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 1,423 records · Page 79Linked to original sources

PubMed2004

Mucosal immunization against dental caries with plasmid DNA encoding pac gene of Streptococcus mutans in rats.

Salivary secretory immunoglobulin A (S-IgA) antibodies act as the first line of defense against dental caries by blocking of adherence of Streptococcus mutans to tooth surfaces. This study focused on finding proper mucosal immunization route and delivery system to induce higher level of specific anti-S. mutans saliva S-IgA and inhibit dental caries in animal model. By immunizing rats with an anti-caries DNA vaccine, pCIA-P, via different mucosal routes, we found that intranasal (i.n.) immunization with pCIA-P/bupivacaine DNA complexes elicited the highest specific anti-S. mutans saliva S-IgA mucosal antibody responses compared with naked DNA and other routes. Correspondingly, rats immunized with pCIA-P/bupivacaine DNA complex via i.n. displayed the least carious lesions. Our findings suggested that DNA vaccination via intranasal immunization with bupivacaine delivery system be a promising approach against dental caries.

Administration, Intranasal↗

PubMed2005

Characterization of Streptococcus mutans diversity by determining restriction fragment-length polymorphisms of the gtfB gene of isolates from 5-year-old children and their mothers.

The diversity between Streptococcus mutans clinical isolates from 5-year-old children and their mothers in two South African ethnic groups was investigated. The gtfB gene encoding for glucosyltransferase (EC 2.4.1.5), an enzyme responsible for the synthesis of extracellular polysaccharides was characterized by PCR-RFLP with HaeIII restriction enzyme digestion. Forty-seven children were examined for dental caries and 128 S. mutans clinical isolates cultured from samples of their saliva and plaque and from the saliva of their mothers. Thirty-three children had active caries (70%) and the remainder (n = 14) were caries-free. Caries prevalence was significantly different (p = 0.02) between black African and coloured children, but no differences were found between gtfB amplitypes by caries or ethnic grouping. Thirty-four (27%) of the S. mutans clinical isolates investigated did not ferment melibiose. Melibiose-negative phenotypes (n = 10) isolated from four families showed gtfB RFLP patterns identical to each other. Mothers and children harboured between one and three amplitypes. GtfB amplitypes were identical in 17 families (17/47), of which nine only were identical to S. mutans reference strains. The percentage match between S. mutans amplitype from mothers and their children was low (13%) in the caries-free group compared to children with caries (44%). RFLP analysis of the gtfB gene showed the diversity of S. mutans genotypes within two South African populations that were acquired from mothers and other sources.

Child, Preschool↗

PubMed1986

Activity of branched dextrans in the acceptor reaction of a glucosyltransferase (GTF-I) from Streptococcus mutans OMZ176.

The ability of several native and chemically synthesized, branched dextrans to stimulate the activity of an alpha-D-glucosyltransferase (GTF-I) of Streptococcus mutans has been compared. The enzyme catalysed the transfer of glucosyl residues from sucrose with the formation of water-insoluble (1----3)-alpha-D-glucan. The rate of this reaction was greatly increased in the presence of dextran, and the extent of stimulation was negatively correlated with the degree of branching of the added dextran. The results refute the concept that growth of water-insoluble glucan occurs from the multiple, non-reducing termini of dextran acceptors.

Carbon Radioisotopes↗

PubMed1984

Growth-inhibitory and bactericidal effects of human parotid salivary histidine-rich polypeptides on Streptococcus mutans.

