the aim of this study was to compare the serum immunoglobulin a (iga) and immunoglobulin g (igg) levels and the presence of treponema denticola in the root canals in a group of teeth with/without periapical lesion. a total of 66 children aged 8 to 13 years old were involved in this study. five milliliters of blood samples were taken to detect the serum iga and igg levels. sixty-six endodontic samplings were also obtained to determine the presence of t. denticola by polymerase chain reaction. the ...200718037048
identification of actinobacillus actinomycetemcomitans, treponema denticola and porphyromonas gingivalis within human dental calculus: a pilot investigation.dental calculus is considered to be simply a "plaque-retentive factor", and therefore only a secondary aetiological factor in the pathogenesis of periodontitis. recent studies have suggested a more active role for calculus. our objective was to demonstrate the presence of periodontal pathogens in the non-mineralised areas of supra- and subgingival dental calculus.200717987882
treponema denticola activates mitogen-activated protein kinase signal pathways through toll-like receptor 2.treponema denticola, a spirochete indigenous to the oral cavity, is associated with host inflammatory responses to anaerobic polymicrobial infections of the root canal, periodontium, and alveolar bone. however, the cellular mechanisms responsible for the recognition of t. denticola by the innate immune system and the underlying cell signaling pathways that regulate the inflammatory response to t. denticola are currently unresolved. in this study, we demonstrate that t. denticola induces innate i ...200717923521
polymerase chain reaction of porphyromonas gingivalis, treponema denticola, and tannerella forsythia in primary endodontic infections.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 gingiva ...200717931930
structure of arabidopsis thaliana 5-methylthioribose kinase reveals a more occluded active site than its bacterial homolog.metabolic variations exist between the methionine salvage pathway of humans and a number of plants and microbial pathogens. 5-methylthioribose (mtr) kinase is a key enzyme required for methionine salvage in plants and many bacteria. the absence of a mammalian homolog suggests that mtr kinase is a good target for the design of specific herbicides or antibiotics.200717961230
assessment of cell-surface exposure and vaccinogenic potentials of treponema pallidum candidate outer membrane proteins.syphilis, a sexually transmitted infection caused by the spirochetal bacterium treponema pallidum, remains a global public health problem. t. pallidum is believed to be an extracellular pathogen and, as such, the identification of t. pallidum outer membrane proteins that could serve as targets for opsonic or bactericidal antibodies has remained a high research priority for vaccine development. however, the identification of t. pallidum outer membrane proteins has remained highly elusive. recent ...200717890130
benefits of additional courses of systemic azithromycin in periodontal disease case report.the strong association of subgingival anaerobic bacteria, such as porphyromonas gingivalis, treponema denticola and tannerella forsythia, with destructive periodontal disease has been well documented in the literature. several double-blind studies have also shown the beneficial use of systemic antimicrobials that are active against these microorganisms in conjunction with conventional periodontal treatment, especially when periodontal abscesses and/or suppuration upon probing are present. four c ...200717891880
genome differences between treponema pallidum subsp. pallidum strain nichols and t. paraluiscuniculi strain cuniculi a.the genome of treponema paraluiscuniculi strain cuniculi a was compared to the genome of the syphilis spirochete treponema pallidum subsp. pallidum strain nichols using dna microarray hybridization, whole-genome fingerprinting, and dna sequencing. a dna microarray of t. pallidum subsp. pallidum nichols containing all 1,039 predicted open reading frame pcr products was used to identify deletions and major sequence changes in the cuniculi a genome. using these approaches, deletions, insertions, an ...200717893135
