| streptococcus gordonii utilizes several distinct gene functions to recruit porphyromonas gingivalis into a mixed community. | dental plaque biofilm formation proceeds through a developmental pathway initiated by the attachment of pioneer organisms, such as streptococcus gordonii, to tooth surfaces. through a variety of synergistic interactions, pioneer organisms facilitate the colonization of later arrivals including porphyromonas gingivalis, a potential periodontal pathogen. we have investigated genes of s. gordonii required to support a heterotypic biofilm community with p. gingivalis. by screening a plasmid integrat ... | 2006 | 16556225 |
| characterization and structure of the manganese-responsive transcriptional regulator scar. | the streptococcal coaggregation regulator (scar) of streptococcus gordonii is a manganese-dependent transcriptional regulator. when intracellular manganese concentrations become elevated, scar represses transcription of the scacba operon, which encodes a manganese uptake transporter. a member of the dtxr/mntr family of metalloregulators, scar shares sequence similarity with other family members, and many metal-binding residues are conserved. here, we show that scar is an active dimer, with two d ... | 2009 | 19795834 |
| microbial interactions influence inflammatory host cell responses. | the inflammatory response plays an important role in the tissue destruction associated with periodontitis. bacterial species can regulate the inflammatory responses of host cells, triggered by pathogens. it was hypothesized that, in the field of oral microbiology/immunology, such effects of bacterial interactions on inflammatory host cell responses might also be present. in this study, the effects of beneficial, commensal, and pathogenic species on aggregatibacter actinomycetemcomitans-induced i ... | 2009 | 19828891 |
| influence of mouse prolactin-inducible protein in saliva on the aggregation of oral bacteria. | mouse prolactin-inducible protein (mpip) is secreted in mouse saliva and has been found to bind oral bacteria, showing the highest affinity for streptococci. comparisons between the oral flora of mpip knockout mice and their wild-type controls showed differences in the genera colonizing the two groups of mice. these findings suggested a role for mpip in the colonization of the mouse oral cavity, possibly modulating the oral flora. in this in vitro study, we focused on the contribution of this pr ... | 2009 | 19832805 |
| a single mutation in enzyme i of the sugar phosphotransferase system confers penicillin tolerance to streptococcus gordonii. | tolerance is a poorly understood phenomenon that allows bacteria exposed to a bactericidal antibiotic to stop their growth and withstand drug-induced killing. this survival ability has been implicated in antibiotic treatment failures. here, we describe a single nucleotide mutation (tol1) in a tolerant streptococcus gordonii strain (tol1) that is sufficient to provide tolerance in vitro and in vivo. it induces a proline-to-arginine substitution (p483r) in the homodimerization interface of enzyme ... | 2010 | 19858257 |
| human platelets recognize a novel surface protein, pada, on streptococcus gordonii through a unique interaction involving fibrinogen receptor gpiibiiia. | the concept of an infectious agent playing a role in cardiovascular disease is slowly gaining attention. among several pathogens identified, the oral bacterium streptococcus gordonii has been implicated as a plausible agent. platelet adhesion and subsequent aggregation are critical events in the pathogenesis and dissemination of the infective process. here we describe the identification and characterization of a novel cell wall-anchored surface protein, pada (397 kda), of s. gordonii dl1 that bi ... | 2010 | 19884334 |
| intranasal immunization with vaccine vector streptococcus gordonii elicits primed cd4+ and cd8+ t cells in the genital and intestinal tracts. | generation of primed t cells is crucial for the development of optimal vaccination strategies. using a tcr-transgenic cd4(+) and cd8(+) t cell adoptive transfer model, we demonstrate that a single nasal immunization with recombinant streptococcus gordonii induces antigen-specific primed t cells in lymph nodes draining the genital and intestinal tracts with about 80% of cd4(+) and 50% of cd8(+) proliferating cells. t cell clonal expansion was also observed in cervical lymph nodes, draining the im ... | 2010 | 19945415 |
| the effects of antimicrobials on endodontic biofilm bacteria. | in the present study, confocal microscopy, a miniflow cell system, and image analysis were combined to test in situ the effect of antimicrobials and alkali on biofilms of enterococcus faecalis, lactobacillus paracasei, streptococcus anginosus, and streptococcus gordonii isolated from root canals with persistent infections. | 2010 | 20003938 |
| shear-enhanced oral microbial adhesion. | shear-enhanced adhesion, although not observed for fimbria-mediated adhesion of oral actinomyces spp., was noted for hsa-mediated adhesion of streptococcus gordonii to sialic acid-containing receptors, an interaction implicated in the pathogenesis of infective endocarditis. | 2010 | 20023085 |
| epithelial cell pro-inflammatory cytokine response differs across dental plaque bacterial species. | the dental plaque is comprised of numerous bacterial species, which may or may not be pathogenic. human gingival epithelial cells (hgecs) respond to perturbation by various bacteria of the dental plaque by production of different levels of inflammatory cytokines, which is a putative reflection of their virulence. the aim of the current study was to determine responses in terms of interleukin (il)-1beta, il-6, il-8 and il-10 secretion induced by porphyromonas gingivalis, aggregatibacter actinomyc ... | 2010 | 20096064 |
| two intramolecular isopeptide bonds are identified in the crystal structure of the streptococcus gordonii sspb c-terminal domain. | streptococcus gordonii is a primary colonizer and is involved in the formation of dental plaque. this bacterium expresses several surface proteins. one of them is the adhesin sspb, which is a member of the antigen i/ii family of proteins. sspb is a large multi-domain protein that has interactions with surface molecules on other bacteria and on host cells, and is thus a key factor in the formation of biofilms. here, we report the crystal structure of a truncated form of the sspb c-terminal domain ... | 2010 | 20138058 |
| in vivo activation of naive cd4+ t cells in nasal mucosa-associated lymphoid tissue following intranasal immunization with recombinant streptococcus gordonii. | the antigen-specific primary activation of cd4+ t cells was studied in vivo by adoptive transfer of ovalbumin-specific transgenic t cells (kj1-26+ cd4+) following intranasal immunization with recombinant streptococcus gordonii. a strain of s. gordonii expressing on its surface a model vaccine antigen fused to the ovalbumin (ova) peptide from position 323 to 339 was constructed and used to study the ova-specific t-cell activation in nasal mucosa-associated lymphoid tissue (nalt), lymph nodes, and ... | 2006 | 16622213 |
