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[infective endocarditis of the mitral valve complicated with preoperative rupture of the mycotic iliocolic artery aneurysm].a 55-year-old man was diagnosed with infective endocarditis( ie) of the mitral valve caused by streptococcus sanguinis. his ie was controlled immediately after the initiation of intravenous antibiotic therapy lasting for 4 weeks. a few days before surgery, he complained of abdominal discomfort and computed tomography (ct) scan revealed rupture of the mycotic iliocolic artery aneurysm. emergency transcatheter arterial embolization( tae) was successfully conducted. after additional 4 weeks' intrav ...201222314165
novel bacterial lipoprotein structures conserved in low-gc content gram-positive bacteria are recognized by toll-like receptor 2.bacterial lipoproteins/lipopeptides inducing host innate immune responses are sensed by mammalian toll-like receptor 2 (tlr2). these bacterial lipoproteins are structurally divided into two groups, diacylated or triacylated lipoproteins, by the absence or presence of an amide-linked fatty acid. the presence of diacylated lipoproteins has been predicted in low-gc content gram-positive bacteria and mycoplasmas based on the absence of one modification enzyme in their genomes; however, we recently d ...201222303020
design, structural and spectroscopic elucidation, and the in vitro biological activities of new diorganotin dithiocarbamates.the reaction of 2,2-dimethoxy-n-methylethyllamine or 2-methyl-1,3-dioxolane with cs(2) in alkaline media produced two novel dithiocarbamate salts. subsequent reactions with organotin halides yielded six new complexes: [snme(2){s(2)cnr(r(1))(2)}(2)] (1), [sn(n-bu)(2){s(2)cnr(r(1))(2)}(2)] (2), [snph(2){s(2)cnr(r(1))(2)}(2)] (3), [snme(2){s(2)cnr(r(2))(2)}(2)] (4), [sn(n-bu)(2){s(2)cnr(r(2))(2)}(2)] (5), [snph(2){s(2)cnr(r(2))(2)}(2)] (6), where r = methyl, r(1) = ch(2)ch(ome)(2), and r(2) = 2-met ...201223159807
[comparison of culture and real-time pcr methods in the detection of streptococcus pneumoniae and haemophilus influenzae in acute otitis media effusion specimens].streptococcus pneumoniae and haemophilus influenzae are the major etiologic agents of acute otitis media. this study was aimed to compare the detection rate of s.pneumoniae and h.influenzae by culture and real-time polymerase chain reaction (rt-pcr) in the middle ear effusions of patients diagnosed as acute otitis media. a total of 60 middle ear effusion samples collected from children with acute otitis media were included in the study. the samples were inoculated and incubated in bactec ped plu ...201223188581
the effect of various topical peri-implantitis antiseptics on staphylococcus epidermidis, candida albicans, and streptococcus sanguinis.although peri-implantitis has presented an ever increasing problem in modern dentistry, satisfying therapeutic strategies or scientifically based treatment recommendations are still not available. the main object of the present study was to evaluate the antibacterial efficacy of six different topical antiseptics on three test microorganisms attached to titanium implant specimens.201222365324
isothermal microcalorimetry provides new insights into biofilm variability and dynamics.the purpose of this study was to investigate a three-species in vitro biofilm with peri-implantitis-related bacteria for its variability and metabolic activity. streptococcus sanguinis, fusobacterium nucleatum, and porphyromonas gingivalis were suspended in simulated body fluid containing 0.2% glucose to form biofilms on polished, protein-coated implant-grade titanium disks over 72 h using a flow chamber system. thereafter, biofilm-coated disks were characterized by scanning electron microscopy ...201222967269
effect of streptococcus sanguinis/porphyromonas gingivalis single and combined biofilms upon platelet aggregation.to assess the effect of two oral bacteria streptococcus sanguinis and porphyromonas gingivalis upon platelet aggregation.201222393917
factors related to maternal transmission of mutans streptococci in high-risk children-pilot study.the purpose of this study was to investigate virulence factors associated with maternal transmission of mutans streptococci (ms).201223014079
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
comparison of oral streptococci biofilm in caries-free and caries-affected preschool mexican children.interaction of oral streptococci biofilm is the main etiological factor for dental caries. the aim of the study was to compare oral streptococci (os) distribution in the biofilm of primary dentition from caries-free and caries-affected preschool mexican children. this cross-sectional study involved 40 caries-free and 40 caries-affected children with primary dentition. each child was examined using the dmfs index, dna was extracted from saliva and presence of os was determined by pcr. data obtain ...201222928378
the role of hydrogen peroxide in environmental adaptation of oral microbial communities.oral streptococci are able to produce growth-inhibiting amounts of hydrogen peroxide (h(2)o(2)) as byproduct of aerobic metabolism. several recent studies showed that the produced h(2)o(2) is not a simple byproduct of metabolism but functions in several aspects of oral bacterial biofilm ecology. first, the release of dna from cells is closely associated to the production of h(2)o(2) in streptococcus sanguinis and streptococcus gordonii. extracellular dna is crucial for biofilm development and st ...201222848782
effect of xylitol on cariogenic and beneficial oral streptococci: a randomized, double-blind crossover trial.although habitual consumption of xylitol reduces cariogenic streptococci levels, its effect on beneficial oral streptococci is less clear. the main aim of the study is to investigate the effect of short-term xylitol consumption on the oral beneficial streptococci level of saliva, streptococcus sanguinis and s. mitis.201222973473
raman microspectroscopy for species identification and mapping within bacterial biofilms.: a new method of mapping multiple species of oral bacteria in intact biofilms has been developed, using the optical technique of confocal raman microscopy. a species classification algorithm, developed on dried biofilms, was used to analyze spectra of hydrated biofilms containing two microbial species central to dental health: streptococcus sanguinis and streptococcus mutans. the algorithm transferred successfully to the hydrated environment, correctly identifying the species of origin of singl ...201222794329