Growth inhibition and cell viability assays demonstrate that the histidine-rich polypeptides isolated from human parotid saliva are bacteriostatic and bactericidal for strains of Streptococcus mutans belonging to the serotype b and c classifications. Both inhibition of growth and cell division are enhanced by preincubation of bacteria with these polypeptides in low-ionic-strength buffers of acidic and neutral pH before dilution into enriched growth media. With prior exposure at pH 6.8, inhibition by these polypeptides of the serotype c strains, S. mutans GS5 and SB, as well as the serotype b strain, S. mutans BHT, is reversible over time under the experimental conditions selected. With similar exposure at pH 5.2, however, irreversible damage is manifested by complete inhibition of both growth and cell viability. At concentrations of 250 micrograms of the mixture of histidine-rich polypeptides per 5 X 10(5) bacterial cells per ml in the acidic preincubation buffer, bacterial lethality is maintained for a period of 48 h in the enriched growth media. At a 50-micrograms/ml concentration of these salivary agents, approximately 80% killing of S. mutans SB is noted after a 24-h incubation; however, surviving bacteria multiply and reach turbidities of untreated control cells when examined at the 48-h growth point. Similarly, hen egg white lysozyme is also found to be bactericidal for these microorganisms when preincubation is carried out under acidic conditions. However, in contrast to the histidine-rich polypeptides, lysozyme under these experimental conditions does not inhibit growth of S. mutans SB at neutral pH, although it does inhibit growth of both S. mutans BHT and S. mutans GS5 at this pH. Preexposure of S. mutans SB to the peptides in buffer at ionic strengths of 0.025 to 0.125, followed by either viability assays under nongrowing conditions or growth inhibition studies, suggests that there is very little effect of ionic strength on the antibacterial function of these peptides. In contrast to the inhibition of viability noted under growing conditions, lower concentrations of the histidine-rich polypeptides were required to elicit immediate cell death under nongrowing conditions.

Acetates↗

PubMed1975

Production of bacteriocins in a liquid medium by Streptococcus mutans.

A sterile-filtered, liquid medium composed of one-half-strength APT broth and 4% (wt/vol) yeast extract was found to support the production of bacteriocins by Streptococcus mutans strains BHT and GS-5. Culture supernatants, adjusted to pH 7.0 and sterilized by filtration, contained bacteriocin-like activity, which could be demonstrated by spotting dilutions onto top agar lawns seeded with Streptococcus pyogenes as the sensitive indicator and by adding dilutions to log-phase indicator broth cultures. A quantitative assay was developed for BHT bacteriocin, based on its lethal effects. Bacteriocin production did not occur until after the log phase of growth had ceased and was not inducible by ultraviolet irradiation or treatment with mitomycin C. Non-bacteriocinogenic clones of strain BHT occurred spontaneously at high frequency, suggesting control by a plasmid, but this frequency was not increased by treatment with the plasmid-curing agents acridine orange and ethidium bromide.

Bacteriocins↗

PubMed1987

Inhibition of Streptococcus mutans glucosyltransferase by M-GTFI, a new inhibitor.

Two hundred strains of soil microorganisms were screened for the production of inhibitors of the glucosyltransferase activity of Streptococcus mutans strain, K1-R. The strain producing the greatest amount of inhibitor was one recently isolated in our laboratory. It has now been identified as a strain of Micromonospora narashinoensis on the basis of morphological and physiological studies. The inhibitor, M-GTFI, affects the glucosyltransferase that produces the water-insoluble glucan rather than that which produces the water-soluble glucan. Fuchsin-sulphite staining of the inhibitor after its purification by polyacrylamide gel electrophoresis indicates that it is probably an acidic substance. It had Mr 5700 as was determined by gel filtration. From an examination of the effects of this inhibitor on representative strains of S. mutans other than K1-R, there is a suggestion of a similar selectivity for the water-insoluble glucan-forming activity in other strains.

Dental Caries↗

PubMed1993

Production, characterization, and application of monoclonal antibodies which distinguish three glucosyltransferases from Streptococcus mutans.

Thirty-three murine monoclonal antibodies (MAbs) against the three glucosyltransferases (GTFs) (GTF-I, -SI, and -S) from Streptococcus mutans were obtained by the fusion of murine myeloma cells (P3X63-Ag8-U1) with spleen cells of BALB/c mice immunized with pure GTF-S or partially purified GTF-I from serotype c S. mutans PS14. The immunoreactivities of these MAbs were tested by enzyme-linked immunosorbent assay and Western blotting (immunoblotting) with various GTF preparations. GTF-I and GTF-SI were expressed from two Streptococcus milleri or Escherichia coli transformants harboring gtfB or gtfC, respectively. All of the five MAbs raised against the GTF-S from PS14 reacted only with the homologous enzymes. Of these, 8 MAbs reacted only with the gtfB gene product (GTF-I), 4 MAbs reacted only with the gtfC gene product (GTF-SI), and the remaining 16 MAbs reacted with both gene products. The existence of GTF-SI in the purified GTF-I from PS14 was demonstrated by Western blot analysis using the representative monospecific MAbs. Further, the relative levels of the three GTFs in the extracellular and cellular fractions of S. mutans clinical isolates were examined by immunoblot analysis. The findings indicated that the relative level of GTF-SI, unlike that of GTF-I or GTF-S, differed markedly among isolates although the three GTFs were synthesized extracellularly by all the strains.