| interplay of protease-activated receptors and nod pattern recognition receptors in epithelial innate immune responses to bacteria. | protease-activated receptors (pars), nucleotide-binding oligomerization domain (nod) receptors and toll-like receptors (tlrs) play a role in innate immunity, but little is known about interaction between these receptors. the goal of this study was to investigate how silencing one receptor affects the expression of other receptors and downstream innate immune markers in response to bacteria. human gingival epithelial cells (gecs) were transfected with sirna specific for par1 or par2, then stimula ... | 2010 | 20219537 |
| [dissertations 25 years after date 21. enhancing resistance to bacteria with chlorhexidine varnish and probiotics]. | the aim of the research described in 'chemotherapy against streptococcus mutans' was to increase colonization resistance against mutans streptococci by inoculating actinomyces naeslundii on the dentition. actinomyces naeslundii established better after chlorhexidine application than after dental cleansing only but did not exceed the 1% level of the total actinomyces population. this was insufficient to increase the colonization resistance against mutans streptococci. a 33% chlorhexidine varnish ... | 2010 | 20225702 |
| a genetic determinant in streptococcus gordonii challis encodes a peptide with activity similar to that of enterococcal sex pheromone cam373, which facilitates intergeneric dna transfer. | enterococcus faecalis strains secrete multiple peptides representing different sex pheromones that induce mating responses by bacteria carrying specific conjugative plasmids. the pheromone cam373, which induces a response by the enterococcal plasmid pam373, has been of interest because a similar activity is also secreted by streptococcus gordonii and staphylococcus aureus. the potential to facilitate intergeneric dna transfer from e. faecalis is of concern because of extensive multiple antibioti ... | 2010 | 20233933 |
| profiling of subgingival plaque biofilm microflora from periodontally healthy subjects and from subjects with periodontitis using quantitative real-time pcr. | qualitative and quantitative changes of the subgingival plaque biofilm microflora in periodontal pockets are thought to be associated with the development and progression of periodontitis. the aims of the present study were to quantify the proportions of nine periodontitis-associated bacterial species and four streptococcus species in subgingival plaque, and to evaluate their relationship with periodontitis quantitatively. | 2010 | 20337892 |
| development of snap-tag-mediated live cell labeling as an alternative to gfp in porphyromonas gingivalis. | porphyromonas gingivalis is an anaerobic periodontal pathogen that resides in the complex multispecies microbial biofilm known as dental plaque. effective reporter tools are increasingly needed to facilitate physiological and pathogenetic studies of dental biofilm. fluorescent proteins are ideal reporters for conveniently monitoring biofilm growth, but are restricted by several environmental factors, such as a requirement of oxygen to emit fluorescence. we developed a fluorescent reporter plasmi ... | 2010 | 20482622 |
| expression of a pertussis toxin s1 fragment by inducible promoters in oral streptococcus and the induction of immune responses during oral colonization in mice. | previous work aimed at developing a live oral vaccine expressing pertussis toxin s1 fragment on the surface of the bacterium streptococcus gordonii elicited a lower than expected antibody response, perhaps because of low antigen expression. in this study, in-frame promoter fusions were constructed to investigate whether an increase in antigen production by the streptococcal vaccine strain results in a better antibody response. the promoters tested were (i) the streptococcus mutans sucrose-induci ... | 2006 | 16699568 |
| molecular basis of l-rhamnose branch formation in streptococcal coaggregation receptor polysaccharides. | the presence of l-rhamnose (rha) branches in the coaggregation receptor polysaccharides (rps) of streptococcus gordonii 38 and streptococcus oralis j22 was eliminated by replacement of wefb with ermam in these strains. the expression of this gene in s. oralis 34 did not, however, result in the addition of rha branches to the linear rps of this strain, which is identical to that produced by the wefb-deficient mutant of s. gordonii 38. this paradoxical finding was explained by a subtle difference ... | 2006 | 16707704 |
| mechanical non-surgical treatment of peri-implantitis: a single-blinded randomized longitudinal clinical study. ii. microbiological results. | peri-implantitis is common in patients with dental implants. we performed a single-blinded longitudinal randomized study to assess the effects of mechanical debridement on the peri-implant microbiota in peri-implantitis lesions. | 2010 | 20507380 |
| antimicrobial activity of n-6, n-7 and n-9 fatty acids and their esters for oral microorganisms. | this study is to assess the antibacterial activity of omega-6, -7, -9 (n-6, n-7, n-9) fatty acids against various oral microorganisms. | 2010 | 20541177 |
| mechanisms of oral bacteria-induced platelet activation. | the oral cavity is inhabited by over 500 different bacterial species that normally exist in ecological balance both with each other and with the host. when this equilibrium is disturbed, an overgrowth of individual organisms can occur, which, in turn, can lead to the onset of pathological processes, notably dental caries and periodontitis. generally, bacteraemias occur more frequently in individuals with periodontal disease, and these bacteraemias have been implicated in the development of a ran ... | 2010 | 20555421 |
| transport of preproteins by the accessory sec system requires a specific domain adjacent to the signal peptide. | the accessory sec (seca2/y2) systems of streptococci and staphylococci are dedicated to the transport of large serine-rich repeat (srr) glycoproteins to the bacterial cell surface. the means by which the glycosylated preproteins are selectively recognized by the accessory sec system have not been fully characterized. in streptococcus gordonii, the srr glycoprotein gspb has a 90-residue amino-terminal signal sequence that is essential for transport by seca2/y2 but is not sufficient to mediate the ... | 2010 | 20562303 |
| role of arginine deiminase of streptococcus cristatus in porphyromonas gingivalis colonization. | the ability to attach to a variety of oral surfaces is an important characteristic of porphyromonas gingivalis. previous studies have demonstrated that expression and production of fima, a major subunit protein of the long fimbriae, is required for p. gingivalis colonization. here we report that a surface protein, arginine deiminase (arca) of streptococcus cristatus, represses fima production and inhibits biofilm formation of p. gingivalis. this inhibitory function of arca is also observed in th ... | 2010 | 20660674 |
| inhibition of streptococcus mutans adherence and biofilm formation using analogues of the sspb peptide. | streptococcus gordonii is a pioneer colonizer of the enamel salivary pellicle that forms biofilm on the tooth surfaces. recent reports show the surface protein analogue peptide {400 (t) of sspb 390-402 is substituted to k forming sspb (390-t400k-402)} from s. gordonii interacts strongly with salivary receptors to cariogenic bacteria, streptococcus mutans. to characterize the analogue peptide biological activities, we investigated its binding and inhibiting effects, and the role of its amino acid ... | 2010 | 20673869 |
