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protease-dependent mechanisms of complement evasion by bacterial pathogens.the human immune system has evolved a variety of mechanisms for the primary task of neutralizing and eliminating microbial intruders. as the first line of defense, the complement system is responsible for rapid recognition and opsonization of bacteria, presentation to phagocytes and bacterial cell killing by direct lysis. all successful human pathogens have mechanisms of circumventing the antibacterial activity of the complement system and escaping this stage of the immune response. one of the w ...201222944688
structural, bioinformatic, and in vivo analyses of two treponema pallidum lipoproteins reveal a unique trap transporter.treponema pallidum, the bacterial agent of syphilis, is predicted to encode one tripartite atp-independent periplasmic transporter (trap-t). trap-ts typically employ a periplasmic substrate-binding protein (sbp) to deliver the cognate ligand to the transmembrane symporter. herein, we demonstrate that the genes encoding the putative trap-t components from t. pallidum, tp0957 (the sbp), and tp0958 (the symporter), are in an operon with an uncharacterized third gene, tp0956. we determined the cryst ...201222306465
bioinformatic characterization of the 4-toluene sulfonate uptake permease (tsup) family of transmembrane proteins.the ubiquitous sequence diverse 4-toluene sulfonate uptake permease (tsup) family contains few characterized members and is believed to catalyze the transport of several sulfur-based compounds. prokaryotic members of the tsup family outnumber the eukaryotic members substantially, and in prokaryotes, but not eukaryotes, extensive lateral gene transfer occurred during family evolution. despite unequal representation, homologues from the three taxonomic domains of life share well-conserved motifs. ...201222192777
bioinformatic characterization of the 4-toluene sulfonate uptake permease (tsup) family of transmembrane proteins.the ubiquitous sequence diverse 4-toluene sulfonate uptake permease (tsup) family contains few characterized members and is believed to catalyze the transport of several sulfur-based compounds. prokaryotic members of the tsup family outnumber the eukaryotic members substantially, and in prokaryotes, but not eukaryotes, extensive lateral gene transfer occurred during family evolution. despite unequal representation, homologues from the three taxonomic domains of life share well-conserved motifs. ...201222192777
sialic acid, periodontal pathogens and tannerella forsythia: stick around and enjoy the feast!periodontal pathogens, like any other human commensal or pathogenic bacterium, must possess both the ability to acquire the necessary growth factors and the means to adhere to surfaces or reside and survive in their environmental niche. recent evidence has suggested that sialic acid containing host molecules may provide both of these requirements in vivo for several periodontal pathogens but most notably for the red complex organism tannerella forsythia. several other periodontal pathogens also ...201222230462
sialic acid, periodontal pathogens and tannerella forsythia: stick around and enjoy the feast!periodontal pathogens, like any other human commensal or pathogenic bacterium, must possess both the ability to acquire the necessary growth factors and the means to adhere to surfaces or reside and survive in their environmental niche. recent evidence has suggested that sialic acid containing host molecules may provide both of these requirements in vivo for several periodontal pathogens but most notably for the red complex organism tannerella forsythia. several other periodontal pathogens also ...201222230462
porphyromonas endodontalis in chronic periodontitis: a clinical and microbiological cross-sectional study.although previous studies have shown the presence of porphyromonas endodontalis in chronic periodontitis associated with periapical lesions, the occurrence of this pathogen in diseased periodontal sites without periapical lesions has been poorly investigated.201222232719
periodontal pathogens affect the level of protease inhibitors in gingival crevicular fluid.in periodontitis, an effective host-response is primarily related to neutrophils loaded with serine proteases, including elastase (ne) and protease 3 (pr3), the extracellular activity of which is tightly controlled by endogenous inhibitors. in vitro these inhibitors are degraded by gingipains, cysteine proteases produced by porphyromonas gingivalis. the purpose of this study was to determine the level of selected protease inhibitors in gingival crevicular fluid (gcf) in relation to periodontal i ...201222230465
Highly Specific Protease-Based Approach for Detection of Porphyromonas gingivalis in Diagnosis of Periodontitis.Porphyromonas gingivalis is associated with the development of periodontitis. Here we describe the development of a highly specific protease-based diagnostic method for the detection of P. gingivalis in gingival crevicular fluid. Screening of a proteolytic peptide substrate library, including fluorogenic dipeptides that contain d-amino acids, led to the discovery of five P. gingivalis-specific substrates. Due to the presence of lysine and arginine residues in these substrates, it was hypothesize ...201222075590
molecular detection of in-vivo microbial contamination of metallic orthodontic brackets by checkerboard dna-dna hybridization.knowing the microbiota that colonizes orthodontic appliances is important for planning strategies and implementing specific preventive measures during treatment. the purpose of this clinical trial was to evaluate in vivo the contamination of metallic orthodontic brackets with 40 dna probes for different bacterial species by using the checkerboard dna-dna hybridization (cddh) technique.201222196182
polymicrobial interactions: impact on pathogenesis and human disease.summary: microorganisms coexist in a complex milieu of bacteria, fungi, archaea, and viruses on or within the human body, often as multifaceted polymicrobial biofilm communities at mucosal sites and on abiotic surfaces. only recently have we begun to appreciate the complicated biofilm phenotype during infection; moreover, even less is known about the interactions that occur between microorganisms during polymicrobial growth and their implications in human disease. therefore, this review focuses ...201222232376
microbial profile of patients with periodontitis compared with healthy subjects.objective: to define and compare the microbiologic profile of subgingival plaque in german patients with periodontitis (including aggressive and advanced chronic periodontitis) and healthy subjects and to determine significant association between isolates and clinical status. aggregatibacter actinomycetemcomitans, porphyromonas gingivalis, and tannerella forsythia are major periodontal pathogens, though it is recognized that other species may also contribute to the pathogenesis of periodontal di ...201222257880
