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binding properties of treponema denticola lipooligosaccharide.the cell-surface lipooligosaccharide (los) of treponema denticola possesses several biological properties. the aim of this study was to investigate the binding properties of t. denticola los to extracellular matrix (ecm) proteins, mucosal cells, and oral bacteria.201324049558
functional role of oligomerization for bacterial and plant sweet sugar transporter family.eukaryotic sugar transporters of the mfs and sweet superfamilies consist of 12 and 7 α-helical transmembrane domains (tms), respectively. structural analyses indicate that mfs transporters evolved from a series of tandem duplications of an ancestral 3-tm unit. sweets are heptahelical proteins carrying a tandem repeat of 3-tm separated by a single tm. here, we show that prokaryotes have ancestral sweet homologs with only 3-tm and that the bradyrhizobium japonicum semisweet1, like arabidopsis swee ...201324027245
characterization of c-s lyase from c. diphtheriae: a possible target for new antimicrobial drugs.the emergence of antibiotic resistance in microbial pathogens requires the identification of new antibacterial drugs. the biosynthesis of methionine is an attractive target because of its central importance in cellular metabolism. moreover, most of the steps in methionine biosynthesis pathway are absent in mammals, lowering the probability of unwanted side effects. herein, detailed biochemical characterization of one enzyme required for methionine biosynthesis, a pyridoxal-5'-phosphate (plp-) de ...201324106714
transcriptome analysis of encystation in entamoeba invadens.encystation is an essential differentiation process for the completion of the life cycle of a group of intestinal protozoa including entamoeba histolytica, the causative agent of intestinal and extraintestinal amebiasis. however, regulation of gene expression during encystation is poorly understood. to comprehensively understand the process at the molecular level, the transcriptomic profiles of e. invadens, which is a related reptilian species that causes an invasive disease similar to that of e ...201324040350
the thiamine biosynthetic enzyme thic catalyzes multiple turnovers and is inhibited by s-adenosylmethionine (adomet) metabolites.thic (4-amino-5-hydroxymethyl-2-methylpyrimidine phosphate synthase; ec 4.1.99.17) is a radical s-adenosylmethionine (adomet) enzyme that uses a [4fe-4s](+) cluster to reductively cleave adomet to methionine and a 5'-deoxyadenosyl radical that initiates catalysis. in plants and bacteria, thic converts the purine intermediate 5-aminoimidazole ribotide to 4-amino-5-hydroxymethyl-2-methylpyrimidine phosphate, an intermediate of thiamine pyrophosphate (coenzyme b1) biosynthesis. in this study, assay ...201324014032
the effect of adjunctive low-dose doxycycline and licorice therapy on gingival crevicular fluid matrix metalloproteinase-8 levels in chronic periodontitis.this study compared the effect of adjunctive low dose doxycycline and licorice on gingival crevicular fluid (gcf) matrix metalloproteinase-8 (mmp-8) levels in patients with chronic periodontitis.201324348620
dental abscess: a microbiological review.dental abscess is a frequently occurring infectious process known to the health practice. the fate of the infection depends on the virulence of the bacteria, host resistance factors, and regional anatomy. serious consequences arising from the spread of a dental abscess lead to significant morbidity and mortality. acute dental abscess is polymicrobial, comprising of strict anaerobes, such as anaerobic cocci, prevotella, fusobacterium species, and facultative anaerobes, such as viridans group stre ...201324348613
effect of controlled-release periochip™ on clinical and microbiological parameters in patients of chronic periodontitis.the aim of the present study was to evaluate and compare the clinical and microbiological effectiveness of periochip™ as an adjunct to scaling and root planing (srp) with srp alone in patients with chronic periodontitis.201324174754
a consortium of aggregatibacter actinomycetemcomitans, streptococcus parasanguinis, and filifactor alocis is present in sites prior to bone loss in a longitudinal study of localized aggressive periodontitis.aggregatibacter actinomycetemcomitans-induced localized aggressive periodontitis (lap) in african-american adolescents has been documented but is poorly understood. two thousand fifty-eight adolescents aged 11 to 17 years were screened for their periodontal status and the presence of a. actinomycetemcomitans in their oral cavity. seventy-one a. actinomycetemcomitans-negative and 63 a. actinomycetemcomitans-positive periodontally healthy subjects were enrolled, sampled, examined, and radiographed ...201323784124
anticardiolipin in porphyromonas gingivalis antisera causes fetal loss in mice.β2-glycoprotein i (β2gpi)-dependent anticardiolipin autoantibodies (acl) are associated with thrombosis and fetal loss. some microbial pathogens can induce pathogenic antibodies cross-reactive with β2gpi. sera from a significant percentage of periodontitis patients contain acl, and some periodontal pathogens contain antigens with peptide sequences having homology to β2gpi. we hypothesized that antibodies raised against p. gingivalis (apg) contain pathogenic acl that induce fetal resorption. we i ...201323857644
quantitative analysis of periodontal pathogens present in the saliva of geriatric subjects.at present, information regarding periodontal disease in geriatric patients is scarce. the purpose of this study was to quantify the periodontal pathogens present in the saliva of korean geriatric patients and assess the relationship between the bacterial levels and the periodontal condition.201324040571
decontamination of dental implant surface in peri-implantitis treatment: a literature review.etiological treatment of peri-implantitis aims to reduce the bacterial load within the peri-implant pocket and decontaminate the implant surface in order to promote osseointegration. the aim of this literature review was to evaluate the efficacy of different methods of implant surface decontamination. a search was conducted using the pubmed (medline) database, which identified 36 articles including in vivo and in vitro studies, and reviews of different decontamination systems (chemical, mechanic ...201323986023
stimulation of mmp-1 and ccl2 by nampt in pdl cells.periodontitis is an inflammatory disease caused by pathogenic microorganisms and characterized by the destruction of the periodontium. obese individuals have an increased risk of periodontitis, and elevated circulating levels of adipokines, such as nicotinamide phosphoribosyltransferase (nampt), may be a pathomechanistic link between both diseases. the aim of this in vitro study was to examine the regulation of periodontal ligament (pdl) cells by nampt and its production under inflammatory and i ...201324058270
