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distribution of oral streptococci highly resistant to amoxicillin in dental plaque specimens from japanese children and adolescents.oral streptococci are major pathogens of infective endocarditis (ie). prophylactic antibiotics are commonly given to subjects with certain kinds of heart disorders when invasive dental treatments are performed, with amoxicillin (ampc) widely used for this purpose. however, there is scant information regarding ampc-resistant oral streptococci. a total of 344 dental plaque specimens collected from 253 healthy japanese children, adolescents, and young adults (aged 2-22 years) were diluted and strea ...201121799198
misidentification of alpha-hemolytic streptococci by routine tests in clinical practice.accurate species-level identification of viridans group streptococci (vgs) is very important for understanding of their pathogenicity and virulence. however, an extremely high level of the similarity between vgs, especially streptococcus pneumoniae, streptococcus mitis, streptococcus oralis and streptococcus pseudopneumoniae, often results in misidentification of these organisms, so there is an urgent need of novel approaches to species identification. a set of 50 randomly selected clinical isol ...201121798371
in vitro destruction of streptococcus pneumoniae biofilms with bacterial and phage peptidoglycan hydrolases.host- and phage-coded cell wall hydrolases have been used to fight streptococcus pneumoniae growing as planktonic cells in vitro as well as in animal models. until now, however, the usefulness of these enzymes in biofilm-grown pneumococci has gone untested. the anti-pneumococcal activity of different cell wall hydrolases produced by s. pneumoniae and a number of its phages was examined in an in vitro biofilm model. the major pneumococcal autolysin lyta, an n-acetylmuramoyl-l-alanine amidase, sho ...201121746941
antibiotic and antiseptic resistance genes are linked on a novel mobile genetic element: tn6087.objectives tn916-like elements are one of the most common types of integrative and conjugative element (ice). in this study we aimed to determine whether novel accessory genes, i.e. genes whose products are not involved in mobility or regulation, were present on a tn916-like element (tn6087) isolated from streptococcus oralis from the human oral cavity. methods a minocycline-resistant isolate was analysed using restriction fragment length polymorphism (rflp) analysis on amplicons derived from tn ...201121816764
antimicrobial efficacy of denture adhesives on some oral malodor-related microbes.the objective of the study was to determine the antimicrobial efficacy of three denture adhesives toward streptococcus oralis, mutans, prevotella oralis and fusobacterium nucleatum. adhesives used were corega ultra(®), fixodent pro original(®) and biotene(®) denture grip. for streptococcus oralis and streptococcus mutans, four tubes of trypticase soy broth 10 ml and 1 g denture of adhesive were used. in addition four tubes of trypticase soy broth 10 ml without any denture adhesive was employed a ...201122075753
identification of bacteria in blood culture broths using matrix-assisted laser desorption-ionization sepsityper™ and time of flight mass spectrometry.matrix-assisted laser desorption ionization time of flight mass spectrometry (maldi-tof ms) is a novel method for the direct identification of bacteria from blood culture broths. we evaluate for the first time, the performance of the maldi sepsityper™ kit and ms for the identification of bacteria compared to standard phenotypic methods using the manufacturer's specified bacterial identification criteria (spectral scores ≥1.700-1.999 and ≥2.000 indicated identification to genus and species level, ...201121858058
Early microbial succession in redeveloping dental biofilms in periodontal health and disease.Teles FR, Teles RP, Uzel NG, Song XQ, Torresyap G, Socransky SS, Haffajee AD. Early microbial succession in redeveloping dental biofilms in periodontal health and disease. J Periodont Res 2011; doi: 10.1111/j.1600-0765.2011.01409.x. © 2011 John Wiley & Sons A/S Background and Objective: The development of dental biofilms after professional plaque removal is very rapid. However, it is not clear whether most bacterial species return at similar rates in periodontally healthy and periodontitis subj ...201121895662
thermal treatments modulate bacterial adhesion to dental enamel.numerous studies have demonstrated the effects of laser-induced heat on demineralization of enamel; however, no studies have investigated the link between heat/laser-induced changes in physicochemical properties and bacterial adhesion. in this study, we investigated the effects of thermal treatment on surface properties of enamel such as hydrophobicity and zeta potential. bacterial adhesion to treated surfaces was characterized by confocal laser scanning microscopy, and adhesion force was quanti ...201121960683
oral streptococcal bacteremia in hospitalized patients: taxonomic identification and clinical characterization.oral streptococci have been associated with systemic diseases including infective endocarditis and neutropenic bacteremia. we analyzed 58 recent oral streptococcal bloodstream isolates, and obtained clinical and demographic data for source patients. the soda gene was found to be a better target than the 16s-23s rrna internal transcribed spacer for dna sequence-based species identification. together, streptococcus mitis and streptococcus oralis were significantly more likely than the 12 combined ...201122189124
identification of interspecies interactions affecting porphyromonas gingivalis virulence phenotypes.periodontitis is recognized as a complex polymicrobial disease, however, the impact of the bacterial interactions among the 700-1,000 different species of the oral microbiota remains poorly understood. we conducted an in vitro screen for oral bacteria that mitigate selected virulence phenotypes of the important periodontal pathogen, porphyromonas gingivalis.201122022641
effects of saliva or serum coating on adherence of streptococcus oralis strains to titanium.the use of dental implants to treat tooth loss has increased rapidly over recent years. 'smooth' implants showing high long-term success rates have successively been replaced by implants with rougher surfaces, designed to stimulate rapid osseointegration and promote tissue healing. if exposed in the oral cavity, rougher surfaces may promote bacterial adhesion leading to formation of microbial biofilms which can induce peri-implant inflammation. streptococcus oralis is an early colonizer of oral ...201122075030
effect of saliva viscosity on the co-aggregation between oral streptococci and actinomyces naeslundii.gerodontology 2011; doi: 10.1111/j.1741-2358.2011.00595.x effect of saliva viscosity on the co-aggregation between oral streptococci and actinomyces naeslundii background:  the co-aggregation of oral bacteria leads to their clearance from the oral cavity. poor oral hygiene and high saliva viscosity are common amongst the elderly; thus, they frequently suffer from pneumonia caused by the aspiration of oral microorganisms. objectives:  to examine the direct effect of saliva viscosity on the co-agg ...201122077758
