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Abstract
The Stephan Curve has played a dominant role in caries research over the past several decades. What is so remarkable about the Stephan Curve is the plethora of interactions it illustrates and yet acid production remains the dominant focus. Using sophisticated technology, it is possible to measure pH changes in plaque; however, these observations may carry a false sense of accuracy. Recent observations have shown that there may be multiple pH values within the plaque matrix, thus emphasizing the importance of the milieu within which acid is formed. Although acid production is indeed the immediate proximate cause of tooth dissolution, the influence of alkali production within plaque has received relative scant attention. Excessive reliance on Stephan Curve leads to describing foods as "safe" if they do not lower the pH below the so-called "critical pH" at which point it is postulated enamel dissolves. Acid production is just one of many biological processes that occur within plaque when exposed to sugar. Exploration of methods to enhance alkali production could produce rich research dividends.
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Affiliation(s)
- William H Bowen
- Center for Oral Biology, University of Rochester, 601 Elmwood Avenue, Rochester, NY 14642, USA.
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Shumi W, Lim J, Nam SW, Lee K, Kim SH, Kim MH, Cho KS, Park S. Environmental factors that affect Streptococcus mutans biofilm formation in a microfluidic device mimicking teeth. BIOCHIP JOURNAL 2010. [DOI: 10.1007/s13206-010-4401-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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3
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Dall LH, Herndon BL, Smith R. Reactivity of the glycocalyx of endocarditis-producing viridans group streptococci. Diagn Microbiol Infect Dis 1993; 17:259-64. [PMID: 8112039 DOI: 10.1016/0732-8893(93)90033-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
We correlated quantity of streptococcal polysaccharides and endocarditis production by those bacterial strains. To investigate this finding further, we studied the composition of the glycocalyx using a spectrophotometric assay and lectin analysis of exopolysaccharides from endocarditis- and non-endocarditis-producing strains of viridans streptococci. Identical weights of glycocalyx from the clinical endocarditis isolates produced significantly different absorbances as compared with the nonendocarditis isolates (P < 0.0012, Wilcoxon rank test). Lectin-binding experiments showed that endocarditis-producing streptococci contained increased amounts of glucose, galactose, sialic acid, and mannose. These data suggest that the glycocalyx of endocarditis-producing viridans streptococci is both qualitatively and quantitatively different from non-endocarditis-producing isolates. These differences can be measured in vitro.
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Affiliation(s)
- L H Dall
- Department of Medicine, University of Missouri-Kansas City School of Medicine 64133
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Barrett JF, Curtiss R. Renaturation of dextranase activity from culture supernatant fluids of Streptococcus sobrinus after sodium dodecylsulfate polyacrylamide gel electrophoresis. Anal Biochem 1986; 158:365-70. [PMID: 2433959 DOI: 10.1016/0003-2697(86)90562-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
A rapid and reproducible method for the assay of individual fractions of the multicomponent dextranase activity of Streptococcus sobrinus after reduction/denaturation and electrophoresis in acrylamide gels is described. Multiple forms of dextranase, possible virulence factors in the formation of dental caries by oral Streptococci (S. mutans, S. sobrinus, S. sanguis, S. cricetus, and S. rattus), have been separated in sodium dodecylsulfate-polyacrylamide gels into which an indicator substrate, blue dextran, has been incorporated, and identified after renaturation to remove the reducing/denaturing agents of the Laemmli buffer system.
