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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
the subgingival microbiome in health and periodontitis and its relationship with community biomass and inflammation.the goals of this study were to better understand the ecology of oral subgingival communities in health and periodontitis and elucidate the relationship between inflammation and the subgingival microbiome. accordingly, we used 454-pyrosequencing of 16s rrna gene libraries and quantitative pcr to characterize the subgingival microbiome of 22 subjects with chronic periodontitis. each subject was sampled at two sites with similar periodontal destruction but differing in the presence of bleeding, a ...201323303375
does propolis help to maintain oral health?propolis, known also as bee glue, is a wax-cum-resin substance which is created out of a mix of buds from some trees with the substance secreted from bee's glands. its diverse chemical content is responsible for its many precious salubrious properties. it was used in medicine already in ancient egypt. its multiple applications during the centuries have been studied and described in details. the purpose of this study is to present the possible use of propolis in treatment of various diseases of o ...201323365605
association between selected oral pathogens and gastric precancerous lesions.we examined whether colonization of selected oral pathogens is associated with gastric precancerous lesions in a cross-sectional study. a total of 119 participants were included, of which 37 were cases of chronic atrophic gastritis, intestinal metaplasia, or dysplasia. an oral examination was performed to measure periodontal indices. plaque and saliva samples were tested with real-time quantitative pcr for dna levels of pathogens related to periodontal disease (porphyromonas gingivalis, tannerel ...201323308100
periodontal disease and diabetes mellitus.periodontal disease (pd) is one of the most commonly known human chronic disorders. the relationship between pd and several systemic diseases such as diabetes mellitus (dm) has been increasingly recognized over the past decades.201323559105
comparative evaluation of locally delivered minocycline and metronidazole in the treatment of periodontitis.the aim of this study was to evaluate and compare the efficacy of subgingivally delivered minocycline microspheres and 25% metronidazole gel when used as an adjunct to scaling and root planing (srp) in the treatment of chronic periodontitis.201323853452
halitosis: from diagnosis to management.halitosis is formed by volatile molecules which are caused because of pathological or nonpathological reasons and it originates from an oral or a non-oral source. it is very common in general population and nearly more than 50% of the general population have halitosis. although halitosis has multifactorial origins, the source of 90% cases is oral cavity such as poor oral hygiene, periodontal disease, tongue coat, food impaction, unclean dentures, faulty restorations, oral carcinomas, and throat ...201323633830
treponema diversity in root canals with endodontic failure.this study sought to investigate the prevalence of eight oral treponemas (treponema denticola, t. amylovorum, t. maltophilum, t. medium, t. pectinovorum, t. socranskii, t. vicentii and t. lecithinolyticum) in teeth with endodontic treatment failure and periapical lesion.201323408792
structures of trans-2-enoyl-coa reductases from clostridium acetobutylicum and treponema denticola: insights into the substrate specificity and the catalytic mechanism.ters (trans-2-enoyl-coa reductases; ec 1.3.1.44), which specifically catalyse the reduction of crotonyl-coa to butyryl-coa using nadh as cofactor, have recently been applied in the design of robust synthetic pathways to produce butan-1-ol as a biofuel. we report in the present paper the characterization of a cater (a ter homologue in clostridium acetobutylicum), the structures of cater in apo form and in complexes with nadh and nad+, and the structure of tdter (treponema denticola ter) in comple ...201323050861
the sociodemographic characteristics, periodontal health status, and subgingival microbiota of patients with chronic periodontitis and type 2 diabetes mellitus: a case-control study in a chinese population.in china, chronic periodontitis (cp) is common in patients with type 2 diabetes mellitus (t2dm). the purpose of this study is to identify the sociodemographic characteristics associated with such patients and to assess the periodontal health status and subgingival microbiota of patients with cp and t2dm (t2dmcp) in the chinese population.201323030242
the relationship between turbidity of mouth-rinsed water and oral health status.the purpose of this study was to examine the relationship between turbidity of mouth rinsed water and oral health status such as dental and periodontal conditions, oral hygiene status, flow rate of saliva and oral bacteria.201322339260