identification of a signalling molecule involved in bacterial intergeneric communication.the development of complex multispecies communities such as biofilms is controlled by interbacterial communication systems. we have previously reported an intergeneric communication between two oral bacteria, streptococcus cristatus and porphyromonas gingivalis, that results in inhibition of fima expression. here, we demonstrate that a surface protein, arginine deiminase (arca), of s. cristatus serves as a signal that initiates intergeneric communication. an arca-deficient mutant of s. cristatus ...200717906122
implant surface analysis and microbiologic evaluation of failed implants retrieved from smokers.the aim of this study was to evaluate the microbiota and surface of failed titanium dental implants from 4 manufacturers. twelve mobile dental implants were retrieved from 10 smokers after 3 to 10 years of functional loading. before implant removal, microbial samples were taken and evaluated using polymerase chain reaction. after implant removal, analyses of the failed implant surfaces were performed using scanning electron microscopy and energy-dispersive spectrometer x-ray. periodontal pathoge ...200717912965
effect of adjunctive systemic azithromycin with periodontal surgery in the treatment of chronic periodontitis in smokers: a pilot study.along with conventional surgical therapy, systemic antibiotics may provide more effective treatment in smokers by targeting tissue-invasive bacteria. the aim of this randomized, placebo-controlled, double-masked clinical trial was to evaluate the adjunctive effects of systemic azithromycin (azm) in combination with periodontal pocket reduction surgery in the treatment of chronic periodontitis in smokers.200717915999
structural and biochemical basis for polyamine binding to the tp0655 lipoprotein of treponema pallidum: putative role for tp0655 (tppotd) as a polyamine receptor.tp0655 of treponema pallidum, the causative agent of syphilis, is predicted to be a 40 kda membrane lipoprotein. previous sequence analysis of tp0655 noted its homology to polyamine-binding proteins of the bacterial potd family, which serve as periplasmic ligand-binding proteins of atp-binding-cassette (abc) transport systems. here, the 1.8 a crystal structure of tp0655 demonstrated structural homology to escherichia coli potd and potf. the latter two proteins preferentially bind spermidine and ...200717868688
physiological ecology of stenoxybacter acetivorans, an obligate microaerophile in termite guts.stenoxybacter acetivorans is a newly described, obligately microaerophilic beta-proteobacterium that is abundant in the acetate-rich hindgut of reticulitermes. here we tested the hypotheses that cells are located in the hypoxic, peripheral region of reticulitermes flavipes hindguts and use acetate to fuel their o(2)-consuming respiratory activity in situ. physical fractionation of r. flavipes guts, followed by limited-cycle pcr with s. acetivorans-specific 16s rrna gene primers, indicated that c ...200717827335
delineation of species-specific binding properties of the cspz protein (bbh06) of lyme disease spirochetes: evidence for new contributions to the pathogenesis of borrelia spp.borrelia burgdorferi cspz (tigr open reading frame designation, bbh06) is part of a functionally related group of proteins that bind one or more members of the factor h (fh) protein family. in this report we assess the conservation, distribution, properties, and ligand binding abilities of cspz from the three main borrelia species associated with lyme disease infections in humans. cspz (also referred to as bbcrasp-2 in the literature) was found to be highly conserved at the intraspecies level bu ...200717846117
two subgingival plaque-sampling strategies used with rna probes.the purpose of this study was to compare the results of microbiological rna-probe analysis after subgingival plaque sampling applying two different strategies.200717199542
rat model of polymicrobial infection, immunity, and alveolar bone resorption in periodontal disease.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 we hypothesized that p. gingivalis, t. denticola, and t. forsythia are synergistic in terms of virulence potential and induce chronic periodontal inflammation that leads to alveolar bone resorption in ...200717210663
fatty acids synthesized by oral treponemes in chemically defined media.omiz-w68, a chemically defined medium that contains no long-chain fatty acids and yet supports in vitro proliferation of a wide range of fastidious oral anaerobes, is described. the type strains of treponema denticola, treponema lecithinolyticum, treponema maltophilum, treponema pectinovorum, treponema socranskii, and an as yet unpublished canine treponema species could be propagated indefinitely in this medium with sugar supplements for the saccharolytic species. analysis of the cellular fatty ...200717229060
