Regulation of water‐soluble glucan synthesis by the Streptococcus mutans dexA gene effects biofilm aggregation and cariogenic pathogenicity

2019 ◽  
Vol 34 (2) ◽  
pp. 51-63 ◽  
Author(s):  
Yan Yang ◽  
Mengying Mao ◽  
Lei Lei ◽  
Meng Li ◽  
Jiaxin Yin ◽  
...  
Keyword(s):  
Streptococcus Mutans ◽  
Water Soluble ◽  
Gene Effects ◽  
Glucan Synthesis

scholarly journals Streptococcus mutans Dextransucrase: Functioning of Primer Dextran and Endogenous Dextranase in Water-Soluble and Water-Insoluble Glucan Synthesis

1977 ◽  
Vol 16 (2) ◽  
pp. 637-648 ◽  
Author(s):  
Greg R. Germaine ◽  
Susan K. Harlander ◽  
Woon-Lam S. Leung ◽  
Charles F. Schachtele
Keyword(s):  
Streptococcus Mutans ◽  
Water Soluble ◽  
Insoluble Glucan ◽  
Glucan Synthesis

scholarly journals Inhibitory Potential of Mangiferin on Glucansucrase Producing Streptococcus mutans Biofilm in Dental Plaque

2020 ◽  
Vol 10 (22) ◽  
pp. 8297
Author(s):  
Promise M. Emeka ◽  
Lorina I. Badger-Emeka ◽  
Hairul-Islam M. Ibrahim ◽  
Krishnaraj Thirugnanasambantham ◽  
Jamal Hussen
Keyword(s):  
Streptococcus Mutans ◽  
Virulence Genes ◽  
Inhibitory Effect ◽  
Water Soluble ◽  
Oral Microbiota ◽  
Sem Images ◽  
Bacteria Growth ◽  
Dental Biofilm ◽  
Reverse Transcription Pcr ◽  
Glucan Synthesis

Glucansucrase secreted by Streptococcus mutans and composed of virulence genes alters oral microbiota, creating adherent environment for structural bacteria colony forming dental biofilm. The present investigation studied the inhibitory and binding potentials of mangiferin against S. mutans and its enzyme glucansucrase implicated in biofilm formation. Antibacterial activity against planktonic S. mutans was carried out. Using reverse transcription PCR, the expression of crucial virulence genes, gtfB, gtfC, gtfD, gbpB, and comDE were determined. The effect of mangiferin on teeth surfaces biofilm was ascertained by scanning electron microscopy (SEM). Docking analysis of S. mutans glucansucrase and mangiferin revealed the binding energy of −7.35 and ten hydrogen interactions. Antibacterial study revealed that mangiferin was not lethal to planktonic S. mutans, but a concentration-dependent inhibition of glucansucrase activity was observed. The inhibitory effect of water-insoluble glucan synthesis was apparently more marked relative to water-soluble glucan synthesis attenuation. Mangiferin significantly downregulated the expression of the virulence genes, indicating a mechanism involving glucanotranferases, specifically inhibiting colony formation by attenuating bacterial adherence. SEM images revealed that S. mutans biofilm density was scanty in mangiferin treated teeth compared to non-treated control teeth. Our data therefore suggest that mangiferin inhibited S. mutans biofilms formation by attenuating glucansucrase activities without affecting bacteria growth.

scholarly journals Functional Analyses of a Conserved Region in Glucosyltransferases of Streptococcus mutans

1998 ◽  
Vol 66 (10) ◽  
pp. 4797-4803 ◽  
Author(s):  
Jean-San Chia ◽  
Czau-Siung Yang ◽  
Jen-Yang Chen
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Enzymatic Activity ◽  
Streptococcus Mutans ◽  
Water Soluble ◽  
Single Amino Acid ◽  
Single Mutation ◽  
Insoluble Glucan ◽  
Conserved Region ◽  
Glucan Synthesis