the short-term treatment effects on the microbiota at the dorsum of the tongue in intra-oral halitosis patients--a randomized clinical trial.this study aims to assess the effects of rinsing with zinc- and chlorhexidine-containing mouth rinse with or without adjunct tongue scraping on volatile sulfur compounds (vscs) in breath air, and the microbiota at the dorsum of the tongue.201322573244
[relationships of five periodontal pathogens causing subgingival plaque in patients with chronic periodontitis under different periodontal conditions].this study aimed to assess the relationship between the distributions of haemophilus aggregatibacter (h. aggregatibacter ), porphyromonas gingivalis (p. gingivalis ), prevotella intermedia (p. intermedia), tannerella forsythensis (t. forsythensis), and treponema denticola (t. denticola) in subgingival plaque and different periodontal conditions of chronic periodontitis.201324298807
pathogen levels and clinical response to periodontal treatment in patients with interleukin 8 haplotypes.the aim of this study was to investigate the effect of non-surgical treatment of periodontitis on the levels of periodontopathogens and clinical parameters in patients with different genetic backgrounds produced by polymorphisms in the interleukin ( il8) gene. thirty patients grouped according to il8 atc/ttc or agt/ttc haplotypes were submitted to non-surgical periodontal treatment. levels of porphyromonas gingivalis, tannerella forsythia, and treponema denticola were determined in 240 subgingiv ...201323821559
[detection of periodontal pathogens from saliva of type 2 diabetic patients in urban area of beijing].to investigate the prevalence of periodontal pathogens from saliva of patients with type 2 diabetes mellitus (t2dm), and to characterize the association between the glucose status and periodontal pathogens in oral cavity.201323751528
periodontopathogens levels and clinical response to periodontal therapy in individuals with the interleukin-4 haplotype associated with susceptibility to chronic periodontitis.periodontitis is an inflammatory disease that results from an interaction between dental biofilm agents and the host immune-inflammatory response. periodontopathogenic organisms, such as porphyromonas gingivalis, tannerella forsythia, and treponema denticola, as well as the host's susceptibility, represented by the host's genetic makeup, are the key factors that influence this complex disease. recently, we identified haplotypes in the il4 gene that were associated with chronic periodontitis (cp) ...201323748736
clinical, microbiologic, and host response characteristics in patients with peri-implant mucositis.to analyze the clinical, microbiologic, and host response characteristics (interleukins 1β and 6) in the peri-implant sulcus fluid (pisf) of patients with healthy dental implants and with peri-implant mucositis.201323748323
determining the presence of periodontopathic virulence factors in short-term postmortem alzheimer's disease brain tissue.the aim of this study was to establish a link between periodontal disease and alzheimer's disease (ad) with a view to identifying the major periodontal disease bacteria (treponema denticola, tannerella forsythia, and porphyromonas gingivalis) and/or bacterial components in brain tissue from 12 h postmortem delay. our request matched 10 ad cases for tissue from brains for dementia research alongside 10 non-ad age-related controls with similar or greater postmortem interval. we exposed svgp12, an ...201323666172
association between il8 haplotypes and pathogen levels in chronic periodontitis.chronic periodontitis (cp) is considered to be a multifactorial disease influenced by microbial and genetic factors. the aim of the present study was to investigate whether the genetic susceptibility to cp in individuals with the il8 atc/ttc haplotype is associated with subgingival levels of periodontopathogens. sixty-five individuals, grouped according to the presence (n = 28) or absence (n = 37) of the il8 haplotype, were evaluated. after clinical periodontal evaluation, each group was subdivi ...201323660697
interleukin-10 gene promoter polymorphisms are associated with cyclosporin a-induced gingival overgrowth in renal transplant patients.interleukin-10 (il-10) is an anti-inflammatory cytokine whose genetic polymorphisms are associated with the production of il-10 and the susceptibility to periodontal diseases. the aim of this study was to investigate the possible association of il-10 single nucleotide polymorphisms (snps) and cyclosporin a (csa)-induced gingival overgrowth (go) in renal transplant patients in a chinese population, taking into account subgingival microbiota as additional variables.201323643609