full-mouth disinfection and systemic antimicrobial therapy in generalized aggressive periodontitis: a randomized, placebo-controlled trial.aim: the present investigation aimed to analyse clinical and microbiological effects of systemic administration of metronidazole and amoxicillin combined with the one-stage-full-mouth-disinfection protocol (osfmd) in generalized aggressive periodontitis patients (g-agp). materials and methods: thirty-nine systemically healthy patients with g-agp were consecutively included. the test group (n = 19) received amoxicillin-metronidazole combination (500 mg of each, three times a day for 7 days) and t ...201222220822
impact of supragingival therapy on subgingival microbial profile in smokers versus non-smokers with severe chronic periodontitis.the aim of this study was to assess subgingival microbiological changes in smokers versus non-smokers presenting severe chronic periodontitis after supragingival periodontal therapy (st).201222232720
necrotizing periodontal diseases in hiv-infected brazilian patients: a clinical and microbiologic descriptive study.objective: nowadays, necrotizing periodontal diseases have a low prevalence; however, a better understanding of the etiopathogenesis of these diseases is necessary for determining more adequate preventive and therapeutic strategies. method and materials: from a pool of 1,232 hiv-infected patients, 15 presented with necrotizing periodontal diseases, which were evaluated by full-mouth periodontal clinical measurements. subgingival biofilm samples were collected from necrotizing lesions of six of t ...201222259811
microflora and periodontal disease.periodontitis is a disease that affects and destroys the tissues that support teeth. tissue damage results from a prolonged inflammatory response to an ecological shift in the composition of subgingival biofilms. three bacterial species that constitute the red complex group, porphyromonas gingivalis, tannerella forsythia, and treponema denticola, are considered the main pathogens involved in periodontitis.201223814584
plaque retention on elastomeric ligatures. an in vivo study.fixed orthodontic appliances make it difficult to maintain the oral hygiene, resulting in plaque accumulation. retention of bacterial plaque, represents a risk for white spot lesions and development of periodontal disease.201223741603
plaque retention on elastomeric ligatures. an in vivo study.fixed orthodontic appliances make it difficult to maintain the oral hygiene, resulting in plaque accumulation. retention of bacterial plaque, represents a risk for white spot lesions and development of periodontal disease.201223741603
evaluation of periodontal pathogens in amniotic fluid and the role of periodontal disease in pre-term birth and low birth weight.pre-term birth and/or low birth weight (ptlbw) is a serious problem in developing countries. the absence of known risk factors in ≈ 50% of ptlbw cases has resulted in a continued search for other causes. the aim of this study was to examine the effect of periodontitis on pregnancy outcomes.201223638858
periodontal conditions during the pregnancy associated with periodontal pathogens.to describe the bacterial associations in the periodontal pockets of pregnant women and to correlate the presence of prevotella intermedia, tannerella forsythia (t. forsythia), treponema denticola (t. denticola), aggregatibacter actinomycetemcomitans, and porphyromona gingivalis (p. gingivalis) with periodontal parameters of severity.201223335585
[expression of cytokines in dentogingival sulcus in patients after dental implantation and during development of peri-implantitis].determination of cytokine content in various areas of dentition in patients with peri-implantitis associated with parodontopathogenic bacteria species of i and ii order.201223297645
treponema denticola associates with increased levels of mmp-8 and mmp-9 in gingival crevicular fluid.objectives: the aim was to assess the association between the presence of site-specific subgingival micro-organisms and the levels of matrix metalloproteinases-8 and matrix metalloproteinases-9 (mmp-8 and mmp-9) in gingival crevicular fluid (gcf). materials and methods: the patient group consisted of 56 subjects with periodontitis and the control group of 43 subjects without periodontitis. gcf samples from four test sites for each subject were collected. polymerase chain reaction was used to det ...201223294114
treponema pallidum infection in the wild baboons of east africa: distribution and genetic characterization of the strains responsible.it has been known for decades that wild baboons are naturally infected with treponema pallidum, the bacterium that causes the diseases syphilis (subsp. pallidum), yaws (subsp. pertenue), and bejel (subsp. endemicum) in humans. recently, a form of t. pallidum infection associated with severe genital lesions has been described in wild baboons at lake manyara national park in tanzania. in this study, we investigated ten additional sites in tanzania and kenya using a combination of macroscopic obser ...201223284649
vima mediates multiple functions that control virulence in porphyromonas gingivalis.porphyromonas gingivalis, a black-pigmented, gram-negative anaerobe, is an important etiological agent of periodontal disease. its ability to survive in the periodontal pocket and orchestrate the microbial/host activities that can lead to disease suggest that p. gingivalis possesses a complex regulatory network involving transcriptional and post-transcriptional mechanisms. the vima (virulence modulating) gene is part of the 6.15-kb bcp-reca-vima-vime-vimf-arog locus and plays a role in oxidative ...201223279905
vima mediates multiple functions that control virulence in porphyromonas gingivalis.porphyromonas gingivalis, a black-pigmented, gram-negative anaerobe, is an important etiological agent of periodontal disease. its ability to survive in the periodontal pocket and orchestrate the microbial/host activities that can lead to disease suggest that p. gingivalis possesses a complex regulatory network involving transcriptional and post-transcriptional mechanisms. the vima (virulence modulating) gene is part of the 6.15-kb bcp-reca-vima-vime-vimf-arog locus and plays a role in oxidative ...201223279905
validation of a quantitative real-time pcr assay and comparison with fluorescence microscopy and selective agar plate counting for species-specific quantification of an in vitro subgingival biofilm model.subgingival biofilms are the prime etiological factor of periodontal disease. owing to their complex polymicrobial nature, quantification of individual bacterial species within the biofilm for research and diagnostic purposes can be methodologically challenging. the aims of this study were to establish a quantitative real-time pcr (qpcr) assay to quantify the bacteria used in our 10-species in vitro 'subgingival' biofilm model and to compare the quantitative outcome with fluorescence microscopy ...201223278531
management of peri-implantitis.peri-implantitis is a site-specific infectious disease that causes an inflammatory process in soft tissues, and bone loss around an osseointegrated implant in function. the etiology of the implant infection is conditioned by the status of the tissue surrounding the implant, implant design, degree of roughness, external morphology, and excessive mechanical load. the microorganisms most commonly associated with implant failure are spirochetes and mobile forms of gram-negative anaerobes, unless the ...201223559913