environmental stimuli shape biofilm formation and the virulence of periodontal pathogens.periodontitis is a common inflammatory disease affecting the tooth-supporting structures. it is initiated by bacteria growing as a biofilm at the gingival margin, and communication of the biofilms differs in health and disease. the bacterial composition of periodontitis-associated biofilms has been well documented and is under continual investigation. however, the roles of several host response and inflammation driven environmental stimuli on biofilm formation is not well understood. this review ...201323965982
genome-wide relatedness of treponema pedis, from gingiva and necrotic skin lesions of pigs, with the human oral pathogen treponema denticola.treponema pedis and t. denticola are two genetically related species with different origins of isolation. treponema denticola is part of the human oral microbiota and is associated with periodontitis while t. pedis has been isolated from skin lesions in animals, e.g., digital dermatitis in cattle and necrotic ulcers in pigs. although multiple treponema phylotypes may exist in ulcerative lesions in pigs, t. pedis appears to be a predominant spirochete in these lesions. treponema pedis can also be ...201323977007
bacterial community development in experimental gingivitis.current knowledge of the microbial composition of dental plaque in early gingivitis is based largely on microscopy and cultural methods, which do not provide a comprehensive description of oral microbial communities. this study used 454-pyrosequencing of the v1-v3 region of 16s rrna genes (approximately 500 bp), and bacterial culture, to characterize the composition of plaque during the transition from periodontal health to gingivitis. a total of 20 healthy volunteers abstained from oral hygiene ...201323967169
a surface-exposed neuraminidase affects complement resistance and virulence of the oral spirochaete treponema denticola.neuraminidases (sialidases) catalyse the removal of terminal sialic acid from glycoconjugates. bacterial pathogens often utilize neuraminidases to scavenge host sialic acid, which can be utilized either as a nutrient or as a decorating molecule to disguise themselves from host immune attacks. herein, a putative neuraminidase (tde0471) was identified in treponema denticola, an oral spirochaete associated with human periodontitis. tde0471 is a cell surface-exposed exo-neuraminidase that removes si ...201323808705
monitoring the prevalence of viable and dead cariogenic bacteria in oral specimens and in vitro biofilms by qpcr combined with propidium monoazide.streptococcus mutans and streptococcus sobrinus are associated with the development of dental caries in humans. however, previous diagnostic systems are unsuitable for monitoring viable cell numbers in oral specimens. assessing the relationship between the numbers of viable and dead bacterial cells and oral status is important for understanding oral infectious diseases. propidium monoazide (pma) has been reported to penetrate dead cells following membrane damage and to cross-link dna, thereby in ...201323848601
role of bacterial infections in pancreatic cancer.established risk factors for pancreatic cancer, including tobacco smoking, chronic pancreatitis, obesity and type 2 diabetes, collectively account for less than half of all pancreatic cancer cases. inflammation plays a key role in pancreatic carcinogenesis, but it is unclear what causes local inflammation, other than pancreatitis. epidemiological data suggest that helicobacter pylori may be a risk factor for pancreatic cancer, and more recently, data suggest that periodontal disease, and porphyr ...201323843038
multilevel analysis of bacterial counts from chronic periodontitis after root planing/scaling, surgery, and systemic and local antibiotics: 2-year results.to follow changes (over 2 years) in subgingival bacterial counts of five microbial complexes including health-related actinomyces spp. in deeper pockets (≥5 mm) after periodontal treatments.201323853701
the correlation between chronic periodontitis and oral cancer.infections are increasingly considered as potential trigger for carcinogenesis apart from risk factors like alcohol and tobacco. the discussion about human papilloma virus (hpv) in oral squamous cell carcinoma (oscc) points at a general role of infection for the development of oral carcinomas. furthermore, first studies describe a correlation between chronic periodontitis and oscc, thus, characterizing chronic inflammation as being a possible trigger for oscc. in front of this background, we pre ...201323936684
quantitative and qualitative analysis of microorganisms in root-filled teeth with persistent infection: monitoring of the endodontic retreatment.the aim of this study was to investigate in vivo microorganisms detected in root-filled teeth with post-treatment apical periodontitis and quantify colony-forming units (cfu) during endodontic retreatment.201324926210
combination of inflammatory and amlodipine induced gingival overgrowth in a patient with cardiovascular disease.gingival overgrowth (go) is among one of the most important clinical features of gingival pathology frequently seen in periodontal clinic. amlodipine is a comparatively new calcium channel blocker and is being used with increasing frequency in the management of hypertension and angina. a 48-year-old indian woman who was on amlodipine for 3 years for hypertension reported to the department of periodontics with the complaint of swollen, un esthetic gums. the patient developed go 6 months before he ...201324251234
microbial dysbiosis in periodontitis.periodontitis is a biofilm-associated inflammatory disease of the periodontium. this disease appears to have multiple etiologies with microbial factor contributing to initiation of the disease and immunological factor of the host propagating the disease. this review is on the concept of "microbial dysbiosis" and molecular nature of periodontitis, and the scope of traditional and emerging technologies for treating this disease.201324174742
salivary ph: a diagnostic biomarker.saliva contains a variety of host defense factors. it influences calculus formation and periodontal disease. different studies have been done to find exact correlation of salivary biomarkers with periodontal disease. with a multitude of biomarkers and complexities in their determination, the salivary ph may be tried to be used as a quick chairside test. the aim of this study was to analyze the ph of saliva and determine its relevance to the severity of periodontal disease.201324174725
targeting the treponemal microbiome of digital dermatitis infections by high-resolution phylogenetic analyses and comparison with fluorescent in situ hybridization.modern pyrosequencing technology allows for a more comprehensive approach than traditional sanger sequencing for elucidating the etiology of bovine digital dermatitis. we sought to describe the composition and diversity of treponemes in digital dermatitis lesions by using deep sequencing of the v3 and v4 hypervariable regions of the 16s rrna gene coupled with species-level taxonomic identification. treponema-specific 16s rrna gene pcrs and pyrosequencing were performed on biopsy specimens origin ...201323658264
