Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| characterization of glucosyltransferaseb, gtfc, and gtfd in solution and on the surface of hydroxyapatite. | glucosyltransferaseb, gtfc, and gtfd were purified by hydroxyapatite column chromatography, followed by ultrafiltration from the culture supernatant fluids of three streptococcus milleri constructs (gift from dr. h.k. kuramitsu) which harbored individual gtf genes of streptococcus mutans gs5. gtfb, gtfc, and gtfd were enzymatically active both in solution and in an experimental pellicle (ha-cws-gtf) formed by adsorbing gtf onto the surface of clarified human whole saliva (cws)-coated hydroxyapat ... | 1995 | 7499593 |
| cariogenic potential of foods. ii. relationship of food composition, plaque microbial counts, and salivary parameters to caries in the rat model. | a series of rat caries experiments was carried out to test the relative cariogenic potential and to identify the major carcinogenic elements of 22 popular snack foods. parameters that were measured included rat caries, number of cariogenic bacteria in plaque, salivary parameters including flow rate, buffering capacity, total protein, lysozyme and amylase content, and composition of test foods including protein, fat, phosphorus, calcium, fluoride, galactose, glucose, total reducing sugar, sucrose ... | 1994 | 7512447 |
| killing of cariogenic bacteria by light from a gallium aluminium arsenide diode laser. | suspensions of streptococcus mutans, s. sobrinus, lactobacillus casei and actinomyces viscosus were exposed to light from a gallium aluminium arsenide laser in the presence of aluminium disulphonated phthalocyanine and the numbers of survivors determined. exposure to the laser light in the absence of the dye, or the dye in the absence of the laser light, had no significant effect on the viability of the organisms. however, a light-dose-related decrease in the viable count of all four target orga ... | 1994 | 7525674 |
| influence of growth rate on the relative activities of free and bound dextranase and dextranase inhibitor in continuous cultures of streptococcus sobrinus. | the rate of growth of streptococcus sobrinus was a major factor governing the activity of free dextranase and free dextranase inhibitor in continuous culture filtrates. depending on the growth conditions, a variable proportion of dextranase and dextranase inhibitor was combined in a tightly bound enzyme-inhibitor (ei) complex. dissociation of the ei complexes revealed that the total productivity (free + bound) of both the enzyme and the inhibitor increased with growth rate, and that the activiti ... | 1994 | 7526133 |
| chemiluminescent detection of dextran bound to streptococcal glucan-binding lectin. | 1995 | 7539984 | |
| marginal ditching and staining as a predictor of secondary caries around amalgam restorations: a clinical and microbiological study. | caries at the margins of restorations is difficult to diagnose. in particular, the relevance of both marginal ditching and staining around amalgam restorations is unclear. this clinical study questions the relevance of marginal ditching and color change to the level of infection of the dentin beneath the margins of amalgam restorations. clinically visible sites (330) on the tooth/restoration margin were selected on 175 teeth. the enamel adjacent to each site was noted as stained (a grey discolor ... | 1995 | 7540634 |
| streptococcal glucan-binding lectins do not recognize methylated alpha-1,6 glucans. | the glucan-binding lectin (gbl) of streptococcus sobrinus is cell associated, enabling the bacteria to be aggregated by alpha-1,6 glucans. glucans, such as amylose, pullulan, laminarin and nigeran, have no affinity for the lectin. high molecular weight alpha-1,6 glucans (dextrans) readily aggregate the bacteria, whereas low molecular weight glucans inhibit the aggregation brought about by the high molecular weight species. methylated glucan t-2000 (an alpha-1,6 glucan with an average molecular w ... | 1995 | 7542513 |
| effect of lactobacillus rhamnosus strain gg (atcc 53103) on the growth of streptococcus sobrinus in vitro. | lactobacillus gg, a recently characterized l. rhamnosus gg strain (atcc 53103), has been shown to exert inhibitory activity against a variety of bacterial species, including streptococci. we isolated and studied the effect of the inhibitory substance of lactobacillus gg on some oral streptococci. the inhibitory activity of the isolated substance was weak, but some growth inhibition was observed in streptococcus sobrinus pretreated with the substance in comparison with untreated controls. zones o ... | 1995 | 7552958 |
| effect of aluminum concentration on dental caries formation in the rat. | topically applied aluminum (ai) reduced fissure caries in rats with indigenous microflora, but neither therapeutic activity nor concentration effects have been studied in animals infected with caries-inducing bacteria. this study investigated the effects of solutions containing various ai concentrations on formation of smooth surface and sulcal caries in cariogenically challenged rats infected with streptococcus sobrinus. | 1995 | 7553390 |
| nucleotide sequence of the lantibiotic pep5 biosynthetic gene cluster and functional analysis of pepp and pepc. evidence for a role of pepc in thioether formation. | the biosynthesis of pep5, a lanthionine-containing antimicrobial peptide, is directed by the 20-kbp plasmid ped503. we identified a 7.9-kbp dna-fragment within this plasmid which covers the information for pep5 synthesis in the homologous host staphylococcus epidermidis 5 which has been cured of ped503. this fragment contained, in addition to the previously described structural gene pepa and the immunity gene pepi [reis, m., eschbach-bludau, m., iglesias-wind, m. i., kupke, t. & sahl, h.-g. (199 ... | 1995 | 7556197 |
| [prevention of cariogenic dental plaque. study of the structures implicated in the adhesion and coaggregation in streptococcus mutans and streptococcus sobrinus]. | cariogenic dental plaque may be assimilated to a biofilm resulting from the adhesion of s. mutans, then from the coaggregation of other streptococci, or other genus. we used a static monospecific biofilm model. supports or bacteria were treated with inhibitors before adhesion in order to clarify the nature of adhesins responsible for the primary adhesion of s. mutans and s. sobrinus on tygon. to determine the bindings of coaggregation, inhibitors were applied on one-day-old biofilms. analysis of ... | 1995 | 7567131 |
| susceptibility of streptococcus mutans and streptococcus sobrinus to antimicrobial agents after short-term oral chlorhexidine treatments. | effects of three different types of short-term applications (1-3 times during 1 week) of chlorhexidine (1 or 40%) on the susceptibility of 863 clinical isolates of streptococcus mutans and 53 isolates of streptococcus sobrinus from 58 subjects were studied. chlorhexidine-resistant isolates were not found either before or after the treatment. the minimum inhibitory concentrations (mics) to chlorhexidine of all isolates of s. mutans were < or = 1 microgram/ml, and of s. sobrinus < or = 2 microgram ... | 1995 | 7600247 |
| investigation of the effects of aluminum mouthrinses on rat dental caries and plaque. | the effects of topically applied mouthrinses containing alcl3, or alk(so4)2 on dental caries and plaque were investigated in a rat model. for comparison, naf and a two-step treatment of alcl3 and naf were also tested. six groups of 20 weanling rats were inoculated with streptococcus sobrinus 6715 and provided a caries-inducing diet and distilled water ad libitum. test agents were topically applied twice daily 5 days per week at a concentration of 0.037 mol/l in a mouthrinse vehicle and were comp ... | 1995 | 7621501 |