altered phenotype and function of dendritic cells in individuals with chronic periodontitis.to investigate the effects of periodontal bacterial lysates on maturation and function of mature monocyte-derived dendritic cells (m-mddcs) derived from individuals with chronic periodontitis (cp) or healthy periodontal tissue (hp).201323623310
[relationship between volatile fatty acids and porphyromonas gingivalis and treponema denticola in gingival crevicular fluids of patients with aggressive periodontitis].short chain fatty acids (scfas), such as succinic acid, acetic acid, propionic acid, butyric acid, etc. are metabolic product of putative periodontal pathogens, which play significant roles in periodontitis. the aim of this study was to analyze the relationship between porphyromonas gingivalis (p. gingivalis), treponema denticola (t. denticola), and the concentration of scfas in gingival crevicular fluid (gcf) of patients with aggressive periodontitis (agp).201323411512
treponema denticola improves adhesive capacities of porphyromonas gingivalis.porphyromonas gingivalis, an important etiological agent of periodontal disease, is frequently found associated with treponema denticola, an anaerobic spirochete, in pathogenic biofilms. however, interactions between these two bacteria are not well understood at the molecular level. in this study, we seek to link the influence of t. denticola on the expression of p. gingivalis proteases with its capacities to adhere and to form biofilms. the p. gingivalis genes encoding arg-gingipain a (rgpa), l ...201323194417
boric acid irrigation as an adjunct to mechanical periodontal therapy in patients with chronic periodontitis: a randomized clinical trial.the purpose of this single-masked, randomized, controlled clinical trial was to evaluate the effects of boric acid irrigation as an adjunct to scaling and root planing (srp) on clinical and microbiologic parameters and compare this method with chlorhexidine irrigation and srp alone in patients with chronic periodontitis (cp).201323121460
prediction of periodontopathic bacteria in dental plaque of periodontal healthy subjects by measurement of volatile sulfur compounds in mouth air.the aim of this study was to determine whether measurements of volatile sulfur compounds (vscs) are useful to predict colonization of periodontopathic bacteria. for this purpose, we assessed the relationships among distributions of 4 species of periodontopathic bacteria in tongue coating and dental plaque, oral conditions including vsc concentration in mouth air, and smoking habit of periodontal healthy young subjects.201323107050
frequency of periodontal pathogens in equivalent peri-implant and periodontal clinical statuses.this study tested the hypotheses that there is: (1) higher bacterial frequency in peri-implantitis/periodontitis, followed by mucositis/gingivitis and peri-implant/periodontal health; (2) similar bacterial frequency between comparable peri-implant and periodontal clinical statuses.201323127822
prevalence of periodontal pathogens and metabolic control of type 1 diabetes patients.the aim of the study was to evaluate the prevalence of periodontal pathogens aggregatibacter actinomycetemcomitans, porphyromonas gingivalis, prevotella intermedia, tannerella forsythia and treponema denticola in subgingival plaque collected at different probing depths of type 1 diabetes patients with periodontal disease in correlation to metabolic control.201323413629
the anti-phospholipid antibody-dependent and independent effects of periodontopathic bacteria on threatened preterm labor and preterm birth.periodontal disease is considered to be a risk factor for threatened preterm labor (tpl) and preterm birth (pb), but pathogenic mechanisms have not yet been elucidated. we hypothesized that infection with periodontopathic bacteria may enhance thrombosis through molecular mimicry with tlrvyk peptides on beta-2 glycoprotein i, a target molecule in anti-phospholipid syndrome. this study aimed to examine the effects of periodontitis on tpl and pb.201323400354
influence of periodontal status and periodontopathogens on levels of oral human β-defensin-2 in saliva.expression patterns of human β-defensin-2 (hbd-2) mrna or hbd-2 protein concentration and periodontal diseases have been a focus of scientific research. this study compares the salivary levels of hbd-2 protein concentration of healthy patients and patients with gingivitis and chronic periodontitis (cp) and correlates these levels with the presence of periodontopathogens.201323173827
detection of oral bacterial dna in synovial fluid.as periodontal bacteria might be involved in the aetiology of rheumatic diseases, we analysed synovial fluid obtained from patients with rheumatoid arthritis (ra) and controls for the presence of dna of aggregatibacter actinomycetemcomitans, porphyromonas gingivalis, prevotella intermedia, tannerella forsythia, and treponema denticola.201323534379