association between periodontal disease and plasma levels of cholesterol and triglycerides.untreated periodontal disease seems to cause low grade systemic inflammation and blood lipid alteration leading to increased cardiovascular disease risk. to start testing this hypothesis in colombian patients, a multicentre study was conducted including the three main state capitals: bogota, medellin and cali.201324892452
ornithine cyclodeaminase-based proline production by corynebacterium glutamicum.the soil bacterium corynebacterium glutamicum, best known for its glutamate producing ability, is suitable as a producer of a variety of bioproducts. glutamate is the precursor of the amino acid proline. proline biosynthesis typically involves three enzymes and a spontaneous cyclisation reaction. alternatively, proline can be synthesised from ornithine, an intermediate of arginine biosynthesis. the direct conversion of ornithine to proline is catalysed by ornithine cyclodeaminase. an ornithine o ...201323806148
a high-throughput microfluidic dental plaque biofilm system to visualize and quantify the effect of antimicrobials.few model systems are amenable to developing multi-species biofilms in parallel under environmentally germane conditions. this is a problem when evaluating the potential real-world effectiveness of antimicrobials in the laboratory. one such antimicrobial is cetylpyridinium chloride (cpc), which is used in numerous over-the-counter oral healthcare products. the aim of this work was to develop a high-throughput microfluidic system that is combined with a confocal laser scanning microscope (clsm) t ...201323800904
oral microflora and periodontal disease: new technology for diagnosis in dentistry.periodontitis is a disease that affects and destroys the tissues that support teeth. tissues 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. in the present study a real-time pcr based assay was designed to detect and quantify red ...201323991267
predictive, preventive, personalised and participatory periodontology: 'the 5ps age' has already started.an impressive progress in dentistry has been recorded in the last decades. in order to reconsider guidelines in dentistry, it is required to introduce new concepts of personalised patient treatments: the wave of predictive, preventive and personalised medicine is rapidly incoming in dentistry. worldwide dentists have to make a big cultural effort in changing the actual 'reactive' therapeutic point of view, belonging to the last century, into a futuristic 'predictive' one. the first cause of toot ...201323763842
differential expression of mitogen activating protein kinases in periodontitis.following toll-like receptor (tlr) engagement, lipopolysaccharide (lps) can stimulate the expression of pro-inflammatory cytokines thus activating the innate immune response. the production of inflammatory cytokines results, in part, from the activation of kinase-induced signalling cascades and transcriptional factors. of the four distinct classes of mitogen-activated protein kinases (mapk) described in mammals, p38, c-jun n-terminal activated kinases (jnk1-3) and extracellular activated kinases ...201323742695
periodontopathogen profile of healthy and oral lichen planus patients with gingivitis or periodontitis.oral lichen planus (olp) is a chronic inflammatory disease that is frequently detected in oral tissues. the aim of our study was to identify the prevalence of the detection of periodontopathogenic microorganisms (aggregatibacter actinomycetemcomitans, porphyromonas gingivalis, prevotella intermedia, tannerella forsythia and treponema denticola in olp patients and to compare with this prevalence of periodontopathogenic microorganisms in healthy non-olp patients. our study included 27 (18 chronic ...201323743616
periodontal disease: a covert source of inflammation in chronic kidney disease patients.the prevalence of atherosclerotic complications (myocardial infarction, stroke, and sudden death) is increased in end-stage renal disease (esrd) patients, especially in haemodialysis patients. increasing evidence suggests that both in general population and in dialysis patients, systemic inflammation plays a dominant role in the pathogenesis of atherosclerotic complications. in general population, also, evidence shows that moderate to severe periodontitis can contribute to inflammatory burden by ...201323840952
oral microbiome of deep and shallow dental pockets in chronic periodontitis.we examined the subgingival bacterial biodiversity in untreated chronic periodontitis patients by sequencing 16s rrna genes. the primary purpose of the study was to compare the oral microbiome in deep (diseased) and shallow (healthy) sites. a secondary purpose was to evaluate the influences of smoking, race and dental caries on this relationship. a total of 88 subjects from two clinics were recruited. paired subgingival plaque samples were taken from each subject, one from a probing site depth > ...201323762384
spanner: taxonomic assignment of sequences using pyramid matching of similarity profiles.homology-based taxonomic assignment is impeded by differences between the unassigned read and reference database, forcing a rank-specific classification to the closest (and possibly incorrect) reference lineage. this assignment may be correct only to a general rank (e.g. order) and incorrect below that rank (e.g. family and genus). algorithms like lca avoid this by varying the predicted taxonomic rank based on matches to a set of taxonomic references. lca and related approaches can be conservati ...201323732273
bacterial sex in dental plaque.genes are transferred between bacteria in dental plaque by transduction, conjugation, and transformation. membrane vesicles can also provide a mechanism for horizontal gene transfer. dna transfer is considered bacterial sex, but the transfer is not parallel to processes that we associate with sex in higher organisms. several examples of bacterial gene transfer in the oral cavity are given in this review. how frequently this occurs in dental plaque is not clear, but evidence suggests that it affe ...201323741559
treponema denticola major outer sheath protein impairs the cellular phosphoinositide balance that regulates neutrophil chemotaxis.the major outer sheath protein (msp) of treponema denticola inhibits neutrophil polarization and directed chemotaxis together with actin dynamics in vitro in response to the chemoattractant n-formyl-methionine-leucine-phenylanine (fmlp). msp disorients chemotaxis through inhibition of a rac1-dependent signaling pathway, but the upstream mechanisms are unknown. we challenged murine bone marrow neutrophils with enriched native msp to determine the role of phospholipid modifying enzymes in chemotax ...201323755300