role of sex steroid hormones in bacterial-host interactions.sex steroid hormones play important physiological roles in reproductive and nonreproductive tissues, including immune cells. these hormones exert their functions by binding to either specific intracellular receptors that act as ligand-dependent transcription factors or membrane receptors that stimulate several signal transduction pathways. the elevated susceptibility of males to bacterial infections can be related to the usually lower immune responses presented in males as compared to females. t ...201223509808
role of sex steroid hormones in bacterial-host interactions.sex steroid hormones play important physiological roles in reproductive and nonreproductive tissues, including immune cells. these hormones exert their functions by binding to either specific intracellular receptors that act as ligand-dependent transcription factors or membrane receptors that stimulate several signal transduction pathways. the elevated susceptibility of males to bacterial infections can be related to the usually lower immune responses presented in males as compared to females. t ...201223509808
periodontitis and systemic diseases: a literature review.studies have revealed possible link between periodontitis and different systemic diseases. there is need to review this interesting subject. the aims are: to provide a comprehensive literature that can easily be consulted, on the subject; to draw the attention of health practitioners to the impact of oral health on the general well-being; and to emphasize the need for a deeper interaction between medical and dental training. the medline database was searched for relevant literature by combining ...201223493942
the low incidence of diversity-generating retroelements in sequenced genomes.the insertion of a retrotransposable element is usually associated with adverse or, at best, neutral effects on the host. diversity-generating retroelements (dgrs) are the first elements that seem to offer a direct selective advantage to their phage or prokaryote host by exact replacement of a short, defined region of a host gene with a hypermutated variant. in a previous study, we presented the software digref for identification of dgrs in genome sequences, and compiled the first comprehensive ...201223481467
chemotactic behavior of pathogenic and nonpathogenic leptospira species.we have developed a capillary tube assay in combination with real-time pcr to quantitate the number of chemoattracted leptospira cells. we identified tween 80, glucose, sucrose, and pyruvate as attractants for leptospira cells; amino acids and vitamin b(12) were found to be nonchemotactic or weakly chemotactic. this assay has the general applicability to further our understanding of leptospiral chemotaxis.201223001652
characterization of biofilm formation by borrelia burgdorferi in vitro.borrelia burgdorferi, the causative agent of lyme disease, has long been known to be capable of forming aggregates and colonies. it was recently demonstrated that borrelia burgdorferi aggregate formation dramatically changes the in vitro response to hostile environments by this pathogen. in this study, we investigated the hypothesis that these aggregates are indeed biofilms, structures whose resistance to unfavorable conditions are well documented. we studied borrelia burgdorferi for several kno ...201223110225
whole genome sequence of treponema pallidum ssp. pallidum, strain mexico a, suggests recombination between yaws and syphilis strains.treponema pallidum ssp. pallidum (tpa), the causative agent of syphilis, and treponema pallidum ssp. pertenue (tpe), the causative agent of yaws, are closely related spirochetes causing diseases with distinct clinical manifestations. the tpa mexico a strain was isolated in 1953 from male, with primary syphilis, living in mexico. attempts to cultivate tpa mexico a strain under in vitro conditions have revealed lower growth potential compared to other tested tpa strains.201223029591
comparative genomics of brachyspira pilosicoli strains: genome rearrangements, reductions and correlation of genetic compliment with phenotypic diversity.the anaerobic spirochaete brachyspira pilosicoli causes enteric disease in avian, porcine and human hosts, amongst others. to date, the only available genome sequence of b. pilosicoli is that of strain 95/1000, a porcine isolate. in the first intra-species genome comparison within the brachyspira genus, we report the whole genome sequence of b. pilosicoli b2904, an avian isolate, the incomplete genome sequence of b. pilosicoli wesb, a human isolate, and the comparisons with b. pilosicoli 95/1000 ...201222947175
the rickettsial ompb β-peptide of rickettsia conorii is sufficient to facilitate factor h-mediated serum resistance.pathogenic species of the spotted fever group rickettsia are subjected to repeated exposures to the host complement system through cyclic infections of mammalian and tick hosts. the serum complement machinery is a formidable obstacle for bacteria to overcome if they endeavor to endure this endozoonotic cycle. we have previously demonstrated that that the etiologic agent of mediterranean spotted fever, rickettsia conorii, is susceptible to complement-mediated killing only in the presence of speci ...201222615250
two chew coupling proteins are essential in a chemosensory pathway of borrelia burgdorferi.in the model organism escherichia coli, the coupling protein chew, which bridges the chemoreceptors and histidine kinase chea, is essential for chemotaxis. unlike the situation in e. coli, borrelia burgdorferi, the causative agent of lyme disease, has three chew homologues (chew(1) , chew(2) and chew(3) ). here, a comprehensive approach is utilized to investigate the roles of the three chews in chemotaxis of b. burgdorferi. first, genetic studies indicated that both the chew(1) and chew(3) genes ...201222780444
borrelia burgdorferi needs chemotaxis to establish infection in mammals and to accomplish its enzootic cycle.borrelia burgdorferi, the causative agent of lyme disease, can be recovered from different organs of infected animals and patients, indicating that the spirochete is very invasive. motility and chemotaxis contribute to the invasiveness of b. burgdorferi and play important roles in the process of the disease. recent reports have shown that motility is required for establishing infection in mammals. however, the role of chemotaxis in virulence remains elusive. our previous studies showed that chea ...201222508862
bactquant: an enhanced broad-coverage bacterial quantitative real-time pcr assay.bacterial load quantification is a critical component of bacterial community analysis, but a culture-independent method capable of detecting and quantifying diverse bacteria is needed. based on our analysis of a diverse collection of 16 s rrna gene sequences, we designed a broad-coverage quantitative real-time pcr (qpcr) assay--bactquant--for quantifying 16 s rrna gene copy number and estimating bacterial load. we further utilized in silico evaluation to complement laboratory-based qpcr characte ...201222510143
