SEARCH · PubMed Health

Results for “Streptococcus mutans”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,027 records · Page 57Linked to original sources

PubMed1989

Interaction between surface protein antigens of Streptococcus mutans and human salivary components.

The potential involvement of surface antigens (Ags) I/II and III of Streptococcus mutans in its adherence to salivary pellicle-coated tooth surfaces was investigated. The binding of radiolabelled Ag I/II to hydroxyapatite was increased by pretreating the mineral with human parotid saliva, and binding was maintained in the continuous presence of saliva. Binding of Ag III to hydroxyapatite was inhibited by pretreatment with, or in the presence of, saliva. Various aminohexoses, and also tris, inhibited the binding of Ag I/II. When Ags I/II and III were tested for their ability to bind to salivary components separated by SDS gel electrophoresis, several proteins capable of binding Ag I/II were identified, notably 2 proteins of apparent relative molecular mass 28,000 and 38,000. Analysis of these proteins, isolated by micro-preparative electrophoresis, indicated high proportions of proline, glycine, and glutamic acid, and overall compositions similar to basic proline-rich salivary proteins.

Antigens, Bacterial↗

PubMed1997

Effects of acidification on growth and glycolysis of Streptococcus sanguis and Streptococcus mutans.

After carbohydrate intake, pH in dental plaque decreases rapidly and reaches about 4 within a few minutes. The acidification not only promotes demineralization of tooth surface but can also cause damage to bacteria in dental plaque. We, therefore, investigated the effect of acidification on the dental plaque bacteria Streptococcus sanguis and Streptococcus mutans. At pH 4.0 and 4.2, both growth and glycolytic activities in these streptococci were repressed. Prolonged acidification (for 60 min at pH 4.0) not only repressed both growth and glycolytic activities but also impaired them in S. sanguis cells with concomitant inactivation of the glycolytic enzymes, hexokinase, phosphofructokinase, glyceraldehydephosphate dehydrogenase and enolase. The impaired abilities of glycolysis and growth recovered following incubation at pH 7.0 for 80-90 min, and this was accompanied by reactivation of the glycolytic enzymes. On the other hand, these impairments were not observed in S. mutans cells exposed to prolonged acidification. These results indicate that the low pH frequently occurring in dental plaque may transiently impair streptococcal glycolysis and growth and that S. mutans is more durable to the acidification than S. sanguis.

Culture Media, Conditioned↗

PubMed1989

Genetic linkage among cloned genes of Streptococcus mutans.

Mapping vectors containing antibiotic resistance markers inserted adjacent to or within different cloned genes from Streptococcus mutans were used to determine the relative positions of these genes on the chromosome. The gtfA, ftf, and scrB genes were inserted into streptococcal mapping vector pVA891 adjacent to an Emr gene, whereas the Emr marker was inserted directly into the gtfB gene. These chimeric plasmids were transformed into S. mutans GS-5, selecting for Emr transformants. To determine the positions of the cloned genes relative to each other, it was necessary to construct plasmids labeled with a different antibiotic resistance marker. Thus, a Tetr gene was inserted adjacent to gtfB in the appropriate mapping vector and within the ftf and scrB genes with a mini-Mu transposon (Mu dT). The chimeric plasmids were transformed into the appropriate Emr recipients, and the DNA from the resulting Emr Tetr transformants was used in linkage studies. Based on the cotransfer data, gtfB was not closely linked to gtfA, ftf, or scrB. However, gtfA cotransferred with ftf and scrB at frequencies of approximately 96 and 80%, respectively. The percent cotransfer of ftf and scrB was approximately 92. These data indicate that the three genes are clustered on the GS-5 chromosome, with ftf located between gtfA and scrB. Little, if any, linkage was observed between these genes and a variety of other random markers.

Cloning, Molecular↗

PubMed1984

Oral implantation in humans of Streptococcus mutans strains with different degrees of hydrophobicity.

The more hydrophobic, rough-colony-forming, streptomycin-resistant Streptococcus mutans parent strains GW Smr and LK Smr and the less hydrophobic, smooth-colony-forming, streptomycin-resistant variant strains GW36 Smr and LK36 Smr were implanted in oral cavities. Strains GW Smr and LK Smr implanted significantly better than strains GW36 Smr and LK36 Smr. The hydrophobicity of and the colony morphology formed by the different S. mutans strains did not seem to be affected throughout the experiment.