| immunization of rats with synthetic peptide constructs from the glucan-binding or catalytic region of mutans streptococcal glucosyltransferase protects against dental caries. | previously, we have described peptide constructs from two regions of glucosyltransferase (gtf) of mutans streptococci. a putative catalytic site in the amino-terminal half of the molecule and a repeated glucan-binding site in the carboxyl-terminal half of gtf were the regions upon which sequences were based. the present study explored the effects of immunization with these peptide constructs (called cat or glu) and with streptococcal gtfs from streptococcus sobrinus and s. mutans on immunologica ... | 1995 | 7622235 |
| anticariogenicity of calcium phosphate complexes of tryptic casein phosphopeptides in the rat. | casein phosphopeptides (cpp) stabilize calcium phosphate through the formation of casein-phosphopeptide amorphous calcium-phosphate complexes (cpp-cp). the ability of cpp-cp to reduce caries activity was investigated by use of specific-pathogen-free rats inoculated with streptococcus sobrinus. the animals consumed a defined cariogenic diet free of dairy products. solutions (100 microl) of the cpp-cp (0.1, 0.2, 0.5, 1.0% w/v) were applied to the animals' molar teeth twice daily. other groups of a ... | 1995 | 7629336 |
| intrafamilial similarity in immunoblot profiles of salivary immunoglobulin a antibody activity to oral streptococci. | analysis of the salivary immunoglobulin a (iga) antibody activity to antigens separated from oral streptococci was carried out on 49 individuals in 11 families. the aim of this study were to i) study the human salivary iga activity within families to antigens separated from reference strains of streptococcus mutans, streptococcus sobrinus and streptococcus parasanguis and ii) to search for potential differences in the salivary iga activity to the streptococcal antigens several years apart. the i ... | 1995 | 7644270 |
| use of a novel mobilizable vector to inactivate the scra gene of streptococcus sobrinus by allelic replacement. | the virulence factors of the cariogenic bacterium streptococcus sobrinus have been difficult to assess because of a lack of tools for the genetic manipulation of this organism. the construction of an escherichia coli-streptococcus shuttle vector, pdl289, that can be mobilized into s. sobrinus by the conjugative plasmid pam beta 1 was described in a previous report. the vector contains pva380-1 for replication and mobilization in streptococci, the psc101 replicon for maintenance in e. coli, a kan ... | 1995 | 7665480 |
| identification of antigenic epitopes in an alanine-rich repeating region of a surface protein antigen of streptococcus mutants. | a surface protein antigen (pac) of streptococcus mutans with a molecular mass of 190 kda is considered to play an important role in the initial attachment of this streptococcus to the tooth surface. two internal repeating amino acid sequences are present in the pac molecule. one repeating region located in the n-terminal region is rich in alanine (a-region), and the other, located in the central region, is rich in proline (p-region). to identify antigenic epitopes on the a-region of the pac prot ... | 1993 | 7681043 |
| the effect of ovariectomy and high-sucrose diet on dentine formation and caries in growing rats. | ovariectomized (ovx) or sham-operated (cnt) and tetracycline-labelled growing rats were fed either a commercial powdered standard rat diet (ovx and cnt) or a high-sucrose diet (ovxsuc and cntsuc). all animals were inoculated in the mouth with streptococcus sobrinus. at 11 weeks of age the areas of caries lesions and dentinal apposition of the first and second molars and the areas of the pulpal cross-section of the incisors were determined. the area of dentinal apposition was largest in cnt anima ... | 1994 | 7695511 |
| rapid and constant detection of hiv antibody response in saliva of hiv-infected patients; selective distribution of anti-hiv activity in the igg isotype. | anti-hiv antibodies can be specifically detected with a sensitivity and a specificity of 100% in the saliva of all hiv-infected patients. a saliva collection device facilitates the sampling procedure, and if a rapid test is used, the diagnosis of infection can be established in as little as 10 min. the analysis of a group of cdc stage iv aids patients showed a decrease in lactoferrin (produced by the oral mucosa) in comparison with hiv-negative controls, associated with an increase in albumin (f ... | 1994 | 7709073 |
| effect of polyclonal and monoclonal antibodies on surface properties of streptococcus sobrinus. | in this study, the effect of antibody adsorption on physicochemical properties of streptococcus sobrinus was studied. bacteria were preincubated with polyclonal antibodies or with omvu10, a monoclonal antibody (mab) reactive with s. sobrinus. the zeta potentials and the hydrophobicity as determined by microbial adhesion to hydrocarbons were measured in potassium phosphate buffer with a ph ranging from 2 to 9. s. sobrinus preincubated with polyclonal antibodies was positively charged at ph 2, 3, ... | 1995 | 7729874 |
| oral immunization with recombinant salmonella typhimurium expressing surface protein antigen a of streptococcus sobrinus: dose response and induction of protective humoral responses in rats. | an attenuated, recombinant salmonella typhimurium mutant, chi 4072(pya2905), expressing the surface protein antigen a (spaa) of streptococcus sobrinus was investigated for its effectiveness in inducing protective immune responses against s. sobrinus-induced dental caries in an experimental caries model. fischer rats were orally immunized with either 10(8) or 10(9) cfu of s. typhimurium chi 4072(pya2905). persistence of salmonellae in peyer's patches and spleens and the induction of immune respon ... | 1995 | 7729915 |
| influence of caries-preventive measures in mothers on cariogenic bacteria and caries experience in their children. | preventive measures, which reduced the salivary level of mutans streptococci in mothers, delayed colonization by these organisms in their children. the preventive programme was discontinued when the children were 3 years old. these children, at the age of 7 years, and their mothers were now examined to determine the effect of the earlier caries-preventive approach. the control mothers had significantly higher levels of salivary mutans streptococci and lactobacilli than the test mothers (p < 0.05 ... | 1994 | 7741661 |
| mutans streptococci, lactobacilli and caries experience in 12-year-old icelandic urban children, 1984 and 1991. | in order to evaluate changes in salivary counts of cariogenic bacteria and relate these to trends in caries experience, stimulated saliva was collected from a 20% random sample of 12-yr-old residents of reykjavik, iceland (252 children) in 1991 under conditions consistent with those of a survey conducted in 1984. the mean and median counts of salivary mutans streptococci and lactobacilli remained similar in the two studies. however, the frequency distribution at lower levels of mutans streptococ ... | 1995 | 7781301 |
| chlorhexidine susceptibilities of mutans streptococcal serotypes and ribotypes. | the susceptibilities of 379 clinical mutans streptococcal isolates to chlorhexidine (chx) were tested by agar dilution according to the standards of the national committee for clinical laboratory standards. isolates were obtained from saliva samples of 34 young mothers who had high or moderate salivary levels of mutans streptococci at baseline. samples were collected on three occasions, before childbirth, when each child was 6 months old, and 1 year later. of these isolates, 50% were inhibited a ... | 1995 | 7785991 |