development of a modified gentamicin resistance cassette for genetic manipulation of the oral spirochete treponema denticola.herein, we report that a modified gentamicin cassette and a pcr-based method can be used for targeted mutagenesis of the oral spirochete treponema denticola. this approach minimizes polar effects and spontaneous antibiotic resistance. therefore, it can serve as a reliable tool for genetic manipulation of t. denticola.201222247130
structure of factor h-binding protein b (fhbb) of the periopathogen, treponema denticola: insights into progression of periodontal disease.periodontitis is the most common disease of microbial etiology in humans. periopathogen survival is dependent upon evasion of complement-mediated destruction. treponema denticola, an important contributor to periodontitis, evades killing by the alternative complement cascade by binding factor h (fh) to its surface. bound fh is rapidly cleaved by the t. denticola protease, dentilisin. in this report, the structure of the t. denticola fh-binding protein, fhbb, was solved to 1.7 å resolution. fhbb ...201222371503
the unique paradigm of spirochete motility and chemotaxis.spirochete motility is enigmatic: it differs from the motility of most other bacteria in that the entire bacterium is involved in translocation in the absence of external appendages. using the lyme disease spirochete borrelia burgdorferi (bb) as a model system, we explore the current research on spirochete motility and chemotaxis. bb has periplasmic flagella (pfs) subterminally attached to each end of the protoplasmic cell cylinder, and surrounding the cell is an outer membrane. these internal h ...201222994496
prevalence, biogenesis, and functionality of the serine protease autotransporter espp.enterohemorrhagic e. coli (ehec) causes severe diseases in humans worldwide. one of its virulence factors is espp, which belongs to the serine protease autotransporters of enterobacteriaceae (spate) family. in this review we recapitulate the current data on prevalence, biogenesis, structural properties and functionality. espp has been used to investigate mechanistic details of autotransport, and recent studies indicate that this transport mechanism is not autonomous but rather dependent on addit ...201223274272
prevalence, biogenesis, and functionality of the serine protease autotransporter espp.enterohemorrhagic e. coli (ehec) causes severe diseases in humans worldwide. one of its virulence factors is espp, which belongs to the serine protease autotransporters of enterobacteriaceae (spate) family. in this review we recapitulate the current data on prevalence, biogenesis, structural properties and functionality. espp has been used to investigate mechanistic details of autotransport, and recent studies indicate that this transport mechanism is not autonomous but rather dependent on addit ...201223274272
metagenomic analysis of subgingival microbiota following non-surgical periodontal therapy: a pilot study.this study tested the feasibility of a high throughput metagenomic approach to analyze the pre- and posttreatment of subgingival plaque in two subjects with aggressive periodontitis. dna was extracted from subgingival samples and subjected to pcr amplification of the c2-c4 regions of the 16s rdna using primers with bar codes to identify individual samples. the pcr products were pooled and sequenced for the v4 region of the 16s rdna using the 454 flx standard platform. the results were analyzed f ...201223341849
structure of the essential diversity-generating retroelement protein bavd and its functionally important interaction with reverse transcriptase.diversity-generating retroelements (dgrs) are the only known source of massive protein sequence variation in prokaryotes. these elements transfer coding information from a template region (tr) through an rna intermediate to a protein-encoding variable region. this retrohoming process is accompanied by unique adenine-specific mutagenesis and, in the prototypical bpp-1 dgr, requires a reverse transcriptase (brt) and an accessory variability determinant (bavd) protein. to understand the role of bav ...201223273427
structure of the essential diversity-generating retroelement protein bavd and its functionally important interaction with reverse transcriptase.diversity-generating retroelements (dgrs) are the only known source of massive protein sequence variation in prokaryotes. these elements transfer coding information from a template region (tr) through an rna intermediate to a protein-encoding variable region. this retrohoming process is accompanied by unique adenine-specific mutagenesis and, in the prototypical bpp-1 dgr, requires a reverse transcriptase (brt) and an accessory variability determinant (bavd) protein. to understand the role of bav ...201223273427
regulation of tlr2-mediated tolerance and cross-tolerance through irak4 modulation by mir-132 and mir-212.innate immune response is the first defense against pathogens via recognition by various conserved pattern recognition receptors, such as tlrs, to initiate a rapid and strong cytokine alarm. tlr signaling-mediated cytokine production must be properly regulated to prevent pathological conditions deriving from overproduction of cytokines. in this study, the role of specific micrornas in tlr-signaling pathway was investigated to reveal the cross-interaction and -regulation in the myd88 pathway. in ...201223264652
regulation of tlr2-mediated tolerance and cross-tolerance through irak4 modulation by mir-132 and mir-212.innate immune response is the first defense against pathogens via recognition by various conserved pattern recognition receptors, such as tlrs, to initiate a rapid and strong cytokine alarm. tlr signaling-mediated cytokine production must be properly regulated to prevent pathological conditions deriving from overproduction of cytokines. in this study, the role of specific micrornas in tlr-signaling pathway was investigated to reveal the cross-interaction and -regulation in the myd88 pathway. in ...201223264652
conservation and revised annotation of the treponema denticola prcb-prca-prtp locus encoding the dentilisin (ctlp) protease complex.interstrain differences in antigenic surface proteins may reflect immunological pressure or differences in receptor specificity of the antigen. treponema denticola exhibits considerable interstrain variability in its major surface protein (msp), but no studies have addressed this issue in dentilisin (ctlp), a surface protease complex that has a significant role in t. denticola-host interactions in periodontal disease. furthermore, the genome annotation of the prcb-prca-prtp operon encoding denti ...201223253337
conservation and revised annotation of the treponema denticola prcb-prca-prtp locus encoding the dentilisin (ctlp) protease complex.interstrain differences in antigenic surface proteins may reflect immunological pressure or differences in receptor specificity of the antigen. treponema denticola exhibits considerable interstrain variability in its major surface protein (msp), but no studies have addressed this issue in dentilisin (ctlp), a surface protease complex that has a significant role in t. denticola-host interactions in periodontal disease. furthermore, the genome annotation of the prcb-prca-prtp operon encoding denti ...201223253337