characterization of the thermotoga maritima chemotaxis methylation system that lacks pentapeptide-dependent methyltransferase cher:mcp tethering.sensory adaptation in bacterial chemotaxis is mediated by covalent modifications of specific glutamate and glutamine residues within the cytoplasmic domains of methyl-accepting chemotaxis proteins (mcps). in escherichia coli and salmonella enterica, efficient methylation of mcps depends on the localization of methyltransferase cher to mcp clusters through an interaction between the cher beta-subdomain and a pentapeptide sequence (nwetf or nwesf) at the c-terminus of the mcp. in vitro methylation ...200717163981
characterization of the thermotoga maritima chemotaxis methylation system that lacks pentapeptide-dependent methyltransferase cher:mcp tethering.sensory adaptation in bacterial chemotaxis is mediated by covalent modifications of specific glutamate and glutamine residues within the cytoplasmic domains of methyl-accepting chemotaxis proteins (mcps). in escherichia coli and salmonella enterica, efficient methylation of mcps depends on the localization of methyltransferase cher to mcp clusters through an interaction between the cher beta-subdomain and a pentapeptide sequence (nwetf or nwesf) at the c-terminus of the mcp. in vitro methylation ...200717163981
antibodies to periodontal organisms are associated with decreased kidney function. the dental atherosclerosis risk in communities study.increasing evidence suggests that clinical signs of periodontal disease are independently associated with renal impairment. however, no studies have examined the possible linkage of kidney disease with serum antibody to oral pathogens.200717170550
identification of specific chemoattractants and genetic complementation of a borrelia burgdorferi chemotaxis mutant: flow cytometry-based capillary tube chemotaxis assay.measuring the chemotactic response of borrelia burgdorferi, the bacterial species that causes lyme disease, is relatively more difficult than measuring that of other bacteria. because these spirochetes have long generation times, enumerating cells that swim up a capillary tube containing an attractant by using colony counts is impractical. furthermore, direct counts with a petroff-hausser chamber is problematic, as this method has a low throughput and necessitates a high cell density; the latter ...200717172459
identification of specific chemoattractants and genetic complementation of a borrelia burgdorferi chemotaxis mutant: flow cytometry-based capillary tube chemotaxis assay.measuring the chemotactic response of borrelia burgdorferi, the bacterial species that causes lyme disease, is relatively more difficult than measuring that of other bacteria. because these spirochetes have long generation times, enumerating cells that swim up a capillary tube containing an attractant by using colony counts is impractical. furthermore, direct counts with a petroff-hausser chamber is problematic, as this method has a low throughput and necessitates a high cell density; the latter ...200717172459
phylogenetic analysis of bacterial and archaeal species in symptomatic and asymptomatic endodontic infections.phylogenetic analysis of bacterial and archaeal 16s rrna was used to examine polymicrobial communities within infected root canals of 20 symptomatic and 14 asymptomatic patients. nucleotide sequences from approximately 750 clones amplified from each patient group with universal bacterial primers were matched to the ribosomal database project ii database. phylotypes from 37 genera representing actinobacteria, bacteroidetes, firmicutes, fusobacteria and proteobacteria were identified. results were ...200717172525
[pathogenic potential of porphyromonas gingivalis, treponema denticola and tannerella forsythia, the red bacterial complex associated with periodontitis].periodontitis are mixed bacterial infections leading to destruction of tooth-supporting tissues, including periodontal ligament and alveolar bone. among over 500 bacterial species living in the oral cavity, a bacterial complex named "red complex" and made of porphyromonas gingivalis, treponema denticola and tannerella forsythia has been strongly related to advanced periodontal lesions. while periodontopathogenic bacteria are the primary etiologic factor of periodontitis, tissue destruction essen ...200717049750