| heterologous expression of candida albicans cell wall-associated adhesins in saccharomyces cerevisiae reveals differential specificities in adherence and biofilm formation and in binding oral streptococcus gordonii. | colonization and infection of the human host by opportunistic pathogen candida albicans derive from an ability of this fungus to colonize mucosal tissues and prosthetic devices within the polymicrobial communities present. to determine the functions of c. albicans cell wall proteins in interactions with host or bacterial molecules, saccharomyces cerevisiae was utilized as a surrogate host to express c. albicans cell wall proteins als3p, eap1p, hwp1p, and rbt1p. salivary pellicle and fibrinogen w ... | 2010 | 20709785 |
| the pneumococcal serine-rich repeat protein is an intra-species bacterial adhesin that promotes bacterial aggregation in vivo and in biofilms. | the pneumococcal serine-rich repeat protein (psrp) is a pathogenicity island encoded adhesin that has been positively correlated with the ability of streptococcus pneumoniae to cause invasive disease. previous studies have shown that psrp mediates bacterial attachment to keratin 10 (k10) on the surface of lung cells through amino acids 273-341 located in the basic region (br) domain. in this study we determined that the br domain of psrp also mediates an intra-species interaction that promotes t ... | 2010 | 20714350 |
| natural transformation of oral streptococci. | natural transformation is found in most groups of oral streptococci, including the mitis, the anginosus, and the mutans groups. this ability has been applied as a powerful tool to explore streptococcal gene functions and regulatory pathways, particularly in streptococcus mutans and streptococcus gordonii. the range of strains and species amenable to transformation has expanded in recent years with the identification of several competence-stimulating peptide signals (csps). in this chapter we pre ... | 2010 | 20717785 |
| [infection of a tophaceous nodule of the middle finger]. | gouty involvement of the hand is uncommon and the complications the most described are bony destruction, digital joint instability, tenosynovitis and double ipsilateral tunnel syndrome of the median and ulnar nerves at the wrist. septic complications, such as infection of a tophaceous nodule, are a rare entity. the authors report a case of an infection of a tophaceous nodule of the middle finger in a 67-year-old man. the diagnosis was suspected on physical examination and radiological findings b ... | 2011 | 20724196 |
| selective substitution of amino acids limits proteolytic cleavage and improves the bioactivity of an anti-biofilm peptide that targets the periodontal pathogen, porphyromonas gingivalis. | the interaction of the periodontal pathogen, porphyromonas gingivalis, with oral streptococci such as streptococcus gordonii precedes colonization of the subgingival pocket and represents a target for limiting p. gingivalis colonization of the oral cavity. previous studies showed that a synthetic peptide (designated bar) derived from the antigen i/ii protein of s. gordonii was a potent competitive inhibitor of p. gingivalis adherence to s. gordonii and subsequent biofilm formation. here we show ... | 2010 | 20800634 |
| interaction of candida albicans cell wall als3 protein with streptococcus gordonii sspb adhesin promotes development of mixed-species communities. | candida albicans colonizes human mucosa and prosthetic surfaces associated with artificial joints, catheters, and dentures. in the oral cavity, c. albicans coexists with numerous bacterial species, and evidence suggests that bacteria may modulate fungal growth and biofilm formation. streptococcus gordonii is found on most oral cavity surfaces and interacts with c. albicans to promote hyphal and biofilm formation. in this study, we investigated the role of the hyphal-wall protein als3p in interac ... | 2010 | 20805332 |
| asp3 mediates multiple protein-protein interactions within the accessory sec system of streptococcus gordonii. | bacterial binding to human platelets is an important step in the pathogenesis of infective endocarditis. streptococcus gordonii can mediate its platelet attachment through a cell wall glycoprotein termed gspb ('gordonii surface protein b'). gspb export is mediated by a seven-component accessory sec system, containing two homologues of the general secretory pathway (seca2 and secy2) and five accessory sec proteins (asps1-5). here we show that the asps are required for optimal export of gspb indep ... | 2010 | 20807195 |
| bacterial 16s sequence analysis of severe caries in young permanent teeth. | previous studies have confirmed the association of the acid producers streptococcus mutans and lactobacillus spp. with childhood caries, but they also suggested these microorganisms are not sufficient to explain all cases of caries. in addition, health-associated bacterial community profiles are not well understood, including the importance of base production and acid catabolism in ph homeostasis. the bacterial community composition in health and in severe caries of the young permanent dentition ... | 2010 | 20826648 |
| a novel plasmid for delivering genes into mammalian cells with noninvasive food and commensal lactic acid bacteria. | using food and commensal lactic acid bacteria (lab) as vehicles for dna delivery into epithelial cells is a new strategy for vaccine delivery or gene therapy. however, present methods for dna delivery with lab have suffered low efficiency. our goal was to develop a new system to deliver dna into epithelial cells with high efficiency using food and commensal lab. an escherichia coli-lab shuttle plasmid, plkv1, for dna delivery into eukaryotic cells was constructed. two reporter plasmids with gree ... | 2011 | 20832422 |
| effects of electrodeposited poly(ethylene glycol) on biofilm adherence to titanium. | protein-resistant coatings have been studied for inhibiting biofilm formation on implant devices. in this study, titanium (ti) surfaces were biofunctionalized with poly(ethylene glycol) (peg) by electrodeposition and were evaluated as biofilm substrates under an oral simulated environment. streptococcus gordonii, an early colonizer of oral biofilms, was inoculated on ti and peg-electrodeposited ti (peg-ti) surfaces and was analyzed quantitatively and topographically. streptococcus mutans supplem ... | 2010 | 20878986 |
| cdkn2bas is associated with periodontitis in different european populations and is activated by bacterial infection. | epidemiological studies have indicated a relationship between coronary heart disease (chd) and periodontitis. recently, cdkn2bas was reported as a shared genetic risk factor of chd and aggressive periodontitis (agp), but the causative variant has remained unknown. to identify and validate risk variants in different european populations, we first explored 150 kb of the genetic region of cdkn2bas including the adjacent genes cdkn2a and cdkn2b, covering 51 tagging single nucleotide polymorph ... | 2010 | 20978019 |
| deletion of competence-induced genes over-expressed in biofilms caused transformation deficiencies in streptococcus mutans. | previous studies identified nine genes with increased expression in streptococcus mutans biofilms of which six possessed putative comx promoter sequences and were homologous to competence-induced genes in streptococcus pneumoniae, streptococcus gordonii and bacillus subtilis. as competence increases in biofilms, a study was undertaken into the roles that these biofilm-induced genes might play in transformation. only five of the nine gene deletions had a significant effect on transformation effic ... | 2010 | 21040514 |