clonal structure of streptococcus sanguinis strains isolated from endocarditis cases and the oral cavity.a collection of streptococcus sanguinis strains from patients with endocarditis (n = 21) and from the oral cavity (n = 34) was subjected to a multi-locus sequence typing analysis using seven housekeeping genes, carbamoyl-phosphate synthetase (carb), co/zn/cd efflux system component (czcd), d-alanyl-d-alanine ligase (ddl), dna polymerase iii (dnax), glucose-6-phosphate dehydrogenase (gdh), dna-directed rna polymerase, beta subunit (rpob) and superoxide dismutase (soda). the scheme was expanded by ...201121896156
activity of in vitro forms of dentifrices containing the hydroalcoholic extract of the ripe fruit of eugenia uniflora l. (surinam cherry) on cariogenic bacteria.the aim of this study was to evaluate the in vitro activity of dentifrices containing the hydroalcoholic extract of the ripe fruit of eugenia uniflora l. (surinam cherry) on streptococcus oralis (atcc 10557) and lactobacillus casei (atcc 7469). five dentifrices were used: d1: containing hydroalcoholic extract of eugenia uniflora l.; d2: containing fluoride and hydroalcoholic extract of eugenia uniflora l.; d3: containing triclosan and hydroalcoholic extract of eugenia uniflora l; d4: containing ...201122010405
Development of a real-time PCR assay for the specific detection and identification of Streptococcus pseudopneumoniae using the recA gene.Clin Microbiol Infect ABSTRACT: We sequenced the evolutionarily conserved genes 16S rRNA, atpD, tuf, and recA from Streptococcus pseudopneumoniae, Streptococcus pneumoniae, Streptococcus mitis, and Streptococcus oralis. Phylogenetic analysis revealed that recA provided good resolution between these species, including discrimination of the novel species S. pseudopneumoniae. By contrast, the more conserved 16S rRNA, tuf and atpD are not sufficiently discriminatory. Therefore, recA sequences were u ...201122022828
Antimicrobial and antibiofilm action of Casbane Diterpene from Croton nepetaefolius against oral bacteria.OBJECTIVE: The antibacterial activity of Casbane Diterpene (CD) was evaluated in vitro against Streptococcus oralis, S. mutans, S. salivarius, S. sobrinus, S. mitis and S. sanguinis. The viability of planktonic cells was analysed by susceptibility tests (MIC and MBC) and antibiofilm action was assayed. METHODS: The minimal inhibitory and bactericidal concentrations (MIC and MBC) of oral Streptococcus were evaluated through microdilution tests. To assay antibiofilm activity, biofilms were generat ...201122119044
[effect of beryllium on chemical elements of cell membrane and h2o2 production of streptococcus oralis].to evaluate the effect of beryllium (be(2+)) on chemical elements of cell membrane and h2o2 production of streptococcus oralis (s.oralis), thus to explore the microbiologic mechanisms of periodontal diseases which may occur after prosthodontic treatment.201122241302
cell surface proteins in s. pneumoniae, s. mitis and s. oralis.streptococcus pneumoniae, a major human pathogen, is closely related to the commensal species s. mitis and s. oralis. s. pneumoniae surface proteins are implicated in virulence and host interaction of this species, but many of them have recently been detected in s. mitis b6 in silico. we tested for the presence of such genes usinga set of eight s. mitis and eleven s. oralis strains from different geographic locations.201122347584
biosynthesis of teichoic acids in streptococcus pneumoniae and closely related species: lessons from genomes.the cell wall of streptococcus pneumoniae contains an unusually complex wall teichoic acid (wta), which has identical repeating units as the membrane-anchored lipoteichoic acid (lta). both polymers share a common cytoplasmic pathway of precursor synthesis, but several ta enzymes have remained elusive. bioinformatic analysis of the genome of various pneumococcal strains, including choline-independent mutant strains, has allowed us to identify the missing ta genes. we present here the deduced comp ...201222432701
bacterial viability on surface-modified resin-based dental restorative materials.the purpose of the present investigation was to investigate the viability of early colonizers on the surfaces of resin-based dental restorative materials modified with low-surface tension active agents in comparison with the unmodified material. a novel polymeric sorption material, loaded with two low-surface tension γ(l) active agents (hydroxyfunctional polydimethylsiloxane and polydimethylsiloxane) or a polymerizable active agent (silicone polyether acrylate), was used to modify commonly formu ...201222673754
streptococcus tigurinus, a novel member of the streptococcus mitis group, causes invasive infections.we recently described the novel species streptococcus tigurinus sp. nov. belonging to the streptococcus mitis group. the type strain az_3a(t) of s. tigurinus was originally isolated from a patient with infective endocarditis. according to its phenotypic and molecular characteristics, s. tigurinus is most closely related to streptococcus mitis, streptococcus pneumoniae, streptococcus pseudopneumoniae, streptococcus oralis, and streptococcus infantis. accurate identification of s. tigurinus is fac ...201222760039
autoinducer-2 influences interactions amongst pioneer colonizing streptococci in oral biofilms.streptococcus gordonii and streptococcus oralis are among the first bacterial species to colonize clean tooth surfaces. both produce autoinducer-2 (ai-2): a family of inter-convertible cell-cell signal molecules synthesized by the luxs enzyme. the overall aim of this work was to determine whether ai-2 alters interspecies interactions between s. gordonii dl1 and s. oralis 34 within dual-species biofilms in flowing human saliva. based upon ai-2 bioluminescence assays, s. gordonii dl1 produced more ...201222493304
left atrial endocarditis as a rare complication of mitral valve endocarditis: a clinical case.infective endocarditis (ie) is considered as a multifaceted problem in every aspect from etiology and presentation to diagnosis and management. early recognition of this disease and especially its complications, remain a critical task for the cardiologist. atrial endocarditis is a rare and sometimes unrecognized complication of mitral valve endocarditis.201223151277
inhibitory effect on in vitro streptococcus oralis biofilm of a soda-lime glass containing silver nanoparticles coating on titanium alloy.this paper reports the effect of soda-lime-glass-nag coating on the viability of an in vitro biofilm of streptococcus oralis. three strains (atcc 35037 and two clinical isolates from periodontitis patients) were grown on coated with glass, glass containing silver nanoparticles, and uncoated titanium alloy disks. two different methods were used to quantify biofilm formation abilities: crystal violet staining and determination of viable counts. the influence of the surface morphology on the cell a ...201222879961