Adhesiveness↗

PubMed1981

Isolation and characterization of Streptococcus mutans mutants defective in adherence and aggregation.

A method was developed which enriched for mutants of Streptococcus mutans that exhibit defects in adherence to glass, aggregation, or both. Mutants were isolated from derivatives of strains PS14 (serotype c) and 6715 (serotype g) after mutagenesis with either ethyl methane sulfonate or nitrous acid. Cell survival after mutagenesis was kept above 1 to 2% to enhance the probability that mutants resulted from single mutational events. A total of 117 mutants were isolated; they also displayed non-wild-type colony morphology on mitis salivarius agar. These mutants were examined for (i) adherence and aggregation after overnight growth in sucrose-containing medium, (ii) aggregation of nongrowing cells in the presence of 200 microgram of sucrose per ml or 20 microgram of dextran per ml, and (iii) dextranase production on blue dextran agar plates. Although we isolated mutants which exhibited a variation from the parent strain in only one of the traits tested, the majority of mutants exhibited defects in two or more characteristics. Thirty-eight stable mutants of independent origin were categorized into 13 separate phenotypic groups.

Cell Adhesion↗

PubMed1986

A comparative study of the extracellular glucosyl- and fructosyltransferases from cariogenic and non-cariogenic Streptococcus mutans strains of two different serotypes.

Extracellular proteins from continuous cultures of serotype c and g Streptococcus mutans strains were separated by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulphate. Gels stained with raffinose after electrophoresis revealed that although serotype c strains secrete two fructosyltransferases of molecular mass 68 kDa and 79 kDa, no fructosyltransferase was secreted by the serotype g strain K1. A sucrose activity stain was used to detect two glucosyltransferases (GTF) of molecular mass 162 kDa (bifunctional 1,6-alpha-D-glucan 3-alpha- and 6-alpha GTF or 'dextransucrase') and 153 kDa (a 1,3-alpha-D-glucan 3-alpha-GTF) in samples from cariogenic serotype c strains. Neither the 153 kDa protein nor the corresponding GTF activity was secreted by the non-cariogenic mutant C 67-25. The molecular masses of the corresponding 1,3-alpha and 1,6-alpha-GTF proteins from the serotype g strain K1 were 164 kDa and 158 kDa, respectively. All of the GTF proteins were degraded to discrete bands of lower molecular mass on storage at 4 degrees C even after extensive purification. The results provide an explanation for several outstanding controversies in the GTF literature.

Dental Caries↗

PubMed1990

Evidence that mutacin II production is not mediated by a 5.6-kb plasmid in Streptococcus mutans.

Here we present evidence that the cryptic 5.6-kb plasmid found in certain strains of Streptococcus mutans is not involved in mutacin production. This evidence comes from demonstrating similarities between a plasmid-less strain T8 and a group II plasmid strain UA96. Both produce what appears to be an identical mutacin based on spectrum of activity and physiological properties. Also, T8 and UA96 are members of the same immunity group (group II). Genotypically, both strains appear similar except for plasmid content based on DNA fingerprinting profiles. T8 and UA96 exhibit identical hybridization patterns following transformation of T8 with a mutacin-negative (bac-1::Tn916) sequence from a Tn916-insertionally inactivated mutant of UA96. This transformation also resulted in the mutacin-negative phenotype in T8 transformants, showing recombination between a mutacin-associated gene in UA96 and its apparent homologous sequence in T8. Moreover, when a plasmid containing a putative repeat element from UA96 (pPC264) was used as a probe, it hybridized to the same five EcoRI fragments in both T8 and UA96. Collectively, these data, coupled with data from other sources, indicate that the plasmid resident in mutacin II strains is not involved in mutacin production.

Bacteriocins↗

PubMed1998

Generation of bioluminescent Streptococcus mutans and its usage in rapid analysis of the efficacy of antimicrobial compounds.