| immunoglobulin a antibodies to mutans streptococci in human saliva and serum comparing fresh and subcultivated strains and activity in repeated saliva samples. | the aims of this study were i) to characterize and compare the sodium dodecyl sulfate-polyacrylamide gel electrophoresis protein patterns of reference streptococcus mutans and streptococcus sobrinus strains, subcultivated for years, with fresh isolates of the same serotype; ii) to study possible differences between the human salivary immunoglobulin a (iga) activity to reference strains and to fresh bacterial isolates of the saliva donors; iii) to examine for potential differences in the salivary ... | 1994 | 7808769 |
| organic solvents and oils as vehicles for triclosan in mouthrinses: a clinical study. | previous experiments have shown that the nature of the detergents used in aqueous triclosan-containing mouthrinses affects the plaque-inhibiting effect of these mouthrinses, probably because of the properties of the micelles formed. it has also been shown that triclosan has a marked plaque-inhibiting effect when dissolved in pure propylene glycol. the aim of the present study was to compare the clinical effect of triclosan dissolved in oils and in the pure solvents glycerol (gly) and polyethylen ... | 1994 | 7817156 |
| site-related streptococcal attachment to buccocervical tooth surfaces. a correlative micromorphologic and microbiologic study. | scanning electron (sem) microscopy of epoxy replicas made from dental impressions has shown that in buccal gingival recession the root surfaces are devoid of cementum, leaving the dentin exposed. in this study replication techniques were applied to correlate the micromorphology of the buccocervical region with early streptococcal attachment. the subjects were 27 healthy young adults. the buccocervical surfaces of all the premolars were meticulously cleaned. the subjects fasted for 2 h before imp ... | 1994 | 7825399 |
| growth inhibition of glass ionomer cements on mutans streptococci. | this study was conducted to identify the factors involved in the antibacterial activity of glass ionomer cement (gic) on mutans streptococci. the antibacterial effect of gic was estimated using agar plates infected with strains of s. mutans and s. sobrinus. the effect of ph and fluoride release of gic on mutans streptococci was studied under acid and neutral ph. strains of s. sobrinus were more sensitive to gic antibacterial activity, the difference being statistically significant (p < 0.001). t ... | 1994 | 7831139 |
| the effect of acid and fluoride release on the antimicrobial properties of four glass ionomer cements. | 1994 | 7831144 | |
| polydimethylsiloxane as a tooth surface-bound carrier of triclosan: a new concept in chemical plaque inhibition. | polydimethylsiloxane (silicone oil) has an extremely low surface tension: it spreads over solid surfaces and forms a tenacious film which is hydrophobic and water-repellent. it is known that this liquid binds to hydroxyapatite and to dental enamel and changes the properties of these solids. it has been suggested that silicone oil may be applied to teeth and serve as a reservoir of lipid-soluble antibacterial substances which presumably will be slowly released into saliva due to their low solubil ... | 1994 | 7865086 |
| cariogenic bacteria in a longitudinal study of approximal caries. | two hundred and seventeen approximal spaces, initially caries free, in 58 patients were studied clinically and radiographically, at intervals of 6 months, for 3 years. samples of approximal dental plaque were removed for culture of streptococcus mutans, streptococcus sobrinus, and lactobacilli. during the study approximal caries developed in 16 subjects (27.6%) at 30 sites (13.8%), involving 42 teeth. 56 of 58 (96.7%) subjects harboured s. mutans at some time during the study, 62.1% lactobacilli ... | 1995 | 7867049 |
| a comparison of the microbial flora in carious dentine of clinically detectable and undetectable occlusal lesions. | it is not known whether the aetiology of occlusal hidden caries lesions (hcl) is identical to that of small visible lesions (svl). previous studies of the microflora of hcl suggest that relatively few species can be isolated. the aim of the present study was to compare the bacterial composition of dentine from 10 hcl and 17 svl in a population of children aged 8-18 years. the following bacteria were identified: actinomyces spp., mutans streptococci, streptococcus sanguis, streptococcus oralis, s ... | 1995 | 7867050 |
| effects of sugar restriction on streptococcus mutans and streptococcus sobrinus in saliva and dental plaque. | the effect of sugar restriction on the oral levels of mutans streptococci was studied in 20 subjects fulfilling three criteria: (1) having more than 300,000 cfu mutans streptococci/ml saliva, (2) harbouring both streptococcus mutans and streptococcus sobrinus in saliva, and (3) eating sugar frequently. the subjects were randomly divided into a test group (n = 12), who were asked to refrain from using sugar-containing foods between meals and to reduce sugar in main meals for 6 weeks, and a contro ... | 1995 | 7867052 |
| subinhibitory concentrations of antibiotics affect cell surface properties of streptococcus sobrinus. | several antibiotics, at subinhibitory concentrations, caused an increase in the ability of streptococcus sobrinus to bind alpha-1,6-glucans, whereas other antibiotics decreased glucan binding. in every case, glucan binding was inversely proportional to cell surface hydrophobicity. high levels of glucan-binding activity resulted in low levels of hydrophobicity, whereas low levels of glucan binding caused high levels of cellular hydrophobicity. the results show that low concentrations of antibioti ... | 1995 | 7868618 |
| purification, characterization, and specificity of dextranase inhibitor (dei) expressed from streptococcus sobrinus uab108 gene cloned in escherichia coli. | the dextranase inhibitor gene (dei) from streptococcus sobrinus uab108 was previously cloned, expressed, and sequenced. its gene product (dei) has now been purified as a single band with apparent molecular mass of 43 kda, as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. the specific activity of dei increased 121-fold upon purification. most dei activity (91.2%) was located in the periplasmic fraction from recombinant escherichia coli cells. dei competitively inhibits d ... | 1995 | 7896691 |
| effect of seaweed extracts on streptococcus sobrinus adsorption to saliva-coated hydroxyapatite. | the inhibitory effect of the extracts of seaweeds on the adsorption of streptococcus sobrinus b13 to the tooth surface was investigated in vitro. using saliva-coated hydroxyapatite beads (s-ha) as experimental salivary pellicle, extracts from gloiopeltis furcata and gigartina teedii (rhodopheceae) strongly inhibited the adsorption of s. sobrinus b13 to s-ha. the g. furcata extract, which strongly inhibited the adsorption of s. sobrinus b13 to s-ha, was a high molecular weight sulfated polysaccha ... | 1994 | 7923511 |
| immunological characteristics of a synthetic peptide associated with a catalytic domain of mutans streptococcal glucosyltransferase. | the immunogenicity of a multiple antigenic peptide construct consisting of four copies of the synthetic 21-mer peptide danfdsirvdavdnvdadllq was measured. the composition of this peptide was derived from a sequence in the n-terminal region of mutans streptococcal glucosyltransferases (gtfs) containing an aspartic acid implicated in catalysis. the peptide (cat) construct was synthesized as a tetramer on a lysine backbone and subcutaneously injected into sprague-dawley rats for polyclonal antibody ... | 1994 | 7960128 |