microbial interactions in building of communities.establishment of a community is considered to be essential for microbial growth and survival in the human oral cavity. biofilm communities have increased resilience to physical forces, antimicrobial agents and nutritional variations. specific cell-to-cell adherence processes, mediated by adhesin-receptor pairings on respective microbial surfaces, are able to direct community development. these interactions co-localize species in mutually beneficial relationships, such as streptococci, veillonell ...201223253299
microbial interactions in building of communities.establishment of a community is considered to be essential for microbial growth and survival in the human oral cavity. biofilm communities have increased resilience to physical forces, antimicrobial agents and nutritional variations. specific cell-to-cell adherence processes, mediated by adhesin-receptor pairings on respective microbial surfaces, are able to direct community development. these interactions co-localize species in mutually beneficial relationships, such as streptococci, veillonell ...201223253299
teth137, a conserved factor of unknown function from thermoanaerobacter ethanolicus jw200, represses the transcription of the adhe gene in vitro.teth137, a 13.7 kd protein of unknown function from thermoanaerobacter ethanolicus jw200, is encoded by 360 nucleotides and has been obtained by dna-coupled column previously. however, no function study of teth137 has been published. homologous modeling of teth137 shows the protein is comprised of a helix-turn-helix motif which is a typical dna-binding domain. therefore, it is speculated teth137 is a dna-binding protein and involved in transcription of the adhe gene (encodes alcohol dehydrogenas ...201224426101
teth137, a conserved factor of unknown function from thermoanaerobacter ethanolicus jw200, represses the transcription of the adhe gene in vitro.teth137, a 13.7 kd protein of unknown function from thermoanaerobacter ethanolicus jw200, is encoded by 360 nucleotides and has been obtained by dna-coupled column previously. however, no function study of teth137 has been published. homologous modeling of teth137 shows the protein is comprised of a helix-turn-helix motif which is a typical dna-binding domain. therefore, it is speculated teth137 is a dna-binding protein and involved in transcription of the adhe gene (encodes alcohol dehydrogenas ...201224426101
papillon-lefèvre syndrome: a series of six cases in the same family.papillon-lefèvre syndrome (pls) is a rare, autosomal recessive heterogeneous disorder, which is characterized by palmoplantar hyperkeratosis, early loss of primary and permanent teeth, and associated calcification of the dura mater. herein we described six cases of pls in the same family. in this series, six cases (two females and four males) with the mean age of 15.6 ± 10.4 years were recruited. palmoplantar hyperkeratosis was detected in all of the cases, leading to a difficult and painful wal ...201223251811
optimization of quantitative polymerase chain reactions for detection and quantification of eight periodontal bacterial pathogens.the aim of this study was to optimize quantitative (real-time) polymerase chain reaction (qpcr) assays for 8 major periodontal pathogens, i.e. aggregatibacter actinomycetemcomitans, fusobacterium nucleatum, parvimonas micros, porphyromonas gingivalis, prevotella intermedia, tanerella forsythia and treponema denticola, and of the caries pathogen streptococcus mutans.201223199017
biophysical and bioinformatic analyses implicate the treponema pallidum tp34 lipoprotein (tp0971) in transition metal homeostasis.metal ion homeostasis is a critical function of many integral and peripheral membrane proteins. the genome of the etiologic agent of syphilis, treponema pallidum, is compact and devoid of many metabolic enzyme genes. nevertheless, it harbors genes coding for homologs of several enzymes that typically require either iron or zinc. the product of the tp0971 gene of t. pallidum, designated tp34, is a periplasmic lipoprotein that is thought to be tethered to the inner membrane of this organism. previ ...201223042995
il-17 and il-11 gcf levels in aggressive and chronic periodontitis patients: relation to pcr bacterial detection.this study evaluated il-17 and il-11 in gingival crevicular fluid (gcf) of generalized chronic periodontitis (gcp) and generalized aggressive periodontitis (gagp) patients in relation to periodontopathic bacteria.201223226926
comprehensive analysis of secondary dental root canal infections: a combination of culture and culture-independent approaches reveals new insights.persistence of microorganisms or reinfections are the main reasons for failure of root canal therapy. very few studies to date have included culture-independent methods to assess the microbiota, including non-cultivable microorganisms. the aim of this study was to combine culture methods with culture-independent cloning methods to analyze the microbial flora of root-filled teeth with periradicular lesions. twenty-one samples from previously root-filled teeth were collected from patients with per ...201223152922
development of microorganisms for cellulose-biofuel consolidated bioprocessings: metabolic engineers' tricks.cellulose waste biomass is the most abundant and attractive substrate for "biorefinery strategies" that are aimed to produce high-value products (e.g. solvents, fuels, building blocks) by economically and environmentally sustainable fermentation processes. however, cellulose is highly recalcitrant to biodegradation and its conversion by biotechnological strategies currently requires economically inefficient multistep industrial processes. the need for dedicated cellulase production continues to ...201224688667
proteome variation among filifactor alocis strains.filifactor alocis, a gram-positive anaerobic rod, is now considered one of the marker organisms associated with periodontal disease. although there was heterogeneity in its virulence potential, this bacterium was shown to have virulence properties that may enhance its ability to survive and persist in the periodontal pocket. to gain further insight into a possible mechanism(s) of pathogenesis, the proteome of f. alocis strains was evaluated. proteins including several proteases, neutrophil-activ ...201223008013
cleavage of igg1 in gingival crevicular fluid is associated with the presence of porphyromonas gingivalis.immunoglobulin (ig) g1 plays an important role in the adaptive immune response. kgp, a lysine-specific cysteine protease from porphyromonas gingivalis, specifically hydrolyses igg1 heavy chains. the purpose of this study was to examine whether cleavage of igg1 occurs in gingival crevicular fluid (gcf) in vivo, and whether there is any association with the presence of porphyromonas gingivalis and other periodontopathogens.201223116446