ABSTRACT Streptococcus mutans glucosyltransferases (GTFs; GtfB, -C, and -D) synthesize water-soluble and -insoluble glucan polymers from sucrose. We have identified previously a conserved region of 19 amino acids (aa) (Gtf-P1; aa 409 to 427 of GtfB and aa 435 to 453 of GtfC) which is functionally important for both enzymatic activity and bacterial adherence. Monoclonal antibodies directed against Gtf-P1 selectively inhibited insoluble glucan synthesis by GtfB and -C but had no effect on soluble glucan synthesis by GtfD, suggesting that despite an apparent near identity of sequence, corresponding residues may function differently in these enzymes. To test this hypothesis, we used different strategies of mutagenesis to analyze amino acid residues of GtfB and GtfC in Gtf-P1. In-frame insertion of 6 amino acids preceding, or deletion of 14 amino acids within, this conserved region abolished the enzymatic activities of both GtfB and GtfC. Substitution of several residues in combination by random mutagenesis resulted in GtfB, but not GtfC, enzymes exhibiting decreased glucan synthesis and reduced rates of sucrose hydrolysis. Amino acid substitutions of Asp residues in GtfB or GtfC were found to be more critical for enzymatic activity than at other positions of this region. Interestingly, single mutation at Asp411 or Asp413 of GtfB resulted in enzymes retaining about 20% of wild-type activity, whereas mutagenesis of the corresponding Asp at position 437 or 439 in GtfC resulted in complete loss of enzymatic activity. Furthermore, single amino acid substitution of a Val residue between the two Asp residues enhanced the sucrase- and glucan-synthesizing activities of GtfB and GtfC. These results confirmed the report from another laboratory that Asp residues in the Gtf-P1 region are essential for enzymatic catalysis and provide new evidence that identical residues may function differently in closely related Gtf enzymes.

Interaction of Streptococcus mutans Glucosyltransferases with Teichoic Acids

1980 ◽  
Vol 29 (2) ◽  
pp. 376-382
Author(s):  
H. K. Kuramitsu ◽  
L. Wondrack ◽  
M. McGuinness
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Streptococcus Mutans ◽  
Teichoic Acid ◽  
Lipoteichoic Acid ◽  
Water Soluble ◽  
Heat Inactivation ◽  
Teichoic Acids ◽  
Insoluble Glucan

The Streptococcus mutans GS5 glucosyltransferase activities (both water-soluble and -insoluble glucan-synthesizing fractions) were inhibited by purified lipoteichoic acid. In vitro sucrose-dependent colonization of smooth surfaces by strain GS5 was also markedly reduced in the presence of the amphipathic molecules. The inhibition of soluble glucan synthesis by lipoteichoic acid appeared to be competitive with respect to both sucrose and primer dextran T10. These inhibitory effects were dependent on the presence of the fatty acid components of lipoteichoic acid since deacylated lipoteichoic acids did not inhibit glucosyltransferase activity. However, the deacylated molecules did interact with the enzymes since deacylated lipoteichoic acid partially protected the enzyme activity against heat inactivation and also induced the formation of high-molecular-weight enzyme complexes from the soluble glucan-synthesizing fraction. The presence of teichoic acid in high-molecular-weight aggregates of glucosyltransferase isolated from the culture fluids of strain GS5 was suggested by the detection of polyglycerophosphate in these fractions. In addition to strain GS5, two other organisms containing polyglycerophosphate teichoic acids, Lactobacillus casei and Lactobacillus fermentum , were demonstrated to bind glucosyltransferase activity. These results are discussed relative to the potential role of teichoic acid-glucosyltransferase interactions in enzyme binding to the cell surface of S. mutans and the formation of high-molecular-weight enzyme aggregates in the culture fluids of the organism.

scholarly journals Exopolysaccharides Produced by Streptococcus mutans Glucosyltransferases Modulate the Establishment of Microcolonies within Multispecies Biofilms

2010 ◽  
Vol 192 (12) ◽  
pp. 3024-3032 ◽  
Author(s):  
H. Koo ◽  
J. Xiao ◽  
M. I. Klein ◽  
J. G. Jeon
Keyword(s):  
Streptococcus Mutans ◽  
Extracellular Polysaccharide ◽  
Fluorescence Labeling ◽  
Tooth Surface ◽  
Bacterial Cells ◽  
Actinomyces Naeslundii ◽  
Multispecies Biofilm ◽  
Tooth Surfaces ◽  
Glucan Synthesis