| structural dissection and in vivo effectiveness of a peptide inhibitor of porphyromonas gingivalis adherence to streptococcus gordonii. | the interaction of the minor fimbrial antigen (mfa) with streptococcal antigen i/ii (e.g., sspb) facilitates colonization of the dental biofilm by porphyromonas gingivalis. we previously showed that a 27-mer peptide derived from sspb (designated bar) resembles the nuclear receptor (nr) box protein-protein interacting domain and potently inhibits this interaction in vitro. here, we show that the exxp motif upstream of the nr core α-helix contributes to the mfa-sspb interaction and that bar reduce ... | 2010 | 21041492 |
| purification, crystallization and preliminary x-ray diffraction analysis of the carbohydrate-binding region of the streptococcus gordonii adhesin gspb. | the carbohydrate-binding region of the bacterial adhesin gspb from streptococcus gordonii strain m99 (gspb(br)) was expressed in escherichia coli and purified using affinity and size-exclusion chromatography. separate sparse-matrix screening of gspb(br) buffered in either 20 mm tris ph 7.4 or 20 mm hepes ph 7.5 resulted in different crystallographic behavior such that different precipitants, salts and additives supported crystallization of gspb(br) in each buffer. while both sets of conditions s ... | 2010 | 21045307 |
| detection of live and antibiotic-killed bacteria by quantitative real-time pcr of specific fragments of rrna. | assessing bacterial viability by molecular markers might help accelerate the measurement of antibiotic-induced killing. this study investigated whether rrna could be suitable for this purpose. cultures of penicillin-susceptible and penicillin-tolerant (tol1 mutant) streptococcus gordonii were exposed to mechanistically different penicillin and levofloxacin. bacterial survival was assessed by viable counts and compared to quantitative real-time pcr amplification of either the 16s rrna genes or th ... | 2006 | 16723545 |
| mechanism of outside-in {alpha}iib{beta}3-mediated activation of human platelets by the colonizing bacterium, streptococcus gordonii. | to better understand the mechanism of platelet recruitment and activation by streptococcus gordonii. the oral bacterium streptococcus gordonii, is amongst the most common pathogens isolated from infective endocarditis patients, and has the property of being able to activate platelets, leading to thrombotic complications. the mechanism of platelet recruitment and activation by s. gordonii is poorly understood. | 2010 | 21071690 |
| proteases of an early colonizer can hinder streptococcus mutans colonization in vitro. | streptococcus mutans is the primary cariogen that produces several virulence factors that are modulated by a competence-stimulating peptide (csp) signaling system. in this study, we sought to determine if proteases produced by early dental plaque colonizers such as streptococcus gordonii interfere with the subsequent colonization of s. mutans bm71 on the existing streptococcal biofilms. we demonstrated that s. mutans bm71 colonized much less efficiently in vitro on streptococcal biofilms than on ... | 2010 | 21088146 |
| adherence and internalization of streptococcus gordonii by epithelial cells involves beta1 integrin recognition by sspa and sspb (antigen i/ii family) polypeptides. | streptococcus gordonii is a commensal bacterium that colonizes the hard and soft tissues present in the human mouth and nasopharynx. the cell wall-anchored polypeptides sspa and sspb expressed by s. gordonii mediate a wide range of interactions with host proteins and other bacteria. in this article we have determined the role of sspa and sspb proteins, which are members of the streptococcal antigen i/ii (agi/ii) adhesin family, in s. gordonii adherence and internalization by epithelial cells. wi ... | 2007 | 16879454 |
| community signalling between streptococcus gordonii and porphyromonas gingivalis is controlled by the transcriptional regulator cdhr. | interspecies signalling between porphyromonas gingivalis and streptococcus gordonii serves to constrain development of dual species communities. contact with s. gordonii propagates a tyrosine phosphorylation-dependent signal within p. gingivalis that culminates in reduced transcription of adhesin and signalling genes. here we demonstrate the involvement of the p. gingivalis orphan luxr family transcription factor pgn_1373, which we designate cdhr, in this control pathway. expression of cdhr is e ... | 2010 | 21143321 |
| microbiological profiles in saliva and supragingival plaque from caries-active adolescents before and after a short-term daily intake of milk supplemented with probiotic bacteria - a pilot study. | the aim of the present pilot study was to investigate the microbial profile in saliva and supragingival plaque samples collected from caries-active adolescents before and after a daily short-term intake of milk supplemented with the probiotic bacteria. | 2010 | 21180676 |
| molecular characterization and phylogenetic analysis of quinolone resistance-determining regions (qrdrs) of gyra, gyrb, parc and pare gene loci in viridans group streptococci isolated from adult patients with cystic fibrosis. | ciprofloxacin is the most frequently used member of the fluoroquinolones during initial eradication therapy of pseudomonas aeruginosa, as well as during acute pulmonary exacerbations. however, its long-term effect on the susceptibility of the commensal flora within the cystic fibrosis (cf) airways has not yet been examined. the aim of this study was therefore to examine the consequence of oral ciprofloxacin usage on the resistance of the commensal viridans group streptococci (vgs), in terms of m ... | 2010 | 21193474 |
| mutations in penicillin-binding protein (pbp) genes and in non-pbp genes during selection of penicillin-resistant streptococcus gordonii. | penicillin resistance in streptococcus spp. involves multiple mutations in both penicillin-binding proteins (pbps) and non-pbp genes. here, we studied the development of penicillin resistance in the oral commensal streptococcus gordonii. cyclic exposure of bacteria to twofold-increasing penicillin concentrations selected for a progressive 250- to 500-fold mic increase (from 0.008 to between 2 and 4 microg/ml). the major mic increase (> or = 35-fold) was related to non-pbp mutations, whereas pbp ... | 2006 | 17000741 |
| scm, a novel m-like protein from streptococcus canis, binds (mini)-plasminogen with high affinity and facilitates bacterial transmigration. | streptococcus canis is an important zoonotic pathogen capable of causing serious invasive diseases in domestic animals and humans. in the present paper we report the binding of human plasminogen to s. canis and the recruitment of proteolytically active plasmin on its surface. the binding receptor for plasminogen was identified as a novel m-like protein designated scm (s. canis m-like protein). spr (surface plasmon resonance) analyses, radioactive dot-blot analyses and heterologous expression on ... | 2011 | 21210764 |