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Inhibition of plaque and caries formation by a glucan produced by Streptococcus mutans mutant UAB108. Infect Immun 1985; 50:833-43. [PMID: 2415455 PMCID: PMC261156 DOI: 10.1128/iai.50.3.833-843.1985] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
A mutant (UAB108) derived from Streptococcus mutans UAB66, a spectinomycin-resistant (Spcr) isolate of strain 6715, inhibited plaque formation when grown with strain 6715 in a sucrose medium and also inhibited caries formation in gnotobiotic rats infected with both strain UAB108 and 6715. A substance obtained from UAB108 culture supernatant fluid after ethanol precipitation and DEAE-cellulose treatment, designated glucan 108, inhibited S. mutans 6715 virulence and was shown to be a water-soluble glucan. In the presence of sucrose and increasing concentrations of glucan 108, the activity of a glucosyltransferase (GTase) preparation from S. mutans 6715 to synthesize adhesive water-insoluble glucan (ad-WIG) was inhibited, and the activity to synthesize non-ad-WIG was stimulated. Glucan 108 similarly inhibited sucrose-dependent adherence of heat-treated cells, was a poor inducer of cell aggregation, and inhibited S. mutans 6715-induced dental caries in gnotobiotic rats. In the presence of GTase, glucan 108, and sucrose, the glucose moiety of sucrose was found to be incorporated into glucan 108, and most of this glucose-incorporated glucan 108 was found in the non-ad-WIG fraction. The mode of inhibition of plaque formation by S. mutans 6715 appears to involve a shift from ad-WIG to non-ad-WIG formation. The water-soluble glucan 108 was found to have an approximate molecular weight of 2 X 10(6) and was hydrolyzed by fungal dextranase to yield glucans with an average molecular weight of about 1.2 X 10(4). This glucan (designated glucan 12k) was further hydrolyzed by bacterial dextranase to yield smaller glucans and oligosaccharides, but was refractile to alpha (1----3) glucanase. These results suggest that glucan 108 is a branched alpha (1----6) glucan, and it is proposed that UAB108 is defective in its ability to polymerize glucan 12k with alpha (1----3)-linked glucosyl residues.
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Ota F, Fukui K. Scanning electron microscopic studies of the extracellular polysaccharides (EP) synthesized in colonies of Streptococcus mutans: development of EP and the effect of dextranase on them. Microbiol Immunol 1982; 26:623-8. [PMID: 7132791 DOI: 10.1111/mim.1982.26.7.623] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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Trautner K, Felgenhauer B, Rieder H. Extracellular polysaccharide synthesized by the oral bacterium Streptococcus mutans of serotype a to e in vitro. Arch Oral Biol 1981; 26:1005-13. [PMID: 6951508 DOI: 10.1016/0003-9969(81)90111-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Extracellular polysaccharide (EPS) synthesized in vitro by Streptococcus mutans belonging to serotypes a, b, c, d and e was shown to consist mainly of glucan. Only strains of type b and e regularly produced substantial amounts of fructan, too. Strains of type d synthesized significantly higher quantities of glucan than strains of the other types per gram of bacterial mass. The percentage of insoluble glucan was lowest in samples from strains of type a and c, and highest in samples from strains of type d. In contrast to the insoluble glucan, the linkage pattern of the soluble glucan of the five types showed only small differences. The percentage of alpha-1,3-linked glucose units was highest in the insoluble glucan from strains of type d and e, and lowest in glucan from type c. The differences were significant. Incubation of Strep. mutans under various culture conditions showed that the quantities and composition of EPS formed depend on the culture condition used. The effect of culture conditions, however, was similar for all strains. Therefore the differences found with respect to the quantities and composition of EPS synthesized in vitro by Strep. mutans of different types are apparently type-dependent.