ABSTRACT Streptococcus mutans is a key contributor to the formation of the extracellular polysaccharide (EPS) matrix in dental biofilms. The exopolysaccharides, which are mostly glucans synthesized by streptococcal glucosyltransferases (Gtfs), provide binding sites that promote accumulation of microorganisms on the tooth surface and further establishment of pathogenic biofilms. This study explored (i) the role of S. mutans Gtfs in the development of the EPS matrix and microcolonies in biofilms, (ii) the influence of exopolysaccharides on formation of microcolonies, and (iii) establishment of S. mutans in a multispecies biofilm in vitro using a novel fluorescence labeling technique. Our data show that the ability of S. mutans strains defective in the gtfB gene or the gtfB and gtfC genes to form microcolonies on saliva-coated hydroxyapatite surfaces was markedly disrupted. However, deletion of both gtfB (associated with insoluble glucan synthesis) and gtfC (associated with insoluble and soluble glucan synthesis) is required for the maximum reduction in EPS matrix and biofilm formation. S. mutans grown with sucrose in the presence of Streptococcus oralis and Actinomyces naeslundii steadily formed exopolysaccharides, which allowed the initial clustering of bacterial cells and further development into highly structured microcolonies. Concomitantly, S. mutans became the major species in the mature biofilm. Neither the EPS matrix nor microcolonies were formed in the presence of glucose in the multispecies biofilm. Our data show that GtfB and GtfC are essential for establishment of the EPS matrix, but GtfB appears to be responsible for formation of microcolonies by S. mutans; these Gtf-mediated processes may enhance the competitiveness of S. mutans in the multispecies environment in biofilms on tooth surfaces.

scholarly journals Antibody to Glucosyltransferase Induced by Synthetic Peptides Associated with Catalytic Regions of α-Amylases

1999 ◽  
Vol 67 (5) ◽  
pp. 2638-2642 ◽  
Author(s):  
Daniel J. Smith ◽  
Rhonda L. Heschel ◽  
William F. King ◽  
Martin A. Taubman
Keyword(s):  
Catalytic Activity ◽  
Immune Responses ◽  
Streptococcus Mutans ◽  
Immunoglobulin G ◽  
Inhibitory Activity ◽  
Synthetic Peptides ◽  
Serum Immunoglobulin ◽  
Salivary Iga ◽  
Glucan Synthesis

ABSTRACT We examined the immunogenicity and induction of inhibitory activity of 19-mer synthetic peptides which contained putative catalytic regions that were associated with the β5 (EAW) and β7 (HDS) strand elements of the suggested (β,α)8 catalytic barrel domain of Streptococcus mutans glucosyltransferase (GTF). Both peptides readily induced serum immunoglobulin G (IgG) and salivary IgA antipeptide activity which was reactive both with the inciting peptide and with intactS. mutans GTF. Antisera to each peptide construct also inhibited the ability of S. mutans GTF to synthesize glucan. These observations support the existence of catalytic subdomains containing glutamate and tryptophan (EAW) or aspartate and histidine (HDS) residues, each of which have been suggested to be involved with the catalytic activity of GTF. Furthermore, the epitopes defined in these sequences have significant immunogenicity and can induce immune responses which interfere with GTF-mediated glucan synthesis.

scholarly journals Cationic Lipid Content in Liposome-Encapsulated Nisin Improves Sustainable Bactericidal Activity against Streptococcus mutans

2016 ◽  
Vol 10 (1) ◽  
pp. 360-366 ◽  
Author(s):  
Kazuo Yamakami ◽  
Hideaki Tsumori ◽  
Yoshitaka Shimizu ◽  
Yutaka Sakurai ◽  
Kohei Nagatoshi ◽  
...  
Keyword(s):  
Dental Caries ◽  
Streptococcus Mutans ◽  
Cationic Lipid ◽  
Cationic Liposome ◽  
Bactericidal Effect ◽  
Insoluble Glucan ◽  
Inhibitory Efficiency ◽  
Bactericidal Activities ◽  
Glucan Synthesis ◽  
Sustained Inhibition