| invasion of human aortic endothelial cells by oral viridans group streptococci and induction of inflammatory cytokine production. | oral viridans group streptococci are the major commensal bacteria of the supragingival oral biofilm and have been detected in human atheromatous plaque. atherosclerosis involves an ongoing inflammatory response, reportedly involving chronic infection caused by multiple pathogens. the aim of this study was to examine the invasion of human aortic endothelial cells (haecs) by oral viridans group streptococci and the subsequent cytokine production by viable invaded haecs. the invasion of haecs by ba ... | 2010 | 21214874 |
| the eiiabman phosphotransferase system permease regulates carbohydrate catabolite repression in streptococcus gordonii. | commensal oral streptococci play critical roles in oral biofilm formation and promote dental health by competing with, and antagonizing the growth of, pathogenic organisms, such as streptococcus mutans. efficient utilization of the spectrum of carbohydrates in the oral cavity by commensal streptococci is essential for their persistence, and yet very little is known about the regulation of carbohydrate catabolism by these organisms. carbohydrate catabolite repression (ccr) in the abundant oral co ... | 2011 | 21239541 |
| streptococcus mutans glucan-binding protein-a affects streptococcus gordonii biofilm architecture. | the glucan-binding protein-a (gbpa) of streptococcus mutans has been shown to contribute to the architecture of glucan-dependent biofilms formed by this species and influence virulence in a rat model. as s. mutans synthesizes multiple glucosyltransferases and nonglucosyltransferase glucan-binding proteins (gbps), it is possible that there is functional redundancy that overshadows the full extent of gbpa contributions to s. mutans biology. glucan-associated properties such as adhesion, aggregatio ... | 2007 | 17166223 |
| the effect of xylitol on the composition of the oral flora: a pilot study. | our aim was to investigate the effect of short-term xylitol consumption on the microbial composition of plaque and saliva. | 2011 | 21311610 |
| induction of experimental endocarditis by continuous low-grade bacteremia mimicking spontaneous bacteremia in humans. | transient high-grade bacteremia following invasive procedures carries a risk of infective endocarditis (ie). this is supported by experimental endocarditis. on the other hand, case-control studies showed that ie could be caused by cumulative exposure to low-grade bacteremia occurring during daily activities. however, no experimental demonstration of this latter possibility exists. this study investigated the infectivity in animals of continuous low-grade bacteremia compared to that of brief high ... | 2011 | 21321073 |
| streptococcus gordonii peritonitis in a patient on capd. | we report the first case of streptococcus gordonii-related continuous ambulatory peritoneal dialysis (capd) peritonitis. he is a 69-year-old man with end-stage renal failure due to chronic glomerulonephritis who had been put on capd for 1 year. he was successfully treated with a 2-week course of cefazolin. this case highlights the emerging threat that s. gordonii can be the source of infection in patients on capd. | 2011 | 21332347 |
| an artificial biofilm induced secondary caries model for in vitro studies. | the aim of this study was to establish a new in vitro model for biofilm induced secondary caries studies using an oral biofilm reactor. | 2011 | 21332739 |
| short- and medium-chain fatty acids exhibit antimicrobial activity for oral microorganisms. | this study assessed the antibacterial activity of short-, medium-, and long-chain fatty acids against various oral microorganisms. | 2011 | 21333271 |
| physiological and molecular characterization of genetic competence in streptococcus sanguinis. | streptococcus sanguinis is a major component of the oral flora and an important cause of infective endocarditis. although s. sanguinis is naturally competent, genome sequencing has suggested significant differences in the s. sanguinis competence system relative to those of other streptococci. an s. sanguinis mutant possessing an in-frame deletion in the comc gene, which encodes competence-stimulating peptide (csp), was created. addition of synthetic csp induced competence in this strain. gene ex ... | 2011 | 21375701 |
| a new small molecule specifically inhibits the cariogenic bacterium streptococcus mutans in multispecies biofilms. | streptococcus mutans is a major cariogenic bacterium. it has adapted to the biofilm lifestyle, which is essential for pathogenesis of dental caries. we aimed to identify small molecules that can inhibit cariogenic s. mutans and to discover lead structures that could give rise to therapeutics for dental caries. in this study, we screened a focused small-molecule library of 506 compounds. eight small molecules which inhibited s. mutans at a concentration of 4 µm or less but did not affect cell gro ... | 2011 | 21402858 |
| mechanism of adhesion maintenance by methionine sulphoxide reductase in streptococcus gordonii. | methionine sulphoxide reductase maintains adhesin function during oxidative stress. using streptococcus gordonii as a model, we now show the mechanistic basis of adhesin maintenance provided by msra. in biofilms, s. gordonii selectively expresses the msra gene. when the wild-type strain was grown with exogenous hydrogen peroxide (h(2)o(2)), msra-specific mrna expression significantly increased, while acid production was unaffected. in the presence of h(2)o(2), a msra-deletion mutant (?msra) show ... | 2011 | 21410565 |
| novel model for multispecies biofilms that uses rigid gas-permeable lenses. | oral biofilms comprise complex multispecies consortia aided by specific inter- and intraspecies interactions occurring among commensals and pathogenic bacterial species. oral biofilms are primary initiating factors of periodontal disease, although complex multifactorial biological influences, including host cell responses, contribute to the individual outcome of the disease. to provide a system to study initial stages of interaction between oral biofilms and the host cells that contribute to the ... | 2011 | 21421785 |
| egg yolk-derived immunoglobulin (igy) against porphyromonas gingivalis 40-kda outer membrane protein inhibits coaggregation activity. | the anaerobic bacterium porphyromonas gingivalis, a major pathogen in periodontitis, aggregates with a number of oral bacteria to form dental plaque, which is important for its colonization. we previously cloned the gene coding the 40-kda outer membrane protein (omp) of p. gingivalis 381 and produced large amounts of the recombinant (r) protein. affinity-purified rabbit antiserum against r40-kda omp effectively inhibited the coaggregation activity of p. gingivalis to oral bacteria, thus 40-kda o ... | 2007 | 17275778 |
| isoleucine 259 and isoleucine 260 residues in streptococcus gordonii soluble inorganic pyrophosphatase play an important role in enzyme activity. | the hinge region of the family ii soluble inorganic pyrophosphatase (ppase) found in streptococcus gordonii dl1 (challis) has previously been shown to play an important role in opening and closing of the active site between the n- and c-terminal domains of ppase. amino acid residues isoleucine 259 (i259) and isoleucine 260 (i260) are highly conserved among catalytically active family ii ppases and are located very close to the hinge region. substitution of either i259 or i260 with a hydrophilic ... | 2011 | 21450519 |