familial oral microbial imbalance and dental caries occurrence in their children.develop a familial liability index for oral microbial status that reflects an imbalance of oral domains based on the presence of risk indicators in saliva, inter-proximal plaque, tongue, and throat.201324600078
lessons learned and unlearned in periodontal microbiology.periodontal diseases are initiated by bacterial species living in polymicrobial biofilms at or below the gingival margin and progress largely as a result of the inflammation elicited by specific subgingival species. in the past few decades, efforts to understand the periodontal microbiota have led to an exponential increase in information about biofilms associated with periodontal health and disease. in fact, the oral microbiota is one of the best-characterized microbiomes that colonize the huma ...201323574465
periodontitis: a host-mediated disruption of microbial homeostasis. unlearning learned concepts.new concepts evolve when existing ones fail to address known factors adequately or are invalidated by new evidence. for decades periodontitis has been considered to be caused by specific bacteria or groups of bacteria and, accordingly, treatment protocols have largely been based on anti-infective therapies. however, close inspection of current data leads one to question whether these bacteria are the cause or the result of periodontitis. good evidence is emerging to suggest that it is indeed the ...201323574467
relaxed cleavage specificity within the rele toxin family.bacterial type ii toxin-antitoxin systems are widespread in bacteria. among them, the rele toxin family is one of the most abundant. the rele(k-12) toxin of escherichia coli k-12 represents the paradigm for this family and has been extensively studied, both in vivo and in vitro. rele(k-12) is an endoribonuclease that cleaves mrnas that are translated by the ribosome machinery as these transcripts enter the a site. earlier in vivo reports showed that rele(k-12) cleaves preferentially in the 5'-en ...201323543711
motility is crucial for the infectious life cycle of borrelia burgdorferi.the lyme disease spirochete, borrelia burgdorferi, exists in a zoonotic cycle involving an arthropod tick and mammalian host. dissemination of the organism within and between these hosts depends upon the spirochete's ability to traverse through complex tissues. additionally, the spirochete outruns the host immune cells while migrating through the dermis, suggesting the importance of b. burgdorferi motility in evading host clearance. b. burgdorferi's periplasmic flagellar filaments are composed p ...201323529620
structure and immunogenicity of the rough-type lipopolysaccharide from the periodontal pathogen tannerella forsythia.tannerella forsythia is a gram-negative anaerobic organism that inhabits subgingival plaque biofilms and is covered with a so far unique surface layer composed of two glycoproteins. it belongs to the so-called "red complex" of bacteria comprising species that are associated with periodontal disease. while the surface layer glycoprotein glycan structure had been elucidated recently and found to be a virulence factor, no structural data on the lipopolysaccharide (lps) of this organism were availab ...201323616409
transplantation-associated long-term immunosuppression promotes oral colonization by potentially opportunistic pathogens without impacting other members of the salivary bacteriome.solid-organ transplant recipients rely on pharmacological immunosuppression to prevent allograft rejection. the effect of such chronic immunosuppression on the microflora at mucosal surfaces is not known. we evaluated the salivary bacterial microbiome of 20 transplant recipients and 19 nonimmunosuppressed controls via 454 pyrosequencing of 16s rrna gene amplicons. alpha-diversity and global community structure did not differ between transplant and control subjects. however, principal coordinate ...201323616410
mobile microbiome: oral bacteria in extra-oral infections and inflammation.the link between oral infections and adverse systemic conditions has attracted much attention in the research community. several mechanisms have been proposed, including spread of the oral infection due to transient bacteremia resulting in bacterial colonization in extra-oral sites, systemic injury by free toxins of oral pathogens, and systemic inflammation caused by soluble antigens of oral pathogens. mounting evidence supports a major role of the systemic spread of oral commensals and pathogen ...201323625375
gingipain-dependent degradation of mammalian target of rapamycin pathway proteins by the periodontal pathogen porphyromonas gingivalis during invasion.porphyromonas gingivalis and tannerella forsythia are gram-negative pathogens strongly associated with periodontitis. their abilities to interact, invade and persist within host cells are considered crucial to their pathogenicity, but the mechanisms by which they subvert host defences are not well understood. in this study, we set out to investigate whether p. gingivalis and t. forsythia directly target key signalling molecules that may modulate the host cell phenotype to favour invasion and per ...201323714361
periodontitis in pregnant baboons: systemic inflammation and adaptive immune responses and pregnancy outcomes in a baboon model.chronic periodontal infections have been suggested to contribute to the risk of adverse pregnancy outcomes.201323710643
periodontitis in pregnant baboons: systemic inflammation and adaptive immune responses and pregnancy outcomes in a baboon model.chronic periodontal infections have been suggested to contribute to the risk of adverse pregnancy outcomes.201323710643
effect of periodontal therapy on the subgingival microbiota over a 2-year monitoring period. i. overall effect and kinetics of change.to examine the 2-year post-therapy kinetics of change in the composition of subgingival biofilms.201323710672
interaction of human dopa decarboxylase with l-dopa: spectroscopic and kinetic studies as a function of ph.human dopa decarboxylase (hddc), a pyridoxal 5'-phosphate (plp) enzyme, displays maxima at 420 and 335 nm and emits fluorescence at 384 and 504 nm upon excitation at 335 nm and at 504 nm when excited at 420 nm. absorbance and fluorescence titrations of hddc-bound coenzyme identify a single pk(spec) of ~7.2. this pk(spec) could not represent the ionization of a functional group on the schiff base but that of an enzymic residue governing the equilibrium between the low- and the high-ph forms of th ...201323781496
as-yet-uncultivated oral bacteria: breadth and association with oral and extra-oral diseases.it has been shown that 40-60% of the bacteria found in different healthy and diseased oral sites still remain to be grown in vitro, phenotypically characterized, and formally named as species. the possibility exists that these as-yet-uncultivated bacteria play important ecological roles in oral bacterial communities and may participate in the pathogenesis of several oral infectious diseases. there is also a potential for these as-yet-uncultivated oral bacteria to take part in extra-oral infectio ...201323717756