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Takehara T, Inoue M. Inhibitory effects of endo-alpha-1,3-glucanase on glucan film formation and glucan synthesis by the glucosyltransferase of the oral bacterium Streptococcus mutans. Arch Oral Biol 1981; 26:217-22. [PMID: 6459076 DOI: 10.1016/0003-9969(81)90133-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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Porter EV, Chassy BM, Holmlund CE. Partial purification and properties of a mannofructokinase from Streptococcus mutans SL-1. Infect Immun 1980; 30:43-50. [PMID: 6254885 PMCID: PMC551274 DOI: 10.1128/iai.30.1.43-50.1980] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Fructokinase activity was demonstrated in seven strains of oral streptococci. The enzyme purified from Streptococcus mutans SL-1 was capable of phosphorylating both D-fructose and D-mmannose to their respective 6-phosphates. Phosphorylation of both fructose and mannose was dependent on adenosine 5'-triphosphate and a divalent metal ion. The molecular weight of the purified enzyme was estimated to be 49,000. The apparent Km of the enzyme for fructose was 0.63 mM. This enzyme also utilized mannose as a substrate, with an apparent Km for mannose of 0.37 mM. Since the activities of the enzyme toward mannose and fructose were not separated upon purification of the enzyme and since mannose was a competitive inhibitor of fructose phosphorylation, the purified kinase is a single enzyme, mannofructokinase, with dual specificity for both mannose and fructose. A role for this enzyme in carbohydrate metabolism in S. mutans is postulated.
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Structural studies of extracellular glucans of Streptococcus mutans by proton magnetic resonance. Carbohydr Res 1978. [DOI: 10.1016/s0008-6215(00)83236-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Freedman M, Birked D, Granath K. Analyses of glucans from cariogenic and mutant Streptococcus mutans. Infect Immun 1978; 21:17-27. [PMID: 711313 PMCID: PMC421951 DOI: 10.1128/iai.21.1.17-27.1978] [Citation(s) in RCA: 36] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
The extracellular, water-soluble and cell-associated, 1 N NaOH-soluble glucans from cariogenic Streptococcus mutans 6715-13 "wild type" (WT) and glucan synthesis-defective mutants with diminished virulence have been quantitatively and qualitatively analyzed by methylation analysis and gel chromatography. The mutants synthesized more of a highly branched alpha-(1 --> 6)-rich extracellular polymer than WT, and some of this glucan was also found to be cell associated in all but one case. WT, in distinction to the mutants, also synthesized a highly branched, alpha-(1 --> 3)-rich, cell-associated polymer. Treatment of these two distinct polymer types with dextranase or an alpha-(1 --> 3)-hydrolyzing enzyme indicated they were composed of both alpha-(1 --> 3) and alpha-(1 --> 6) linkages and of alpha-(1 --> 6) with branches at the 3-position, rather than of separate alpha-(1 --> 3) and alpha-(1 --> 6) homopolymer mixtures. Gel chromatography before enzymatic hydrolysis disclosed a high degree of polydispersity in both glucan classes. After hydrolysis polydispersity was reduced, again without resolution of two glucan populations. These findings suggest that (i) there are two distinct glucan classes, one alpha-(1 --> 3) rich and the other alpha-(1 --> 6) rich in WT, (ii) diminution of virulence in the mutants is probably ascribable to a failure to form the alpha-(1 --> 3)-rich component, (iii) both alpha-(1 --> 6)- and alpha-(1 --> 3)-rich glucans are found in association with the cell, and (iv) both highly branched glucan types are dextranase and alpha-(1 --> 3)-hydrolase sensitive, and methylation analysis and gel chromatography suggest polymers with highly polydisperse molecular weights which contain mixtures of linkage types.
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Koga T, Inoue M. Cellular adherence, glucosyltransferase adsorption, and glucan synthesis of Streptococcus mutans AHT mutants. Infect Immun 1978; 19:402-10. [PMID: 631879 PMCID: PMC414097 DOI: 10.1128/iai.19.2.402-410.1978] [Citation(s) in RCA: 38] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Streptococcus mutans AHT mutants M1, M2, and M13 failed to adhere to a glass surface, whereas mutants M9 and M35 exhibited decreased and increased adherence, respectively, as compared with the parent strain, when grown in sucrose broth. Extracellular glucosyltransferase prepared from glucose-grown cultures of the adherent strains (wild type, M9, and M35) induced adherence of heat-killed cells of the homologous and heterologous streptococcal strains as well as of Escherichia coli K-12 and uncoated resin particles. The glucosyltransferase was adsorbed on all the streptococcal cells and glucan-coated resins, but not on E. coli cells and the uncoated resins. Glucosyltransferase from the nonadhering mutants (M1, M2, M13) neither was significantly adsorbed on nor induced adherence of any of the cells and resins. Cell-free enzymes from the glucose-grown adherent strains produced water-soluble and water-insoluble glucans, whereas those from the nonadhering mutants produced only water-soluble glucans. Small amounts of alkali-soluble, cell-associated glucan were recovered from the sucrose-grown nonadhering mutants. Thus, the relative proportions of glucosyltransferase isozymes elaborated by the S. mutans mutants, insofar as they affect the physico-chemical properties of the glucans produced, seem to determine the adherence abilities of the cells. The adsorption of glucosyltransferase on glucan molecules on the cell surface is not required for the adherence of S. mutans, but de novo glucan synthesis is important in the adherence process.