spxa1 involved in hydrogen peroxide production, stress tolerance and endocarditis virulence in streptococcus sanguinis.streptococcus sanguinis is one of the most common agents of infective endocarditis. spx proteins are a group of global regulators that negatively or positively control global transcription initiation. in this study, we characterized the spxa1 gene in s. sanguinis sk36. the spxa1 null mutant displayed opaque colony morphology, reduced hydrogen peroxide (h(2)o(2)) production, and reduced antagonistic activity against streptococcus mutans ua159 relative to the wild type strain. the δspxa1 mutant al ...201222768210
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
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
photodynamic inactivation of streptococcus mutans and streptococcus sanguinis biofilms in vitro.the purpose of this study was to evaluate specific effects of photodynamic inactivation (pdi) using erythrosine (er) and rose bengal (rb) photosensitizers and a blue light-emitting diode (led) on the viability of streptococcus mutans and streptococcus sanguinis biofilms. biofilms were grown in acrylic disks immersed in broth to production of biofilms, inoculated with microbial suspension (10(6) cells/ml) and incubated for 48 h. after the formation of biofilms, the effects of the photosensitizers ...201322847685
involvement of gshab in the interspecies competition within oral biofilm.although streptococcus sanguinis has been reported to produce h2o2 to gain a competitive edge over streptococcus mutans, the molecular mechanisms evolved by s. mutans to counter this "peer stress" are still to be identified. the current study was designed to investigate the ecological role of glutathione synthetase (gshab) in the interspecies interaction between s. mutans and s. sanguinis. a gshab in-frame deletion strain of s. mutans was constructed, and its phenotypic traits were characterized ...201323872989
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
divalent cations enhance fluoride binding to streptococcus mutans and streptococcus sanguinis cells and subsequently inhibit bacterial acid production.one preventive effect of topical fluoride application is derived from the fact that fluoride can inhibit bacterial acid production. furthermore, divalent cations such as ca(2+) and mg(2+) increase the binding of fluoride to bacterial cells. these findings suggest that exposure of oral bacteria to fluoride in the presence of divalent cations increases fluoride binding to bacterial cells and subsequently enhances fluoride-induced inhibition of bacterial acid production. this study investigated the ...201323207788
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
distribution of streptococcus troglodytae and streptococcus dentirousetti in chimpanzee oral cavities.the aim of this study was to analyze the distribution and phenotypic properties of the indigenous streptococci in chimpanzee (pan troglodytes) oral cavities. eleven chimpanzees (aged from 9 to 44 years, mean ± sd, 26.9 ± 12.6 years) in the primate research institute of kyoto university were enrolled in this research and brushing bacterial samples collected from them. streptococci were isolated from the oral cavities of all chimpanzees. the isolates (n = 46) were identified as thirteen species by ...201323668608
a tissue-dependent hypothesis of dental caries.current understanding of dental caries considers this disease a demineralization of the tooth tissues due to the acid produced by sugar-fermenting microorganisms. thus, caries is considered a diet- and ph-dependent process. we present here the first metagenomic analysis of the bacterial communities present at different stages of caries development, with the aim of determining whether the bacterial composition and biochemical profile are specific to the tissue affected. the data show that microbi ...201324080530
[protein structure prediction of the lactate dehydrogenase of streptococcus oligofermentans].to compare the gene sequence and protein structure of lactate dehydrogenase (ldh) in streptococcus oligofermentans with those of other bacteria with different acid generating capacities in oral cavity and to analyze the differences of their ldh.201324438565
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
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
novel bacteriophage lysin with broad lytic activity protects against mixed infection by streptococcus pyogenes and methicillin-resistant staphylococcus aureus.methicillin-resistant staphylococcus aureus (mrsa) and streptococcus pyogenes (group a streptococcus [gras]) cause serious and sometimes fatal human diseases. they are among the many gram-positive pathogens for which resistance to leading antibiotics has emerged. as a result, alternative therapies need to be developed to combat these pathogens. we have identified a novel bacteriophage lysin (plyss2), derived from a streptococcus suis phage, with broad lytic activity against mrsa, vancomycin-inte ...201323571534
streptococcus sanguinis isolate displaying a phenotype with cross-resistance to several rrna-targeting agents.this study describes a clinical case of a 71-year-old male with a history of ischemic cardiomyopathy after left ventricular assist device (lvad) endocarditis caused by methicillin-resistant staphylococcus epidermidis (mrse) and a rare linezolid-resistant streptococcus sanguinis strain (mic, 32 μg/ml). the patient received courses of several antimicrobial agents, including linezolid for 79 days. the s. sanguinis strain had mutations in the 23s rrna (t2211c, t2406c, g2576t, c2610t) and an amino ac ...201323698536
streptococcus danieliae sp. nov., a novel bacterium isolated from the caecum of a mouse.we report the characterization of one novel bacterium, strain erd01g(t), isolated from the cecum of a tnf(deltaare) mouse. the strain was found to belong to the genus streptococcus based on phylogenetic analysis of partial 16s rrna gene sequences. the bacterial species with standing name in nomenclature that was most closely related to our isolate was streptococcus alactolyticus (97 %). the two bacteria were characterized by a dna-dna hybridization similarity value of 35 %, demonstrating that th ...201323052149