| the oral commensal, streptococcus gordonii, synergizes with tat protein to induce hiv-1 promoter activation in monocytes/macrophages. | trans-activator of transcription (tat) is an hiv-1 protein essential for viral replication. oral periodontopathogens (e.g. fusobacterium nucleatum) enhance hiv-1ltr promoter activation in monocytes/macrophages in absence of tat; however, some oral commensals fail to trigger this response. we sought to determine the effect of tat on hiv-1ltr promoter activation induced by the representative oral commensal streptococcus gordonii in monocytes/macrophages. s. gordonii enhanced hiv-1ltr reactivation ... | 2011 | 21459369 |
| the major autolysin of streptococcus gordonii is subject to complex regulation and modulates stress tolerance, biofilm formation, and extracellular-dna release. | a gene, designated atls, encoding a major autolysin from streptococcus gordonii, was identified and characterized. the predicted atls protein is 1,160 amino acids and 127 kda and has a conserved β1,4-n-acetylmuramidase domain. zymographic analysis of wild-type s. gordonii revealed peptidoglycan hydrolase activities with molecular masses of 130 and 90 kda that were absent in an atls deletion mutant. western blotting revealed that the 90-kda band was derived from the 130-kda protein. inactivation ... | 2011 | 21478346 |
| metabolite cross-feeding enhances virulence in a model polymicrobial infection. | microbes within polymicrobial infections often display synergistic interactions resulting in enhanced pathogenesis; however, the molecular mechanisms governing these interactions are not well understood. development of model systems that allow detailed mechanistic studies of polymicrobial synergy is a critical step towards a comprehensive understanding of these infections in vivo. in this study, we used a model polymicrobial infection including the opportunistic pathogen aggregatibacter actinomy ... | 2011 | 21483753 |
| phylogenetic analyses and detection of viridans streptococci based on sequences and denaturing gradient gel electrophoresis of the rod shape-determining protein gene. | population analysis of viridans streptococci is important because these species are associated with dental caries, bacteremia, and subacute endocarditis, in addition to being important members of the human oral commensal microbiota. | 2009 | 21523207 |
| asp2 and asp3 interact directly with gspb, the export substrate of the streptococcus gordonii accessory sec system. | gspb is a serine-rich glycoprotein adhesin of streptococcus gordonii that is exported to the bacterial surface by the accessory sec system. this dedicated export pathway is comprised of seven components (seca2, secy2, and five accessory sec proteins [asps 1-5]). the latter proteins have no known homologs beyond the asps of other species. asps 1-3 are absolutely required for export of the substrate gspb, but their roles in this process are unknown. using co-purification analysis and far western b ... | 2011 | 21531800 |
| antimicrobial penetration and efficacy in an in-vitro oral biofilm model. | the penetration and overall efficacy of six mouthrinse actives was evaluated using an in vitro flow cell oral biofilm model. the technique involved pre-loading biofilm cells with a green fluorescent dye that leaked out as the cells were permeabilized by a treatment. the loss of green color, and of biomass, was observed by time-lapse microscopy during 60 min of treatment under continuous flow conditions. the six actives analyzed were ethanol, sodium lauryl sulfate (sls), triclosan (trn), chlorhex ... | 2011 | 21537022 |
| interaction of oral bacteria with gingival epithelial cell multilayers. | primary gingival epithelial cells were cultured in multilayers as a model for the study of interactions with oral bacteria associated with health and periodontal disease. multilayers maintained at an air-liquid interface in low-calcium medium displayed differentiation and cytokeratin properties characteristic of junctional epithelium. multilayers were infected with fluorescently labeled porphyromonas gingivalis, aggregatibacter actinomycetemcomitans, fusobacterium nucleatum or streptococcus gord ... | 2011 | 21545698 |
| gingival epithelial cell transcriptional responses to commensal and opportunistic oral microbial species. | transcriptional profiling and ontology tools were utilized to define the biological pathways of gingival epithelial cells modulated by coculture with the oral commensal streptococcus gordonii and the opportunistic commensal fusobacterium nucleatum. overall, f. nucleatum and s. gordonii perturbed the gingival epithelial cell transcriptome much less significantly than the oral pathogens porphyromonas gingivalis and aggregatibacter actinomycetemcomitans perturbed the transcriptome, indicating that ... | 2007 | 17307939 |
| differential response of streptococcus mutans towards friend and foe in mixed species cultures. | in the oral biofilm, the mitis streptococci are among the first group of organisms to colonize the tooth surface. their proliferation is thought to be an important factor required for antagonizing the growth of cariogenic species such as streptococcus mutans. in this study, we used a 3-species mixed culture to demonstrate that another ubiquitous early colonizing species, veillonella parvula, could greatly impact the competitive outcome of a pair of antagonists like s. mutans and s. gordonii. tra ... | 2011 | 21565931 |
| contribution of phosphoglucosamine mutase to determination of bacterial cell morphology in streptococcus gordonii. | phosphoglucosamine mutase (glmm; ec 5.4.2.10) catalyzes the interconversion of glucosamine-6-phosphate to glucosamine-1-phosphate, an essential step in the biosynthetic pathway leading to the formation of the peptidoglycan precursor uridine 5'-diphospho-n-acetylglucosamine. we have recently identified the gene (glmm) encoding the enzyme of streptococcus gordonii, an early colonizer on the human tooth and an important cause of infective endocarditis, and indicated that the glmm mutation in s. gor ... | 2011 | 21567120 |
| loss of penicillin tolerance by inactivating the carbon catabolite repression determinant ccpa in streptococcus gordonii. | antibiotic tolerance is a phenomenon allowing bacteria to withstand drug-induced killing. here, we studied a penicillin-tolerant mutant of streptococcus gordonii (tol1), which was shown to be deregulated in the expression of the arginine deiminase operon (arc). arc was not directly responsible for tolerance, but is controlled by the global regulator ccpa. therefore, we sought whether ccpa might be implicated in tolerance. | 2007 | 17327292 |
| regulation of d-alanylation of lipoteichoic acid in streptococcus gordonii. | d-alanyl esters on lipoteichoic acid (lta) are involved in adhesion, biofilm formation, resistance to cationic antimicrobial peptides, and immune stimulation. there is evidence that bacteria can modulate the level of d-alanyl esters on lta in response to challenge, but the mechanism of regulation appears to be different among bacteria. in this study, the expression of the dlt operon responsible for d-alanylation of lta was examined in the commensal bacterium streptococcus gordonii. dlt expressio ... | 2011 | 21602218 |