streptococcus oralis coaggregation receptor polysaccharides induce inflammatory responses in human aortic endothelial cells.streptococcus oralis, belonging to the oral viridans group streptococci, has been detected in human cardiovascular lesions including infective endocarditis and atheromatous plaques. the organism has coaggregation receptor polysaccharides (rps) on the cell wall, which function as receptors for surface adhesins on other members of the oral biofilm community. the present study examined the capacity of s. oralis rps to induce inflammatory responses in human aortic endothelial cells (haecs). purified ...201222759314
immune reactivity of four monoclonal and two polyclonal antibodies raised against recombinant pneumococcal surface adhesin a.in this study four monoclonal antibodies (mabs) and two polyclonal antisera were raised against pneumococcal surface adhesion a (psaa), a 37 kda cell wall protein, and were characterized. the mabs were purified, isotyped, and epitope mapped with peptide microarrays. all monoclonals and polyclonals underwent testing in immunodot blot, western blot, and elisa assays to assess their specificity. all monoclonal antibodies belonged to isotype igg1 κ. peptide microarray mapping identified two likely e ...201222741580
rupture of renal mycotic aneurysm that developed during the treatment of streptococcal infective endocarditis and vertebral osteomyelitis.a 50-year-old woman received two weeks of cefozopran and two weeks of imipenem for streptococcal endocarditis and vertebral osteomyelitis. subsequently she received four weeks of oral levofloxacin and eight weeks of oral clarithromycin due to persistent elevation of c-reactive protein. finally, she was admitted to our hospital due to massive hematuria. abdominal ct showed rupture of an aneurysm in the right kidney and emergent coil embolization was performed. multiple sets of blood culture grew ...201222687800
effect of penicillin g every three weeks on oral microflora by penicillin resistant viridans streptococci.benzathine penicillin g every 3 weeks is the standard protocol for secondary prophylaxis for recurrent rheumatic fever.201222522720
[a surgical technique of tricuspid valve repair for infective endocarditis using an autologous pericardium].we report a surgically treated case of tricuspid valve endocarditis. a 33-year-old man was diagnosed with ventricular septal defect (vsd) and active infective endocarditis associated with severe tricuspid regurgitation. ultrasonic echocardiography (ucg) showed vegetations attached to the tricuspid valve. his blood culture was positive for streptococcus oralis. although intravenous antibiotics therapy was effective, chest computed tomography( ct) revealed multiple septic pulmonary enboli in right ...201222485034
long-term survival of salivary streptococci on dental devices made of ethylene vinyl acetate.bacterial infection associated with the use of medical or dental devices is a serious concern. although devices made of ethylene vinyl acetate (eva) are often used in the oral cavity, there are no established standards for their storage. we investigated bacterial survival on eva sheets under various storage conditions to establish a standard for hygienic storage of such dental devices. bacterial counts were evaluated, which showed a significant decrease after washing with sterilized water, mecha ...201222422084
streptococcus pseudopneumoniae identification by pherotype: a method to assist understanding of a potentially emerging or overlooked pathogen.the recent identification of streptococcus pseudopneumoniae (pseudopneumococcus) has complicated classification schemes within members of the "mitis" streptococcal group. accurate differentiation of this species is necessary for understanding its disease potential and identification in clinical settings. this work described the use of the competence-stimulatory peptide comc sequence for identification of s. pseudopneumoniae. comc sequences from clinical sources were determined for 17 strains of ...201222378913
amoxicillin-resistant oral streptococci identified in dental plaque specimens from healthy japanese adults.infective endocarditis (ie) is known to be a life-threatening disease and invasive dental procedures are considered to be important factors. oral amoxicillin (ampc) is widely used for prophylaxis in patients with heart disorders who are at risk for ie. however, there is only limited information regarding the inhibition of oral bacteria by ampc.201222341432
antibiotic modulation of the plasminogen binding ability of viridans group streptococci.the ability of viridans group streptococci to bind human plasminogen and its subsequent activation into plasmin may contribute to the pathogenesis of infective endocarditis (ie) by leading to a decreased stability of the streptococcal vegetation and facilitating dehiscence of emboli. at levels greater than or equal to their mics, penicillin, vancomycin, and linezolid are efficacious in the treatment of streptococcal endocarditis. however, at sub-mics, antibiotics can modulate the expression of b ...201222037854
in vitro antimicrobial activity of mouth washes and herbal products against dental biofilm-forming bacteria.to evaluate in vitro, the antimicrobial effect of cymbopogon citrates (lemon grass), plectranthusamboinicus (mexican mint) and conyzabonariensis (hairy fleabane) tinctures as well as pure and diluted commercial mouth washes (malvatricin(®), periogard(®) and listerine(®)) on wild isolates of streptococcusmutans and reference strains of s. mutans, streptococcus salivarius, streptococcus oralis and lactobacillus casei by determination of minimum inhibitory dilution (mid).201223293486
validation of a quantitative real-time pcr assay and comparison with fluorescence microscopy and selective agar plate counting for species-specific quantification of an in vitro subgingival biofilm model.subgingival biofilms are the prime etiological factor of periodontal disease. owing to their complex polymicrobial nature, quantification of individual bacterial species within the biofilm for research and diagnostic purposes can be methodologically challenging. the aims of this study were to establish a quantitative real-time pcr (qpcr) assay to quantify the bacteria used in our 10-species in vitro 'subgingival' biofilm model and to compare the quantitative outcome with fluorescence microscopy ...201223278531
simultaneous detection of streptococcus pneumoniae, s. mitis, and s. oralis by a novel multiplex pcr assay targeting the gyrb gene.a multiplex pcr (mpcr) protocol was developed for simultaneous detection of the gyrb gene in streptococcus pneumoniae, streptococcus mitis, and streptococcus oralis, and the specificity was evaluated using 141 coccus strains. genomic dnas purified from s. pneumoniae, s. mitis, and s. oralis strains were efficiently detected with size differences, whereas no pcr products were amplified from any of the reference strains tested. a pilot study of 47 human oral swab specimens was conducted in paralle ...201223269740