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Trautner K, Gehring F, Lohmann D. Extracellular glucans synthesized by strains of two types of Streptococcus mutans in vitro. Arch Oral Biol 1978; 23:175-81. [PMID: 278550 DOI: 10.1016/0003-9969(78)90213-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Walker GJ, Hare MD. Metabolism of the polysaccharides of human dental plaque. Part II. Purification and properties of Cladosporium resinae (1 leads to 3)-alpha-D-glucanase, and the enzymic hydrolysis of glucans synthesised by extracellular D-glucosyltransferases of oral streptococci. Carbohydr Res 1977; 58:415-32. [PMID: 334367 DOI: 10.1016/s0008-6215(00)84368-2] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Cladosporium resinae (1 leads to 3)-alpha-D-glucanase has been characterized as an endoglucanase capable of completely hydrolysing insoluble (1 leads to 3)-alpha-D-glucans isolated from fungal cell-walls. D-Glucose was the major product, but a small amount of nigerose was also produced. The enzyme was specific for the hydrolysis of (1 leads to 3) bonds that occur in sequence, and nigerotetraose was the smallest substrate that was rapidly attacked. Isolated (1 leads to 3)-alpha-D-glucosidic linkages that occur in mycodextran, isolichein, dextrans, and oligosaccharides derived from dextran were not hydrolysed. Insoluble glucan synthesised from sucrose by culture filtrates of Streptococcus spp. were all hydrolysed to various limits; the range was 11-61%. A soluble glucan, synthesised by an extracellular D-glucosyltransferase of S. mutans OMZ176, was not a substrate, whereas insoluble glucans synthesised by a different D-glucosyltransferase, isolated from S. mutans strains OMZ176 and K1-R, were extensively hydrolysed (84 and 92%, respectively). It is suggested that dextranase-CB, a bacterial endo(1 leads to 6)-alpha-D-glucanase that does not release D-glucose from any substrate, could be used together with C. resinae (1 leads to 3)-alpha-D-glucanase to determine the relative proportions of (1 leads to 6)-linked to (1 leads to 3)-linked sequences of D-glucose residues in the insoluble glucans produce by oral streptococci. The simultaneous action of the two D-glucanoses was highly effective in solubilizing the glucans.
