Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
|---|
| 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 |
| the two-component system bfrab regulates expression of abc transporters in streptococcus gordonii and streptococcus sanguinis. | the putative two-component system bfrab is involved in streptococcus gordonii biofilm development. here, we provide evidence that bfrab regulates the expression of bfrcd and bfrefg, which encode two atp-binding cassette (abc) transporters, and bfrh, which encodes a caax amino-terminal protease family protein. bfrc and bfre are atp-binding proteins, and bfrd, bfrf and bfrg are homologous membrane-spanning polypeptides. similarly, bfrabss, the bfrab homologous system in streptococcus sanguinis, co ... | 2009 | 19118357 |
| zinc and copper play a role in coaggregation inhibiting action of porphyromonas gingivalis. | we investigated the mechanisms of adherence of salivary and serum proteins, which mimic gingival crevicular fluid (gcf), to porphyromonas gingivalis, and the effects of these adhered proteins on coaggregation and hemagglutination properties. | 2009 | 19121071 |
| glycosylation and biogenesis of a family of serine-rich bacterial adhesins. | glycosylation of bacterial proteins is an important process for bacterial physiology and pathophysiology. both o- and n-linked glycan moieties have been identified in bacterial glycoproteins. the n-linked glycosylation pathways are well established in gram-negative bacteria. however, the o-linked glycosylation pathways are not well defined due to the complex nature of known o-linked glycoproteins in bacteria. in this review, we examine a new family of serine-rich o-linked glycoproteins which are ... | 2009 | 19202081 |
| correlations of oral bacterial arginine and urea catabolism with caries experience. | alkali generation by oral bacteria plays a key role in plaque ph homeostasis and may be a major impediment to the development of dental caries. to determine if the capacity of oral samples to produce ammonia from arginine or urea was related to caries experience, the arginine deiminase system (ads) and urease activity in saliva and dental plaque samples were measured in 45 adult subjects. | 2009 | 19239634 |
| role of lysine in interaction between surface protein peptides of streptococcus gordonii and agglutinin peptide. | streptococcus gordonii interacts with the salivary pellicle on the tooth surface and plays an important role in dental biofilm formation. reports show that the analog ssp peptide (a11k; alanine to lysine at position 11 in the arranged sequence, (1)dyqaklaayqael(13)) of sspa and sspb of s. gordonii increased binding to the salivary agglutinin (gp-340/dmbt1) peptide (scavenger receptor cysteine-rich domain 2: srcrp2). to determine the role of lysine in the binding of the ssp(a11k) peptide to srcrp ... | 2009 | 19239644 |
| surface characterization of dental ceramics and initial streptococcal adhesion in vitro. | the aim of this in vitro study was to investigate the surface properties of dental ceramic materials belonging to different ceramic classes, and to correlate the findings to the initial adherence of three oral streptococcal strains. | 2009 | 19278720 |
| synergistic bm-dc activation and immune induction by the oral vaccine vector streptococcus gordonii and exogenous tumor necrosis factor. | streptococcus gordonii, a potential mucosal vaccine delivery vector, is proficient at colonizing murine oral mucosa; however, it often fails to elicit significant antibody titers against its vaccine antigen payloads. the poor response may be due to an inability of s. gordonii to elicit cytokines needed to suppress mucosal tolerance; exogenously supplied cytokines, such as tnf, could overcome this effect. to test this, murine bone marrow-derived dendritic cells (bm-dcs) were stimulated with uv-ki ... | 2009 | 19278729 |
| differential activation of dendritic cells by toll-like receptor agonists isolated from the gram-positive vaccine vector streptococcus gordonii. | the oral commensal bacterium streptococcus gordonii has been gathering interest as a candidate live mucosal vaccine delivery vector. s. gordonii has been shown to be capable of activating antigen presenting immune cells in a manner which leads to their activation and maturation, yet the mechanism used by s. gordonii to do so is poorly understood. the aim of this work was to investigate the immunostimulatory components of s. gordonii in inducing murine dendritic cell (dc) activation and maturatio ... | 2009 | 19284500 |
| rhodomyrtone: a new candidate as natural antibacterial drug from rhodomyrtus tomentosa. | rhodomyrtone [6,8-dihydroxy-2,2,4,4-tetramethyl-7-(3-methyl-1-oxobutyl)-9-(2-methylpropyl)-4,9-dihydro-1h-xanthene-1,3(2h)-di-one] from rhodomyrtus tomentosa (aiton) hassk. displayed significant antibacterial activities against gram-positive bacteria including bacillus cereus, bacillus subtilis, enterococcus faecalis, staphylococcus aureus, methicillin-resistant s. aureus (mrsa), staphylococcus epidermidis, streptococcus gordonii, streptococcus mutans, streptococcus pneumoniae, streptococcus pyo ... | 2009 | 19303274 |