role of complement in host-microbe homeostasis of the periodontium.complement plays a key role in immunity and inflammation through direct effects on immune cells or via crosstalk and regulation of other host signaling pathways. deregulation of these finely balanced complement activities can link infection to inflammatory tissue damage. periodontitis is a polymicrobial community-induced chronic inflammatory disease that can destroy the tooth-supporting tissues. in this review, we summarize and discuss evidence that complement is involved in the dysbiotic transf ...201323684627
high-resolution transcriptome maps reveal strain-specific regulatory features of multiple campylobacter jejuni isolates.campylobacter jejuni is currently the leading cause of bacterial gastroenteritis in humans. comparison of multiple campylobacter strains revealed a high genetic and phenotypic diversity. however, little is known about differences in transcriptome organization, gene expression, and small rna (srna) repertoires. here we present the first comparative primary transcriptome analysis based on the differential rna-seq (drna-seq) of four c. jejuni isolates. our approach includes a novel, generic method ...201323696746
metagenomic sequencing reveals microbiota and its functional potential associated with periodontal disease.although attempts have been made to reveal the relationships between bacteria and human health, little is known about the species and function of the microbial community associated with oral diseases. in this study, we report the sequencing of 16 metagenomic samples collected from dental swabs and plaques representing four periodontal states. insights into the microbial community structure and the metabolic variation associated with periodontal health and disease were obtained. we observed a str ...201323673380
the biological activity of propolis-containing toothpaste on oral health environment in patients who underwent implant-supported prosthodontic rehabilitation.the soft and periodontal tissues surrounding dental implants are particularly susceptible to bacteria invasion and inflammatory reactions due to complex histological structures. this study was carried out to investigate the influence of a propolis-containing hygienic agent on selected oral health parameters, oral microflora, and the condition of periodontal health. sixteen subjects who underwent an oral rehabilitation with dental implants were selected and randomly assigned into two groups, whic ...201323762153
from in vitro to in vivo models of bacterial biofilm-related infections.the influence of microorganisms growing as sessile communities in a large number of human infections has been extensively studied and recognized for 30-40 years, therefore warranting intense scientific and medical research. nonetheless, mimicking the biofilm-life style of bacteria and biofilm-related infections has been an arduous task. models used to study biofilms range from simple in vitro to complex in vivo models of tissues or device-related infections. these different models have progressi ...201325437038
single or repeated antimicrobial photodynamic therapy as adjunct to ultrasonic debridement in residual periodontal pockets: clinical, microbiological, and local biological effects.this study aims to assess in residual periodontal pockets the clinical, microbiological, and local biological effects of antimicrobial photodynamic therapy (pdt), delivered after ultrasonic instrumentation either once or twice in a 1-week interval. a single center, three-arm randomized longitudinal study was carried out for 6 months. twenty-eight systemically healthy patients on periodontal maintenance with residual pockets (pocket depth (pd) ≥5 mm, clinical attachment loss ≥2 mm, and bleeding u ...201323660738
single or repeated antimicrobial photodynamic therapy as adjunct to ultrasonic debridement in residual periodontal pockets: clinical, microbiological, and local biological effects.this study aims to assess in residual periodontal pockets the clinical, microbiological, and local biological effects of antimicrobial photodynamic therapy (pdt), delivered after ultrasonic instrumentation either once or twice in a 1-week interval. a single center, three-arm randomized longitudinal study was carried out for 6 months. twenty-eight systemically healthy patients on periodontal maintenance with residual pockets (pocket depth (pd) ≥5 mm, clinical attachment loss ≥2 mm, and bleeding u ...201323660738
porphyromonas gingivalis fimbriae.marginal periodontitis is not a homogeneous disease but is rather influenced by an intricate set of host susceptibility differences as well as diversities in virulence among the harbored organisms. it is likely that clonal heterogeneity of subpopulations with both high and low levels of pathogenicity exists among organisms harbored by individuals with negligible, slight, or even severe periodontal destruction. therefore, specific virulent clones of periodontal pathogens may cause advanced and/or ...201323667717
short-term microbiological effects of scaling and root planing and essential-oils mouthwash in chinese adults.to assess the short-term effect of scaling and root planing (srp) and essential-oils mouthwash on the levels of specific bacteria in chinese adults.201323645178
the major outer sheath protein (msp) of treponema denticola has a bipartite domain architecture and exists as periplasmic and outer membrane-spanning conformers.the major outer sheath protein (msp) is a primary virulence determinant in treponema denticola, as well as the parental ortholog for the treponema pallidum repeat (tpr) family in the syphilis spirochete. the conserved domain database (cdd) server revealed that msp contains two conserved domains, major outer sheath protein(n) (mosp(n)) and mosp(c), spanning residues 77 to 286 and 332 to 543, respectively, within the n- and c-terminal regions of the protein. circular dichroism (cd) spectroscopy, t ...201323457251
surface display of a massively variable lipoprotein by a legionella diversity-generating retroelement.diversity-generating retroelements (dgrs) are a unique family of retroelements that confer selective advantages to their hosts by facilitating localized dna sequence evolution through a specialized error-prone reverse transcription process. we characterized a dgr in legionella pneumophila, an opportunistic human pathogen that causes legionnaires disease. the l. pneumophila dgr is found within a horizontally acquired genomic island, and it can theoretically generate 10(26) unique nucleotide seque ...201323633572