The oral bacterium Streptococcus mutans was transformed by electroporation with a shuttle vector (pCSS945) containing insect luciferase gene from a click beetle (Pyrophorus plagiophthalamus) resulting in a bioluminescent phenotype. This S. mutans strain was used in experiments in which light emission was used as a rapid and, compared to conventional CFU counting, more convenient means of estimating the effects of various antimicrobial treatments. The basic parameters affecting in vivo light production by the strain were studied. It was found that pH 6.0 was optimal for incorporation of the substrate D-luciferin for the luciferase reaction. The optimum concentration of D-luciferin was approximately 150 microM at room temperature. Under optimum conditions the light emission in vivo increased rapidly to a constant level and thereafter had a decay of 0.6%/min when logarithmic-growth-phase cells were used. The light emission closely paralleled the numbers of CFU, giving a detectable signal from 30,000 cells and having a dynamic measurement range over 4 log CFU/relative light unit. The cells were treated with various antimicrobial agents, and the emitted bioluminescence was measured. With the bioluminescent measurements, the results were obtained within hours compared to the days required for agar plates, and also, the kinetics of the antibacterial actions could be followed. Thus, the light emission was found to be a reliable, sensitive, and real-time indicator of the bacteriostatic actions of the antimicrobial agents tested.

Adenosine Triphosphate↗

PubMed1981

Virulence of Streptococcus mutans: characterization of a serotype g antigen-defective mutants and its revertants.

A mutant of Streptococcus mutans 6715 HSR, which is defective in serotype antigen and designated C307, was shown to exhibit full virulence on buccal, sulcal, and proximal surfaces similar to that of 6715 HSR. In addition, this bacterium caused significant decay on the lingual surfaces. Its colonial morphology and certain biochemical activities which may be related to caries production were distinct from those of 6715 HSR. This mutant adsorbed to saliva-treated hydroxyapatite beads in greater amounts and aggregated in the presence of either sucrose or dextran in excess of that seen with the parent strain. The abilities of C307 to grow and to produce acid from sucrose and to adhere to glass surfaces were similar to that of 6715 HSR. Although revertants of C307 exhibited biological activities and a content of serotype g antigen similar to that of 6715 HSR, the virulence pattern was still unlike the parent strain. These results suggest that the serotype g antigen is not required for the adherence of cells to smooth surfaces or for caries formation and that the loss of this antigen may alter the surface of cells causing enhanced ability of the cells to aggregate and to adsorb to saliva-treated hydroxyapatite beads.

Animals↗

PubMed2002

[Intranasal immunization against dental caries with plasmid DNA encoding pac gene of Streptococcus mutans in gnotobiotic rats].

OBJECTIVES: To assess the efficacy of plasmid DNA encoding pac gene of Streptococcus mutans (S. mutans) intranasally immunized in gnotobiotic rats and to compare the effect of two different delivery systems. METHODS: Sprague Dawley rats, infected with S. mutans at 20 days of age, were intranasally immunized with plasmid pCIA-P (group A), Dosper-DNA complex (group B), Bupivacaine-DNA complex (group C). Control rats were either immunized with plasmid pCI (group D), distilled water (group E) or immunized intramuscularly (group F). All the rats were boosted 2 weeks later. ELISA determined the antibodies against the vaccines. Keyes caries score was used to evaluate the anti- caries effectiveness of the vaccines at the terminal study. RESULTS: As for the antibody reactions, there were significantly (P < 0.01) differences between rats immunized with DNA vaccine and non-immunized rats. And rats in group B and C had the significantly (P < 0.01) higher level of specific salivary anti-PAc IgA antibodies and rats (group B, C, F) had the significantly (P < 0.01) higher specific serum anti-PAc IgG responses to DNA vaccine. Keyes scores of rats (group B and C) were significantly (P < 0.01) lower than others. CONCLUSIONS: Intranasal immunization with plasmid pCIA-P encoding pac gene successfully reduces the caries and appears to be a promising approach against dental caries. Cationic liposome Dosper and local anesthetic bupivacaine could enhance the efficacy of DNA vaccine.

Administration, Intranasal↗

PubMed1982

Synthesis of glucan on the cell surface of Streptococcus mutans: chemical and scanning electron microscopic studies.