| overproduction of a dextranase inhibitor by streptococcus sobrinus mutants. | an inhibitor of streptococcus sobrinus endodextranase was detected in the extracellular fractions of uab66 mutants identified following ethyl methanesulfonate mutagenesis as either devoid of dextranase activity (dex-) or overproducing water-soluble glucan. the two groups of mutants had the same phenotype and displayed no dextranase activity in assays of extracellular fractions (h. murchison, s. larrimore, and r. curtiss iii, infect. immun. 34:1044-1055, 1981) and had been shown to be defective i ... | 1994 | 7961492 |
| cloning and dna sequencing of the dextranase inhibitor gene (dei) from streptococcus sobrinus. | some dextranase-deficient (dex-) mutants of streptococcus sobrinus uab66 (serotype g) synthesize a substance which inhibits dextranase activity (s.-y. wanda, a. camilli, h. m. murchison, and r. curtiss iii, j. bacteriol. 176:7206-7212, 1994). this substance produced by the dex- mutant uab108 was designated dextranase inhibitor (dei) and identified as a protein. the dei gene (dei) from uab108 has been cloned into pacyc184 to yield pya2651, which was then used to generate several subclones (pya265 ... | 1994 | 7961493 |
| action of sodium fluoride on phagocytosis by systemic polymorphonuclear leucocytes. | alterations in phagocytosis appear to be important in the onset and development of periodontitis. we investigated new substances that may be of use in the treatment of periodontitis. in a preliminary study, we tested the effect of sodium fluoride on phagocytosis by circulating polymorphonuclear leucocytes (pmns) in 10 replicate assays using blood from six healthy subjects. sodium fluoride was tested at concentrations of 1.0 micron to 4.0 microns against streptococcus oralis, streptococcus mutans ... | 1994 | 7962905 |
| reduction of caries and of demineralization around orthodontic brackets: effect of a fluoride-releasing resin in the rat model. | the effectiveness of fluoride in reduction of caries is well known. this study examined the ability of a fluoride-releasing resin to reduce caries, as well as demineralization around orthodontic brackets, by using the sprague-dawley rat as a model. eighteen-day-old rats were infected with cariogenic streptococcus sobrinus 6715. after infection was confirmed, standard orthodontic techniques were used to bond miniature orthodontic brackets to the lingual surfaces of maxillary first molars, with ei ... | 1994 | 7977203 |
| fluoride inhibits the glucan-binding lectin of streptococcus sobrinus. | the glucan-binding lectins of streptococcus cricetus aht and streptococcus sobrinus 6715 were reversibly inhibited by sodium fluoride. fluoride was superior to chloride, bromide, iodide and thiocyanate in preventing glucan-mediated aggregation of the bacteria. fluoride was also an effective inhibitor of the sucrose-dependent adhesion of s. sobrinus to glass surfaces. the inhibition of glucan-binding lectin activities may be one of the mechanisms of action of fluoride in preventing dental disease ... | 1994 | 7988914 |
| composition and flow rate of saliva and caries development in young rats following administration of lithium. | lithium carbonate (li2co3), an antipsychotic medication, was investigated to determine the effects on the stimulated flow and composition of saliva and on caries development in rats. lithium carbonate was delivered via osmotic pumps at 10, 15 and 60 mg/kg/day. all animals were infected with streptococcus sobrinus 6715 and fed a cariogenic diet. lithium administration exerted a caries-protective effect on sulcal surfaces, though the reduction in caries scores was statistically significant only fo ... | 1994 | 8001056 |
| immunochemical study of polysaccharide antigen in streptococcus sobrinus and streptococcus downei with a cross-reactive monoclonal antibody. | a monoclonal antibody (mab h-448) was prepared after cell fusion of mouse myeloma cells (sp2/0-ag-14) to the spleen cells of mice immunised with serotype h strain (mf25) of streptococcus downei. the antibody (igm class) reacted in enzyme immunoassay only with whole cells as well as purified polysaccharide (ps) antigen of streptococcus sobrinus (types d and g) and streptococcus downei (serotype h), but not with cells or purified ps antigen from any other serotypes of the mutans group of streptoco ... | 1994 | 8004057 |
| in vitro activation of the classical pathway of complement by a streptococcal lipoteichoic acid. | the purpose of this study was to find whether a glycerolphosphate-containing lipoteichoic acid prepared from streptococcus sobrinus omz 176 cells would activate the classical pathway of complement while in solution. reference activators were lipopolysaccharide from escherichia coli 0111:b4 and heat-aggregated immunoglobulin g. serum samples were taken from healthy students. analysis through crossed immunoelectrophoresis showed that lipoteichoic acid caused an almost complete dissociation of the ... | 1994 | 8008432 |
| localization on the cell surface of streptococcal protein antigen a. | the cellular localization of the major surface protein spaa of streptococcus sobrinus 6715 was examined by immunoelectron microscopy with rabbit polyclonal antibodies directed against purified spaa protein. immunoelectron microscopic analysis of thin sections of s. sobrinus cells revealed that the spaa protein is associated with the fibrillar fuzzy coat of s. sobrinus cells and appears to be distributed over the entire surface of s. sobrinus cells. | 1994 | 8013876 |
| enamel dissolution in relation to fluoride concentrations in the fluid of dental plaque-like layers of precultured streptococcus sobrinus. | two experiments were conducted to find out what concentration of fluoride (f), when added as naf to the fluid of an in vitro caries model, would be sufficient for full protection of the underlying enamel during a long (20 or 40 h) fall in 'plaque' ph. an existing caries model with bovine enamel and streptococcus sobrinus 'plaque' was employed, while the fluid phase was initially either fully or partially saturated with tricalcium phosphate. in the model with fully saturated and more strongly buf ... | 1994 | 8018049 |
| an investigation of diterpenes from the leaves of rabdosia trichocarpa and their antibacterial activity against oral microorganisms. | the ethanolic extract of rabdosia trichocarpa leaves showed antibacterial activity against cariogenic mutans streptococci and periodontopathic porphyromonas gingivalis. chromatographic separation and purification of the extract afforded ten diterpenes, including one novel ent-kauren type compound named trichoranin. some of these compounds possess potent antibacterial activity against these oral micro-organisms, indicating that these diterpenes may be useful natural substances for the maintenance ... | 1994 | 8020128 |
| purification and characterization of streptococcus sobrinus dextranase produced in recombinant escherichia coli and sequence analysis of the dextranase gene. | the plasmid (pya902) with the dextranase (dex) gene of streptococcus sobrinus uab66 (serotype g) produces a c-terminal truncated dextranase enzyme (dex) with a multicomplex mass form which ranges from 80 to 130 kda. the escherichia coli-produced enzyme was purified and characterized, and antibodies were raised in rabbits. purified dextranase has a native-form molecular mass of 160 to 260 kda and specific activity of 4,000 u/mg of protein. potential immunological cross-reactivity between dextrana ... | 1994 | 8021165 |