subgingival aggregatibacter actinomycetemcomitans associates with the risk of coronary artery disease.we investigated the association between angiographically verified coronary artery disease (cad) and subgingival aggregatibacter actinomycetemcomitans, porphyromonas gingivalis, tannerella forsythia and treponema denticola.201323521427
subgingival bacterial burden in relation to clinical and radiographic periodontal parameters.this cross-sectional study characterizes the association between subgingival bacterial profile and periodontal parameters in patients assigned to coronary angiography because of cardiologic problems, which may affect the oral microbiota.201323489235
characterization of periodontal biofilm in down syndrome patients: a comparative study.the aim of this study was to characterize the main periodontal bacterial species in down syndrome (ds) patients with and without periodontitis.201323855174
quantification of key periodontal pathogens in insulin-dependent type 2 diabetic and non-diabetic patients with generalized chronic periodontitis.periodontitis is a common problem in patients with diabetes mellitus (dm), however, differences in the putative periodontal pathogens in subjects with dm compared to non-dm subjects are still inconclusive. the red complex, which includes porphyromonas gingivalis, treponema denticola, and tannerella forsythia, encompasses the most important pathogens in adult periodontal disease. the aim of the present study was to compare cell numbers of p. gingivalis, t. denticola, t. forsythia and aggregatibac ...201323827459
the connection between ruptured cerebral aneurysms and odontogenic bacteria.patients with ruptured saccular intracranial aneurysms have excess long-term mortality due to cerebrovascular and cardiovascular diseases compared with general population. chronic inflammation is detected in ruptured intracranial aneurysms, abdominal aortic aneurysms and coronary artery plaques. bacterial infections have been suggested to have a role in the aetiology of atherosclerosis. bacteria have been detected both in abdominal and coronary arteries but their presence in intracranial aneurys ...201323761916
porphyromonas gingivalis, treponema denticola and toll-like receptor 2 are associated with hypertensive disorders in placental tissue: a case-control study.to explore the associations between the presence of periodontal pathogens and the expression of toll-like receptors (tlr-2 and tlr-4) in the placental tissue of patients with hypertensive disorders compared to the placentas of healthy normotensive patients.201323711357
salivary detection of periodontopathic bacteria in fanconi's anemia patients.fanconi's anemia (fa) is characterized by bone marrow failure and can lead to infections such as periodontal disease. the aim of this study was to compare the prevalence of four periodontopathic bacteria including aggregatibacter actinomycetemcomitans, porphyromonas gingivalis, fusobacterium nucleatum and treponema denticola in saliva samples from children with and without fa. paraffin-stimulated saliva samples were collected from 71 children and adolescents, aged 6-18 years old. the samples wer ...201324055631
detection of putative periodontopathic bacteria in type 1 diabetic and healthy children: a comparative study.the aim of this study was to compare and assess the risk of periodontitis due to the presence of four putative periodontopathic bacteria (porphyromonas gingivalis, treponema denticola, tannerella forsythia, and aggregatibacter actinomycetemcomitans) in type 1 diabetic and healthy children.201324025882
autoinducer 2 of fusobacterium nucleatum as a target molecule to inhibit biofilm formation of periodontopathogens.periodontitis is initiated by bacteria in subgingival biofilms, which are composed mostly of gram-negative anaerobes. autoinducer 2 (ai-2) is a universal quorum sensing (qs) molecule that mediates intergeneric signalling in multispecies bacterial communities and may induce biofilm formation. as fusobacterium nucleatum is the major coaggregation bridge organism that links early colonising commensals and late pathogenic colonisers in dental biofilms via the accretion of periodontopathogens, we hyp ...201322633049
long-term follow-up of turned single implants placed in periodontally healthy patients after 16 to 22 years: microbiologic outcome.survival rates in implant dentistry today are high, although late failures do occur for many reasons, including peri-implant infections. the primary objective of this study is to investigate microbiota around single turned implants after 16 to 22 years. secondary objectives are to compare teeth and implants and to correlate microbiologic, radiographic, and clinical parameters.201322934839
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