identification and characterization of porphyromonas gingivalis client proteins that bind to streptococcus oralis glyceraldehyde-3-phosphate dehydrogenase.coaggregation of porphyromonas gingivalis and oral streptococci is thought to play an important role in p. gingivalis colonization. previously, we reported that p. gingivalis major fimbriae interacted with streptococcus oralis glyceraldehyde-3-phosphate dehydrogenase (gapdh), and that amino acid residues 166 to 183 of gapdh exhibited strong binding activity toward p. gingivalis fimbriae (h. nagata, m. iwasaki, k. maeda, m. kuboniwa, e. hashino, m. toe, n. minamino, h. kuwahara, and s. shizukuish ...201223264054
comparison of microbial changes in early redeveloping biofilms on natural teeth and dentures.surfaces and fluids can affect oral bacterial colonization. the aim of this study is to compare redeveloping biofilms on natural teeth and dentures.201222443543
oral microbial biofilm stimulation of epithelial cell responses.oral bacterial biofilms trigger chronic inflammatory responses in the host that can result in the tissue destructive events of periodontitis. however, the characteristics of the capacity of specific host cell types to respond to these biofilms remain ill-defined. this report describes the use of a novel model of bacterial biofilms to stimulate oral epithelial cells and profile select cytokines and chemokines that contribute to the local inflammatory environment in the periodontium. monoinfection ...201222266273
pantoea agglomerans in immunodeficient patients with different respiratory symptoms.the aim of this paper was to determine in 32 patients from 4 different mexican hospitals the frequency of opportunistic bacteria in the 2010 to 2011 time period. the patients were divided in 4 groups. group 1 included 21 hiv positive patients with acute respiratory syndrome. four hiv positive patients with tuberculosis symptoms were included in group 2; two patients with tuberculosis symptoms and one asymptomatic person formed group 3. reference group 4 included 4 patients from whom 4 strains of ...201222619600
streptococcus mutans protein synthesis during mixed-species biofilm development by high-throughput quantitative proteomics.biofilms formed on tooth surfaces are comprised of mixed microbiota enmeshed in an extracellular matrix. oral biofilms are constantly exposed to environmental changes, which influence the microbial composition, matrix formation and expression of virulence. streptococcus mutans and sucrose are key modulators associated with the evolution of virulent-cariogenic biofilms. in this study, we used a high-throughput quantitative proteomics approach to examine how s. mutans produces relevant proteins th ...201223049864
osteopontin reduces biofilm formation in a multi-species model of dental biofilm.combating dental biofilm formation is the most effective means for the prevention of caries, one of the most widespread human diseases. among the chemical supplements to mechanical tooth cleaning procedures, non-bactericidal adjuncts that target the mechanisms of bacterial biofilm formation have gained increasing interest in recent years. milk proteins, such as lactoferrin, have been shown to interfere with bacterial colonization of saliva-coated surfaces. we here study the effect of bovine milk ...201222879891
the exopolysaccharide matrix modulates the interaction between 3d architecture and virulence of a mixed-species oral biofilm.virulent biofilms are responsible for a range of infections, including oral diseases. all biofilms harbor a microbial-derived extracellular-matrix. the exopolysaccharides (eps) formed on tooth-pellicle and bacterial surfaces provide binding sites for microorganisms; eventually the accumulated eps enmeshes microbial cells. the metabolic activity of the bacteria within this matrix leads to acidification of the milieu. we explored the mechanisms through which the streptococcus mutans-produced eps-m ...201222496649
subgingival microbiota in adult down syndrome periodontitis.the subgingival microbiota in down syndrome and non-down syndrome adults receiving periodic dental care was examined for 40 bacterial species using checkerboard dna-dna hybridization and the results were related to clinical periodontal attachment loss.201222221039
zoocin a and lauricidin in combination reduce streptococcus mutans growth in a multispecies biofilm.dental caries is the most prevalent human infection. it is a multifactorial disease in which the microbial composition of dental plaque plays a major role in the development of clinical symptoms. the bacteria most often implicated in the development of caries are that group of streptococci referred to as the mutans streptococci, in particular streptococcus mutans and streptococcus sobrinus. one approach to the prevention of caries is to reduce the numbers of mutans streptococci in plaque to a le ...201222508519
water-soluble β-cyclodextrin grafted with chitosan and its inclusion complex as a mucoadhesive eugenol carrier.inclusion complex between water-soluble βcd-grafted chitosan derivatives (qcd-g-cs) and eugenol (eg) was investigated as a new type of mucoadhesive drug carrier. the qcd-g-css were synthesized with various βcd moieties ranging from 5 to 23%. spontaneous inclusion complex of these derivatives and eg were found and confirmed by ftir and simulation study. self-aggregated formations of qcd-g-cs were found, according to fluorescence and tem studies, where the formations were preferable for qcd11g-cs ...201224750767
antibacterial activity of dentine and pulp extracellular matrix extracts.to determine whether extracellular matrix (ecm) preparations from pulp (pecm) and dentine (decm) possess antimicrobial activity.201222416895
regulation of neuraminidase expression in streptococcus pneumoniae.sialic acid (n-acetylneuraminic acid; neunac) is one of the most important carbohydrates for streptococcus pneumoniae due of its role as a carbon and energy source, receptor for adhesion and invasion and molecular signal for promotion of biofilm formation, nasopharyngeal carriage and invasion of the lung.201222963456
a novel formulation effective in killing oral biofilm bacteria.to determine if a novel formulation is effective in killing oral biofilm streptococci in vitro and in vivo.201222908534
antimicrobial effects of herbal extracts on streptococcus mutans and normal oral streptococci.streptococcus mutans is associated with dental caries. a cariogenic biofilm, in particular, has been studied extensively for its role in the formation of dental caries. herbal extracts such as cudrania tricuspidata, sophora flavescens, ginkgo biloba, and betula schmidtii have been used as a folk remedy for treating diseases. the purpose of this study was to evaluate and compare the antibacterial activity of herbal extracts against normal oral streptococci, planktonic and biofilm of s. mutans. st ...201323990300
daptomycin concentrations in valve tissue and vegetation in patients with bacterial endocarditis.in a patient with mitral-aortic native-valve streptococcus oralis endocarditis, daptomycin concentrations in aortic and mitral valves were 8.6 and 30.8 μg/g, respectively, and 26 μg/g in the mitral vegetation. in the case of porcine-aortic-valve staphylococcus epidermidis endocarditis, the daptomycin concentrations were 53.1 μg/g in the valve and 18.1 μg/g in perivalvular tissues. daptomycin achieved apparently adequate tissue concentrations. s. epidermidis was eradicated, whereas streptococcus ...201323089753