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Germaine GR, Harlander SK, Leung WL, Schachtele CF. Streptococcus mutans dextransucrase: functioning of primer dextran and endogenous dextranase in water-soluble and water-insoluble glucan synthesis. Infect Immun 1977; 16:637-48. [PMID: 863518 PMCID: PMC421004 DOI: 10.1128/iai.16.2.637-648.1977] [Citation(s) in RCA: 61] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
The extracellular enzyme activities of Streptococcus mutans 6715 that synthesize glucans from sucrose were concentrated and partially purified by ammonium sulfate precipitation and gel permeation column chromatography. Polyacrylamide gel analysis demonstrated that all of the major proteins precipitated by ammonium sulfate were quantitatively recovered in the high-molecular-weight, enzyme-containing aggregates found in the void volume of the gel column. Anion-exchange column chromatography was used to fractionate the aggregates into preparations, alpha and beta, which produced water-insoluble and water-soluble glucans, respectively. Polyacrylamide gel analysis showed that alpha and beta contained unique proteins and dextransucrase (EC 2.4.1.5) activities. Studies on the time course of glucan synthesis by alpha demonstrated that this enzyme preparation contained dextranase activity, which partially degraded nascent alcohol-insoluble glucan into alcohol-soluble products that were subsequently reincorporated into insoluble product. The beta enzyme preparation contained no detectable dextranase activity. Mixing experiments in the absence of primer dextran demonstrated that the dextranase activity present in alpha could modify glucan production by beta. CsCl density gradient analysis of product glucans demonstrated that exogenous primer dextrans were used as acceptor molecules by both the alpha and beta enzyme preparations, and that water-soluble glucans synthesized by beta could be converted into water-insoluble glucans by alpha. It is proposed that the structural heterogeneity of the native glucans produced from sucrose by S. mutans is a result of the concerted action of glucan-forming dextransucrases and endohydrolytic dextranase activity.
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Johnson MC, Bozzola JJ, Shechmeister IL, Shklair IL. Biochemical study of the relationship of extracellular glucan to adherence and cariogenicity in Streptococcus mutans and an extracellular polysaccharide mutant. J Bacteriol 1977; 129:351-7. [PMID: 830643 PMCID: PMC234933 DOI: 10.1128/jb.129.1.351-357.1977] [Citation(s) in RCA: 34] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
A mutant of Streptococcus mutans, GS-5, which differed in extracellular polysaccharide (EPS) produced from sucrose, was used to study the role of EPS in the production of dental caries. The mutant proved to be identical to the parent strain in sugar fermentation, growth rate, and serotype. Strain GS-5 synthesized an EPS, which in electron micrographs appeared to be of fibrillar structure, whereas the mutant produced no fibrillar material but only a globular EPS. Analysis of the EPS revealed that about 30% of the glucose units in the GS-5 polymer carried (1-3)-like bonds either as branch points or as part of the linear backbone and that the mutant material contained only about 3% of these linkages. When grown in sucrose broth, the proportion of the mutant culture adherent to the glass vessel was dramatically less than that of the parent strain. Caries scores produced in conventional rats by the mutant were significantly lower than those obtained with the parent strain. Since the only difference discovered between strain GS-5 and the mutant was the inability of the mutant to synthesize either a fibrillar EPS or an EPS with more than about 3% (1-3)-like linkages, it was concluded that the fibrillar EPS of strain GS-5 contained about 30% (1-3)-like linkages and was necessary for adherence of the bacteria to surfaces and for production of dental caries in test animals.
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Todhunter EN. Chronology of some events in the development and application of the science of nutrition. Nutr Rev 1976; 34:353-65. [PMID: 798138 DOI: 10.1111/j.1753-4887.1976.tb05121.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
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Linzer R, Slade HD. Characterization of an anti-glucosyltransferase serum specific for insoluble glucan synthesis by Streptococcus mutans. Infect Immun 1976; 13:494-500. [PMID: 1262062 PMCID: PMC420639 DOI: 10.1128/iai.13.2.494-500.1976] [Citation(s) in RCA: 34] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
An anti-glucosyltransferase serum, which synthesized 96% insoluble glucans, was prepared against a purified enzyme preparation from Streptococcus mutans strain HS6 (serotype a). This serum was examined for its effects on glucan synthesis by crude enzyme preparations from eight strains (four serotypes) of S. mutans and for the ability of these preparations to promote adherence of S. mutans to a smooth surface. Glucosyltransferase activity was assayed by measuring the incorporation of glucose from [14C]glucose-labeled sucrose into water-insoluble and water-soluble (ethanol-insoluble) glucans. Anti-glucosyltransferase serum inhibited insoluble glucan synthesis by crude enzyme preparations from cells of the four serotypes of S. mutans. Enzymes from strains of types a, b, and d were inhibited between 70 to 90%; enzymes from type c strains were inhibited from 45 to 60%. The adherence to a glass surface of heat-killed cells from these four serotypes was likewise inhibited. Soluble glucan synthesis was not inhibited by the serum, and in some cases its synthesis increased as insoluble glucan synthesis decreased.