characterization of treponema denticola pyrf encoding orotidine-5'-monophosphate decarboxylase.the treponema denticola atcc 35405 genome annotation contains most of the genes for de novo pyrimidine biosynthesis. to initiate characterization of pyrimidine synthesis in treponema, we focused on tde2110 (the putative pyrf, encoding orotidine-5'-monophosphate decarboxlyase). unlike the parent strain, an isogenic pyrf mutant was resistant to 5-fluoroorotic acid. in complex medium, growth of the pyrf mutant was independent of added uracil, indicating activity of a uracil uptake/salvage pathway. ...200717187656
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 ...200718404422
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 ...200718063722
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.200718477431
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. ...200718160759
rmlc, a c3' and c5' carbohydrate epimerase, appears to operate via an intermediate with an unusual twist boat conformation.the striking feature of carbohydrates is their constitutional, conformational and configurational diversity. biology has harnessed this diversity and manipulates carbohydrate residues in a variety of ways, one of which is epimerization. rmlc catalyzes the epimerization of the c3' and c5' positions of dtdp-6-deoxy-d-xylo-4-hexulose, forming dtdp-6-deoxy-l-lyxo-4-hexulose. rmlc is the third enzyme of the rhamnose pathway, and represents a validated anti-bacterial drug target. although several stru ...200717046787
rmlc, a c3' and c5' carbohydrate epimerase, appears to operate via an intermediate with an unusual twist boat conformation.the striking feature of carbohydrates is their constitutional, conformational and configurational diversity. biology has harnessed this diversity and manipulates carbohydrate residues in a variety of ways, one of which is epimerization. rmlc catalyzes the epimerization of the c3' and c5' positions of dtdp-6-deoxy-d-xylo-4-hexulose, forming dtdp-6-deoxy-l-lyxo-4-hexulose. rmlc is the third enzyme of the rhamnose pathway, and represents a validated anti-bacterial drug target. although several stru ...200717046787
molecular analysis of the subgingival microbiota in health and disease.this investigation provides molecular analyses of the periodontal microbiota in health and disease. subgingival samples from 47 volunteers with healthy gingivae or clinically diagnosed chronic periodontitis were characterized by pcr-denaturing gradient gel electrophoresis (dgge) with primers specific for the v2-v3 region of the eubacterial 16s rrna gene. a hierarchical dendrogram was constructed from band patterns. all unique pcr amplicons (dgge bands) were sequenced for identity. samples were a ...200717085691
molecular analysis of the subgingival microbiota in health and disease.this investigation provides molecular analyses of the periodontal microbiota in health and disease. subgingival samples from 47 volunteers with healthy gingivae or clinically diagnosed chronic periodontitis were characterized by pcr-denaturing gradient gel electrophoresis (dgge) with primers specific for the v2-v3 region of the eubacterial 16s rrna gene. a hierarchical dendrogram was constructed from band patterns. all unique pcr amplicons (dgge bands) were sequenced for identity. samples were a ...200717085691
comparison of a taqman-based real-time polymerase chain reaction with conventional tests for the detection of trichomonas vaginalis.to compare a taqman-based real-time polymerase chain reaction (pcr) with conventional pcr, culture, and wet-mount microscopy for the diagnosis of trichomoniasis in women.200717090567
comparison of a taqman-based real-time polymerase chain reaction with conventional tests for the detection of trichomonas vaginalis.to compare a taqman-based real-time polymerase chain reaction (pcr) with conventional pcr, culture, and wet-mount microscopy for the diagnosis of trichomoniasis in women.200717090567
identification of the gene encoding the fhbb protein of treponema denticola, a highly unique factor h-like protein 1 binding protein.the gene encoding the treponema denticola factor h-like protein 1 (fhl-1) binding protein, fhbb, was recovered and characterized. sequence conservation, expression, and properties of fhbb were analyzed. the identification of fhbb represents an important step in understanding the contribution of fhl-1 binding in t. denticola pathogenesis and in development of periodontal disease.200717101650