Animals↗

PubMed1976

Interaction of inflammatory cells and oral microorganisms. III. Modulation of rabbit polymorphonuclear leukocyte hydrolase release response to Actinomyces viscosus and Streptococcus mutans by immunoglobulins and complement.

In the absence of antiserum, rabbit polymorphonuclear leukocytes (PMNs) released lysosomal enzymes in response to Actinomyces viscosus (19246) but not to Streptococcus mutans (6715). Antibodies had a marked modulating influence on these reactions. PMN hydrolase release was significantly enhanced to both organisms when specific rabbit antiserum and isolated immunoglobulin G (IgG) were included in the incubations. Immune complex F(ab')2 fragments of IgG directed against S. mutans agglutinated bacteria. Immune complexes consisting of S. mutans and F(ab')2 fragments of IgG directed against this organism were not effective as bacteria-IgG complexes in stimulating PMN release. The intensity of the release response to bacteria-IgG complexes was also diminished when PMNs were preincubated with isolated Fc fragments derived from IgG. Fresh serum as a source of complement components had no demonstrable effect on PMN release either alone or in conjuction with antiserum in these experiments. These data may be relevant to the mechanisms and consequences of the interaction of PMNs and plaque bacteria in the pathogenesis of periodontal disease.

Actinomyces↗

PubMed1998

Effects of surfactants on glucosyltransferase production and in vitro sucrose-dependent colonization by Streptococcus mutans.

The presence of Tween 80 in media was associated with a significant increase in three glucosyltransferases(GTFs)(I, SI and S), especially GTF-I, produced by Streptococcus mutans strain PS14, indicating that the surfactant is a major cause of the enhanced GTF production observed in cultures in M4 medium. Lecithin and Tween 20 also enhanced GTF-I production, while Triton X-100 depressed it. At a lot concentration of 0.00125%, Tween 80 enhanced markedly only GTF-I production and its effect reached maximum at a concentration of 0.0025%. Water-insoluble glucan synthesis and artificial plaque formation (in vitro sucrose-dependent colonization) by PS14 were significantly enhanced by the addition of Tween 80 at concentrations over 0.00125%. These results suggest that surfactants might vary the cariogenic potential of Strep. mutans even at low concentrations.

Bacterial Adhesion↗

PubMed1992

The antimicrobial effect of an iron-binding agent on Streptococcus mutans.

The antimicrobial activity of 2,2'-bipyridine, an iron-binding agent, was investigated by incorporating this agent into Scotchbond dental adhesive resin. The growth of Streptococcus mutans on the surface of resin, media and culture vessel was determined by optical density measurements. It was observed that 2,2'-bipyridine exhibited excellent antimicrobial properties.

2,2'-Dipyridyl↗

PubMedDate not supplied

Glucose transport in Streptococcus mutans: preparation of cytoplasmic membranes and characteristics of phosphotransferase activity.

Cytoplasmic membranes from Streptococcus mutans were used to study phosphoenolpyruvate (PEP)-dependent glucose transport. The Km values for glucose and PEP were 0.3 and 0.4 mM. The system was sensitive to sulfhydryl reagents and detergents. The nonmetabolizable analogue 2-D-deoxyglucose was readily phosphorylated while alpha-methyl-glucose and 3-0-methylglucose were inefficiently derivatized. The fermentable sugars fructose, galactose, mannitol, and sorbitol were phosphorylated at reduced rates.

Cell Fractionation↗

PubMed1985

The relationship between the bacterium Streptococcus mutans in the saliva and dental caries in children in Mozambique.