An oral infectious disease, dental caries, is caused by the cariogenic streptococci Streptococcus mutans. The expected preventive efficiency for prophylactics against dental caries is not yet completely observed. Nisin, a bacteriocin, has been demonstrated to be microbicidal against S. mutans, and liposome-encapsulated nisin improves preventive features that may be exploited for human oral health. Here we examined the bactericidal effect of charged lipids on nisin-loaded liposomes against S. mutans and inhibitory efficiency for insoluble glucan synthesis by the streptococci for prevention of dental caries. Cationic liposome, nisin-loaded dipalmitoylphosphatidylcholine/phytosphingosine, exhibited higher bactericidal activities than those of electroneutral liposome and anionic liposome. Bactericidal efficiency of the cationic liposome revealed that the vesicles exhibited sustained inhibition of glucan synthesis and the lowest rate of release of nisin from the vesicles. The optimizing ability of cationic liposome-encapsulated nisin that exploit the sustained preventive features of an anti-streptococcal strategy may improve prevention of dental caries.

Genetic variation and correlation among yield and quality traits in cocksfoot (Dactylis glomerata L.)

2007 ◽  
Vol 145 (6) ◽  
pp. 599-610 ◽  
Author(s):  
A. JAFARI ◽  
H. NASERI
Keyword(s):  
Dry Matter ◽  
Additive Genetic Variance ◽  
Heading Date ◽  
Dactylis Glomerata ◽  
Tiller Number ◽  
Water Soluble ◽  
Quality Traits ◽  
Gene Effects ◽  
Yield And Quality ◽  
Selection For

SUMMARYThe objective of the present research was to study the genetic variability for total dry matter (DM) yield, tiller number, heading date and three quality traits, namely content of digestible dry matter (DDM), water-soluble carbohydrate (WSC) and crude protein (CP), in cocksfoot (Dactylis glomerata L.). Twenty-five parents were randomly chosen from a genetically broad-based population, and their respective half-sib (HS) families were generated. Clonally-propagated parents and their HS family seeds were grown as individual plants using a randomized complete block design with two replications in Alborz Research Center, Karaj, Iran, during 2002–04. The results of combined analyses over 2 years showed significant variances between clonal parents for all traits except CP. In the HS generation, between-family variances were only significant for tiller number, heading date and WSC. Clone×year (S2GY) and family×year (S2FY) interactions were significant for all traits except for WSC in HS families. The estimates of broad-sense heritability (h2b) were moderate to high for all traits (h2b=0·37–0·69), except CP. Narrow-sense heritability (h2n) estimates from analyses of progenies and from regression of HS progenies on parents (h2op) were moderate, relatively the same values as h2b for heading date, tiller number and WSC, which suggested that additive genetic variance was the main component controlling these traits. For DM yield and DDM, h2n and h2op estimates were low, whereas h2b estimates were moderate, which suggested that both additive and non-additive gene effects played an important role in the genetic regulation of these traits. Genetic correlations among CP with both WSC and DDM were generally negative, whereas WSC was positively correlated with DDM and tiller number. The genetic correlation among DM yield with DDM was weak and inconsistent and, in general, negative. DM yield had negative and positive correlation with heading date and tiller number, respectively. It was concluded that there was significant variation and moderate heritability for most traits in the cocksfoot populations evaluated to improve yield and quality traits. Selection for high WSC is a means to improve quality in general. The data also indicate that response to combined selection for both DDM and DM yield should be possible. Selection for DDM alone could result in reduction in yield.

Effects of Fluoride, Lithium and Strontium on Extracellular Polysaccharide Production by Streptococcus mutans and Actinomyces viscosus

1981 ◽  
Vol 60 (C) ◽  
pp. 1601-1610 ◽  
Author(s):  
Patrick Treasure
Keyword(s):  
Trace Elements ◽  
Streptococcus Mutans ◽  
Extracellular Polysaccharide ◽  
Water Soluble ◽  
Extracellular Polysaccharides ◽  
Polysaccharide Production

Effects of trace elements on production of extracellular polysaccharides (EPS) by S. mutans and A. viscosus were examined in vitro. Fluoride enhanced EPS production. Lithium and strontium had little effect alone, but tended to reverse the effect of fluoride. The proportion of water-soluble EPS and the proportion of glucosyl-EPS were increased by fluoride.

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