The appearance and continuing growth of extracellular material on Streptococcus mutans HS6 cells in sucrose-containing Merthiolated buffer was observed in a scanning electron microscope and was found to be related to the glucan synthesis on the cell and to adherence of the cell to a smooth surface. Cells grown in broth completely deprived of sucrose by invertase (HS6-IV) had a characteristic, slightly rugged surface structure. On incubation of HS6-IV in the sucrose-containing buffer, a few small globular particles appeared on the surface and grew to an irregular shape (globular to fibrilar) after several hours. The increase in the total glucan content of the cells paralleled the growth of the globular material, to which ferritin-conjugated anti-dextran globulin was found to bind. On the cell surface of cells harvested from conventional broth, both small globular and irregular structures, which possibly formed from sucrose in the broth, existed originally and continued to grow during incubation, along with the material newly appearing on the surface. The accumulation of glucan on the cells resulted in their adherence to a glass surface. The inhibition of growth of the extracellular material on the cells by trypsin, dextranase or anti-glucosyltransferase corresponded to the decrease in glucan synthesis and the loss of adhering ability. These results indicated that the material growing on the cell surface was glucan synthesized by glucosyltransferases.

Adhesiveness↗

PubMed1987

Local response in rat to liposome-associated Streptococcus mutans polysaccharide-protein conjugate.

The effect of gastric intubation with soluble or liposome-associated Streptococcus mutans serovar polysaccharide, 74-kDa saliva receptor (74K SR protein) or polysaccharide-74K SR protein conjugate on the locally induced salivary IgA response and memory in rats was investigated. Animals immunized on four successive days with soluble antigens showed a weak salivary anti-74K SR protein or anti-polysaccharide IgA response. Rats primed and boosted by a single injection of liposome-associated 74K SR protein or polysaccharide-74K SR protein conjugate developed a salivary anti-74K SR protein IgA and IgG primary and secondary response. A primary anti-polysaccharide response was only observed in saliva of animals immunized with either high concentration of liposome-associated polysaccharide or liposome-associated polysaccharide-74K SR protein conjugate. However, a secondary local anti-polysaccharide IgA response was detected in animals boosted with liposome-polysaccharide-74K SR protein conjugate. No such anamnestic response was seen when high dose of liposome-associated polysaccharide was used to boost the animals. Furthermore, the salivary anti-polysaccharide IgA response paralleled the anti-74K SR protein IgA response. These studies showed that intragastric immunization of rats with liposome-associated polysaccharide-74K SR protein conjugate produced a local anti-polysaccharide IgA memory.

Animals↗

PubMed1984

Cytoplasmic proteins of Streptococcus mutans (serotype c) and their interaction with fluoride.

The protein profile of the cytoplasmic proteins of Streptococcus mutans GS-5 was determined by two-dimensional gel electrophoresis. Use of this recently developed, high-resolution analytical tool showed in excess of 140 cytoplasmic proteins. The profile consisted of mostly acidic components with pI values between 3.70 and 5.30 and relative molecular weights mainly in the 13,000 to 90,000 range. With sodium dodecyl sulfate-polyacrylamide gel electrophoresis, the proteins were resolved into 40 to 45 components. The binding of fluoride by the proteins reached a maximum value in 15 min, and it was linear with exogenous F- doses of up to 60 to 80 ppm per mg of protein (60 to 80 micrograms/g). The proteins bound 22 to 138 times more F- from assay mixtures containing 1 mM CaCl2 than from assay mixtures containing such ions as HgCl2, ZnCl2, CuCl2, MgCl2, MnCl2, or SnCl2. When NaF, SnF2, NH4F, CsF, (CH3)4NF, and Na2PO3F were used as sources of F- (adjusted to 10 ppm of F- in all cases), the proteins bound 2.1, 1.8, 1.6, 1.4, and 0.3 ppm of F- per mg of protein, respectively. Initial fractionation of the plasma proteins by preparative column isoelectric focusing indicated that proteins with pI values of 4.1 to 4.5 as well as those with pI values of 5.0 to 5.3 bound twice as much F- as did the proteins outside these pI values.

Adenosine Triphosphatases↗

PubMed2007

In vitro inhibition of Streptococcus mutans biofilm formation on hydroxyapatite by subinhibitory concentrations of anthraquinones.

We report that certain anthraquinones (AQs) reduce Streptococcus mutans biofilm formation on hydroxyapatite at concentrations below the MIC. Although AQs are known to generate reactive oxygen species, the latter do not underlie the observed effect. Our results suggest that AQs inhibit S. mutans biofilm formation by causing membrane perturbation.

Anthraquinones↗

PubMed1991

Construction of scrA::lacZ gene fusions to investigate regulation of the sucrose PTS of Streptococcus mutans.