| oligonucleotide probes for mutans streptococci. | oligodeoxyribonucleotide probes complementary to hypervariable regions of the 16s ribosomal rna were designed for specificity toward streptococcus mutans and streptococcus sobrinus. the probes were tested for specificity and sensitivity by hybridization with nucleic acid from over 100 mutans and non-mutans oral streptococci and other common oropharyngeal bacteria. probes designated sm002 and sm010 were 100% sensitive and > 99% specific for s. mutans. probe ssp001, designed to detect both s. muta ... | 1994 | 8028611 |
| oral immunization with recombinant salmonella typhimurium expressing surface protein antigen a of streptococcus sobrinus: persistence and induction of humoral responses in rats. | recombinant salmonella typhimurium has been used as an oral vaccine for various microbial pathogens. here we report immune responses in fischer rats orally immunized with a recombinant s. typhimurium strain encoding surface protein antigen a (spaa) of streptococcus sobrinus. the attenuated s. typhimurium chi 4072 delta cya delta crp delta asd mutant used in this study contains the asd+ plasmid pya2905 expressing a fragment of the spaa protein. salmonella cells were cleared from spleens by 7 days ... | 1994 | 8039885 |
| definition of a fundamental repeating unit in streptococcal glucosyltransferase glucan-binding regions and related sequences. | the c-termini of the glucosyltransferases (gtfs) of oral streptococci are responsible for glucan binding. these glucan-binding domains (gbds) are composed of a series of repeated sequences that have been classified into four different classes (a-d) by virtue of sequence similarity and which, by inference, have been suggested to be of functional importance. in contrast, we propose that repeat sequences evolve in response to selection for an increase in the number of copies of a particular domain ... | 1994 | 8046101 |
| glucan-binding proteins of streptococcus sobrinus b13 grown in high glucose media. | to improve the yield of an 87-kda glucan-binding protein (gbp) of streptococcus sobrinus b13 (serogroup d), trypticase-yeast extract (tye) medium supplemented with higher (1 and 2%) than the usual amount (0.2%) of glucose was used for growth. the production of this gbp extracellularly in 1.0 and 2.0% glucose-tye media was examined and compared with the control (0.2% glucose). upon analysis using sds-page, extracellular culture concentrates of 1.0 and 2.0% glucose-tye cultures revealed similar pr ... | 1994 | 8055189 |
| a comparison of primary root caries lesions classified according to colour. | three hundred and ninety-five primary root caries lesions in 117 patients were included in this study. each lesion was clinically characterised (colour, dimensions, distance from gingival margin and texture) and a sample of infected or altered dentine was taken using a standardised sampling procedure. the relationships between the colour and the microflora, texture, physical dimensions and distance from the gingival margin of the lesions were investigated. lesions in each colour group (light bro ... | 1994 | 8069878 |
| residual effects of fluoride on a severe cariogenic challenge in rats. | the influence of temporary dietary restriction with and without fluoridated drinking water on the progression of caries was studied in 60 desalivated sprague-dawley rats. dietary restriction alone had little effect on caries progression when the challenge was interrupted and then resumed, in contrast to the effects of dietary restriction plus fluoride. animals subjected to gavage plus fluoride in the drinking water for 11 days developed significantly less severe lesions on their lingual surfaces ... | 1994 | 8069880 |
| significance of choice of solvents for the clinical effect of triclosan-containing mouthrinses. | the aim of this study was to investigate the plaque-inhibiting effect of triclosan. it is known that triclosan and sodium lauryl sulfate (sls) have a marked inhibitory effect. however, since sls has a plaque-reducing effect in itself, the relative importance of triclosan and the surfactant is undecided. twelve dental students participated in the trial, during which oral hygiene was suspended for 4-day periods when the different mouthrinses were used twice daily. the following mouthrinses were us ... | 1994 | 8091119 |
| effects of xylitol/sorbitol combinations on bacterial growth and metabolism in streptococcus sobrinus omz 176. | combinations of the non-cariogenic sugar alcohols xylitol and sorbitol are widely used as sucrose substitutes in lozenges and chewing-gums. in s. sobrinus omz 176 xylitol inhibits the metabolism of sorbitol, and the xylitol-induced bacterial growth inhibition of s. sobrinus omz 176 has been shown to be enhanced by sorbitol. in combination with xylitol the sorbitol transport changes from a pts- to a non-pts transport, while the transport of xylitol is unaffected by the presence of sorbitol. it wo ... | 1993 | 8110450 |
| growth phase-dependent regulation and membrane localization of spab, a protein involved in biosynthesis of the lantibiotic subtilin. | the information responsible for biosynthesis of the lantibiotic subtilin is organized in an operon-like structure that starts with the spab gene. the spab gene encodes an open reading frame consisting of 1,030 amino acid residues, and it was calculated that a protein having a theoretical molecular mass of 120.5 kda could be produced from this gene. this is consistent with the apparent molecular weight for spab of 115,000 which was estimated after sodium dodecyl sulfate-gel electrophoresis and id ... | 1994 | 8117069 |
| dental plaque inhibition by a combination of triclosan and polydimethylsiloxane (silicone oil). | it has previously been shown that a toothpaste which contains triclosan and polydimethylsiloxane (silicone oil) improved gingival health in a test panel with established gingivitis more markedly than usually observed when testing commercial triclosan-containing toothpastes. in the present study the mode of action of combinations of silicone oil and triclosan was investigated. an in vitro experiment showed that triclosan was retained in a thin layer of silicone oil on the inner surfaces of test t ... | 1994 | 8153574 |
| effect of fluoride on the rate of dentin apposition and caries progression in young and old wistar rats. | the effect of fluoride in drinking water on the progression of dentinal caries and dentin apposition was studied separately in young and old wistar rats. the animals were inoculated with streptococcus sobrinus and fed ad libitum on a 43% sucrose diet and distilled water supplemented with 0, 1, or 19 ppm fluoride. after a 7-wk (young) or 13-wk (adult) cariogenic challenge, the areas of dentinal caries and dentin apposition were quantified after tetracycline staining. fluoride in the drinking wate ... | 1994 | 8153575 |
| triclosan-containing mouthwashes--does the nature of the solvent influence their clinical effect? | the effect of triclosan on plaque inhibition was studied with various solvents. eight subjects used the solutions as mouthwashes twice daily for 4 days while refraining from any other form of oral hygiene. bacteriologic tests were also done with the same solutions. the study showed that the nature of the substance used to dissolve triclosan may be of clinical significance. solutions of triclosan in polyethylene glycol, glycerol, or 3% sodium lauryl sulfate (sls) alone showed marked antiplaque ef ... | 1994 | 8153578 |
| subsite specificity of the active site of glucosyltransferases from streptococcus sobrinus. | oral bacterial glucosyltransferases use sucrose as a substrate in synthesis of either alpha-1,3 water-insoluble glucans (gtf-i) or alpha-1,6 water-soluble glucans (gtf-s). the binding specificity of the glucosyl and fructosyl subsites of the sucrose-binding site was examined to identify ligands that bind exclusively to each subsite. such compounds can be used as reporter ligands to localize the subsite binding of any reversible or irreversible active site inhibitor. in examining potential subsit ... | 1994 | 8163499 |