association between infection of different strains of porphyromonas gingivalis and actinobacillus actinomycetemcomitans in subgingival plaque and clinical parameters in chronic periodontitis.the aim of this study was to investigate subgingival infection frequencies of porphyromonas gingivalis and actinobacillus actinomycetemcomitans strains with genetic variation in chinese chronic periodontitis (cp) patients and to evaluate its correlation with clinical parameters.200717266188
evaluation of the incidence of periodontitis-associated bacteria in the atherosclerotic plaque of coronary blood vessels.unstable atherosclerotic plaque is a dangerous clinical condition, possibly leading to acute coronary deficiency resulting in cardiac infarction. questions about the role of inflammatory factors in the formation of pathological lesions in the endothelium of coronary vessels have often been raised. this condition may be caused by bacteria that are able to initiate clot formation in a blood vessel, destabilizing an atherosclerotic plaque that is already present. the sources of these pathogens are ...200717274722
genome of the opportunistic pathogen streptococcus sanguinis.the genome of streptococcus sanguinis is a circular dna molecule consisting of 2,388,435 bp and is 177 to 590 kb larger than the other 21 streptococcal genomes that have been sequenced. the g+c content of the s. sanguinis genome is 43.4%, which is considerably higher than the g+c contents of other streptococci. the genome encodes 2,274 predicted proteins, 61 trnas, and four rrna operons. a 70-kb region encoding pathways for vitamin b(12) biosynthesis and degradation of ethanolamine and propanedi ...200717277061
intermolecular forces and enthalpies in the adhesion of streptococcus mutans and an antigen i/ii-deficient mutant to laminin films.the antigen i/ii family of surface proteins is expressed by most oral streptococci, including streptococcus mutans, and mediates specific adhesion to, among other things, salivary films and extracellular matrix proteins. in this study we showed that antigen i/ii-deficient s. mutans isogenic mutant ib03987 was nearly unable to adhere to laminin films under flow conditions due to a lack of specific interactions (0.8 x 10(6) and 1.1 x 10(6) cells cm(-2) at ph 5.8 and 6.8, respectively) compared wit ...200717277062
physiological osmotic induction of leptospira interrogans adhesion: liga and ligb bind extracellular matrix proteins and fibrinogen.transmission of leptospirosis occurs through contact of mucous membranes and abraded skin with freshwater contaminated by pathogenic leptospira spp. exposure to physiological osmolarity induces leptospires to express high levels of the lig surface proteins containing imperfect immunoglobulin-like repeats that are shared or differ between liga and ligb. we report that osmotic induction of lig is accompanied by 1.6- to 2.5-fold increases in leptospiral adhesion to immobilized extracellular matrix ...200717296754
novel tetracycline resistance determinant isolated from an environmental strain of serratia marcescens.resistances to tetracycline and mercury were identified in an environmental strain of serratia marcescens isolated from a stream highly contaminated with heavy metals. as a step toward addressing the mechanisms of coselection of heavy metal and antibiotic resistances, the tetracycline resistance determinant was cloned in escherichia coli. within the cloned 13-kb segment, the tetracycline resistance locus was localized by deletion analysis and transposon mutagenesis. dna sequence analysis of an 8 ...200717308196
microbiological outcomes of quadrant versus full-mouth root planing as monitored by real-time pcr.to study the short-term microbiological changes following full-mouth compared with quadrant wise scaling and root planing (fmrp and qrp) as well as long-term effects.200717309590
subgingival plaque microbiota in hiv positive patients.to describe and compare the predominant bacterial and fungal species associated with gingivitis, periodontitis, and linear gingival erythema (lge), in hiv positive subjects with different immune status.200717309593
a comparison of implant-supported, bar- or ball-retained mandibular overdentures: a retrospective clinical, microbiologic, and immunologic study of 10 edentulous patients attending a recall visit.clinical, microbiologic, and immunologic comparisons of the peri-implant health in edentulous volunteers wearing long-standing implant-supported ball- or dolder bar-retained mandibular overdentures were performed.200717319360