structure of the catalytic domain of the tannerella forsythia matrix metallopeptidase karilysin in complex with a tetrapeptidic inhibitor.karilysin is the only metallopeptidase identified as a virulence factor in the odontopathogen tannerella forsythia owing to its deleterious effect on the host immune response during bacterial infection. the very close structural and sequence-based similarity of its catalytic domain (kly18) to matrix metalloproteinases suggests that karilysin was acquired by horizontal gene transfer from an animal host. previous studies by phage display identified peptides with the consensus sequence xwfpxxxggg ( ...201323695557
investigation of the effect of type 2 diabetes mellitus on subgingival plaque microbiota by high-throughput 16s rdna pyrosequencing.diabetes mellitus is a major risk factor for chronic periodontitis. we investigated the effects of type 2 diabetes on the subgingival plaque bacterial composition by applying culture-independent 16s rdna sequencing to periodontal bacteria isolated from four groups of volunteers: non-diabetic subjects without periodontitis, non-diabetic subjects with periodontitis, type 2 diabetic patients without periodontitis, and type 2 diabetic patients with periodontitis. a total of 71,373 high-quality seque ...201323613868
structure and mechanism of the 2',3' phosphatase component of the bacterial pnkp-hen1 rna repair system.pnkp is the end-healing and end-sealing component of an rna repair system present in diverse bacteria from many phyla. pnkp is composed of three catalytic modules: an n-terminal polynucleotide 5' kinase, a central 2',3' phosphatase and a c-terminal ligase. the phosphatase module is a mn(2+)-dependent phosphodiesterase-monoesterase that dephosphorylates 2',3'-cyclic phosphate rna ends. here we report the crystal structure of the phosphatase domain of clostridium thermocellum pnkp with mn(2+) and ...201323595150
inhibition of attachment of oral bacteria to immortalized human gingival fibroblasts (hgf-1) by tea extracts and tea components.tea has been suggested to promote oral health by inhibiting bacterial attachment to the oral cavity. most studies have focused on prevention of bacterial attachment to hard surfaces such as enamel.201323578062
comparative analysis of oral treponemes associated with periodontal health and disease.periodontal diseases, such as periodontitis, are chronic inflammatory infections affecting the gingivae (gums), underlying connective tissues and bone that support the teeth. oral treponemes (genus treponema) are widely-considered to play important roles in periodontal disease etiology and pathogenesis; however, precise relationships remain to be fully established.201323578286
porphyromonas gingivalis virulence factor gingipain rgpb shows a unique zymogenic mechanism for cysteine peptidases.zymogenicity is a regulatory mechanism that prevents inadequate catalytic activity in the wrong context. it plays a central role in maintaining microbial virulence factors in an inactive form inside the pathogen until secretion. among these virulence factors is the cysteine peptidase gingipain b (rgpb), which is the major virulence factor secreted by the periodontopathogen porphyromonas gingivalis that attacks host vasculature and defense proteins. the structure of the complex between soluble ma ...201323558682
prevalence of porphyromonas gingivalis four rag locus genotypes in patients of orthodontic gingivitis and periodontitis.porphyromonas gingivalis is considered as a major etiological agent in periodontal diseases and implied to result in gingival inflammation under orthodontic appliance. rag locus is a pathogenicity island found in porphyromonas gingivalis. four rag locus variants are different in pathogenicity of porphyromonas gingivalis. moreover, there are different racial and geographic differences in distribution of rag locus genotypes. in this study, we assessed the prevalence of porphyromonas gingivalis and ...201323593379
effectiveness of sub gingival irrigation of an indigenous 1% curcumin solution on clinical and microbiological parameters in chronic periodontitis patients: a pilot randomized clinical trial.the aim of this study is to evaluate the efficacy of 1% curcumin (cu) solution and compare it with conventional irrigant i.e., 0.2% chlorhexidine (chx) gluconate and a positive control (saline) as an adjunct to thorough scaling and root planing.201324015007
the surface layer of tannerella forsythia contributes to serum resistance and oral bacterial coaggregation.tannerella forsythia is an anaerobic, gram-negative bacterium involved in the so-called "red complex," which is associated with severe and chronic periodontitis. the surface layer (s-layer) of t. forsythia is composed of cell surface glycoproteins, such as tfsa and tfsb, and is known to play a role in adhesion/invasion and suppression of proinflammatory cytokine expression. here we investigated the association of this s-layer with serum resistance and coaggregation with other oral bacteria. the ...201323357386
a novel 3-sulfinopropionyl coenzyme a (3sp-coa) desulfinase from advenella mimigardefordensis strain dpn7t acting as a key enzyme during catabolism of 3,3'-dithiodipropionic acid is a member of the acyl-coa dehydrogenase superfamily.3-sulfinopropionyl coenzyme a (3sp-coa) desulfinase (acddpn7) is a new desulfinase that catalyzes the sulfur abstraction from 3sp-coa in the betaproteobacterium advenella mimigardefordensis strain dpn7(t). during investigation of a tn5::mob-induced mutant defective in growth on 3,3'-dithiodipropionate (dtdp) and also 3-sulfinopropionate (3sp), the transposon insertion was mapped to an open reading frame with the highest homology to an acyl-coa dehydrogenase (acd) from burkholderia phenoliruptrix ...201323354747
microbiology and treatment of acute apical abscesses.acute apical abscess is the most common form of dental abscess and is caused by infection of the root canal of the tooth. it is usually localized intraorally, but in some cases the apical abscess may spread and result in severe complications or even mortality. the reasons why dental root canal infections can become symptomatic and evolve to severe spreading and sometimes life-threatening abscesses remain elusive. studies using culture and advanced molecular microbiology methods for microbial ide ...201323554416
functional differences of porphyromonas gingivalis fimbriae in determining periodontal disease pathogenesis: a literature review.porphyromonas gingivalis is implicated in chronic and aggressive periodontitis. this bacterium has numerous virulence factors and one is the fimbriae, which is quite important for bacterial colonization. fimbriae are appendices that anchor to the bacterial wall and are comprised of the protein fimbriline encoded by the fima gene. thus far, six genotypes have been identified, fima i to v and ib. genotypes ii and iv are associated with periodontal disease, while genotype i is related to gingival h ...201324892323