| characterization of streptococcus gordonii seca2 as a paralogue of seca. | the accessory sec system of streptococcus gordonii is essential for transport of the glycoprotein gspb to the bacterial cell surface. a key component of this dedicated transport system is seca2. the seca2 proteins of streptococci and staphylococci are paralogues of seca and are presumed to have an analogous role in protein transport, but they may be specifically adapted for the transport of large, serine-rich glycoproteins. we used a combination of genetic and biochemical methods to assess wheth ... | 2009 | 19363114 |
| identification of novel lpxtg-linked surface proteins from streptococcus gordonii. | surface adhesion plays an essential part in the survival of the commensal organism streptococcus gordonii in the oral cavity as well as during opportunistic infections such as endocarditis. at least two types of cell surface protein involved in adhesion are found on the surface of gram-positive bacteria: those anchored via an lpxtg motif by the enzyme sortase a (srta) and those associated with the cell surface by, as yet, unknown mechanisms. in srta(-) mutants, lpxtg-containing proteins have bee ... | 2009 | 19383683 |
| in vitro adherence of oral streptococci to zirconia core and veneering glass-ceramics. | plaque formation on dental ceramics may cause gingival inflammation and secondary caries. this in vitro study compared the susceptibility of various dental ceramics to adhere oral streptococci, and verified the influence of substratum surface roughness and surface hydrophobicity. three zirconia ceramic materials and three veneering glass-ceramics were investigated. fifteen test specimens were prepared for each material, polished, and surface roughness and hydrophobicity were determined. after in ... | 2009 | 19388092 |
| human cytomegalovirus and epstein-barr virus inhibit oral bacteria-induced macrophage activation and phagocytosis. | periodontal disease is an inflammatory condition caused by periodontal microorganisms. viruses such as human cytomegalovirus (hcmv) and epstein-barr virus (ebv) are associated with certain types of periodontal disease, but their roles in promoting the disease are unclear. because both viruses infect human macrophages, cells which play key roles in the clearance of pathogenic bacteria, it is likely that the viruses alter the functional capacity of macrophages by inhibiting their defense mechanism ... | 2009 | 19416455 |
| proteomics of porphyromonas gingivalis within a model oral microbial community. | porphyromonas gingivalis is a periodontal pathogen that resides in a complex multispecies microbial biofilm community known as dental plaque. confocal laser scanning microscopy showed that p. gingivalis can assemble into communities in vitro with streptococcus gordonii and fusobacterium nucleatum, common constituents of dental plaque. whole cell quantitative proteomics, along with mutant construction and analysis, were conducted to investigate how p. gingivalis adapts to this three species commu ... | 2009 | 19454014 |
| streptococcus gordonii modulates candida albicans biofilm formation through intergeneric communication. | the fungus candida albicans colonizes human oral cavity surfaces in conjunction with a complex microflora. c. albicans sc5314 formed biofilms on saliva-coated surfaces that in early stages of development consisted of approximately 30% hyphal forms. in mixed biofilms with the oral bacterium streptococcus gordonii dl1, hyphal development by c. albicans was enhanced so that biofilms consisted of approximately 60% hyphal forms. cell-cell contact between s. gordonii and c. albicans involved streptoco ... | 2009 | 19528215 |
| interspecies signaling between veillonella atypica and streptococcus gordonii requires the transcription factor ccpa. | streptococcus gordonii and veillonella atypica, two early-colonizing members of the dental plaque biofilm, participate in a relationship that results in increased transcription of the s. gordonii gene amyb, encoding an alpha-amylase. we show that the transcription factor ccpa is required for this interspecies interaction. | 2009 | 19542285 |
| influences of protein films on antibacterial or bacteria-repellent surface coatings in a model system using silicon wafers. | immobilization of defined chemical functionalities to biomaterial surfaces is employed to optimize them not only for tissue compatibility but also for prevention of bacterial infection. grafting surfaces with chains of poly(ethylene glycol) (peg) results in bacterial repellence whereas modification with cationic groups conveys them with bactericidal properties. since biomaterials in situ will become exposed to a protein-rich environment, it is necessary to investigate the influence of prior prot ... | 2009 | 19545893 |
| contribution of phosphoglucosamine mutase to the resistance of streptococcus gordonii dl1 to polymorphonuclear leukocyte killing. | 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 ... | 2009 | 19552711 |
| molecular analysis of persistent periradicular lesions and root ends reveals a diverse microbial profile. | the microbial etiology of periradicular lesions is recognized; however, the bacterial profile of these lesions is not well elucidated. the purpose of this study was to determine the frequency of bacterial colonization in these lesions and to characterize the bacterial community present in root ends and periradicular lesions. | 2009 | 19567313 |