| pilocarpine alters caries development in partially-desalivated rats. | this study examined the effect of pilocarpine on caries and saliva composition in rats with compromised salivary gland function. eight litters of specific-pathogen-free female sprague-dawley rats were divided into five groups for surgery. partial desalivation was performed in either of three ways: (1) both parotid ducts were ligated; (2) both submandibular/sublingual (sm/sl) glands were excised, or (3) one parotid duct was ligated, and submandibular/sublingual glands were removed unilaterally. c ... | 1994 | 8163734 |
| cloning and sequencing the endocarditis immunodominant antigen of streptococcus sobrinus strain mucob 263. | immunoblotting sera from cases of streptococcus mutans or s. sobrinus endocarditis against an extract from s. sobrinus strain mucob 263 had identified three immunodominant antigenic bands at 190, 200 and 220 kda. a lambda zapii dna library was produced from the sheared genomic dna of s. sobrinus mucob 263 and six identical positive clones were identified when this library was screened with serum from a patient with endocarditis caused by a bacterium from the mutans group of streptococci. on subc ... | 1994 | 8176720 |
| [3 different methods for evaluating streptococcus mutans in the saliva]. | three different methods for detection and count of streptococcus mutans in saliva have been compared with a microbiological method in order to estimate their efficacy and practicality. the study has been carried out on fifty children of six-eleven years old. the first method (stamp method) derives from that of kohler and bratthall, improved on the sampling, without saliva stimulation and, hence, more rapid. furthermore, using a tongue depressor with a shovel-like extremity, we can either restric ... | 1994 | 8183202 |
| cloning of a streptococcus sobrinus oligo-isomaltosaccharide synthase gene and characterization of its product. | a streptococcus sobrinus gene coding for a glucosyltransferase (gtf)-s was cloned into escherichia coli, using the bacteriophage lambda l47.1 and the plasmid vector pacyc184. the md124 clone obtained expressed a 155 kda gtf-s which did not react with any antisera against gtf-s1, -s2 and -i enzymes. the recombinant enzyme (designated rgtf-s3) was homogeneously purified from the md124 cell-extract and characterized. the purified rgtf-s3 synthesized primer-independently alpha-1,6-linked linear olig ... | 1993 | 8193601 |
| microbiological validation of assessments of caries activity during cavity preparation. | the operative management of primary and secondary caries assumes that all discoloured tissue at the enamel-dentine junction (edj) represents active disease and this is removed to arrest the carious process. this study aims to establish clinical criteria to differentiate between active and arrested caries at the edj using microbiological assessment of dentine samples to verify its clinical status. radiographs were available for posterior teeth. cavities (n = 205) were prepared under rubber dam. a ... | 1993 | 8242678 |
| the effect of glass-ionomer cement on carious dentine: an in vivo study. | the effect of a glass-ionomer cement sealant on carious dentine was investigated clinically and bacteriologically. the study group consisted of 24 molar teeth, with small clinical visible occlusal dentine lesions, in 13 children (aged 7-18 years). twenty of these molars were filled and sealed with a glass-ionomer cement (fuji ionomer type iii) and 4 with a resin sealant (delton). from each molar, two dentine samples were collected aseptically with a time interval of 7 months. the first sample wa ... | 1993 | 8242680 |
| dental caries and cariogenic factors in pre-school urban icelandic children. | caries prevalence and several caries-related factors were measured in 158 pre-school children in reykjavík, initially aged 4 years and followed longitudinally for 2 years. the mean dmfs at 4 years was 3.3 and rose to 5.8 at 6 years although 34% remained caries-free throughout the study. caries was very unevenly distributed. children with dmfs > or = 5 at 4 years were significantly more likely to have caries in their permanent dentition at 6 years than those with a lower caries score at 4 years. ... | 1993 | 8242682 |
| phenotypic characterization of oral streptococci by classical methods. | the phenotypic characteristics of 215 strains of oral streptococci were compared on the basis of the results of sorbitol, raffinose and trehalose fermentation, ammonium from arginine production, aesculin hydrolysis, h2o2 production, susceptibility to 2 u bacitracin, and growth in 4% nacl solution. eleven different species were identified. among the most noteworthy findings were the low number of h2o2-producing strains of streptococcus sobrinus, the effective discrimination between streptococcus ... | 1993 | 8264436 |
| [experimental study on the interaction of fibronectin with oral streptococci]. | interaction of fibronectin (fn) with streptococcus mutans, s. sorbrinus, and s. milleri is demonstrated by an enzyme-linked immunosorbent assay (elisa). the results show that the three strains are able to adhere to fn. the interaction may be strengthened while the concentration of fn increases (q test p < 0.01). the ability of adherence among s. mutans, s. sorbrinus and s. milleri is different in fn high concentration (q test p < 0.01). it is speculated the free fn in saliva may serve as an aggl ... | 1993 | 8275808 |
| the effect of propranolol on salivary gland function and dental caries development in young and aged rats. | medications commonly used in elderly people cause hyposalivation and are associated with an enhanced prevalence of dental caries. propranolol (a beta-adrenergic antagonist) is a commonly used antihypertensive agent that is prescribed for long-term use. the purpose of this investigation was to compare the effects of this drug on salivary composition and flow rate, and on caries, in young and aged rats. forty young (28-day) and 36 aged (20-month) female sprague-dawley rats were infected with strep ... | 1993 | 8279990 |
| effect of milk on cariogenesis. | sprague-dawley rats fed diet 2000, infected by streptococcus sobrinus, and offered milk or lactose-reduced milk as drinking fluids developed essentially similar caries scores as controls given distilled water. in contrast, animals given fructose or sucrose solutions developed enhanced levels of caries. significant differences were not detected in the s. sobrinus populations among the groups. in further experiments, the addition of sucrose to milk enhanced the severity of caries scores. however, ... | 1993 | 8281559 |
| a longitudinal study of dental caries and cariogenic microflora in a group of young adults from göteborg. | caries and cariogenic microorganisms were assessed in a group of young adults over a 3-year period. a 30% random sample comprising 101 individuals aged 18-19 years was re-examined under conditions consistent with the baseline survey 3 years earlier. the means for dfs prevalence and increment were 8.9 and 2, respectively. continuing polarization of the disease was observed, with mean dfs score reaching 19.9 in the upper 15% of the frequency distribution. highest caries activity was observed appro ... | 1993 | 8291028 |
| grouping of oral streptococcal species using fourier-transform infrared spectroscopy in comparison with classical microbiological identification. | the grouping and identification made by fourier-transform infrared spectroscopy (ft-ir) of 40 oral streptococcal strains was compared with their known taxonomic positions. grouping was obtained by cluster analysis on the spectral distances between the first derivative spectra of the strains. spectra were divided into five spectral 'windows' and cluster analysis was either on either a combination of all five windows or on a selected window. the oral streptococci were divided into two main cluster ... | 1993 | 8297255 |