expression of human beta defensins (hbds) 1, 2 and 3 in gingival crevicular fluid of patients affected by localized aggressive periodontitis.to study the effect of nonsurgical periodontal therapy on the expression frequencies of human beta-defensin (hbd)-1, -2, and -3 in the gingival crevicular fluid (gcf) of patients affected by localized aggressive periodontitis.201323960559
mixed red-complex bacterial infection in periodontitis.the red complex, which includes porphyromonas gingivalis, treponema denticola, and tannerella forsythia (formerly bacteroides forsythus), are recognized as the most important pathogens in adult periodontal disease. these bacteria are usually found together in periodontal pockets, suggesting that they may cause destruction of the periodontal tissue in a cooperative manner. this article discusses the interspecies pathogenic interactions within the red complex.201323533413
evaluation of the efficacy of green tea catechins as an adjunct to scaling and root planing in the management of chronic periodontitis using pcr analysis: a clinical and microbiological study.increased knowledge of anaerobic bacteria in the development of periodontal diseases has led to new treatment strategies aiming primarily at suppression or elimination of specific periodontal pathogens. over the last few decades, green tea has been subjected to many scientific and medical studies.201323869127
is immunesenescence a contributing factor for periodontal diseases?current concept in periodontal diseases (pds) states that it is the host's response toward the periodontal pathogens which leads to tissue destruction and attachment loss. hence the role of immune response in the progression and resolution of pd must be considered vital. any alteration in the immune system disturbs the homeostasis of the periodontium. decline in immune system is the hallmark of aging, leading to increased susceptibility of elderly individuals to bacterial infections. the periodo ...201323869121
detection of the a2058g and a2059g 23s rrna gene point mutations associated with azithromycin resistance in treponema pallidum by use of a taqman real-time multiplex pcr assay.macrolide treatment failure in syphilis patients is associated with a single point mutation (either a2058g or a2059g) in both copies of the 23s rrna gene in treponema pallidum strains. the conventional method for the detection of both point mutations uses nested pcr combined with restriction enzyme digestions, which is laborious and time-consuming. we initially developed a taqman-based real-time duplex pcr assay for detection of the a2058g mutation, and upon discovery of the a2059g mutation, we ...201323284026
real-time pcr quantification of methanobrevibacter oralis in periodontitis.a real-time pcr assay developed to quantify methanobrevibacter oralis indicated that its inoculum significantly correlated with periodontitis severity (p = 0.003), despite a nonsignificant difference in prevalence between controls (3/10) and patients (12/22) (p = 0.2, fisher test). the m. oralis load can be used as a biomarker for periodontitis.201323254133
exploiting quorum sensing to confuse bacterial pathogens.cell-cell communication, or quorum sensing, is a widespread phenomenon in bacteria that is used to coordinate gene expression among local populations. its use by bacterial pathogens to regulate genes that promote invasion, defense, and spread has been particularly well documented. with the ongoing emergence of antibiotic-resistant pathogens, there is a current need for development of alternative therapeutic strategies. an antivirulence approach by which quorum sensing is impeded has caught on as ...201323471618
role of the nk cell-activating receptor cracc in periodontitis.periodontitis is a highly prevalent, biofilm-mediated chronic inflammatory disease that results in the loss of the tooth-supporting tissues. it features two major clinical entities: chronic periodontitis, which is more common, and aggressive periodontitis, which usually has an early onset and a rapid progression. natural killer (nk) cells are a distinct subgroup of lymphocytes that play a major role in the ability of the innate immune system to steer immune responses. nk cells are abundant in pe ...201323250953
oral biofilms: molecular analysis, challenges, and future prospects in dental diagnostics.oral biofilms are functionally and structurally organized polymicrobial communities that are embedded in an extracellular matrix of exopolymers on mucosal and dental surfaces. these biofilms are found naturally in health, and provide benefits to the host. however, this relationship can break down, and disease can occur; disease is associated with a shift in the balance of the species within these biofilms. simple diagnostic tests have been developed that involve the culture of selected bacteria, ...201323674928
innate immune response to oral bacteria and the immune evasive characteristics of periodontal pathogens.periodontitis is a chronic inflammation of periodontal tissue caused by subgingival plaque-associated bacteria. periodontitis has long been understood to be the result of an excessive host response to plaque bacteria. in addition, periodontal pathogens have been regarded as the causative agents that induce a hyperinflammatory response from the host. in this brief review, host-microbe interaction of nonperiodontopathic versus periodontopathic bacteria with innate immune components encountered in ...201323507986
clinical, microbiological, and salivary biomarker profiles of dental implant patients with type 2 diabetes.regulators of peri-implant bone loss in patients with diabetes appear to involve multiple risk factors that have not been clearly elucidated. this study was conducted to explore putative local etiologic factors on implant bone loss in relation to type 2 diabetes mellitus, including clinical, microbial, salivary biomarker, and psychosocial factors.201323445216
clinical, microbiological, and salivary biomarker profiles of dental implant patients with type 2 diabetes.regulators of peri-implant bone loss in patients with diabetes appear to involve multiple risk factors that have not been clearly elucidated. this study was conducted to explore putative local etiologic factors on implant bone loss in relation to type 2 diabetes mellitus, including clinical, microbial, salivary biomarker, and psychosocial factors.201323445216
the tp0796 lipoprotein of treponema pallidum is a bimetal-dependent fad pyrophosphatase with a potential role in flavin homeostasis.treponema pallidum, an obligate parasite of humans and the causative agent of syphilis, has evolved the capacity to exploit host-derived metabolites for its survival. flavin-containing compounds are essential cofactors that are required for metabolic processes in all living organisms, and riboflavin is a direct precursor of the cofactors fmn and fad. unlike many pathogenic bacteria, treponema pallidum cannot synthesize riboflavin; we recently described a flavin-uptake mechanism composed of an ab ...201323447540