the effect of a silver nanoparticle polysaccharide system on streptococcal and saliva-derived biofilms.in this work, we studied the antimicrobial properties of a nanocomposite system based on a lactose-substituted chitosan and silver nanoparticles: chitlac-nag. twofold serial dilutions of the colloidal chitlac-nag solution were both tested on streptococcus mitis, streptococcus mutans, and streptococcus oralis planktonic phase and biofilm growth mode as well as on saliva samples. the minimum inhibitory and bactericidal concentrations of chitlac-nag were evaluated together with its effect on sessil ...201323812080
reduced adhesion of oral bacteria on hydroxyapatite by fluoride treatment.the mechanisms of action of fluoride have been discussed controversially for decades. the cavity-preventive effect for teeth is often traced back to effects on demineralization. however, an effect on bacterial adhesion was indicated by indirect macroscopic studies. to characterize adhesion on fluoridated samples on a single bacterial level, we used force spectroscopy with bacterial probes to measure adhesion forces directly. we tested the adhesion of streptococcus mutans , streptococcus oralis , ...201323556545
antimicrobial activity of the synthetic peptide lys-a1 against oral streptococci.the peptide lys-[trp(6)]-hy-a1 (lys-a1) is a synthetic derivative of the peptide hy-a1, initially isolated from the frog species hypsiboas albopunctatus. according to previous research, it is a molecule with broad antimicrobial activity. the objective of this study was to evaluate the antimicrobial activity of the synthetic peptide lys-a1 (kifgaiwplalgalknlik-nh2) on the planktonic and biofilm growth of oral bacteria. the methods used to evaluate antimicrobial activity include the following: det ...201323340019
antimicrobial efficiency of ethanol and 2-propanol alcohols used on contaminated storage phosphor plates and impact on durability of the plate.to assess (1) antimicrobial efficiency of wiping intraoral phosphor plates with alcohol tissues based on ethanol or 2-propanol alcohols after contamination with candida albicans and streptococcus oralis, (2) a concept for autodisinfection with ultraviolet light of the transport ramp in a scanner for phosphor plates and (3) the impact of wiping with alcohol tissues on durability of the plate.201323420856
differential effect of autoinducer 2 of fusobacterium nucleatum on oral streptococci.autoinducer 2 (ai-2) is a quorum sensing molecule and plays an important role in dental biofilm formation, mediating interspecies communication and virulence expression of oral bacteria. fusobacterium nucleatum connects early colonizing commensals and late colonizing periodontopathogens. f. nucleatum ai-2 and quorum sensing inhibitors (qsis) can manipulate dental biofilm formation. in this study, we evaluated the effect of f. nucleatum ai-2 and qsis on biofilm formation of streptococcus gordonii ...201324112724
method to quantify live and dead cells in multi-species oral biofilm by real-time pcr with propidium monoazide.real-time pcr (qpcr) is a widely used technique in analysing environmental and clinical microbiological samples. however, its main limitation was its inability to discriminate between live and dead cells.recently, propidium monoazide (pma) together with qpcr has been used to overcome this problem, with good results for different bacterial species in different types of samples.our objective was to implement this technique for analysing mortality in multi-species oral biofilms formed in vitro with ...201323289803
incidence of bacteriocins produced by food-related lactic acid bacteria active towards oral pathogens.in the present study we investigated the incidence of bacteriocins produced by 236 lactic acid bacteria (lab) food isolates against pathogenic or opportunistic pathogenic oral bacteria. this set of lab contained several strains (≥17%) producing bacteriocins active against food-related bacteria. interestingly only streptococcus macedonicus aca-dc 198 was able to inhibit the growth of streptococcus oralis, streptococcus sanguinis and streptococcus gordonii, while lactobacillus fermentum aca-dc 179 ...201323443163
daptomycin activity against uncommonly isolated streptococcal and other gram-positive species groups.a total of 1,356 clinical isolates were tested against daptomycin by broth microdilution methods. daptomycin was active against seven groups of viridans group streptococci (mic50 and mic90 values ranging from ≤0.06 and ≤0.06 μg/ml [streptococcus bovis and streptococcus dysgalactiae] to 0.5 and 1 μg/ml [streptococcus mitis, streptococcus oralis, and streptococcus parasanguinis], respectively), beta-hemolytic streptococci serogroups c, f, and g (mic50 and mic90, ≤0.06 to 0.25 and 0.12 to 0.25 μg/m ...201324080651
antimicrobial activity of pure platelet-rich plasma against microorganisms isolated from oral cavity.autologous platelet concentrates (pcs) have been extensively used in a variety of medical fields to promote soft and hard tissue regeneration. the significance behind their use lies in the abundance of growth factors in platelets α-granules that promotes wound healing. in addition, antibacterial properties of pcs against various bacteria have been recently pointed out. in this study, the antimicrobial effect of pure platelet-rich plasma (p-prp) was evaluated against oral cavity microorganisms su ...201323442413
rapid detection of gram-positive organisms by use of the verigene gram-positive blood culture nucleic acid test and the bact/alert pediatric fan system in a multicenter pediatric evaluation.assays that expedite the reporting of organism identification and antibiotic susceptibility status in positive blood cultures can fast track interventions that improve clinical outcomes. we evaluated the verigene gram-positive blood culture nucleic acid test (bc-gp) in two pediatric hospitals. positive bact/alert pediatric fan blood cultures with gram-positive organisms were tested using the bc-gp in tandem with routine laboratory procedures. to test organisms underrepresented in the clinical bl ...201323966484
characterization of recombinant fluoroquinolone-resistant pneumococcus-like isolates.fourteen fluoroquinolone-resistant streptococcal isolates with recombinant dna topoisomerase genes, preliminarily identified as pneumococci, were further characterized using phenotypic and genotypic approaches. phenotypic tests classified them as atypical pneumococci. phylogenetic relationships were analyzed by using the sequences of seven housekeeping alleles from these isolates and from isolates of streptococcus pneumoniae, streptococcus mitis, streptococcus oralis, and streptococcus pseudopne ...201323114769
impact of early colonizers on in vitro subgingival biofilm formation.the aim of this study was to investigate the impact of early colonizing species on the structure and the composition of the bacterial community developing in a subgingival 10-species biofilm model system. the model included streptococcus oralis, streptococcus anginosus, actinomycesoris, fusobacterium nucleatum subsp. nucleatum, veillonella dispar, campylobacter rectus, prevotella intermedia, porphyromonas gingivalis, tannerella forsythia, and treponema denticola. based on literature, we consider ...201324340084