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Hamada S, Mizuno J, Murayama Y, Ooshima Y, Masuda N. Effect of dextranase on the extracellular polysaccharide synthesis of Streptococcus mutans; chemical and scanning electron microscopy studies. Infect Immun 1975; 12:1415-25. [PMID: 1205620 PMCID: PMC415451 DOI: 10.1128/iai.12.6.1415-1425.1975] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
A dextranase preparation (AD17) partially purified from a culture liquor of Spicaria violacea strain IFO 6120 significantly inhibited the formation of artifcial dental plaque on a steel wire or on an extracted tooth surface. Changes in the surface morphology of Streptococcus mutans cells due to AD17 action were studied using scanning electron microscopy. S. mutans cells grown in 5% sucrose-containing broth were coated with sticky amorphous capsule-like material, whereas cells grown in sucrose in the presence of AD17 or in glucose instead of sucrose did not synthesize such capsular material. AK17 degraded commercially available dextrans of molecular weight 7 X 1(04) and 2 X 10(6) to liberate glucose and various oligosaccharides, including isomaltose. On the other hand, AD17 hydrolyzed the extracellular polysaccharides (mainly glucan in nature) of some strains of S. mutans to a limited degree. Only 15 to 36% of the total polysaccharides were hydrolyzed by AD1M with little release of isomaltose. Prolonged incubation of the polysaccharides from S. mutans with AD17 did not release additional reducing sugars, which indicates that AD17 did not contain alpha-1,3-glucanase activity. These results suggest that glucosidic linkages which are susceptible to AD17 may play an important role in the adherence of S. mutans cells to smooth surfaces.
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Ebisu S, Kato K, Kotani S, Misaki A. Isolation and purification of Flavobacterium alpha-1,3-glucanase-hydrolyzing, insoluble, sticky glucan of Streptococcus mutans. J Bacteriol 1975; 124:1489-501. [PMID: 370 PMCID: PMC236064 DOI: 10.1128/jb.124.3.1489-1501.1975] [Citation(s) in RCA: 41] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Studies were made on the physical and chemical properties of polysaccharides synthesized by cell-free extracts of Streptococcus mutans, Streptococcus sanguis, and Streptococcus sp. and their susceptibilities to dextranases. Among the polysaccharides examined, insoluble glucans were rather resistant to available dextranase preparations, and the insoluble, sticky glucan produced by S. mutans OMZ 176, which could be important in formation of dental plaques, was the most resistant. By enrichment culture of soil specimens, using OMZ 176 glucans as the sole carbon source, an organism was isolated that produced colonies surrounded by a clear lytic zone on opaque agar plates containing the OMZ 176 glucan. The organism was identified as a strain of Flavobacterium and named the Ek-14 bacterium. EK-14 bacterium was grown in Trypticase soy broth, and an enzyme capable of hydrolyzing the OMZ 176 glucan was concentrated from the culture supernatant and purified by negative adsorption on a diethylaminoethyl-cellulose (DE-32) column and gradient elution chromatography with a carboxymethyl-cellulose (CM-32) column. The enzyme was a basic protein with an isoelectric point of pH 8.5 and molecular weight of 65,000. Its optimum pH was 6.3 and its optimal temperature was 42 C. The purified enzyme released 11% of the total glucose residues of the OMZ 176 glucan as reducing sugars and solubilized about half of the substrate glucan. The products were found to be isomaltose, nigerose, and nigerotriose, with some oligosaccharides. The purified enzyme split the alpha-1,3-glucan endolytically and was inactive toward glucans containing alpha-1,6, alpha-1,4, beta-1,3, beta-1,4, and/or beta-1,6 bonds as the main linkages.