patterns of prokaryotic lateral gene transfers affecting parasitic microbial eukaryotes.the influence of lateral gene transfer on gene origins and biology in eukaryotes is poorly understood compared with those of prokaryotes. a number of independent investigations focusing on specific genes, individual genomes, or specific functional categories from various eukaryotes have indicated that lateral gene transfer does indeed affect eukaryotic genomes. however, the lack of common methodology and criteria in these studies makes it difficult to assess the general importance and influence ...201323442822
polymicrobial infection with major periodontal pathogens induced periodontal disease and aortic atherosclerosis in hyperlipidemic apoe(null) mice.periodontal disease (pd) and atherosclerosis are both polymicrobial and multifactorial and although observational studies supported the association, the causative relationship between these two diseases is not yet established. polymicrobial infection-induced periodontal disease is postulated to accelerate atherosclerotic plaque growth by enhancing atherosclerotic risk factors of orally infected apolipoprotein e deficient (apoe(null)) mice. at 16 weeks of infection, samples of blood, mandible, ma ...201323451182
spa: a short peptide assembler for metagenomic data.the metagenomic paradigm allows for an understanding of the metabolic and functional potential of microbes in a community via a study of their proteins. the substrate for protein identification is either the set of individual nucleotide reads generated from metagenomic samples or the set of contig sequences produced by assembling these reads. however, a read-based strategy using reads generated by next-generation sequencing (ngs) technologies, results in an overwhelming majority of partial-lengt ...201323435317
molecular mapping to species level of the tonsillar crypt microbiota associated with health and recurrent tonsillitis.the human palatine tonsils, which belong to the central antigen handling sites of the mucosal immune system, are frequently affected by acute and recurrent infections. this study compared the microbiota of the tonsillar crypts in children and adults affected by recurrent tonsillitis with that of healthy adults and children with tonsillar hyperplasia. an in-depth 16s rrna gene based pyrosequencing approach combined with a novel strategy that included phylogenetic analysis and detection of species ...201323437130
role of an iron-dependent transcriptional regulator in the pathogenesis and host response to infection with streptococcus pneumoniae.iron is a critical cofactor for many enzymes and is known to regulate gene expression in many bacterial pathogens. streptococcus pneumoniae normally inhabits the upper respiratory mucosa but can also invade and replicate in lungs and blood. these anatomic sites vary considerably in both the quantity and form of available iron. the genome of serotype 4 pneumococcal strain tigr4 encodes a putative iron-dependent transcriptional regulator (idtr). a mutant deleted at idtr (δidtr) exhibited growth ki ...201323437050
experimental gingivitis induces systemic inflammatory markers in young healthy individuals: a single-subject interventional study.we here investigated whether experimental gingivitis enhances systemic markers of inflammation which are also known as surrogate markers of atherosclerotic plaque development.201323408963
multilocus sequence analysis of treponema denticola strains of diverse origin.the oral spirochete bacterium treponema denticola is associated with both the incidence and severity of periodontal disease. although the biological or phenotypic properties of a significant number of t. denticola isolates have been reported in the literature, their genetic diversity or phylogeny has never been systematically investigated. here, we describe a multilocus sequence analysis (mlsa) of 20 of the most highly studied reference strains and clinical isolates of t. denticola; which were o ...201323379917
arginine deiminase inhibits porphyromonas gingivalis surface attachment.the oral cavity is host to a complex microbial community whose maintenance depends on an array of cell-to-cell interactions and communication networks, with little known regarding the nature of the signals or mechanisms by which they are sensed and transmitted. determining the signals that control attachment, biofilm development and outgrowth of oral pathogens is fundamental to understanding pathogenic biofilm development. we have previously identified a secreted arginine deiminase (adi) produce ...201323242802
arteriovenous malformation (avm) of the maxilla complicated by a local pathogen infection.arteriovenous malformations (avm) are usually observed on the skin, but they can also rarely affect the visceral organs and the maxillofacial area. in the maxillofacial area, these lesions can spread and they are potentially dangerous, as a biopsy or even a simple tooth extraction can lead to a catastrophic haemorrhage that may eventually cause death. there are several indications for the treatment, including age, size and type of vascular malformation. the purpose of this report is to describe ...201323376660
phylogenetic analysis of pbp genes in treponemes.β-lactamases are the main cause of bacterial resistance to penicillin, cephalosporins, and related β-lactam compounds. the presence of the novel penicillin-binding protein (pbp) tp47 in treponema pallidum has been reported to be a well-known mechanism for turnover of b-lactam antibiotics. although, t. pallidum remains sensitive to penicillin, clinically significant resistance to macrolides has emerged in many developing countries. the genome sequence of t. pallidum has shown the presence of gene ...201323330059
antibody and t cell responses to fusobacterium nucleatum and treponema denticola in health and chronic periodontitis.the characteristics of the t cell response to the members of oral flora are poorly understood. we characterized the antibody and t cell responses to fada and td92, adhesins from fusobacterium nucleatum, an oral commensal, and treponema denticola, a periodontal pathogen, respectively. peripheral blood and saliva were obtained from healthy individuals and patients with untreated chronic periodontitis (cp, n = 11 paris) and after successful treatment of the disease (n = 9). the levels of antigen-sp ...201323335969
inflammasomes and host defenses against bacterial infections.the inflammasome has emerged as an important molecular protein complex which initiates proteolytic processing of pro-il-1β and pro-il-18 into mature inflammatory cytokines. in addition, inflammasomes initiate pyroptotic cell death that may be independent of those cytokines. inflammasomes are central to elicit innate immune responses against many pathogens, and are key components in the induction of host defenses following bacterial infection. here, we review recent discoveries related to nlrp1, ...201323318142
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