| antimicrobial and osteogenic properties of a hydrophilic-modified nanoscale hydroxyapatite coating on titanium. | hydroxyapatite (ha)-coated titanium (ti) is commonly used for implantable medical devices. this study examined in vitro osteoblast gene expression and antimicrobial activity against early and late colonizers of supra-gingival plaque on nanoscale ha-coated ti prepared by discharge in a physiological buffered solution. the ha-coated ti surface showed super-hydrophilicity, whereas the densely sintered ha and ti surfaces alone showed lower hydrophilicity. the sintered ha and ha-coated ti surfaces sh ... | 2011 | 21782779 |
| a structural model for binding of the serine-rich repeat adhesin gspb to host carbohydrate receptors. | gspb is a serine-rich repeat (srr) adhesin of streptococcus gordonii that mediates binding of this organism to human platelets via its interaction with sialyl-t antigen on the receptor gpiba. this interaction appears to be a major virulence determinant in the pathogenesis of infective endocarditis. to address the mechanism by which gspb recognizes its carbohydrate ligand, we determined the high-resolution x-ray crystal structure of the gspb binding region (gspb(br)), both alone and in complex wi ... | 2011 | 21765814 |
| hydrogen peroxide-dependent dna release and transfer of antibiotic resistance genes in streptococcus gordonii. | certain oral streptococci produce h(2)o(2) under aerobic growth conditions to inhibit competing species like streptococcus mutans. additionally, h(2)o(2) production causes the release of extracellular dna (edna). edna can participate in several important functions: biofilm formation and cell-cell aggregation are supported by edna, while edna can serve as a nutrient and as an antimicrobial agent by chelating essential cations. edna contains dna fragments of a size that has the potential to transf ... | 2011 | 21984796 |
| lytf, a novel competence-regulated murein hydrolase in the genus streptococcus. | streptococcus pneumoniae and probably most other members of the genus streptococcus are competent for natural genetic transformation. during the competent state, s. pneumoniae produces a murein hydrolase, cbpd, that kills and lyses noncompetent pneumococci and closely related species. previous studies have shown that cbpd is essential for efficient transfer of genomic dna from noncompetent to competent cells in vitro. consequently, it has been proposed that cbpd together with the cognate immunit ... | 2011 | 22123253 |
| Bioactivity of WLBU2 peptide antibiotic in combination with bioerodible polymer. | WLBU2 is a peptide antibiotic designed for broad antimicrobial activity, including bacteria associated with periodontal disease. Although periodontitis is associated with various systemic conditions, ranging from cardiovascular disease to preterm birth, local therapy is needed to treat the source of infection. Biodegradable polymers are often used to control locally the amount and rate of delivery of drugs. In the present study, a bioerodible association polymer comprising cellulose acetate phth ... | 2011 | 21920706 |
| presence of porphyromonas gingivalis in gingival squamous cell carcinoma. | periodontal disease has been recently linked to a variety of systemic conditions such as diabetes, cardiovascular disease, preterm delivery, and oral cancer. the most common bacteria associated with periodontal disease, porphyromonas gingivalis (p. gingivalis) has not yet been studied in the malignant gingival tissues. the objective of this study was to investigate the presence of p. gingivalis in specimens from squamous cell carcinoma patients. we have performed immunohistochemical staining to ... | 2011 | 22010579 |
| streptococcus gordonii promotes rapid differentiation of monocytes into dendritic cells through interaction with the sialic acid-binding adhesin. | infective endocarditis is frequently attributed to oral streptococci. although the pathogenetic mechanisms are not well understood, interaction between streptococci and phagocytes is thought to be important for infective endocarditis. in this study, hl-60 cell-derived monocytes were characterized following interaction with streptococcus gordonii dl1. exposure of monocytes to s. gordonii dl1 induced up-regulation of the dendritic cell (dc) markers cd83, cd1a, cd86, and interleukin-12, while monoc ... | 2011 | 22006240 |
| the impact of dendrimer-grafted modifications to model silicon surfaces on protein adsorption and bacterial adhesion. | in the oral cavity, omnipresent salivary protein films (pellicle) mediate bacterial adhesion and biofilm formation on natural tissues as well as on artificial implant surfaces, which may cause serious infectious diseases like periimplantitis. the purpose of this in vitro study was to investigate the adsorption/desorption behaviour of human saliva on model surfaces grafted with polyamidoamine (pamam) dendrimer molecules compared to self-assembled monolayers (sams) exhibiting the same terminal fun ... | 2011 | 21906807 |
| evaluation of the subgingival microbiota of alcoholic and non-alcoholic individuals. | the aim of this study was to evaluate the composition of the subgingival microbiota of alcoholic and non-alcoholic individuals. | 2011 | 21864643 |
| differential expression and adherence of porphyromonas gingivalis fima genotypes. | porphyromonas gingivalis is a primary pathogen involved in the initiation and progression of adult chronic periodontitis. its colonization on oral surfaces is a necessary first step leading to infection. fima, a subunit protein of major (long) fimbriae, is a well-known virulence factor. based on its nucleotide sequence, fima is classified into several genotypes. we compared here the transcriptional levels of the fima gene in several p. gingivalis strains using real-time polymerase chain reaction ... | 2011 | 22053966 |
| identification and characterization of a fibronectin-binding protein from granulicatella adiacens. | the interaction of microorganisms with fibronectin plays an important role in infective endocarditis. granulicatella adiacens is a member of the oral microbiota, formerly known as nutritionally variant streptococci, and is often isolated from endocarditis patients. in the present study we identified a surface protein, designated cha, which binds to fibronectin, by a plaque hybridization procedure using the csha sequence as probe, which encodes a fibronectin-binding molecule of streptococcus gord ... | 2011 | 22053963 |
| [streptococcus gordonii extensive multiple subcutanoeus abscesses]. | we describe extensive multiple subcutaneous abscesses involving the peri-scapular region, the right posterior and lateral peri-trochanteric area and ipsilateral thigh occurring in a 66-years-old woman. streptococcus gorgonii was identified as the unique pathogen. despite this microrganism is generally considered not pathogenic, it has been previously described as responsible for two cases of peritonitis and one case of endocarditis. the patient has been treated with immediate surgical incision a ... | 2011 | 22037441 |
| tobacco smoke augments porphyromonas gingivalis-streptococcus gordonii biofilm formation. | smoking is responsible for the majority of periodontitis cases in the us and smokers are more susceptible than non-smokers to infection by the periodontal pathogen porphyromonas gingivalis. p. gingivalis colonization of the oral cavity is dependent upon its interaction with other plaque bacteria, including streptococcus gordonii. microarray analysis suggested that exposure of p. gingivalis to cigarette smoke extract (cse) increased the expression of the major fimbrial antigen (fima), but not the ... | 2011 | 22110637 |