cleavage of igg1 in gingival crevicular fluid is associated with the presence of porphyromonas gingivalis.immunoglobulin (ig) g1 plays an important role in the adaptive immune response. kgp, a lysine-specific cysteine protease from porphyromonas gingivalis, specifically hydrolyses igg1 heavy chains. the purpose of this study was to examine whether cleavage of igg1 occurs in gingival crevicular fluid (gcf) in vivo, and whether there is any association with the presence of porphyromonas gingivalis and other periodontopathogens.201223116446
bana-positive plaque samples are associated with oral hygiene practices and not cd4+ t cell counts in hiv-positive patients.background. the "red complex" microorganisms, namely, porphyromonas gingivalis, treponema denticola, and tannerella forsythia are considered as potential pathogens causing hiv-associated periodontal diseases. moreover, it has been recognized that an association exists between cd4+ t cell counts and periodontal disease progression. objective. to establish whether cd4+ t cell counts or oral hygiene plays a greater role in producing bana-positive results in hiv-associated periodontal disease. mater ...201223258979
analysis of thic variants in the context of the metabolic network of salmonella enterica.in bacteria, the 4-amino-hydroxymethyl-2-methylpyrimidine (hmp) moiety of thiamine is synthesized from 5-aminoimidazole ribotide (air), a branch point metabolite of purine and thiamine biosynthesis. thic is a member of the radical s-adenosylmethionine (adomet) superfamily and catalyzes the complex chemical rearrangement of air to hmp-p. as reconstituted in vitro, the thic reaction requires adomet, air, and reductant. this study analyzed variants of thic in vivo and in vitro to probe the metaboli ...201222961850
complement and dysbiosis in periodontal disease.signaling crosstalk between complement and toll-like receptors (tlrs) normally serves to coordinate host immunity. however, the periodontal bacterium porphyromonas gingivalis expresses c5 convertase-like enzymatic activity and adeptly exploits complement-tlr crosstalk to subvert host defenses and escape elimination. intriguingly, this defective immune surveillance leads to the remodeling of the periodontal microbiota to a dysbiotic state that causes inflammatory periodontitis. understanding the ...201222964237
a phage display selected 7-mer peptide inhibitor of the tannerella forsythia metalloprotease-like enzyme karilysin can be truncated to ser-trp-phe-pro.tannerella forsythia is a gram-negative bacteria, which is strongly associated with the development of periodontal disease. karilysin is a newly identified metalloprotease-like enzyme, that is secreted from t. forsythia. karilysin modulates the host immune response and is therefore considered a likely drug target. in this study peptides were selected towards the catalytic domain from karilysin (kly18) by phage display. the peptides were linear with low micromolar binding affinities. the two best ...201223119051
offense and defense: microbial membrane vesicles play both ways.microbes have evolved over millennia to become adapted and specialized to the environments that they occupy. these environments may include water or soil, extreme environments such as hydrothermal vents, and can even include a host organism. to become adapted to these locations, microbes have evolved specific tools to mediate interactions with the environment. one such tool that prokaryotes have evolved includes the production of membrane vesicles (mvs). mvs are 10-300 nm spherical blebs derived ...201223123555
controlled biosynthesis of odd-chain fuels and chemicals via engineered modular metabolic pathways.microbial systems are being increasingly developed as production hosts for a wide variety of chemical compounds. broader adoption of microbial synthesis is hampered by a limited number of high-yielding natural pathways for molecules with the desired physical properties, as well as the difficulty in functionally assembling complex biosynthetic pathways in heterologous hosts. here, we address both of these challenges by reporting the adaptation of the butanol biosynthetic pathway for the synthesis ...201223071297
glycobiology aspects of the periodontal pathogen tannerella forsythia.glycobiology is important for the periodontal pathogen tannerella forsythia, affecting the bacterium's cellular integrity, its life-style, and virulence potential. the bacterium possesses a unique gram-negative cell envelope with a glycosylated surface (s-) layer as outermost decoration that is proposed to be anchored via a rough lipopolysaccharide. the s-layer glycan has the structure 4‑meo-b-manpnacconh2-(1→3)-[pse5am7gc-(2→4)-]-b-manpnaca-(1→4)-[4-meo-a-galp-(1→2)-]-a-fucp-(1→4)-[-a-xylp-(1→3 ...201224970146
quantitative discrimination of aggregatibacter actinomycetemcomitans highly leukotoxic jp2 clone from non-jp2 clones in diagnosis of aggressive periodontitis.aggregatibacter actinomycetemcomitans is the etiological agent of periodontitis, and there is a strong association between clone jp2 and aggressive periodontitis in adolescents of african descent. the jp2 clone has an approximately 530-bp deletion (∆530) in the promoter region of the lkt/ltx gene, which encodes leukotoxin, and this clone has high leukotoxic activity. therefore, this clone is very important in aggressive periodontitis. to diagnose this disease, culture methods and conventional pc ...201223050598
advancement of the 10-species subgingival zurich biofilm model by examining different nutritional conditions and defining the structure of the in vitro biofilms.periodontitis is caused by a highly complex consortium of bacteria that establishes as biofilms in subgingival pockets. it is a disease that occurs worldwide and its consequences are a major health concern. investigations in situ are not possible and the bacterial community varies greatly between patients and even within different loci. due to the high complexity of the consortium and the availability of samples, a clear definition of the pathogenic bacteria and their mechanisms of pathogenicity ...201223040057
recording and surveillance systems for periodontal diseases.this paper describes tools used to measure periodontal diseases and the integration of these tools into surveillance systems. tools to measure periodontal diseases at the surveillance level have focussed on current manifestations of disease (e.g. gingival inflammation) or disease sequelae (e.g. periodontal pocket depth or loss of attachment). all tools reviewed in this paper were developed based on the state of the science of the pathophysiology of periodontal disease at the time of their design ...201222909105
miswak: a periodontist's perspective.meticulous plaque control on a daily routine basis is the single most important step to achieve good oral health. herbal chewing sticks, commonly known as miswak, are among the ancient and traditional oral hygiene aids popular in india, pakistan, most of the arabian countries, and several african countries. but nowadays, because of low cost, free availability, unique chemical composition, and spiritual beliefs, miswak is being used worldwide. a large number of studies have proved that miswak is ...201223326088