cloning-independent plasmid construction for genetic studies in streptococci.shuttle plasmids are among the few routinely utilized tools in the streptococcus mutans genetic system that still require the use of classical cloning methodologies and intermediate hosts for genetic manipulation. accordingly, it typically requires considerably less time and effort to introduce mutations onto the s. mutans chromosome than it does to construct shuttle vectors for expressing genes in trans. occasionally, shuttle vector constructs also exhibit toxicity in escherichia coli, which pr ...201323673081
[comparison of in vitro antimicrobial activities of bioaggregate and mineral trioxide aggregate].treatment outcome of endodontic perforations depends on successful elimination of the associated microorganisms and infected tissues as well as the effective seal of the root-end or perforation site to prevent future contamination. ideally, perforation repair material has to be bacteriostatic or bactericidal in order to prevent bacterial contamination as well as good sealing properties and biocompatibility. the aim of this study was to evaluate the antimicrobial effects of bioaggregate (ba) and ...201323971930
development of a tunable wide-range gene induction system useful for the study of streptococcal toxin-antitoxin systems.despite the plethora of genetic tools that have been developed for use in streptococcus mutans, the s. mutans genetic system still lacks an effective gene induction system exhibiting low basal expression and strong inducibility. consequently, we created two hybrid gene induction cassettes referred to as xyl-s1 and xyl-s2. both xyl-s cassettes are xylose inducible and controlled by the bacillus megaterium xylose repressor. the xyl-s cassettes each demonstrated >600-fold-increased reporter activit ...201323934493
endodontic bacteria from primary and persistent endodontic lesions in chinese patients as identified by cloning and 16s ribosomal dna gene sequencing.few literatures pertain to the 16s ribosomal dna (16s rdna) analysis of bacteria contributing to primary and persistent endodontic lesions, with no information available for the chinese population. as such, we investigated endodontic bacteria associated with primary and persistent endodontic lesions in adult chinese patients living in beijing, china using 16s rdna gene sequencing techniques.201323422180
serum iga reactivity against groel of streptococcus sanguinis and human heterogeneous nuclear ribonucleoprotein a2/b1 in patients with behçet disease.infectious agents, especially streptococcus sanguinis and herpes simplex virus, have long been postulated as major triggering factors for behçet disease (bd).201323137016
streptococcus sanguinis and the sera of patients with behçet's disease stimulate membrane expression of α-enolase in human dermal microvascular endothelial cells.the glycolytic enzyme α-enolase is a plasminogen-binding protein that is generally found in the cytosolic compartment. however, α-enolase can also be expressed on cell surfaces following an inflammatory stimulus via an unknown mechanism. we investigated the effects of streptococcus sanguinis (s. sanguinis) and the sera of patients with behçet's disease (bd) on the expression and distribution of α-enolase in human dermal microvascular endothelial cells (hdmecs). hdmecs were stimulated with cultur ...201323131860
platelet activation by streptococcus sanguinis is accompanied by map kinase phosphorylation.there is increasing interest in the role of infections in atherothrombotic conditions. in particular, bacteria, notably those of oral origin, have been shown to activate platelets using a variety of mechanisms. previous studies have shown that s. sanguinis strain 2017-78 induces platelet aggregation which requires the presence of both vwf and igg. this aggregation is accompanied by the consecutive phosphorylation/desphosphorylation/rephosphorylation of several signalling proteins. the first two ...201322372533
computer-assisted flapless implant placement reduces the incidence of surgery-related bacteremia.bacteremia--the access of bacterium to the bloodstream--may yield life-threatening complications. the aim of this study was to compare the incidence, duration, and type of bacterium leading to bacteremia with relation to conventional and computer-assisted flapless implant surgery.201323224042
postcaesarean open-heart surgery for streptococcus sanguinis infective endocarditis.a 33-week pregnant (gravida 3), 29-year-old woman was transferred for management of streptococcus sanguinis infective endocarditis. a vegetation was present on the posterior leaflet of the mitral valve with moderate mitral regurgitation. on admission (day 1), the ultrasound examination revealed splenic abscesses and retarded intrauterine growth albeit with normal vessels. the fetal heart rate was 140 bpm. on day 11, the baby was delivered by caesarean, and then the mother underwent tubal ligatio ...201324234426
radial mycotic aneurysm complicated with infective endocarditis caused by streptococcus sanguinis.peripheral mycotic aneurysm is a rare complication of infective endocarditis. we herein report the case of a 61-year-old man with a mycotic aneurysm in the left brachial artery, that appeared during treatment with antibiotics against infective endocarditis caused by streptococcus sanguinis. after confirming the collateral blood flow on arteriography, we resected the aneurysm and performed valvuloplasty, annuloplasty and coronary artery bypass grafting. the patient has been in good condition with ...201324126401
effects of azithromycin on intracellular cytokine responses and mucocutaneous manifestations in behçet's disease.the aim of this study was to investigate the effects of azithromycin on mucocutaneous manifestations and ex vivo intracellular cytokine responses in patients with behçet's disease (bd).201323879671
s. sanguinis adhesion on rough titanium surfaces: effect of culture media.bacterial colonization plays a key role in dental implant failure, because they attach directly on implant surface upon implantation. between different types of bacteria associated with the oral environment, streptococcus sanguinis is essential in this process since it is an early colonizer. in this work the relationship between titanium surfaces modified by shot blasting treatment and s. sanguinis adhesion; have been studied in approached human mouth environment. bacteria pre-inoculated with ro ...201325427478