| bacterial and dye penetration through interim restorations used during endodontic treatment of molar teeth. | the purpose of this study was to investigate the association between dye and bacterial penetration through interim restorations used during endodontic treatment. | 2009 | 19567326 |
| a crystallizable form of the streptococcus gordonii surface antigen sspb c-domain obtained by limited proteolysis. | sspb is a 1500-residue adhesin expressed on the surface of the oral bacterium streptococcus gordonii. its interaction with other bacteria and host cells initiates the development of dental plaque. the full-length c-terminal domain of sspb was cloned, overexpressed in escherichia coli and purified. however, the protein could not be crystallized. limited proteolysis of the full-length c-domain identified a core fragment. the proteolysis product was cloned, expressed and purified. the protein was c ... | 2009 | 19574647 |
| molecular characterization of macrolide resistance determinants [erm(b) and mef(a)] in streptococcus pneumoniae and viridans group streptococci (vgs) isolated from adult patients with cystic fibrosis (cf). | although long-term use of azithromycin has shown a significant clinical improvement for patients with cystic fibrosis (cf), its long-term effect on the susceptibility of commensal flora within cf airways has not yet been examined. we therefore suggest that long-term use of azithromycin increases macrolide resistance in commensal streptococci. | 2009 | 19584106 |
| comparison of the local immune response against giardia lamblia cyst wall protein 2 induced by recombinant lactococcus lactis and streptococcus gordonii. | lactococcus lactis and streptococcus gordonii are lactic acid bacteria (lab) currently being advocated for use as live antigen delivery vehicles to mucosal sites. since both vehicles differ in their capability to persist within the small intestine and in their mode of antigen delivery, we sought to compare them to determine which one was superior. in this study, we compared the efficacy of recombinant l. lactis and s. gordonii to stimulate intestinal immune responses against giardia lamblia cyst ... | 2009 | 18992359 |
| oral bacteria modulate invasion and induction of apoptosis in hep-2 cells by pseudomonas aeruginosa. | pseudomonas aeruginosa is an important opportunistic bacterial pathogen, causing infections of the respiratory and other organ systems in susceptible hosts. p. aeruginosa infection is initiated by adhesion to and invasion of mucosal epithelial cells. the failure of host defenses to eliminate p. aeruginosa from mucosal surfaces results in p. aeruginosa proliferation, sometimes followed by overt infection and tissue destruction. there is growing evidence that associates poor oral health and respir ... | 2009 | 19041936 |
| 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 |
| 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 |
| 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 quinol peroxidase inhibitor prevents secretion of a leukotoxin from aggregatibacter actinomycetemcomitans. | quinol peroxidase (qpo) catalyzes peroxidase activity using quinol in the respiratory chain as a substrate. quinol peroxidase is essential for the secretion of leukotoxin (ltxa), which destroys leukocytes and erythrocytes in humans and is one of the major virulence factors of aggregatibacter actinomycetemcomitans, which is associated with localized aggressive periodontitis. in the present study, we aimed to find a highly potent qpo inhibitor to attenuate the virulence of a. actinomycetemcomitans ... | 2010 | 19602106 |
| 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 |
| differences in the aromatic domain of homologous streptococcal fibronectin-binding proteins trigger different cell invasion mechanisms and survival rates. | group a streptococci (gas, streptococcus pyogenes) and group g streptococci (ggs, streptococcus dysgalactiae ssp. equisimilis) adhere to and invade host cells by binding to fibronectin. the fibronectin-binding protein sfbi from gas acts as an invasin by using a caveolae-mediated mechanism. in the present study we have identified a fibronectin-binding protein, gfba, from ggs, which functions as an adhesin and invasin. although there is a high degree of similarity in the c-terminal sequence of sfb ... | 2010 | 21054741 |
| 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 |
| candida albicans als3, a multifunctional adhesin and invasin. | candida albicans is part of the normal human flora, and it grows on mucosal surfaces in healthy individuals. in susceptible hosts, this organism can cause both mucosal and hematogenously disseminated disease. for c. albicans to persist in the host and induce disease, it must be able to adhere to biotic and abiotic surfaces, invade host cells, and obtain iron. the c. albicans hypha-specific surface protein als3 is a member of the agglutinin-like sequence (als) family of proteins and is important ... | 2010 | 21115738 |
| 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 |