sensing the enemy: new role for a bacterial secretion system in activation of an innate immunity-associated microrna. 201223076273
the prosthodontic management of a young edentulous patient with the papillon lefevre syndrome-a rare case report.the papillon lefevre syndrome is an autosomal recessive disorder which is characterized by various dermatological manifestations and periodontitis as a manifestation of a systemic disease. its aetiopathogenesis is thought to be secondary to the mutation of the cathepsin c gene. various studies have shown that the immune related cells like the polymorphonuclear leucocytes and the macrophages and their precursors were affected.this report elicits about an edentulous male with this syndrome, who wa ...201223373060
a bacterial glycan core linked to surface (s)-layer proteins modulates host immunity through th17 suppression.tannerella forsythia is a pathogen implicated in periodontitis, an inflammatory disease of the tooth-supporting tissues often leading to tooth loss. this key periodontal pathogen is decorated with a unique glycan core o-glycosidically linked to the bacterium's proteinaceous surface (s)-layer lattice and other glycoproteins. herein, we show that the terminal motif of this glycan core acts to modulate dendritic cell effector functions to suppress t-helper (th)17 responses. in contrast to the wild- ...201222968422
a bacterial glycan core linked to surface (s)-layer proteins modulates host immunity through th17 suppression.tannerella forsythia is a pathogen implicated in periodontitis, an inflammatory disease of the tooth-supporting tissues often leading to tooth loss. this key periodontal pathogen is decorated with a unique glycan core o-glycosidically linked to the bacterium's proteinaceous surface (s)-layer lattice and other glycoproteins. herein, we show that the terminal motif of this glycan core acts to modulate dendritic cell effector functions to suppress t-helper (th)17 responses. in contrast to the wild- ...201222968422
beyond the red complex and into more complexity: the polymicrobial synergy and dysbiosis (psd) model of periodontal disease etiology.recent advancements in the periodontal research field are consistent with a new model of pathogenesis according to which periodontitis is initiated by a synergistic and dysbiotic microbial community rather than by select 'periopathogens', such as the 'red complex'. in this polymicrobial synergy, different members or specific gene combinations within the community fulfill distinct roles that converge to shape and stabilize a disease-provoking microbiota. one of the core requirements for a potenti ...201223134607
the keystone-pathogen hypothesis.recent studies have highlighted the importance of the human microbiome in health and disease. however, for the most part the mechanisms by which the microbiome mediates disease, or protection from it, remain poorly understood. the keystone-pathogen hypothesis holds that certain low-abundance microbial pathogens can orchestrate inflammatory disease by remodelling a normally benign microbiota into a dysbiotic one. in this opinion article, we critically assess the available literature that supports ...201222941505
a proteomic investigation of fusobacterium nucleatum alkaline-induced biofilms.the gram negative anaerobe fusobacterium nucleatum has been implicated in the aetiology of periodontal diseases. although frequently isolated from healthy dental plaque, its numbers and proportion increase in plaque associated with disease. one of the significant physico-chemical changes in the diseased gingival sulcus is increased environmental ph. when grown under controlled conditions in our laboratory, f. nucleatum subspecies polymorphum formed mono-culture biofilms when cultured at ph 8.2. ...201222943491
energy filtering transmission electron microscopy immunocytochemistry and antigen retrieval of surface layer proteins from tannerella forsythensis using microwave or autoclave heating with citraconic anhydride.tannerella forsythensis (bacteroides forsythus), an anaerobic gram-negative species of bacteria that plays a role in the progression of periodontal disease, has a unique bacterial protein profile. it is characterized by two unique protein bands with molecular weights of more than 200 kda. it also is known to have a typical surface layer (s-layer) consisting of regularly arrayed subunits outside the outer membrane. we examined the relationship between high molecular weight proteins and the s-laye ...201222984898
porphyromonas gingivalis as a potential community activist for disease.an extensive analysis of dental plaque samples over the years has led to the identification of "red" complex oral bacteria that have a strong association with each other and with disease. consequently, these bacteria have been labeled 'periopathogens'. studies with one of these bacteria, porphyromonas gingivalis, have revealed that it contains several different mechanisms which either impede or modulate periodontal protective mechanisms. in a mouse model of periodontitis, it has been shown that ...201222772362
hcpr of porphyromonas gingivalis is required for growth under nitrosative stress and survival within host cells.although the gram-negative, anaerobic periodontopathogen porphyromonas gingivalis must withstand nitrosative stress, which is particularly high in the oral cavity, the mechanisms allowing for protection against such stress are not known in this organism. in this study, microarray analysis of p. gingivalis transcriptional response to nitrite and nitric oxide showed drastic upregulation of the pg0893 gene coding for hybrid cluster protein (hcp), which is a putative hydroxylamine reductase. althoug ...201222778102
global expression profile of biofilm resistance to antimicrobial compounds in the plant-pathogenic bacterium xylella fastidiosa reveals evidence of persister cells.investigations of biofilm resistance response rarely focus on plant-pathogenic bacteria. since xylella fastidiosa is a multihost plant-pathogenic bacterium that forms biofilm in the xylem, the behavior of its biofilm in response to antimicrobial compounds needs to be better investigated. we analyzed here the transcriptional profile of x. fastidiosa subsp. pauca in response to inhibitory and subinhibitory concentrations of copper and tetracycline. copper-based products are routinely used to contr ...201222730126
association of cd14-260 polymorphisms, red-complex periodontopathogens and gingival crevicular fluid cytokine levels with cyclosporine a-induced gingival overgrowth in renal transplant patients.backgroud and objective: genetic factors may influence the colonization of pathogenic bacteria, therefore increasing the risk for the initiation and development of periodontal disease. the present study was carried out to investigate the association of cd14-260 polymorphisms, subgingival microbiota, and gingival crevicular fluid (gcf) cytokine levels with cyclosporine a (csa)-induced gingival overgrowth (go) in renal transplant patients.201222934794