| the impact of three strains of oral bacteria on the surface and mechanical properties of a dental resin material. | the purpose of this study was to determine if three strains of bacteria could impact the mechanical or surface properties of a dental resin material. resin material specimens were incubated at 37°c in sterile saline, tryptic soy broth supplemented with sucrose (tsbs), or tsbs inoculated with streptococcus mutans, streptococcus gordonii, or streptococcus sanguis. the specimens were subjected to fourier transform infrared spectroscopy before and after incubation. the flexural strength test was per ... | 2011 | 21894502 |
| Synergistic Interaction between Candida albicans and Commensal Oral Streptococci in a Novel In Vitro Mucosal Model. | Candida albicans is a commensal colonizer of the gastrointestinal tract of humans, where it coexists with highly diverse bacterial communities. It is not clear if this interaction limits or promotes the potential of C. albicans to become an opportunistic pathogen. Here we investigate the interaction between C. albicans and three species of streptococci from the viridans group, which are ubiquitous and abundant oral commensal bacteria. The ability of C. albicans to form biofilms with Streptococcu ... | 2011 | 22104105 |
| 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 ... | 2012 | 22266273 |
| uv-c-irradiation sublethal stress does not alter antibiotic susceptibility of the viridans group streptococci to β-lactam, macrolide, and fluoroquinolone antibiotic agents. | previous work has indicated that environmental stresses on bacteria might lead to an upregulation of stress response. led curing lights (315-400 nm) and other uv lights used in tooth whitening cosmetic procedures might act as stresses. we examined the effect of uv-c light, as a high-energy surrogate to the lower-energy uv-a light used in such instruments, to examine its effect on the antibiotic susceptibility of viridans group streptococci. | 2011 | 22887906 |
| a periodontitis-associated multispecies model of an oral biofilm. | while single-species biofilms have been studied extensively, we know notably little regarding multispecies biofilms and their interactions. the purpose of this study was to develop and evaluate an in vitro multispecies dental biofilm model that aimed to mimic the environment of chronic periodontitis. | 2014 | 24778902 |
| functional advantages of porphyromonas gingivalis vesicles. | porphyromonas gingivalis is a keystone pathogen of periodontitis. outer membrane vesicles (omvs) have been considered as both offense and defense components of this bacterium. previous studies indicated that like their originating cells, p. gingivalis vesicles, are able to invade oral epithelial cells and gingival fibroblasts, in order to promote aggregation of some specific oral bacteria and to induce host immune responses. in the present study, we investigated the invasive efficiency of p. gin ... | 2015 | 25897780 |
| a yada-like autotransporter, hag1 in veillonella atypica is a multivalent hemagglutinin involved in adherence to oral streptococci, porphyromonas gingivalis, and human oral buccal cells. | dental biofilm development is a sequential process, and adherence between microbes and the salivary pellicle (adhesion) as well as among different microbes (co-adhesion or coaggregation) plays a critical role in building a biofilm community. the veillonella species are among the most predominant species in the oral cavity and coaggregate with many initial, early, middle, and late colonizers. similar to oral fusobacteria, they are also considered bridging species in biofilm development. however, ... | 2015 | 25440509 |
| reduced glutathione mediates resistance to h2s toxicity in oral streptococci. | periodontal disease is associated with changes in the composition of the oral microflora, where health-associated oral streptococci decrease while gram-negative anaerobes predominate in disease. a key feature of periodontal disease-associated anaerobes is their ability to produce hydrogen sulfide (h2s) abundantly as a by-product of anaerobic metabolism. so far, h2s has been reported to be either cytoprotective or cytotoxic by modulating bacterial antioxidant defense systems. although oral anaero ... | 2016 | 26801579 |
| tyrosine phosphorylation and bacterial virulence. | protein phosphorylation on tyrosine has emerged as a key device in the control of numerous cellular functions in bacteria. in this article, we review the structure and function of bacterial tyrosine kinases and phosphatases. phosphorylation is catalyzed by autophosphorylating adenosine triphosphate-dependent enzymes (bacterial tyrosine (by) kinases) that are characterized by the presence of walker motifs. the reverse reaction is catalyzed by three classes of enzymes: the eukaryotic-like phosphat ... | 2012 | 22388693 |
| glycine residues in the hydrophobic core of the gspb signal sequence route export toward the accessory sec pathway. | the streptococcus gordonii cell surface glycoprotein gspb mediates high-affinity binding to distinct sialylated carbohydrate structures on human platelets and salivary proteins. gspb is glycosylated in the cytoplasm of s. gordonii and is then transported to the cell surface via a dedicated transport system that includes the accessory sec components seca2 and secy2. the means by which the gspb preprotein is selectively recognized by the accessory sec system have not been characterized fully. gspb ... | 2007 | 17369296 |
| a key role of dendritic cells in probiotic functionality. | disruption of the intestinal homeostasis and tolerance towards the resident microbiota is a major mechanism involved in the development of inflammatory bowel disease. while some bacteria are inducers of disease, others, known as probiotics, are able to reduce inflammation. because dendritic cells (dcs) play a central role in regulating immune responses and in inducing tolerance, we investigated their role in the anti-inflammatory potential of probiotic lactic acid bacteria. | 2007 | 17375199 |
| comparison of oral microbiota in tumor and non-tumor tissues of patients with oral squamous cell carcinoma. | bacterial infections have been linked to malignancies due to their ability to induce chronic inflammation. we investigated the association of oral bacteria in oral squamous cell carcinoma (oscc/tumor) tissues and compared with adjacent non-tumor mucosa sampled 5 cm distant from the same patient (n = 10). by using culture-independent 16s rrna approaches, denaturing gradient gel electrophoresis (dgge) and cloning and sequencing, we assessed the total bacterial diversity in these clinical samples. | 2012 | 22817758 |
| arginine-ornithine antiporter arcd controls arginine metabolism and interspecies biofilm development of streptococcus gordonii. | arginine is utilized by the oral inhabitant streptococcus gordonii as a substrate of the arginine deiminase system (ads), eventually producing atp and nh3, the latter of which is responsible for microbial resistance to ph stress. s. gordonii expresses a putative arginine-ornithine antiporter (arcd) whose function has not been investigated despite relevance to the ads and potential influence on inter-bacterial communication with periodontal pathogens that utilize amino acids as a main energy sour ... | 2015 | 26085091 |