| role of the cell wall microenvironment in expression of a heterologous spap-s1 fusion protein by streptococcus gordonii. | the charge density in the cell wall microenvironment of gram-positive bacteria is believed to influence the expression of heterologous proteins. to test this, the expression of a spap-s1 fusion protein, consisting of the surface protein spap of streptococcus mutans and a pertussis toxin s1 fragment, was studied in the live vaccine candidate bacterium streptococcus gordonii. results showed that the parent strain pm14 expressed very low levels of spap-s1. by comparison, the dlt mutant strain, whic ... | 2010 | 21193663 |
| 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 |
| lack of detectable dna uptake by transformation of selected recipients in mono-associated rats. | abstract: | 2010 | 20193062 |
| 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 |
| nucleotide sequence and functional analysis of the tet (m)-carrying conjugative transposon tn5251 of streptococcus pneumoniae. | the tn916-like genetic element tn5251 is part of the composite conjugative transposon (ctn) tn5253 of streptococcus pneumoniae, a 64.5-kb chromosomal element originally called omega(cat-tet) bm6001. dna sequence analysis showed that tn5251 is 18 033-bp long and contains 22 orfs, 20 of which have the same direction of transcription. annotation was possible for 11 out of 22 orfs, including the tet(m) tetracycline resistance gene and int and xis involved in the integration/excision process. autonom ... | 2010 | 20487027 |
| the changing faces of streptococcus antigen i/ii polypeptide family adhesins. | streptococcus mutans antigen i/ii (agi/ii) protein was one of the first cell wall-anchored adhesins identified in gram-positive bacteria. it mediates attachment of s. mutans to tooth surfaces and has been a focus for immunization studies against dental caries. the agi/ii family polypeptides recognize salivary glycoproteins, and are also involved in biofilm formation, platelet aggregation, tissue invasion and immune modulation. the genes encoding agi/ii family polypeptides are found among strepto ... | 2010 | 20497507 |
| 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 |
| 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 |
| 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 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 |
| 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 |
| real-time mapping of a hydrogen peroxide concentration profile across a polymicrobial bacterial biofilm using scanning electrochemical microscopy. | quantitative detection of hydrogen peroxide in solution above a streptococcus gordonii (sg) bacterial biofilm was studied in real time by scanning electrochemical microscopy (secm). the concentration of hydrogen peroxide was determined to be 0.7 mm to 1.6 mm in the presence of 10 mm glucose over a period of 2 to 8 h. the hydrogen peroxide production measured was higher near the biofilm surface in comparison to sg grown planktonically. differential hydrogen peroxide production was observed both b ... | 2011 | 21282623 |
| 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 |
| antimicrobial activity of bifidobacterium spp. isolated from healthy adult koreans against cariogenic microflora. | objective: dental caries is the main common infectious disease in the human oral cavity. streptococcus mutans and streptococcus sobrinus were reported to be the most important etiological factors in human dental caries. thus, we examined the inhibitory effects of bifidobacterium spp. cells and culture supernatants against s. mutans and s. sobrinus, including streptococcus gordonii, and aggregatibacter actinomycetemcomitans, which is associated with periodontal disease. methods: mutans streptococ ... | 2011 | 21439550 |
| 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 |
| 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 |
| carboxypeptidase activity common to viridans group streptococci cleaves angiotensin i to angiotensin ii: a homologous activity to angiotensin converting enzyme (ace). | we have found that streptococcus gordonii fss2, an infective endocarditis isolate, expresses a dipeptidyl-carboxypeptidase with homologous activity to angiotensin converting enzyme (ace). the carboxypeptidase activity was purified to homogeneity as a complex/aggregate from a bacterial surface extract and is also active as a 165 kda monomer. the specific activity for the carboxypeptidase activity was 8-fold higher than recombinant human ace. selected ace inhibitors, captopril, lisinopril and enal ... | 2011 | 21546583 |
| 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 |
| environmental influences on streptococcus gordonii competitive hydrogen peroxide production. | streptococcus gordonii is an important member of the oral biofilm. one of its phenotypic traits is the production of hydrogen peroxide (h(2)o(2)). h(2)o(2) is an antimicrobial component produced by s. gordonii able to antagonize the growth of cariogenic streptococcus mutans. strategies that modulate h(2)o(2) production in the oral cavity may be useful as a simple therapeutic mechanism to improve oral health, but little is known about the regulation of h(2)o(2) production. the enzyme responsible ... | 2011 | 21571883 |
| 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 |