The scrA gene coding for sucrose EnzymeII of the phosphoenolpyruvate dependent phosphotransferase system previously isolated from Streptococcus mutans was fused in vitro to the promoterless lacZ' gene to monitor the expression of the scrA gene. The scrA::lacZ gene fusion was introduced back into S. mutans GS-5IS3 by two independent transformation procedures involving either linear or plasmid DNA to produce both scrA and scrA+ mutants. These mutants should prove useful for analyzing the regulation of sucrose transport in S. mutans.

Biological Transport, Active↗

PubMed2001

Construction of a new integration vector for use in Streptococcus mutans.

A new integration vector, pBGK, was constructed for delivery of heterologous DNA into the chromosome of Streptococcus mutans. A kanamycin resistance element (OmegaKm), which is flanked by transcriptional and translational terminators and which is selectable in both Escherichia coli and streptococci, was inserted into a 2.4-kb EcoRI fragment carrying the S. mutans gtfA gene. A unique SmaI site flanking OmegaKm is available for cloning of promoter:reporter gene fusions or foreign genes, which can then be integrated into the S. mutans chromosome by allelic exchange with the gtfA gene. The vector was used to analyze the activity of an S. mutans promoter by fusing it to a chloramphenicol acetyltransferase gene. The reporter fusions could readily be cloned into the vector at a unique SmaI site and the vector and passenger DNA were stable in E. coli. DNAs flanked by gtfA sequees integrated efficiently into the chromosome of S. mutans and were stably maintained in the absence of selective pressure. Expression levels of the reporter gene were consistent regardless of orientation or repeated subculturing.

Genes, Reporter↗

PubMed1977

Effects of local immunization with glucosyltransferase fractions from Streptococcus mutans on dental caries in rats and hamsters.

The effect of local immunization with glucosyltransferase enzymes of Streptococcus mutans on dental caries in conventional rats, hamsters, and gnotobiotic rats was studied. Injection of these animals with crude or defined glucosyltransferase enzyme preparations incorporated into complete Freund's adjuvant consistently resulted in the presence of antibody in saliva demonstrable by functional inhibition of enzymatic activity and binding of radioactive enzyme. Serum antibody was also present. Two experiments have been completed in conventional rats and one in gnotobiotic rats in which the animals were immunized with crude enzyme antigens. The immunized groups of animals always had lower mean caries scores than comparably sham-immunized or nonimmunized control groups. Hamsters immunized with a defined enzyme preparation, containing no more than three antigenic components (two of which were enzyme), also demonstrated significant reductions in mean caries scores. The numbers of lesions were also always lower in immunized animals. In some cases there were reductions in the numbers of S. mutans that could be recovered from the teeth of immunized, infected animals. The reductions in dental caries and lesions were greater on smooth dental surfaces than on occlusal surfaces, which might be explained as interference with adherence phenomena demonstrated by S. mutans. It is proposed that antibody interference affects dental caries caused by this organism.

Animals↗

PubMed1973

Extraction, purification, and chemical and immunological properties of the Streptococcus mutans group "a" polysaccharide cell wall antigen.

An antigen of Streptococcus mutans has been extracted from HS6 (group "a") whole cells and repeatedly fractionated by Sephadex chromatography. The antigen is shown to be a polysaccharide and contains the S. mutans group "a" antigenic site and also a second antigenic site which is common to "a" strains and 2 of 3 group "d" strains. Immunological electrophoretic and chromatographic data indicate that the two sites exist in a single molecule. The polysaccharide has a molecular weight of 107,000 and is composed of glucose, galactose, glucosamine, and galactosamine. No significant quantities of lipid, phosphorus, glycerol, or ribitol are present. Immunological specificity of the group "a" polysaccharide site depends primarily on a d-glucose . d-glucose sequence, the "a-d" site on a terminal d-galactose. Water at 100 C and pepsin (pH 2.5) at room temperature are very effective in extracting the polysaccharide from lyophilized S. mutans cells. Trypsin and lysozyme are less effective. The antigen-antibody combining site appears to be located at the cell wall surface. A small quantity of enzyme-resistant protein (5%) is firmly linked to the antigen and is considered to be a remnant of a protein to which the polysaccharide is attached in the cell wall. The composition of the protein does not identify it as a part of the peptidoglycan. No reaction to the purified polysaccharide is obtained with antisera specific for teichoic acid glycerophosphate polymers from streptococci, staphylococci, or lactobacilli.

Alkaline Phosphatase↗