Four hundred and sixty-two children, aged 10-14 years, from eight areas were examined for Streptococcus mutans in saliva and for dental caries. Strep. mutans strains from some samples were further characterized by serological and biochemical methods. Strep. mutans was identified in 98 per cent of the children and 40 per cent showed high counts. Serotypes c and d dominated among the strains. The distribution of Strep. mutans among the children varied between the eight areas but was not correlated with the difference in caries prevalence which ranged from 38 to 88 per cent. In individual children, however, there was an association between high counts of Strep. mutans and the presence of dental caries. Thus, Strep. mutans can be widely distributed and occurs in high numbers in a population with a low prevalence of caries.

Adolescent↗

PubMed2005

Activity of amine oxide against biofilms of Streptococcus mutans: a potential biocide for oral care formulations.

AIMS: To assess the potential bactericidal activity of amine oxide (C10-C16-alkyldimethyl N-oxides) against Streptococcus mutans grown as planktonic suspension and as biofilm on hydroxyapatite discs, and its ability to control acidification of the media. METHODS: Amine oxide bacteriostasis was investigated using the Bioscreen C Microbiological Growth Analyser, while a standard suspension test was used to determine its bactericidal efficacy. In addition, the lethal activity of amine oxide was studied against sedimentation biofilms of S. mutans on hydroxyapatite (HA) discs and resuspended biofilms. Several parameters were considered such as the surfactant concentration, pH, the starting inoculum and the maturity of the biofilm. RESULTS: Amine oxide was bacteriostatic against planktonic S. mutans at a low concentration (0.006% v/v) and highly bactericidal against S. mutans in suspension or in a mature biofilm on hydroxyapatite, although the concentration required to achieve the latter effect was four times higher. The activity of amine oxide against biofilms depended upon its concentration and the age of the biofilm. In addition, amine oxide pre-treatment of the HA discs did not affect the growth of the biofilm. Finally, amine oxide did not prevent the acidification of the medium, although lower pHs had a potentiating effect on amine oxide activity. CONCLUSION: Amine oxide showed high potential for controlling early biofilms caused by periodontal bacteria. Further investigations should be carried out, particularly on the potential toxicity of amine oxide and its efficacy in complex formulations for oral care products.

Alkanes↗

PubMed1998

Factors affecting the resting pH of in vitro human microcosm dental plaque and Streptococcus mutans biofilms.

The aim was to examine factors that potentially control the resting pH, defined as the pH unaffected by meals, of microcosm dental plaques and Streptococcus mutans biofilms under standard conditions, and to examine the effect of supplying urea at concentrations found intraorally. Microcosm plaques were cultured from plaque bacteria-enriched saliva in an 'artificial mouth' with a continuous supply of a medium including 0.25% mucin [Basal Medium Mucin, (BMM), 3.6 ml/hr per plaque] and a periodic supply of sucrose. The steady-state resting pH was 6.4 (range +/- 0.1) in BMM containing no urea and supplied at the standard flowrate. This is a robust property of the ecosystem. In one experiment with a replicated (n = 9) set of measurements, the resting pH was approx. pH 6.3, 6.4, 6.7 and 7.3 with 0, 1, 5 and 20 mmol/l urea in the BMM. The magnitude of sucrose- and urea-induced pH responses was unaffected by elevating the resting pH to produce parallel pH curves. The sucrose-induced pH curves were analogous to those classically reported by Stephan that showed an association between caries activity and increasingly acidic plaque pH responses to glucose. Stopping the BMM flow caused a pH rise, indicating continuing net alkali generation from BMM components in the absence of a fluid flow. Step. mutans monoculture biofilms had an acidic resting pH of 5.0 to 5.3, which increased to 6.8 following an adventitious superinfection by Bacillus cereus. It was concluded that the resting pH in plaque results from a delicate balance between alkali and acid generation, which is in turn dependent both on the bacterial composition of the plaque and on the supply of substrates and buffers from, and metabolite clearance into, flowing oral fluid. In vivo the resting pH will vary with site-specific changing saliva flows. Urea continuously supplied at concentrations normal for saliva and gingival crevicular fluid can raise the resting pH of microcosm plaque by an amount tat in vivo would probably be significant in reducing dental caries.

Acids↗

PubMed1976

Activation of the alternative complement pathway by water-insoluble glucans of streptococcus mutans: the relation between their chemical structures and activating potencies.