streptococcus sanguinis meningitis following endoscopic ligation for oesophageal variceal haemorrhage.we report a case of acute purulent meningitis caused by streptococcus sanguinis after endoscopic ligation for oesophageal variceal haemorrhage in a cirrhotic patient without preceding symptoms of meningitis. initial treatment with flomoxef failed. the patient was cured after 20 days of intravenous penicillin g. this uncommon infection due to s. sanguinis adds to the long list of infectious complications among patients with oesophageal variceal haemorrhage.201323429697
a not very nice case of endocarditis.a 69-year-old man, previously independent and with a pre-existing metallic aortic valve, presented with a history of fevers, confusion and malaise and was diagnosed with prosthetic valve endocarditis. blood cultures taken on presentation grew streptococcus sanguinis and vegetations were confirmed on transoesophageal echocardiogram. he had had a dental procedure 10 days before presentation but had not received prophylactic antibiotics; he had been receiving antibiotic prophylaxis for dental treat ...201323365162
microbiological evaluation of bacterial and mycotic seal in implant systems with different implant-abutment interfaces and closing torque values.the aim of this study was to evaluate the possible leakage of 3 species of bacteria (streptococcus sanguinis, fusobacterium nucleatum, and actinomyces odontolyticus) and of candida albicans and candida glabrata in osseointegrated implants with different implant-abutment interface (iai) geometry.201323782848
suppuration-associated bacteria in patients with chronic and aggressive periodontitis.suppuration (sup) on probing may be an indication of active periodontal breakdown. the aim of the present study is to analyze which subgingival species are associated with sup in patients with chronic (cp) and aggressive (agp) periodontitis.201323327648
evaluation of the nanosphere verigene gram-positive blood culture assay with the versatrek blood culture system and assessment of possible impact on selected patients.the verigene gram-positive blood culture (bc-gp) assay (nanosphere, northbrook, il) is a molecular method for the rapid identification of gram-positive organisms and resistance markers directly from blood culture bottles. a total of 148 versatrek redox 1 40-ml aerobic bottles demonstrating gram-positive bacteria were tested. results were compared with those from conventional biochemical and matrix-assisted laser desorption ionization-time of flight (maldi-tof) identifications. we obtained isolat ...201324048531
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
transcriptional responses of treponema denticola to other oral bacterial species.the classic organization by socransky and coworkers categorized the oral bacteria of the subgingival plaque into different complexes. treponema denticola, porphyromonas gingivalis and tannerella forsythia are grouped into the red complex that is highly correlated with periodontal disease. socransky's work closely associates red with orange complex species such as fusobacterium nucleatum and prevotella intermedia but not with members of the other complexes. while the relationship between species ...201424505483
systematic screening of plant extracts from the brazilian pantanal with antimicrobial activity against bacteria with cariogenic relevance.this study proposes a bioprospection methodology regarding the antimicrobial potential of plant extracts against bacteria with cariogenic relevance. sixty extracts were obtained from ten plants--(1) jatropha weddelliana, (2) attalea phalerata, (3) buchenavia tomentosa, (4) croton doctoris, (5) mouriri elliptica, (6) mascagnia benthamiana, (7) senna aculeata, (8) unonopsis guatterioides, (9) allagoptera leucocalyx and (10) bactris glaucescens--using different extraction methods - (a) 70° ethanol ...201424603299
antimicrobial activity of chemokine cxcl10 for dermal and oral microorganisms.cxcl10 (ip-10) is a small 10 kda chemokine with antimicrobial activity. it is induced by ifn-γ, chemoattracts mononuclear cells, and promotes adhesion of t cells. recently, we detected cxcl10 on the surface of the skin and in the oral cavity. in the current study, we used broth microdilution and radial diffusion assays to show that cxcl10 inhibits the growth of escherichia coli, staphylococcus aureus, corynebacterium jeikeium, corynebacterium striatum, and candida albicans hmv4c, but not coryneb ...201425859394
antibacterial efficacy of exogenous nitric oxide on periodontal pathogens.current treatments for periodontitis (e.g., scaling/root planing and chlorhexidine) have limited efficacy since they fail to suppress microbial biofilms satisfactorily over time, and the use of adjunctive antimicrobials can promote the emergence of antibiotic-resistant organisms. herein, we report the novel application of nitric oxide (no)-releasing scaffolds (i.e., dendrimers and silica particles) as anti-periodontopathogenic agents. the effectiveness of macromolecular no release was demonstrat ...201425139363
the bacterial adhesion on and the cytotoxicity of various dental cements used for implant-supported fixed restorations.bacterial adhesion on and cytotoxicity of eight luting agents used for implant-supported restorations were investigated.201424074394
identification and analysis of potential targets in streptococcus sanguinis using computer aided protein data analysis.streptococcus sanguinis is a gram-positive, facultative aerobic bacterium that is a member of the viridans streptococcus group. it is found in human mouths in dental plaque, which accounts for both dental cavities and bacterial endocarditis, and which entails a mortality rate of 25%. although a range of remedial mediators have been found to control this organism, the effectiveness of agents such as penicillin, amoxicillin, trimethoprim-sulfamethoxazole, and erythromycin, was observed. the emphas ...201425473301