| identification and characterization of a mobilization gene in the streptococcal plasmid, pva380-1. | the 4.2-kb cryptic streptococcal plasmid, pva380-1, has a broad host range and replicates via a rolling circle mode. the nucleotide base sequence of the 2.5-kb basic replicon of this plasmid, containing a plus origin, a minus origin, and a rep gene, was reported previously. the completed nucleotide base sequence of pva380-1 revealed the presence of two additional open reading frames, orf2 and orf3. the protein predicted by orf2 shared 74% amino acid identity with the mob protein of the group b s ... | 1993 | 8302939 |
| dna sequence of the glucosyltransferase gene of serotype d streptococcus sobrinus. | a glucosyltransferase (gtf) gene was cloned into escherichia coli from serotype d streptococcus sobrinus omz176. transformed e. coli strain mi expressed water-insoluble glucan synthesizing activity. restriction enzyme map of pgt31 extracted from mi shows that the enzyme gene exists in the 6.4-kb psti-fragment inserted into pbr322 vector. dna sequence analysis indicates that a single orf (530-5,300) is located in the psti-fragment. the putative amino-acid composition (1,590 residues) resembles th ... | 1993 | 8312602 |
| oolong tea polyphenols inhibit experimental dental caries in spf rats infected with mutans streptococci. | an extract of oolong tea (semifermented tea leaves of camellia sinensis) and its chromatographically isolated polyphenolic compound was examined for in vitro inhibitory effects on glucosyltransferases (gtases) of mutans streptococci and on caries development in sprague-dawley rats infected with mutans streptococci. the samples showed no detectable effect on the growth of mutans streptococci. however, insoluble glucan synthesis from sucrose by the gtases of streptococcus mutans mt8148r and strept ... | 1993 | 8319255 |
| distribution of streptococcus mutans and streptococcus sobrinus at sub-sites in human approximal dental plaque. | the distribution and prevalence of streptococcus mutans and streptococcus sobrinus were determined at three sub-sites in human approximal plaque: away from (a), to the side of (s) and below (b) the contact area. small plaque samples were taken from all three sub-sites on clinically sound approximal surfaces of a single premolar from each of 21 schoolchildren. s. mutans was detected significantly more often and in higher proportions than s. sobrinus from sub-sites a (p = 0.019), s (p = 0.034) and ... | 1993 | 8319257 |
| molecular characterization of a negative regulator of streptococcus sobrinus surface protein antigen gene. | mutans streptococci have been shown to give rise to variants in terms of expression of surface protein antigens by repeated subculturing of the organisms, which in turn induces changes in colonial morphologies. a 2,850-bp upstream region of the gene (pag) for a surface protein antigen, pag, of streptococcus sobrinus mt3791 was determined. analysis of the nucleotide sequence revealed the existence of three open reading frames (orfs) located upstream of the pag gene. orf1 extended from an undeterm ... | 1993 | 8331066 |
| essential amino acids involved in glucan-dependent aggregation of streptococcus sobrinus. | the active site of the glucan-binding lectin (or agglutinin) (gbl) of streptococcus sobrinus was probed by specific amino acid modifying reagents. reagents specific for carboxylates, imidazolium, phenolic, and lysyl residues inactivated the cell bound gbl, whereas agents specific for sulfhydryl, disulfide, and guanidinium groups had no effect on the lectin. a low molecular weight alpha-(1-->6)-glucan provided partial protection against the reagents which inactivated the protein, whereas an alpha ... | 1993 | 8339298 |
| a simple method for monitoring mutans streptococci in margins of restorations. | plaque material collected from margins of restorations using a sharp toothpick was streaked across one and the same plastic strip from a commercially available test kit and inoculated in a liquid medium containing bacitracin. the reproducibility of the method was good. the method is simple, inexpensive and suitable for the chairside demonstration of the colonization of mutans streptococci in localized areas of the mouth, such as margins of restorations. | 1993 | 8354746 |
| unexpectedly high levels of some presumably protective secretory immunoglobulin a antibodies to dental plaque bacteria in salivas of both caries-resistant and caries-susceptible subjects. | the role of salivary antibodies in protection against cariogenic bacteria is actually a matter of debate. correlation between caries experience and naturally occurring antibodies was extensively investigated. comparison of salivary antibodies from 21 caries-resistant and 22 caries-susceptible subjects was carried out by using a new quantitative method. secretory immunoglobulin a (s-iga) antibodies to streptococcus sobrinus and streptococcus sanguis cells were detected in all salivas and at simil ... | 1993 | 8359882 |
| in vitro demineralization by strains of actinomyces viscosus and streptococcus sobrinus of sound and demineralized root surfaces. | root sections were inoculated with one of two strains of actinomyces viscosus or a strain of streptococcus sobrinus and then incubated for 9 days in trypticase soy broth (tsb) containing 0.25% glucose or tsb supplemented with 0.25% sucrose (tsb+s). lesion progression was measured from microradiographs. one section from each group was examined with a transmission electron microscope. lesion progression was associated with a fall in the ph of the medium. however, lesion progression was not correla ... | 1993 | 8360359 |
| protective effect of topically applied fluoride in relation to fluoride sensitivity of mutans streptococci. | the aim of the present in vitro experiments was to determine whether the protection of enamel by topically applied fluoride against demineralization by bacterial acids would depend on the fluoride sensitivity of the bacteria. glucose-agarose gel suspensions of fluoride-sensitive and fluoride-resistant mutans streptococci were placed on bovine enamel specimens with different amounts of fluoride. one group of specimens was untreated, a second group had been pretreated with a f-lacquer, and a third ... | 1993 | 8360360 |
| dissociation and electrophoretic separation of dextranase and dextranase inhibitor from a tightly bound enzyme-inhibitor complex of streptococcus sobrinus. | endodextranase was separated from dextranase inhibitor in culture filtrates of streptococcus sobrinus by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (sds-page) in gel slabs containing blue dextran. sample preparation included dissociation of the enzyme from its inhibitor by boiling for 1 min in sds. during subsequent incubation of the gel, dextranase was located as clear bands on a blue background, and dextranase inhibitor appeared as blue zones on a clear background following inc ... | 1993 | 8375352 |
| acquisition of manganous ions by mutans group streptococci. | the cariogenic bacteria streptococcus sobrinus and s. cricetus were shown to have an absolute requirement for manganous ion in order to bind glucans or to adhere to glass in the presence of sucrose. the bacteria possessed a reasonably high affinity transport system for 54mn2+, yielding a km of about 12 microm. the vmax for uptake of 54mn2+ in s. sobrinus was increased when the bacteria were grown in mn-depleted medium, but the km remained the same. there was no evidence for two mn2+ uptake syste ... | 1993 | 8380803 |