morphological plasticity of streptococcus oralis isolates for biofilm production, invasiveness, and architectural patterns.streptococcus oralis is an early coloniser of the oral cavity that contributes to dental plaque formation. many different genotypes can coexist in the same individual and cause opportunistic infections such as bacterial endocarditis. however, little is known about virulence factors involved in those processes. the aim was to analyze the evolving growth of s. oralis colony/biofilm to find out potentially pathogenic features.201324112723
salivary pellicles on titanium and their effect on metabolic activity in streptococcus oralis.titanium implants in the oral cavity are covered with a saliva-derived pellicle to which early colonizing microorganisms such as streptococcus oralis can bind. the protein profiles of salivary pellicles on titanium have not been well characterized and the proteins of importance for binding are thus unknown. biofilm bacteria exhibit different phenotypes from their planktonic counterparts and contact with salivary proteins may be one factor contributing to the induction of changes in physiology. w ...201323866104
hydrogen peroxide produced by oral streptococci induces macrophage cell death.hydrogen peroxide (h2o2) produced by members of the mitis group of oral streptococci plays important roles in microbial communities such as oral biofilms. although the cytotoxicity of h2o2 has been widely recognized, the effects of h2o2 produced by oral streptococci on host defense systems remain unknown. in the present study, we investigated the effect of h2o2 produced by streptococcus oralis on human macrophage cell death. infection by s. oralis was found to stimulate cell death of a thp-1 hum ...201323658745
identification of clinical streptococcus pneumoniae isolates among other alpha and nonhemolytic streptococci by use of the vitek ms matrix-assisted laser desorption ionization-time of flight mass spectrometry system.discrimination between streptococcus pneumoniae and its close relatives of the viridans group is a common difficulty in matrix-assisted laser desorption ionization-time of flight (maldi-tof) mass spectrometry-based identification. in the present study, the performances of the vitek ms maldi-tof mass spectrometry system were assessed using 334 pneumococci, 166 other s. mitis group streptococci, 184 non-s. mitis group streptococci, and 19 related alpha- and nonhemolytic aerobic gram-positive catal ...201323576536
glycoprotein ibα and fcγriia play key roles in platelet activation by the colonizing bacterium, streptococcus oralis.infective endocarditis (ie) is characterized by thrombus formation on a cardiac valve. the oral bacterium, streptococcus oralis, is recognized for its ability to colonize damaged heart valves and is frequently isolated from patients with ie. platelet interaction with s. oralis leads to the development of a thrombotic vegetation on heart valves, which results in valvular incompetence and congestive heart failure.201323413961
effectiveness of crt at measuring the salivary level of bacteria in caries prone children with probiotic therapy.this irb approved clinical trial was to determine the effect of "over the counter" probiotic supplements on the caries risk test- crt- (ivoclar) results of the oral microflora in high caries risk children.201324579284
down syndrome and arterial ischemic stroke in childhood: a potential immunologic link with selective igg4 subclass deficiency.we report four children with down syndrome (ds) without evidence of congenital heart disease who sustained cerebral infarction in the context of an infectious disease. in one child, stroke occurred in the context of acute infection with mycoplasma pneumonia. in another child, stroke occurred in the context of streptococcus oralis (viridans subgroup) infection. in two other children, stroke occurred in the context of a bibasilar pneumonia for which an etiologic agent was not found. all patients h ...201424613243
hydrogen peroxide contributes to the epithelial cell death induced by the oral mitis group of streptococci.members of the mitis group of streptococci are normal inhabitants of the commensal flora of the oral cavity and upper respiratory tract of humans. some mitis group species, such as streptococcus oralis and streptococcus sanguinis, are primary colonizers of the human oral cavity. recently, we found that hydrogen peroxide (h2o2) produced by s. oralis is cytotoxic to human macrophages, suggesting that streptococcus-derived h2o2 may act as a cytotoxin. since epithelial cells provide a physical barri ...201424498253
species-level assessment of the molecular basis of fluoroquinolone resistance among viridans group streptococci causing bacteraemia in cancer patients.viridans group streptococci (vgs) are a major cause of bacteraemia in neutropenic cancer patients, particularly those receiving fluoroquinolone prophylaxis. in this study, we sought to understand the molecular basis for fluoroquinolone resistance in vgs causing bacteraemia in cancer patients by assigning 115 vgs bloodstream isolates to specific species using multilocus sequence analysis (mlsa), by sequencing the quinolone resistance-determining regions (qrdrs) of gyra, gyrb, parc and pare, and b ...201424721231
streptococcus dentisani sp. nov., a novel member of the mitis group.genomic, taxonomic and biochemical studies were performed on two strains of α-haemolytic streptococci that showed them to be clustered with major members of the streptococcus mitis group. these gram-stain-positive strains were isolated from tooth surfaces of caries-free humans and showed the classical spherical shape of streptococcal species growing in chains. sequence analysis from concatenated 16s and 23s rrna gene and soda genes showed that these strains belonged to the mitis group, but both ...201424006481
streptococcal co-infection augments candida pathogenicity by amplifying the mucosal inflammatory response.mitis-group streptococci are ubiquitous oral commensals that can promote polybacterial biofilm virulence. using a novel murine oral mucosal co-infection model we sought to determine for the first time whether these organisms promote the virulence of c. albicans mucosal biofilms in oropharyngeal infection and explored mechanisms of pathogenic synergy. we found that streptococcus oralis colonization of the oral and gastrointestinal tract was augmented in the presence of c. albicans. s. oralis and ...201424079976
probing of microbial biofilm communities for coadhesion partners.investigations of interbacterial adhesion in dental plaque development are currently limited by the lack of a convenient assay to screen the multitude of species present in oral biofilms. to overcome this limitation, we developed a solid-phase fluorescence-based screening method to detect and identify coadhesive partner organisms in mixed-species biofilms. the applicability of this method was demonstrated using coaggregating strains of type 2 fimbrial adhesin-bearing actinomyces and receptor pol ...201425107971