two-component system vicrk regulates functions associated with establishment of streptococcus sanguinis in biofilms.streptococcus sanguinis is a commensal pioneer colonizer of teeth and an opportunistic pathogen of infectious endocarditis. the establishment of s. sanguinis in host sites likely requires dynamic fitting of the cell wall in response to local stimuli. in this study, we investigated the two-component system (tcs) vicrk in s. sanguinis (vicrkss), which regulates genes of cell wall biogenesis, biofilm formation, and virulence in opportunistic pathogens. a vick knockout mutant obtained from strain sk ...201425183732
flavonoids inhibit inos production via mitogen activated proteins in lipoteichoic acid stimulated cardiomyoblasts.infective endocarditis is caused by oral commensal bacteria which are important etiologic agents in this disease and can induce release of nitric oxide (no), promoting an inflammatory response in the endocardium. in this study, we investigated the properties of kaempherol, epigallocatechin, apigenin, and naringin in embryonic mouse heart cells (h9c2) treated with lipoteichoic acid (lta) obtained from streptococcus sanguinis. no production was measured with the griess method. expression of induci ...201424768712
streptococcus sanguinis-induced cytokine and matrix metalloproteinase-1 release from platelets.streptococcus sanguinis (s.sanguinis), a predominant bacterium in the human oral cavity, has been widely associated with the development of infective endocarditis. platelets play both a haemostatic function and can influence both innate and adaptive immune responses. previous studies have shown that s.sanguinis can interact with, and activate, platelets.201424755160
the relationship of the lipoprotein ssab, manganese and superoxide dismutase in streptococcus sanguinis virulence for endocarditis.streptococcus sanguinis colonizes teeth and is an important cause of infective endocarditis. our prior work showed that the lipoprotein ssab is critical for s. sanguinis virulence for endocarditis and belongs to the lrai family of conserved metal transporters. in this study, we demonstrated that an ssab mutant accumulates less manganese and iron than its parent. a mutant lacking the manganese-dependent superoxide dismutase, soda, was significantly less virulent than wild-type in a rabbit model o ...201424750294
giant nonfamilial left atrial myxoma presenting with eye embolism and nonvalvular streptococcus sanguinis endocarditis. 201424681126
myricetin blocks lipoteichoic acid-induced cox-2 expression in human gingival fibroblasts.periodontitis is an infectious disease caused by microorganisms present in dental bacterial plaque. lipoteichoic acid (lta) is a component of the external membrane of gram-positive bacteria. it causes septic shock. ingested flavonoids have been reported to directly affect the regulation of cyclooxygenase-2 (cox-2) expression induced by bacterial toxins. in this study, we examined the effects of four flavonoids (luteolin, fisetin, morin and myricetin) on the activation of erk1/2, p38 and akt, and ...201424569980
streptococcus sanguinis class ib ribonucleotide reductase: high activity with both iron and manganese cofactors and structural insights.streptococcus sanguinis is a causative agent of infective endocarditis. deletion of ssab, a manganese transporter, drastically reduces s. sanguinis virulence. many pathogenic organisms require class ib ribonucleotide reductase (rnr) to catalyze the conversion of nucleotides to deoxynucleotides under aerobic conditions, and recent studies demonstrate that this enzyme uses a dimanganese-tyrosyl radical (mn(iii)2-y(•)) cofactor in vivo. the proteins required for s. sanguinis ribonucleotide reductio ...201424381172
genetic characterization and role in virulence of the ribonucleotide reductases of streptococcus sanguinis.streptococcus sanguinis is a cause of infective endocarditis and has been shown to require a manganese transporter called ssab for virulence and o2 tolerance. like certain other pathogens, s. sanguinis possesses aerobic class ib (nrdef) and anaerobic class iii (nrddg) ribonucleotide reductases (rnrs) that perform the essential function of reducing ribonucleotides to deoxyribonucleotides. the accompanying paper (makhlynets, o., boal, a. k., rhodes, d. v., kitten, t., rosenzweig, a. c., and stubbe ...201424381171
characterization of a novel cold-active esterase isolated from swamp sediment metagenome.a functional screen of a metagenomic library from "upo" swamp sediment in korea identified a gene estl28, the product of which displayed lipolytic properties on a tributyrin-supplemented medium. the estl28 sequence encodes a 290 amino acid protein (designated as estl28), with a predicted molecular weight of 31.3 kda. the encoded estl28 protein exhibited the highest sequence similarity (45 %) to a hydrolase found in streptococcus sanguinis. phylogenetic analysis indicated that estl28 belongs to a ...201424353039
systematic study of genes influencing cellular chain length in streptococcus sanguinis.streptococcus sanguinis is a gram-positive bacterium that is indigenous to the oral cavity. s. sanguinis, a primary colonizer of the oral cavity, serves as a tether for the attachment of other oral pathogens. the colonization of microbes on the tooth surface forms dental plaque, which can lead to the onset of periodontal disease. we examined a comprehensive mutant library to identify genes related to cellular chain length and morphology using phase-contrast microscopy. a number of hypothetical g ...201424295823
a rare case of streptococcus sanguinis mycotic popliteal aneurysm.mycotic popliteal aneurysms are not a common phenomenon. they can initially be easily confused with other more trivial conditions such as a baker's cyst. we present a case of a patient presenting with a progressively worsening leg swelling which was initially misdiagnosed. only until symptoms rapidly progressed was a popliteal aneurysm diagnosed. to our knowledge this is the only identified case of a streptococcus sanguinis mycotic popliteal aneurysm.201428663804
antagonistic effect of protein extracts from streptococcus sanguinis on pathogenic bacteria and fungi of the oral cavity.an antibacterial substance from streptococcus sanguinis (s. sanguinis) is known to have an inhibitory effect on putative periodontal pathogens, but its inhibitory effect on pathogens of oral candidiasis is unknown. in this study, intracellular and exocrine proteins were extracted from s. sanguinis. the antagonistic effect of the protein extracts on prevotella intermedia (p. intermedia) and porphyromonas gingivalis (p. gingivalis) was detected by a well-plate technique, and the effects of the pro ...201424926331