| agglutination of streptococcus mutans serotype c cells but inhibition of porphyromonas gingivalis autoaggregation by human lactoferrin. | the ability of various forms of human lactoferrin (lf) to agglutinate oral streptococcus mutans, strep. sobrinus, strep. rattus, strep. sanguis, porphyromonas gingivalis and actinobacillus actinomycetemcomitans cells was studied spectrophotometrically. fe3+ saturated lf was unable to agglutinate these bacteria, whereas iron-free lf (apo lf) effectively agglutinated strep. mutans cells but not the other bacteria. the efficiency and rate of agglutination of strep. mutans were somewhat lower with a ... | 1993 | 8387771 |
| biochemical properties of streptococcus sobrinus reisolates from the gastrointestinal tract of a gnotobiotic rat. | streptococcus sobrinus strain 6715-13-201 was inoculated into the oral cavity of a gnotobiotic rat and then reisolated from different portions of the gastrointestinal tract. fourteen isolates, selected on the basis of their colonial morphology, were then screened for their ability to adhere to saliva-coated hydroxyapatite (sha) in vitro, and their ability to produce extracellular polysaccharide from sucrose, and low ph in glucose broth. certain isolates were also tested for their cariogenic pote ... | 1993 | 8393069 |
| close association between streptococcus sobrinus in the saliva of young children and smooth-surface caries increment. | three hundred and thirty-eight children (age range 3-5 years) were examined for the presence of mutans streptococci in their saliva. they were divided into four groups according to the prevalent species that were isolated: (1) streptococcus mutans and streptococcus sobrinus group (s. mutans > or = 10(3) cfu/ml and s. sobrinus > or = 10(3) cfu/ml); (2) s. mutans group (s. mutans > or = 10(3) cfu/ml but s. sobrinus < 10(3) cfu/ml); (3) s. sobrinus group (s. sobrinus > or = 10(3) cfu/ml but s. muta ... | 1993 | 8402804 |
| expression and secretion of an arthrobacter dextranase in the oral bacterium streptococcus gordonii. | we have constructed a plasmid to express and secrete dextranase in the oral bacterium streptococcus gordonii. the dextranase gene from arthrobacter sp. strain cb-8 was linked to a promoter and a dna sequence encoding the signal peptide of streptococcus downei glucosyltransferase i (gtfi) followed by the escherichia coli rrnbt1t2 terminator and inserted in the shuttle vector pva838. s. gordonii transformed with this plasmid (pmnk-4) expressed and secreted mature arthrobacter dextranase. the trans ... | 1993 | 8406828 |
| comparison of aminopeptidase activities in four strains of mutans group oral streptococci. | in this study, native cells of streptococcus mutans va-29r and streptococcus rattus fa-1 displayed significantly higher aminopeptidase activity than did cells of streptococcus cricetus aht or streptococcus sobrinus 6715 toward the nitroanilide derivatives of leucine, alanine, methionine, arginine, and lysine. these differences in cellular aminopeptidase activity led us to investigate the subcellular localization of the aminopeptidase in these mutans group streptococci. following conversion of na ... | 1993 | 8418040 |
| effects of n-acetylglucosamine on carbohydrate fermentation by streptococcus mutans nctc 10449 and streptococcus sobrinus sl-1. | we have investigated the ability of two species of streptococci isolated from the human oral cavity (streptococcus mutans nctc 10449 and streptococcus sobrinus sl-1) to metabolize n-acetylglucosamine (glcnac), a naturally occurring amino sugar present in saliva and human glycoproteins, when provided as the sole fermentable carbohydrate and determined the effects of the presence of glcnac on the fermentation of other carbohydrates. s. mutans used glcnac at concentrations of up to 10 mm to increas ... | 1993 | 8418050 |
| effects of selected surfactants on purified glucosyltransferases from mutans streptococci and cellular adherence to smooth surfaces. | the inhibitory effect of non-ionic, anionic, cationic and ampholytic surfactants on cellular growth of streptococcus mutans mt8148 and s. sobrinus 6715, on glucan synthesis by the purified glucosyltransferase (gtase) from these organisms, and on bacterial adherence to glass surfaces was examined in vitro. cationic surfactants exhibited marked bactericidal activities. anionic and ampholytic compounds were less strongly bactericidal and non-ionic surfactants produced only slight inhibition of cell ... | 1993 | 8418294 |
| escherichia coli heat-labile toxin subunit b fusions with streptococcus sobrinus antigens expressed by salmonella typhimurium oral vaccine strains: importance of the linker for antigenicity and biological activities of the hybrid proteins. | a set of vectors possessing the genes for aspartate semialdehyde dehydrogenase (asd) and the b subunit of the heat-labile enterotoxin of escherichia coli (lt-b) has been developed. these vectors allow operon or gene fusions of foreign gene epitopes at the c-terminal end of lt-b. two groups of vectors have been constructed with and without leader sequences to facilitate placing of the foreign antigen in different cell compartments. two streptococcus sobrinus genes coding for principal colonizatio ... | 1993 | 8432584 |
| four different types of glucans synthesised by glucosyltransferases from streptococcus sobrinus. | four different kinds of glucosyltransferases (gtfs) were purified from the cariogenic bacterium streptococcus sobrinus aht. one of them (gtfp3) produced water-insoluble glucan with the alpha-1,3 linkage, exclusively. the others (gtfp1, p2 and p4) produced water-soluble glucans. gtfp2 produced oligosaccharides with linear 1,6-alpha-d-glucan structure. since gtfp1 and p4 produce similar molecular weight glucans, the structural differences between these glucans remain unclear. to clarify the differ ... | 1993 | 8441354 |
| effect of monoclonal antibodies on the colonization of rats by streptococcus sobrinus. | local passive immunization has been suggested as a method of preventing colonization of teeth by mutans streptococci. in this study we describe the effect of local application of monoclonal antibodies (mabs) on the colonization of streptococcus sobrinus. the rats, 37 days old, were divided in 4 groups: group 1 received mab omvu10 (mab reactive with antigen b of s. sobrinus, igg2b), group 2 received clone 24 (mab reactive with lipid a of escherichia coli, igg2b), group 3 received uninoculated cul ... | 1993 | 8448771 |
| a microbiological study of primary root-caries lesions with different treatment needs. | samples of altered or carious dentin for microbiological culture were obtained from 301 primary root-caries lesions in 59 patients by means of a standardized sampling procedure. this involved the cleansing of each root surface of extraneous supragingival plaque by means of a hand-held toothbrush and distilled water and the collection of the sample with a sterile dental excavator passed through the entire vertical dimension of each lesion. the total number of colony-forming units (cfu) in each sa ... | 1993 | 8450122 |
| the use of a caries detector dye during cavity preparation: a microbiological assessment. | during cavity preparation conventional tactile and optical criteria are used to assess the caries status of the enamel-dentine junction, cavity preparation being considered complete when this area is hard to a sharp probe and stain free. in the present study 201 cavities were prepared under rubber dam. when caries removal was considered complete using the conventional tactile and optical criteria, a caries detector dye (1% acid red in propylene glycol), which is claimed to stain 'infected' tissu ... | 1993 | 8461203 |