antimicrobial photodynamic therapy suppresses dental plaque formation in healthy adults: a randomized controlled clinical trial.oral care is important for oral and systemic health, especially for elderly institutionalized individuals and compromised patients. however, conventional mechanical plaque control is often difficult for these patients because of the pain or the risk of aspiration. although antimicrobial photodynamic therapy (apdt), which is considered an alternative or adjunct to mechanical approaches, has potential application as a less stressful method of daily plaque control, no clinical application of this t ...201425511777
isolation of streptococcus tigurinus - a novel member of streptococcus mitis group from a case of periodontitis.streptococcus tigurinus is a new member of the streptococcus viridians group and is closely related to streptococcus mitis, streptococcus pneumoniae, streptococcus pseudopneumoniae, streptococcus oralis, and streptococcus infantis. the type strain az_3a(t) of s. tigurinus was originally isolated from a patient with infective endocarditis. accurate identification of s. tigurinus is facilitated only by newer molecular methods like 16s rrna gene analysis. during the course of study on bacteraemia a ...201424974898
chemical structures of streptococcus pneumoniae capsular polysaccharide type 39 (cps39), cps47f, and cps34 characterized by nuclear magnetic resonance spectroscopy and their relation to cps10a.structural characterization of streptococcus pneumoniae capsular polysaccharides (cps) is a prerequisite for unraveling both antigenic and genetic relationships that exist between different serotypes. in the current study, comparative structural studies of s. pneumoniae cps serogroup 10 (cps10) were extended to include genetically related s. pneumoniae cps34, cps39, and cps47f. high-resolution heteronuclear nuclear magnetic resonance (nmr) spectroscopy confirmed the published structure of cps34 ...201425002537
infective endocarditis associated with mitral valve prolapse in a patient with klinefelter syndrome.we herein report a case of infective endocarditis associated with mitral valve prolapse (mvp) in a 34-year-old man with klinefelter syndrome. the patient was admitted with a fever and headache that had persisted for three weeks. repeated blood cultures showed growth of streptococcus oralis. echocardiography demonstrated severe mitral regurgitation with a large vegetation attached to the prolapsed anterior leaflet. surgical plasty of the mitral valve was performed because the vegetation measured ...201424785888
brain abscess due to streptococcus oralis in an immunocompetent patient.a bacteriologically proven case of brain abscess, due to streptococcus oralis is being reported in a 12-year-old girl who is a known case of congenital heart disease. the patient presented with fever, headache and vomiting. pus cultures yielded s. oralis.201424713909
the novel species streptococcus tigurinus and its association with oral infection.streptococcus tigurinus is a novel species of viridans streptococci, shown to cause severe invasive infections such as infective endocarditis, spondylodiscitis and meningitis. s. tigurinus belongs to the streptococcus mitis group and is most closely related to streptococcus mitis, streptococcus oralis, streptococcus pneumoniae, streptococcus pseudopneumoniae and streptococcus infantis. the presence of s. tigurinus in the human oral cavity has been documented, including in patients with periodont ...201425483862
association between polycystic ovary syndrome, oral microbiota and systemic antibody responses.polycystic ovary syndrome (pcos) is a hormonal disorder of women that not only is the leading cause of infertility but also shows a reciprocal link with oral health. this study aimed to investigate the hypothesis that the levels of putative periodontal pathogens in saliva and their antibody response in serum are elevated in pcos, compared to systemic health. a total of 125 women were included in four groups; 45 women with pcos and healthy periodontium, 35 women with pcos and gingivitis, 25 syste ...201425232962
antibiofilm efficacy of photosensitizer-functionalized bioactive nanoparticles on multispecies biofilm.newer disinfection strategies based on antibacterial nanoparticles and photodynamic therapy (pdt) aim to eliminate residual biofilm bacteria during root canal treatment. the aim of the current study was to test the newly developed rose bengal-functionalized chitosan nanoparticles (csrbnps) for their interaction/uptake with monospecies bacteria/biofilm and assess their antibiofilm efficacy on a multispecies biofilm model in vitro.201425260731
an in vitro biofilm model associated to dental implants: structural and quantitative analysis of in vitro biofilm formation on different dental implant surfaces.the impact of implant surfaces in dental biofilm development is presently unknown. the aim of this investigation was to assess in vitro the development of a complex biofilm model on titanium and zirconium implant surfaces, and to compare it with the same biofilm formed on hydroxyapatite surface.201425110288
salivary pellicle composition and multispecies biofilm developed on titanium nitrided by cold plasma.the aim of this study was to evaluate the composition of the salivary pellicle (sp) and multispecies biofilm developed on titanium nitrided by cold plasma.201424769315
characterization and application of a flow system for in vitro multispecies oral biofilm formation.bacteria in the oral cavity grow in the form of biofilms; these structures are subject to constant saliva or gingival crevicular fluid flow conditions. the aims of this study were: (i) to develop and to characterize an in-vitro biofilm model with oral bacteria growing under flow and shear conditions; and (ii) to demonstrate the usefulness of the model for evaluating the activity of three antiplaque agents.201423815431
colonisation of gingival epithelia by subgingival biofilms in vitro: role of "red complex" bacteria.biofilm formation on tooth surface results in colonisation and invasion of the juxtaposed gingival tissue, eliciting strong inflammatory responses that lead to periodontal disease. this in vitro study investigated the colonisation of human gingival multi-layered epithelium by multi-species subgingival biofilms, and evaluated the relative effects of the "red complex" species (porphyromonas gingivalis, tannerella forsythia and treponema denticola).201424949828
red wine and oenological extracts display antimicrobial effects in an oral bacteria biofilm model.the antimicrobial effects of red wine and its inherent components on oral microbiota were studied by using a 5-species biofilm model of the supragingival plaque that includes actinomyces oris, fusobacterium nucleatum, streptococcus oralis, streptococcus mutans and veillonella dispar. microbiological analysis (cfu counting and confocal laser scanning microscopy) of the biofilms after the application of red wine, dealcoholized red wine, and red wine extract solutions spiked or not with grape seed ...201424773294