salivary microbiota and metabolome associated with celiac disease.this study aimed to investigate the salivary microbiota and metabolome of 13 children with celiac disease (cd) under a gluten-free diet (treated celiac disease [t-cd]). the same number of healthy children (hc) was used as controls. the salivary microbiota was analyzed by an integrated approach using culture-dependent and -independent methods. metabolome analysis was carried out by gas chromatography-mass spectrometry-solid-phase microextraction. compared to hc, the number of some cultivable bact ...201424657864
microcalorimetric determination of the effects of amoxicillin, metronidazole, and their combination on in vitro biofilm.the mechanism of action of adjuvant antibiotic therapy in the treatment of peri-implantitis is not well understood. the aim of this study is to investigate antibiotic susceptibility of an in vitro biofilm by isothermal microcalorimetry (imc).201423594193
the effect of sodium hypochlorite on enterococcus faecalis when grown on dentine as a single- and multi-species biofilm.enterococcus faecalis is often involved in the aetiology of apical periodontitis after endodontic treatment. this project aimed to establish, on dentine in vitro, a multi-species biofilm containing e. faecalis, and to determine if the organism had an increased resistance to sodium hypochlorite compared with an axenic biofilm. biofilms were established on dentine discs in flow cells with either e. faecalis alone (axenic) or together with fusobacterium nucleatum and streptococcus sanguinis. follow ...201425195495
intensity and duration of in-vitro antibacterial activity of different adhesives used in orthodontics.this work investigated the antibacterial activity of 14 bonding agents to predict their ability to inhibit white-spot development during orthodontic treatment. standardized, sterilized disks of each material were continuously rinsed (for up to 180 d) in a flow of sterile saline. at predetermined time points, the residual ability of each material to inhibit bacterial growth (determined by measuring the size of inhibition halos around disks placed onto appropriate culture media seeded with strepto ...201424621259
propolis varnish: antimicrobial properties against cariogenic bacteria, cytotoxicity, and sustained-release profile.varnishes are preparations that differ in the polymeric matrix and therapeutical agents. in dentistry they are used to prevent caries. in this study we developed a propolis varnish, considering propolis properties against cariogenic bacteria. to a chitosan polymeric base (chv) was added ethanolic propolis extract in different concentrations: pv1 (5%), pv2 (10%), and pv3 (15%). antimicrobial activity was carried out against streptococcus mutans (sm), streptococcus sanguinis (sg), streptococcus sa ...201424949436
amplification of bacteria-induced platelet activation is triggered by fcγriia, integrin αiibβ3, and platelet factor 4.bacterial adhesion to platelets is mediated via a range of strain-specific bacterial surface proteins that bind to a variety of platelet receptors. it is unclear how these interactions lead to platelet activation. we demonstrate a critical role for the immune receptor fcγriia, αiibβ3, and src and syk tyrosine kinases in platelet activation by staphylococcus aureus, streptococcus sanguinis, streptococcus gordonii, streptococcus oralis, and streptococcus pneumoniae. fcγriia activation is dependent ...201424642751
effects of er:yag laser on bacteria associated with titanium surfaces and cellular response in vitro.this in vitro study examined (a) the anti-bacterial efficacy of a pulsed erbium-doped yttrium aluminum garnet (er:yag) laser applied to streptococcus sanguinis or porphyromonas gingivalis adhered to either polished or microstructured titanium implant surfaces, (b) the response of osteoblast-like cells and (c) adhesion of oral bacteria to titanium surfaces after laser irradiation. thereto, (a) bacteria adhered to titanium disks were irradiated with a pulsed er:yag laser (λ = 2,940 nm) at two diff ...201423508281
covalent immobilization of hlf1-11 peptide on a titanium surface reduces bacterial adhesion and biofilm formation.bacterial infection represents a major cause of implant failure in dentistry. a common approach to overcoming this issue and treating peri-implant infection consists in the use of antibiotics. however, the rise of multidrug-resistant bacteria poses serious concerns to this strategy. a promising alternative is the use of antimicrobial peptides due to their broad-spectrum activity against bacteria and reduced bacterial resistance responses. the aim of the present study was to determine the in vitr ...201424704699
cell wall-anchored nuclease of streptococcus sanguinis contributes to escape from neutrophil extracellular trap-mediated bacteriocidal activity.streptococcus sanguinis, a member of the commensal mitis group of streptococci, is a primary colonizer of the tooth surface, and has been implicated in infectious complications including bacteremia and infective endocarditis. during disease progression, s. sanguinis may utilize various cell surface molecules to evade the host immune system to survive in blood. in the present study, we discovered a novel cell surface nuclease with a cell-wall anchor domain, termed swan (streptococcal wall-anchore ...201425084357
in-office bleaching gel with 35% hydrogen peroxide enhanced biofilm formation of early colonizing streptococci on human enamel.to compare the effects of 25% and 35% hydrogen peroxide in-office bleaching systems on surface roughness and streptococcal biofilm formation on human enamel.201425132364
effects of simulated microgravity on streptococcus mutans physiology and biofilm structure.long-term spaceflights will eventually become an inevitable occurrence. previous studies have indicated that oral infectious diseases, including dental caries, were more prevalent in astronauts due to the effect of microgravity. however, the impact of the space environment, especially the microgravity environment, on the virulence factors of streptococcus mutans, a major caries-associated bacterium, is yet to be explored. in the present study, we investigated the impact of simulated microgravity ...201425109245