mechanisms of decreased susceptibility to beta-defensins by treponema denticola.treponema denticola, a periodontal pathogen, is relatively resistant to human beta-defensins, which are small cationic antimicrobial peptides produced by a number of cells, including the gingival epithelium. using two independent methods, we previously demonstrated that t. denticola proteases are not responsible for decreased vulnerability to defensins. in this study, we confirmed that the major outer membrane protease, dentilisin, is not responsible for t. denticola insensitivity to defensins a ...200717325047
subgingival chlorhexidine varnish administration as an adjunct to same-day full-mouth root planing. ii. microbiological observations.recently, the clinical additive value of a highly concentrated chlorhexidine (chx) varnish, when applied subgingivally as an adjunct to scaling and root planing, was described. the objective of the present study was to investigate the microbiological impact of a treatment strategy for chronic periodontitis based on a combination of same-day full-mouth root planing and subgingival chx varnish administration.200717335366
flow cytometric analysis of adherence of porphyromonas gingivalis to oral epithelial cells.by using fluorescence microscopy, fluorescently labeled porphyromonas gingivalis w50 was shown to adhere to oral epithelial (kb) cells as discrete cells or small cell aggregates, whereas p. gingivalis atcc 33277 bound as large cell aggregates. flow cytometric analysis showed that for p. gingivalis w50 there was a logarithmic relationship between the bacterial cell ratio (bcr), that is the number of bacterial cells to kb cells, and the percentage of kb cells with w50 cells attached. this percenta ...200717339349
activation of mapk in fibroblasts by treponema denticola major outer sheath protein.the major outer sheath protein (msp) of treponema denticola induces ca(2+) entry and actin reorganization in cultured fibroblasts, but the pathways by which msp mediates these responses are not yet defined. we considered that msp may activate protein kinases as a stress response that precedes actin remodelling. phospho-kinase screens showed that msp induced phosphorylation of multiple kinases in pathways that respond to extracellular agonists and regulate actin assembly. 34 kinases were signific ...200717346673
the detection of eight putative periodontal pathogens in adult and rapidly progressive periodontitis patients: an institutional study.periodontal disease is a commonly prevalent problem faced alike by both the developed and third world countries but showing wide variations in prevalence and severity across different geographical areas. the purpose was to identify actinobacillus actinomycetemcomitans (aa), porphyromonas gingivalis (pg), prevotella intermedia (pi), ekinella corrodens (ec), campylobacter rectus (cr), bacteroides forsythus (bf), treponema denticola (td) and fusobacterium nucleatum (fn) in indian adult periodontiti ...200717347537
a novel prokaryotic trans-2-enoyl-coa reductase from the spirochete treponema denticola.an nadh-dependent trans-2-enoyl-coa reductase (ec1.1.1.36) from the gram negative spirochete treponema denticola was identified, expressed and biochemically characterized. the recombinant protein is a monomeric enzyme with a molecular mass of 44 kda with a specific activity of 43+/-4.8 u/mg (micromol mg(-1)min(-1)) and k(m) value of 2.7 microm for crotonoyl-coa. this nadh-dependent trans-2-enoyl-coa reductase represents the first enzymatically characterized member of a prokaryotic protein family ...200717382934
evidence of periopathogenic microorganisms in placentas of women with preeclampsia.periodontal disease is a chronic inflammatory infectious disease that may act as a focus of infection. preeclampsia is a pregnancy-specific hypertensive disorder that often leads to maternal morbidity and mortality. acute atherosis, the placental lesion of preeclampsia, shares many histopathological features with atherosclerosis. recently, chronic infection was linked to the initiation of atherosclerosis. oral pathogens have been detected in atherosclerotic plaques, where they may play a role in ...200717397314
prevalence of four putative periodontopathic bacteria in saliva of a group of brazilian children with mixed dentition: 1-year longitudinal study.this study aimed at evaluating the prevalence of putative periodontal pathogens (actinobacillus actinomycetemcomitans, porphyromonas gingivalis, prevotella nigrescens, treponema denticola) in saliva of children with mixed dentition at two different time points, correlating these findings with a clinical parameter of gingival health.200717397463