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Schachtele CF, Staat RH, Harlander SK. Dextranases from oral bacteria: inhibition of water-insoluble glucan production and adherence to smooth surfaces by Streptococcus mutans. Infect Immun 1975; 12:309-17. [PMID: 1158523 PMCID: PMC415285 DOI: 10.1128/iai.12.2.309-317.1975] [Citation(s) in RCA: 86] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
The effect of dextranases (EC 3.2.1.11) from the oral isolates Actinomyces israelii and Bacteroides ochraceus on water-insoluble glucan production by the Streptococcus mutans dextransucrase (EC 2.4.1.5) and sucrose-dependent adherence to smooth glass surfaces by S. mutans was studied. Collection on membrane filters of water-insoluble polysaccharides synthesized from radioactive sucrose was used to demonstrate the marked sensitivity of insoluble glucan formation to the presence of dextranase. Concentrations of A. israelii dextranase as low as 0.002 U/ml inhibited insoluble glucan formation by 60%. Similar results were obtained the the B. ochraceus enzyme. An assay for sucrose-stimulated adherence of S. mutans to smooth surfaces involved attachment of radioactively labeled nongrowing cells to the bottom of glass scintillation vials. This facile and sensitive assay was utilized to demonstrate that sucrose-dependent adherence was affected by low levels of dextranase from either A. israelii or B. ochraceus. Enzyme at 0.005 U/ml reduced adherence of S. mutans by 80%. Treatment of S. mutans cells previously attached to glass with low concentrations of the dextranases resulted in removal of 50% to 60% of the bacteria. The results indicate that dextranase-producing oral bacteria may affect sucrose-dependent colonization of S. mutans on the tooth surface and offer a possible explanation for both the difficulties involved in implanting this bacterium into the human mouth and the limited intraoral transmission of S. mutans from one tooth surface to another.
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Lamberts BL, Meyer TS, Simonson LG. Investigation of possible solvents for extracellular polysaccharides from Streptococcus mutans and Streptococcus sanguis. J Dent Res 1975; 54:857-66. [PMID: 1057570 DOI: 10.1177/00220345750540042601] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
The solubilities of extracellular polysaccharide fractions produced by 14 oral streptococcal strains were compared in water, aqueous lithium and guanidine salt solutions, dimethyl sulfoxide (DMSO), and a 9:1 DMSO-water mixture. The best results for solubilizing the fractions were obtained with the DMSO-water mixture procedure, which used the water and DMSO in sequence. By this method all fo the fractions were solubilized.
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Johnson MC, Bozzola JJ, Shechmeister IL. Morphological study of Streptococcus mutans and two extracellular polysaccharide mutants. J Bacteriol 1974; 118:304-11. [PMID: 4132251 PMCID: PMC246670 DOI: 10.1128/jb.118.1.304-311.1974] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Two extracellular polysaccharide mutants of Streptococcus mutans GS-5 were obtained and examined. The mutants were distinguished by colonial morphology and by growth on and adherence to hard surfaces. A technique was devised which allowed these bacteria to be studied as they appeared when grown on a hard surface in liquid medium which contained sucrose. Negative stains, replicas, and scanning electron micrography clearly revealed differences in cellular aggregation due to the various extracellular polysaccharides produced. Comparison of sections of the adherent parent strain (GS-5) with those of the nonadherent mutant (GS-511) allowed the extracellular polysaccharide(s) responsible for adhesion to be visually localized.