influence of time, toothpaste and saliva in the retention of streptococcus mutans and streptococcus sanguinis on different toothbrushes.the intraoral transmission of cariogenic and periodontopathogenic species seems to be facilitated by contaminated toothbrushes and other oral hygiene devices. the aim of this investigation was to analyze the in vitro retention and survival rate of streptococcus mutans and streptococcus sanguinis on different toothbrushes. the impacts of human saliva and antimicrobial toothpaste on these parameters were further evaluated.201425025554
the influence of a glucosyltransferase, encoded by gtfp, on biofilm formation by streptococcus sanguinis in a dual-species model.streptococcus sanguinis is an early colonizer of tooth surfaces and forms biofilms with other species of microorganisms. in vitro, s. sanguinis produces water-soluble glucans from sucrose and releases them into the culture supernatant; however, the role played by these glucans in biofilm formation is unclear. the present study examined both the effect of glucans on biofilm formation by s. sanguinis and the proportion of this bacterial species within the biofilms. inactivation of the gtfp gene, a ...201424628454
adherence of streptococcus sanguinis and streptococcus mutans to saliva-coated s-prg resin blocks.this in vitro study performed elemental analysis of the ions absorbed into the salivary coat covering the surfaces of s-prg resin blocks and assessed the adherence of streptococcus sanguinis and streptococcus mutans to these saliva-coated s-prg resin blocks. elemental analysis of ions absorbed into the salivary coat of resin blocks exposed to the saliva was performed using an inductive coupled plasma atomic emission spectrometer and the fluoride electrode method. quantitative adherence of radio- ...201424615002
microbiologically influenced corrosion of orthodontic metallic appliances.biocorrosion (microbiologically influenced corrosion; mic) occur in aquatic habitats varying in nutrient content, temperature, stress and ph. the oral environment of organisms, including humans, should be one of the most hospitable for mic. corrosion of metallic appliances in the oral region is one cause of metal allergy in patients. in this study, an inductively coupled plasma-optical emission spectrometer revealed elution of fe, cr and ni from stainless steel (sus) appliances incubated with or ...201424583645
effect of nicotine on dual-species biofilms of streptococcus mutans and streptococcus sanguinis.both streptococcus mutans and streptococcus sanguinis are normal bacterial inhabitants of dental plaque. streptococcus mutans is the major agent causing dental caries. it has been well documented that nicotine affects the growth of s. mutans. this study investigated the effect of nicotine on mono- and dual-species growth of s. mutans and s. sanguinis. the results indicate that nicotine has no significant effect on s. sanguinis grown in either mono- or dual-species biofilms. however, nicotine sig ...201424164376
oral streptococci utilize a siglec-like domain of serine-rich repeat adhesins to preferentially target platelet sialoglycans in human blood.damaged cardiac valves attract blood-borne bacteria, and infective endocarditis is often caused by viridans group streptococci. while such bacteria use multiple adhesins to maintain their normal oral commensal state, recognition of platelet sialoglycans provides an intermediary for binding to damaged valvular endocardium. we use a customized sialoglycan microarray to explore the varied binding properties of phylogenetically related serine-rich repeat adhesins, the gspb, hsa, and srpa homologs fr ...201425474103
comparison of genes required for h2o2 resistance in streptococcus gordonii and streptococcus sanguinis.hydrogen peroxide (h2o2) is produced by several members of the genus streptococcus mainly through the pyruvate oxidase spxb under aerobic growth conditions. the acute toxic nature of h2o2 raises the interesting question of how streptococci cope with intrinsically produced h2o2, which subsequently accumulates in the microenvironment and threatens the closely surrounding population. here, we investigate the h2o2 susceptibility of oral streptococcus gordonii and streptococcus sanguinis and elucidat ...201425280752
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
the influence of oral veillonella species on biofilms formed by streptococcus species.oral veillonella, veillonella atypica, veillonella denticariosi, veillonella dispar, veillonella parvula, veillonella rogosae, and veillonella tobetsuensis are known as early colonizers in oral biofilm formation. to investigate the role of oral veillonella, biofilms formed by the co-culture of streptococcus gordonii, streptococcus mutans, streptococcus salivarius, or streptococcus sanguinis, with oral veillonella were examined at the species level. the amount of biofilm formed by s. mutans, s. g ...201424862495
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
aggravation of inflammatory bowel diseases by oral streptococci.streptococcus mutans can aggravate colitis in mice. we evaluated the virulence of colitis using type strains as well as blood isolates of several oral streptococcal species.201423679203
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
effect of punica granatum l. flower water extract on five common oral bacteria and bacterial biofilm formation on orthodontic wire.use of herbal extracts and essences as natural antibacterial compounds has become increasingly popular for the control of oral infectious diseases. therefore, finding natural antimicrobial products with the lowest side effects seems necessary. the present study sought to assess the effect of punica granatum l. water extract on five oral bacteria and bacterial biofilm formation on orthodontic wire.201426171362
penetration of streptococcus sobrinus and streptococcus sanguinis into dental enamel.the aim of this pilot study was to assess the difference in virulence of acidogenic and aciduric oral streptococci in an in vitro caries model using their penetration depths into dental enamel. 30 caries-free extracted molars from 11- to 16-year-olds were cleaned ultrasonically for 1 min with de-ionized water and, after air-drying, embedded in epoxy resin. after 8-h of setting at room temperature, the specimens were ground on the buccal side with sic-paper 1200 (particle size 13-16 μm). enamel w ...201525805186