pilus hijacking by a bacterial coaggregation factor critical for oral biofilm development.the formation of dental plaque, a highly complex biofilm that causes gingivitis and periodontitis, requires specific adherence among many oral microbes, including the coaggregation of actinomyces oris with streptococcus oralis that helps to seed biofilm development. here, we report the discovery of a key coaggregation factor for this process. this protein, which we named coaggregation factor a (cafa), is one of 14 cell surface proteins with the lpxtg motif predicted in a. oris mg1, whose functio ...201424567409
molecular detection of bacteria associated to dental caries in 4-12-year-old tunisian children.the occurrence of several microbial species in the oral cavity of 4-12-year-old tunisian children was investigated. samples were taken from 158 children (81 caries actives and 77 caries free). genomic dna was extracted and analyzed for the presence of 17 microbial species using a polymerase chain reaction assay. all samples were positive for at least one of the target microbial strains. streptococcus mutans was the most prevalent species (76.5%) detected in genomic dna collected from carious les ...201424814824
evaluation of the stability and antimicrobial activity of an ethanolic extract of libidibia ferrea.biofilm is a dense, whitish, noncalcified aggregate of bacteria, with desquamated epithelial cells and food debris creating conditions for an imbalance of resident oral microflora and favoring the destruction of hard and soft tissues by development of caries and gingivitis. the aim of this study was to obtain and characterize an extract of libidibia ferrea, ex caesalpinia ferrea l. and to evaluate its feasibility for formulation as a mouthwash, according to current legislation. for this purpose, ...201424501546
effective oral health in infective endocarditis: efficacy of high-street mouthwashes against the viridans group streptococci.recent uk national institute for health and clinical excellence guidelines state that there is no longer a need for oral antibiotic prophylaxis in patients undergoing dental procedures who are at risk of infective endocarditis (ie), and advocate the importance of maintaining good oral health. as viridans group streptococci (vgs) are common etiological agents of ie and inhabitants of the mouth, the purpose of this study was to examine the efficacy of common high-street mouthwashes against four cl ...201424610586
colostrum of healthy slovenian mothers: microbiota composition and bacteriocin gene prevalence.microbial communities inhabiting the breast milk microenvironment are essential in supporting mammary gland health in lactating women and in providing gut-colonizing bacterial 'inoculum' for their infants' gastro-intestinal development. bacterial dna was extracted from colostrum samples of 45 healthy slovenian mothers. characteristics of the communities in the samples were assessed by polymerase chain reaction (pcr) coupled with denaturing gradient gel electrophoresis (dgge) and by quantitative ...201425919457
crystalline anatase-rich titanium can reduce adherence of oral streptococci.dental implant abutments that emerge through the mucosa are rapidly covered with a salivary protein pellicle to which bacteria bind, initiating biofilm formation. in this study, adherence of early colonizing streptococci, streptococcus gordonii, streptococcus oralis, streptococcus mitis and streptococcus sanguinis to two saliva-coated anodically oxidized surfaces was compared with that on commercially pure titanium (cpti). near edge x-ray absorption (nexafs) showed crystalline anatase was more p ...201424881929
genetic basis of coaggregation receptor polysaccharide biosynthesis in streptococcus sanguinis and related species.interbacterial adhesion between streptococci and actinomyces promotes early dental plaque biofilm development. recognition of coaggregation receptor polysaccharides (rps) on strains of streptococcus sanguinis, streptococcus gordonii and streptococcus oralis by actinomyces spp. type 2 fimbriae is the principal mechanism of these interactions. previous studies of genetic loci for synthesis of rps (rps) and rps precursors (rml, gale1 and gale2) in s. gordonii 38 and s. oralis 34 revealed difference ...201424397790
plasma components and platelet activation are essential for the antimicrobial properties of autologous platelet-rich plasma: an in vitro study.autologous platelet concentrates are successfully adopted in a variety of medical fields to stimulate bone and soft tissue regeneration. the rationale for their use consists in the delivery of a wide range of platelet-derived bioactive molecules that promotes wound healing. in addition, antimicrobial properties of platelet concentrates have been pointed out. in this study, the effect of the platelet concentration, of the activation step and of the presence of plasmatic components on the antimicr ...201425232963
using color histograms and spa-lda to classify bacteria.in this work, a new approach is proposed to verify the differentiating characteristics of five bacteria (escherichia coli, enterococcus faecalis, streptococcus salivarius, streptococcus oralis, and staphylococcus aureus) by using digital images obtained with a simple webcam and variable selection by the successive projections algorithm associated with linear discriminant analysis (spa-lda). in this sense, color histograms in the red-green-blue (rgb), hue-saturation-value (hsv), and grayscale cha ...201425023972
molecular identification and antibiotic resistant bacteria isolated from primary dentition infections.bacterial resistance to antibiotics is a health problem in many parts of the world. the aim of this study was to identify bacteria from dental infections and determine bacterial resistance to antibiotics used in dental care in the primary dentition.201425091293
the effect of dentifrice abrasion on denture topography and the subsequent retention of microorganisms on abraded surfaces.denture surfaces provide hard nonshedding niches for the adhesion and subsequent accumulation of oral microorganisms into denture plaque, which can harbor various potential pathogens linked with oral mucosal lesions and inhalation pneumonia. the initial adhesion is the prerequisite for subsequent biofilm growth, and surface roughness niches facilitate this process by trapping cells. retained microorganisms are then able to proliferate when the denture is returned to the oral cavity.201424998324
transduction of the streptococcus pyogenes bacteriophage φm46.1, carrying resistance genes mef(a) and tet(o), to other streptococcus species.φm46.1 - streptococcus pyogenes bacteriophage carrying mef(a) and tet(o), respectively, encoding resistance to macrolides (m phenotype) and tetracycline - is widespread in s. pyogenes but has not been reported outside this species. φm46.1 is transferable in vitro among s. pyogenes isolates, but no information is available about its transferability to other streptococcus species. we thus investigated φm46.1 for its ability to be transduced in vitro to recipients of different streptococcus species ...201425620959
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