intrinsic apoptotic pathways of gingival epithelial cells modulated by porphyromonas gingivalis.porphyromonas gingivalis can inhibit chemically induced apoptosis in primary cultures of gingival epithelial cells through blocking activation of the effector caspase-3. the anti-apoptotic phenotype of p. gingivalis is conserved across strains and does not depend on the presence of fimbriae, as fimbriae-deficient mutants and a naturally occurring non-fimbriated strain were able to impede apoptosis. to dissect the survival pathways modulated by p. gingivalis, protein and gene expression of a numb ...200717419719
aggregatibacter actinomycetemcomitans as indicator for aggressive periodontitis by two analysing strategies.to compare the subgingival microbiota of aggressive and chronic periodontitis (chp) using single-site and pooled plaque samples.200717433043
performance of captia selectsyph-g enzyme-linked immunosorbent assay in syphilis testing of a high-risk population: analysis of discordant results.using the captia select syph-g enzyme-linked immunosorbent assay (elisa), we analyzed the sera of 1,771 patients from a high-risk population attending sexually transmitted disease (std) clinics. we focused on discrepancies between the results of the immunoglobulin g (igg) elisa and the treponema pallidum hemagglutination (tpha) test. we identified 57 patients (3.22%) with conflicting results in the igg elisa and tpha test. in order to resolve these discrepancies, these patients' health records w ...200717442795
identification of intracellular oral species within human crevicular epithelial cells from subjects with chronic periodontitis by fluorescence in situ hybridization.interactions between oral bacteria and gingival epithelial cells play an important role in the pathogenesis of periodontal diseases. this study used in situ hybridization with 16 rrna probes and confocal microscopy to detect the periodontal pathogens porphyromonas gingivalis, actinobacillus actinomycetemcomitans, tannerella forsythia, and treponema denticola within epithelial cells from periodontal pockets, gingival crevice, and buccal mucosa collected from subjects with chronic periodontitis (n ...200717451543
periodontal pathogens in periodontal pockets and in carotid atheromatous plaques.in the last years the relationship between periodontitis and cardiovascular diseases has been a subject of increasing research. the identification of periodontopathic bacteria in atheromas can contribute to our knowledge of such an association. the aim of our study was to assess the concomitant presence of 5 periodontal pathogens (actinobacillus actinomycetemcomitans, prevotella intermedia, porphyromonas gingivalis, treponema denticola, and tannerella forsythia) in periodontal pockets and in car ...200717452955
periopathogenic bacteria in persistent periapical lesions: an in vivo prospective study.the aim of this in vivo prospective study was to detect the presence of periopathogenic bacteria in persistent periapical lesions and to compare the reliability of two different methods: anaerobic culture and the dna hybridization technique.200717470025
comparison of curet and paper point sampling of subgingival bacteria as analyzed by real-time polymerase chain reaction.the outcome of microbiological diagnostics may depend on the sampling technique. it was the aim of the present study to compare two widely used sampling techniques for subgingival bacteria using quantitative real-time polymerase chain reaction.200717470026
herpesviral-bacterial synergy in the pathogenesis of human periodontitis.periodontitis is an infectious disease, but the specific mechanisms by which tooth-supportive tissues are lost remain obscure. this article proposes an infectious disease model for periodontitis in which herpesviral-bacterial interactions assume a major etiopathogenic role.200717471038
the microbiological profiles of saliva, supragingival and subgingival plaque and dental caries in adults with and without type 2 diabetes mellitus.the relationships between suspected bacteria in saliva, yeasts in oral rinse, and supragingival and subgingival plaque versus root surface and coronal caries in adults with type 2 diabetes mellitus and a non-diabetic group were explored.200717488443
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