the bacterial sealing capacity of morse taper implant-abutment systems in vitro.the use of morse taper systems in dental implantology has been associated widely with a more precise adaptation between implants and their respective abutments. this may lead to an increase in the stability of the implant system and may also prevent microbial invasion through the implant-abutment interface. the aim of this study was to investigate in vitro the ability of four commercially available morse taper system units to impede bacterial penetration through their implant-abutment interfaces ...201525658884
identifying essential streptococcus sanguinis genes using genome-wide deletion mutation.essential genes in pathogens are important for the development of antibacterial drugs. in this report, we described a protocol to identify essential genes in the streptococcus sanguinis sk36 strain using genome-wide deletion mutation. a fusion pcr-based method is used to construct gene deletion fragments, which contain kanamycin resistance cassettes with two flanking arms of dna upstream and downstream of the target gene. the linear fused pcr amplicons were transformed into s. sanguinis sk36 cel ...201525636610
characterization of the arginolytic microflora provides insights into ph homeostasis in human oral biofilms.a selected group of oral bacteria commonly associated with dental health is capable of producing alkali via the arginine deiminase system (ads), which has a profound impact on the ph of human oral biofilms. an increased risk for dental caries has been associated with reduced ads activity of the bacteria in oral biofilms. arginolytic bacterial strains from dental plaque samples of caries-free and caries-active adults were isolated and characterized to investigate the basis for differences in plaq ...201525634570
levels and complexity of iga antibody against oral bacteria in samples of human colostrum.streptococcus mutans (sm) have three main virulence antigens: glucan binding protein b (gbpb), glucosyltransferase (gtf) and antigens i/ii (ag i/ii) envolved in the capacity of those bacteria to adhere and accumulate in the dental biofilm. also, the glycosyltransferases 153 kda of streptococcus gordonii (sgo) and 170kda of streptococcus sanguinis (ssa) were important antigens associated with the accumulation of those bacterias. streptococcus mitis (smi) present iga1 protease of 202 kda. we inves ...201525175558
association of oral streptococci community dynamics with severe early childhood caries as assessed by pcr-denaturing gradient gel electrophoresis targeting the rnpb gene.this study sought to investigate the possible association between the dynamics of oral streptococci community profiles and severe early childhood caries (s-ecc) development, compared with caries-free (cf) controls. supragingival plaque samples were evaluated from 8-32-month-old children who had previously been assessed for overall profiles of their oral microbial community. twelve children were in each group. bacterial genomic dna was extracted and amplified using rnpb-specific primers for strep ...201526002941
effect of antibacterial dental adhesive on multispecies biofilms formation.antibacterial adhesives have favorable prospects to inhibit biofilms and secondary caries. the objectives of this study were to investigate the antibacterial effect of dental adhesives containing dimethylaminododecyl methacrylate (dmaddm) on different bacteria in controlled multispecies biofilms and its regulating effect on development of biofilm for the first time. antibacterial material was synthesized, and streptococcus mutans, streptococcus gordonii, and streptococcus sanguinis were chosen t ...201525715378
comparison of species identification of endocarditis associated viridans streptococci using rnpb genotyping and 2 maldi-tof systems.streptococcus spp. are important causes of infective endocarditis but challenging in species identification. this study compared identification based on sequence determination of the rnpb gene with 2 systems of matrix-assisted laser desorption ionization-time of flight mass spectrometry, maldi biotyper (bruker) and vitek ms ivd (biomérieux). blood culture isolates of viridans streptococci from 63 patients with infective endocarditis were tested. the 3 methods showed full agreement for all 36 iso ...201525616316
effect of enamel morphology on nanoscale adhesion forces of streptococcal bacteria : an afm study.we explore the influence of enamel surface morphology on nanoscale bacterial adhesion forces. three dimensional morphology characteristics of enamel slices, which were treated with phosphoric acid (for 0 s, 5 s, 10 s, 20 s, and 30 s), were acquired. adhesion forces of three initial colonizers (streptococcus oralis, streptococcus sanguinis, and streptococcus mitis) and two cariogenic bacterial strains (streptococcus mutans and streptococcus sobrinus) with etched enamel surfaces were determined. c ...201526482011
neuraminidase-producing oral mitis group streptococci potentially contribute to influenza viral infection and reduction in antiviral efficacy of zanamivir.influenza is a serious respiratory disease among immunocompromised individuals, such as the elderly, and its prevention is an urgent social issue. influenza viruses rely on neuraminidase (na) activity to release progeny viruses from infected cells and spreading the infection. na is, therefore, an important target of anti-influenza drugs. a causal relationship between bacteria and influenza virus infection has not yet been established, however, a positive correlation between them has been reporte ...201525001578
adherence of oral streptococci to nanostructured titanium surfaces.peri-implantitis and peri-mucositis pose a severe threat to the success of dental implants. current research focuses on the development of surfaces that inhibit biofilm formation while not inferring with tissue integration. this study compared the adherence of two oral bacterial species, streptococcus sanguinis and streptococcus mutans to nanostructured titanium surfaces.201526467718
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