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Ghring F, Mäkinen KK, Larmas M, Scheinin A. Turku sugar studies. IV. An intermediate report on the differentiation of polysaccharide-forming streptococci (S. mutans). Acta Odontol Scand 1974; 32:435-44. [PMID: 4533574 DOI: 10.3109/00016357409026552] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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Cook WJ, Bugg CE. Calcium interactions with D-glucans: crystal structure of alpha, alpha-trehalose-calcium bromide monohydrate. Carbohydr Res 1973; 31:265-75. [PMID: 4784221 DOI: 10.1016/s0008-6215(00)86191-1] [Citation(s) in RCA: 46] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Mukasa H, Slade HD. Mechanism of adherence of Streptococcus mutans to smooth surfaces. I. Roles of insoluble dextran-levan synthetase enzymes and cell wall polysaccharide antigen in plaque formation. Infect Immun 1973; 8:555-62. [PMID: 4582634 PMCID: PMC422891 DOI: 10.1128/iai.8.4.555-562.1973] [Citation(s) in RCA: 158] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
The mechanism of adherence of Streptococcus mutans to smooth glass surfaces has been studied. The results with both viable and heat-killed cells showed that the process required (i) the synthesis of a water-insoluble dextran-levan polymer by cell-bound enzymes and (ii) the participation of a binding site on the surface of the S. mutans cell. Synthesis of the polymer from sucrose in the presence of the cells was required for adherence, and indicates that an "active" form of the polymer was required. Polymer synthesized by cell-free S. mutans enzymes when added to S. mutans cells did not produce adherence. Purified antibody globulin, specific for the a-d site in the polysaccharide S. mutans group a antigen, completely inhibited adherence. Antibody to the second antigen present in the polysaccharide molecule, the a antigen, did not inhibit adherence. The evidence indicates that adherence did not require an antigenic binding site which might be common to all S. mutans strains. The orientation of the synthetase enzyme(s), antigenic binding site, and dextran-levan polymer on the cell surface is under study.
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Hoffman S, Tow HD, Cole JS. Scanning electron microscope studies of dextranase-treated plaque streptococci. J Dent Res 1973; 52:551-7. [PMID: 4521648 DOI: 10.1177/00220345730520032901] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
The in vitro effects of dextranase on extracellular polysaccharide-producing streptococci grown on autoclaved enamel samples were evaluated by scanning electron microscopy. This enzyme was found to be highly effective in dispersing both strains of streptococci when compared with controls.
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Mukasa H, Slade HD. Structure and immunological specificity of the Streptococcus mutans group b cell wall antigen. Infect Immun 1973; 7:578-85. [PMID: 4128403 PMCID: PMC422725 DOI: 10.1128/iai.7.4.578-585.1973] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
The Streptococcus mutans group b antigen of strain FA1 has been defined as to chemical composition and immunological specificity. The antigen in cold trichloroacetic acid extracts was fractionated on diethylaminoethyl-Sephadex A-25 at pH 8.5. Two forms were isolated: a polysaccharide and a mucoprotein. The two polymers reacted as a single substance in agar gel diffusion against specific adsorbed FA1 rabbit antisera but were separated by gel immunoelectrophoresis. No reaction with any other S. mutans or streptococcal group sera occurred. Galactose composed about one-third and galactosamine about 3% of the total weight of each polymer. Rhamnose was a major component of the polysaccharide (47%) but was present only in traces in the mucoprotein. The protein content of the latter was about 40%. No significant quantities of glycerol, phosphorus, or muramic acid were present in either case. Pepsin and trypsin had no effect on the serological specificity of the mucoprotein. d-Galactose and d-galactosamine were strong inhibitors (70%) of the precipitin reaction, whereas d-glucose, d-glucosamine, and N-acetyl-d-glucosamine inhibited between 25 and 35%. The results indicate that the antigen is a major antigenic component of the cell wall and that the specificity of the antigen resides in binding sites which contain both d-galactose and d-galactosamine. Agglutination of whole cells by specific group b antiserum indicates the antibody receptor sites of the polysaccharide antigen are at the surface of the streptococcal cell. The mucoprotein, but not the polysaccharide, was released from the cell by lysozyme. Lysis did not occur. The immunological specificity and other characteristics of the antigen establishes it as the identifying antigen of S. mutans group b.
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