association of cd14-260 polymorphisms, red-complex periodontopathogens and gingival crevicular fluid cytokine levels with cyclosporine a-induced gingival overgrowth in renal transplant patients.backgroud and objective: genetic factors may influence the colonization of pathogenic bacteria, therefore increasing the risk for the initiation and development of periodontal disease. the present study was carried out to investigate the association of cd14-260 polymorphisms, subgingival microbiota, and gingival crevicular fluid (gcf) cytokine levels with cyclosporine a (csa)-induced gingival overgrowth (go) in renal transplant patients.201222934794
bacterial cell surface heterogeneity: a pathogen's disguise. 201222952444
bugs that debugs: probiotics.the oral cavity harbors a diverse array of bacterial species. there are more than 600 species that colonize in the oral cavity. these include a lot of organisms that are not commonly known to reside in the gastrointestinal (gi) tract and also are more familiar: lactobacillus acidophilus, lactobacillus casei, lactobacillus fermentum, lactobacillus plantarum, lactobacillus rhamnosus, and lactobacillus salivarius. the balance of all these microorganisms can easily be disturbed and a prevalence of p ...201223066281
staphylococcal superantigen-like protein 3 binds to the toll-like receptor 2 extracellular domain and inhibits cytokine production induced by staphylococcus aureus, cell wall component, or lipopeptides in murine macrophages.staphylococcal superantigen-like proteins (ssls) are a family of exoproteins sharing structural similarity with superantigens, but no superantigenic activity. corresponding host target proteins or receptors against a portion of ssls in the family have been identified. in this study, we show that ssl3 specifically binds to toll-like receptor 2 (tlr2) and inhibits the stimulation of macrophages by tlr2 ligands. an approximately 100-kda protein was recovered by using recombinant his-tagged ssl3-con ...201222665377
oral spirochetes implicated in dental diseases are widespread in normal human subjects and carry extremely diverse integron gene cassettes.the nih human microbiome project (hmp) has produced several hundred metagenomic data sets, allowing studies of the many functional elements in human-associated microbial communities. here, we survey the distribution of oral spirochetes implicated in dental diseases in normal human individuals, using recombination sites associated with the chromosomal integron in treponema genomes, taking advantage of the multiple copies of the integron recombination sites (repeats) in the genomes, and using a ta ...201222635997
bacterial community shift in treated periodontitis patients revealed by ion torrent 16s rrna gene amplicon sequencing.periodontitis, one of the most common diseases in the world, is caused by a mixture of pathogenic bacteria and inflammatory host responses and often treated by antimicrobials as an adjunct to scaling and root planing (srp). our study aims to elucidate explorative and descriptive temporal shifts in bacterial communities between patients treated by srp alone versus srp plus antibiotics. this is the first metagenomic study using an ion torrent personal genome machine (pgm). eight subgingival plaque ...201222870235
exploration of the active site of escherichia coli cystathionine γ-synthase.cystathionine γ-synthase (cgs) catalyzes the condensation of o-succinyl-l-homoserine (l-oshs) and l-cysteine (l-cys), to produce l-cystathionine (l-cth) and succinate, in the first step of the bacterial transsulfuration pathway. in the absence of l-cys, the enzyme catalyzes the futile α,γ-elimination of l-oshs, yielding succinate, α-ketobutyrate, and ammonia. a series of 16 site-directed variants of escherichia coli cgs (ecgs) was constructed to probe the roles of active-site residues d45, y46, ...201222855027
movement of dna sequence recognition domains between non-orthologous proteins.comparisons of proteins show that they evolve through the movement of domains. however, in many cases, the underlying mechanisms remain unclear. here, we observed the movements of dna recognition domains between non-orthologous proteins within a prokaryote genome. restriction-modification (rm) systems, consisting of a sequence-specific dna methyltransferase and a restriction enzyme, contribute to maintenance/evolution of genomes/epigenomes. rm systems limit horizontal gene transfer but are thems ...201222821560
antibacterial effects of blackberry extract target periodontopathogens.antimicrobial agents provide valuable adjunctive therapy for the prevention and the control of oral diseases. limitations in their prolonged use have stimulated the search for new, naturally occurring agents with more specific activity and fewer adverse effects. here we sought to determine the antibacterial properties of blackberry extract (bbe) in vitro against oral bacterial commensals and periodontopathogens.201222812456
antibacterial effects of blackberry extract target periodontopathogens.antimicrobial agents provide valuable adjunctive therapy for the prevention and the control of oral diseases. limitations in their prolonged use have stimulated the search for new, naturally occurring agents with more specific activity and fewer adverse effects. here we sought to determine the antibacterial properties of blackberry extract (bbe) in vitro against oral bacterial commensals and periodontopathogens.201222812456
pathogenicity of treponema denticola wild-type and mutant strain tested by an active mode of periodontal infection using microinjection.the available passive mode of periodontal infections in mice requires high efficiency of bacterial attachment and invasiveness and is not always suitable to test the pathogenicity of genetically engineered mutant strains. we developed an active mode of oral infection, using microinjection in the marginal gingiva of mice, to test the pathogenicity of a genetically engineered treponema denticola mutant strain deficient in intermediate-like filaments, compared to the wild-type strain. this targeted ...201222829826
comparative evaluation of 0.1% turmeric mouthwash with 0.2% chlorhexidine gluconate in prevention of plaque and gingivitis: a clinical and microbiological study.the aim of our clinical trial was to assess the efficacy of 0.1% turmeric mouthwash as an anti-plaque agent and its effect on gingival inflammation and to compare it with 0.2% chlorhexidine gluconate by evaluating the effect on plaque and gingival inflammation and on microbial load.201223162334
fusobacterium nucleatum and tannerella forsythia induce synergistic alveolar bone loss in a mouse periodontitis model.tannerella forsythia is strongly associated with chronic periodontitis, an inflammatory disease of the tooth-supporting tissues, leading to tooth loss. fusobacterium nucleatum, an opportunistic pathogen, is thought to promote dental plaque formation by serving as a bridge bacterium between early- and late-colonizing species of the oral cavity. previous studies have shown that f. nucleatum species synergize with t. forsythia during biofilm formation and pathogenesis. in the present study, we show ...201222547549
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