Water insoluble, sticky glucan was synthesized by reacting glucosyltransferase obtained from the sulture filtrate of cariogenic Streptococcus mutans OMZ 176 on sucrose. This glucan (OMZ 176 glucan), that consisted of the backbone chains of consecutive alpha-1, 3 glucosidic linkages (65%) and the side chain of alpha-1, 6 glucosidic bonds (35%), showed an ability to activate the alternative pathway of the complment system in human serum. Water soluble glucans synthesized from the reaction of glycosyltransferases of S. mutans strain AHT, FA-I, and Ingbritt with sucrose, that have a high content of alpha-1,6 and a low content of alpha-1, 3 glucosidic linkages, were less effective to activate the complement system. Sephadex (G-25) and Dextran (T-2,000 and T-40), that consisted exclusively of alpha-1, 6 glucosidic linkages, did not significantly activate the complement system. Controlled Smith degradation products of OMZ 176 glucan, composed of the alpha-1, 3 linked glucose backbone chain alone, lost its activity. From these results it was concluded that both backbone chain of alpha-1, 3 glucose units and branched alpha-1, 6 glucose units were essential for the OMZ 176 glucan to activate the alternative pathway of the human complement system.

Aspergillus niger↗

PubMed1997

[The immune response in rats immunized systemically by the surface protein antigen P1 from streptococcus mutans conjugated with procholeragenoid].

This study was carried out to observe the antibody responses in rats after they were immunized with the surface protein P1 of streptococcus mutans when a special adjuvant was used. Antigen P1 was conjugated covalently with procholeragenoid (PCG), and then Sprague Dawley rats were immunized with P1 or the conjugated antigen P1-PCG subcutaneously or intragastrically. Anti-P1 antibody level was assayed at different time points by ELISA. The results showed that the levels of anti-P1 SIgA antibody in saliva rose when P1-PCG was given subcutaneously or intragastrically; the antibody level following the subcutaneous injection was higher and lasted longer, compared with that following the intragastric administretion. The level of anti-P1 IgG antibody in serum only rose when the rats were immunized subcutaneously. These results implied that mucosal immune response or humoral immune response could be induced subcutaneously when PCG was used as an adjuvant.

Animals↗

PubMed1982

Teflon chemostat for studies of trace metal metabolism in Streptococcus mutans and other bacteria.

A teflon chemostat constructed for studies of microbial trace metal metabolism is described. The utility of this continuous culture system was demonstrated with Streptococcus mutans, in which iron and manganese stimulated growth in ranges of 0.18 to 0.45 and 18 to 54 microM, respectively. This device should facilitate studies of the effect of trace metals on a variety of physiological functions.

Bacteriological Techniques↗

PubMed2006

Effect of water-soluble reduced chitosan on Streptococcus mutans, plaque regrowth and biofilm vitality.

The purpose of the present study was to examine the effects of a newly developed water-soluble reduced chitosan on Streptococcus mutans, plaque regrowth, and biofilm vitality. A 1.0%, water-soluble reduced chitosan, with pH ranging from 6.0 to 6.5, molecular weights between 3,000 and 5,000 Da, and 70% degree of deacetylation, was used. To determine antibacterial and antiplaque potency of chitosan, minimal inhibitory concentrations (MICs) for S. mutans and S. sanguinis (formerly S. sanguis), short-term exposure to S. mutans, and clinical trial of plaque regrowth and biofilm vitality were conducted. Twelve dental students volunteered to participate in the 6-week, double blind, randomized clinical trial using the classical 4-day plaque regrowth design. The MIC of water-soluble reduced chitosan for S. mutans was 1.25 g/l. While the cells exposed to distilled water (DW) grew rapidly, with a maximum turbidity reached by 16 h postinoculation, S. mutans exposed to chitosan (5.0 g/l) exhibited a substantial delay in growth and reached a maximum turbidity by 32 h postinoculation. The chitosan solution reduced the plaque index and the vitality of the plaque flora significantly when compared to DW, but this was less than the reductions found with the positive control of 0.1% chlorhexidine solution. The water-soluble reduced chitosan exhibited potent antibacterial effect on S. mutans, and displayed a significant antibacterial and plaque-reducing action during the 4-day plaque regrowth.

Adult↗