PubMed Health⌕ Search

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 199 records · Page 11Linked to original sources
PubMed1993

Effects of N-acetylglucosamine on carbohydrate fermentation by Streptococcus mutans NCTC 10449 and Streptococcus sobrinus SL-1.

We have investigated the ability of two species of streptococci isolated from the human oral cavity (Streptococcus mutans NCTC 10449 and Streptococcus sobrinus SL-1) to metabolize N-acetylglucosamine (GlcNAc), a naturally occurring amino sugar present in saliva and human glycoproteins, when provided as the sole fermentable carbohydrate and determined the effects of the presence of GlcNAc on the fermentation of other carbohydrates. S. mutans used GlcNAc at concentrations of up to 10 mM to increase cell numbers, but S. sobrinus was unable to ferment the amino sugar alone and its uptake only occurred in the presence of a fermentable carbohydrate. GlcNAc had a marked inhibitory effect on the ability of S. sobrinus to produce lactic acid from glucose, sucrose, and fructose, at the same time increasing the lag period and doubling time of batch-grown cells. Such patterns of inhibition were found with S. mutans, but the effects were less than those seen in S. sobrinus. In mixed culture studies of the two species, S. sobrinus became the predominant organism when 10 mM glucose was supplied as the sole fermentable carbohydrate, with a concomitant decrease in the numbers of S. mutans cells, but supplementation of the broth with 10 mM glucose and 10 mM GlcNAc resulted in the emergence of S. mutans as the predominant organism. S. mutans and S. sobrinus grown in media containing glucose possessed the ability to transport glucose and GlcNAc, probably via the same glucose-phosphotransferase system at similar rates. However, intracellular levels of N-acetylglucosamine-6-phosphate deacetylase and glucosamine-6-phosphate deaminase were markedly higher in S. mutans grown on glucose and GlcNAc than in S. sobrinus: 34 and 398 and 8 and 17 nmol of NADPH formed per mi per mg of protein for S. mutans and S. sobrinus, respectively. We propose that GlcNAc inhibited growth of S. sobrinus in media containing glucose and GlcNAc by competing with glucose for the glucose phosphotransferase, depleting intracellular levels of phosphoenolpyruvate, and possessing, in contrast to S. mutans, low levels of N-acetyl-glucosamine-6-phosphate deacetylase and glucosamine-6-phosphate deaminase activity. Together, these data suggest that in dental plaque, S. sobrinus when exposed to GlcNAc will have a reduced ability to compete with S. mutans for dietary carbohydrates, contributing to the greater frequency of isolation of S. mutans from human populations.

Acetylglucosamine↗
PubMed1988

Nucleotide sequence analysis of tetracycline resistance gene tetO from Streptococcus mutans DL5.

Streptococcus mutans DL5, isolated from the dental plaque of a pig, was resistant to high levels of streptomycin (Sm, 20 mg/ml), erythromycin (Em, 1 mg/ml), and tetracycline (Tc, greater than 100 micrograms/ml), but contained no detectable plasmid DNA. The Smr and Emr determinants were cloned from cellular DNA on the self-replicating 5-kilobase-pair (kbp) EcoRI fragment of pAM beta 1 and the 4.2-kbp cryptic plasmid pVA380-1, respectively, by transformation of Streptococcus sanguis Challis. Helper plasmid cloning, with a Challis host containing pVA380-1, was required to clone the Tcr determinant of strain DL5 on this vector. A single-colony isolate of the original Tcr clone contained a hybrid plasmid, pDL421, composed of 2.6 kbp of vector DNA and 11.4 kbp of S. mutans DNA. Plasmid pDL421 did not hybridize to plasmids containing the streptococcal Tcr determinants tetL, tetM, and tetN. A shortened derivative of this hybrid plasmid, pDL422, missing a 4.9-kbp HincII fragment from the S. mutans DNA but still encoding Tcr, was obtained by subcloning in S. sanguis Challis. The Tcr gene was located in a 1,917-base-pair open reading frame (ORF) corresponding to a 72-kilodalton protein. The ORF exhibited 99.4% sequence identity with the 1,917-base-pair tetO gene from a strain of Campylobacter coli (W. Sougakoff, B. Papadopoulou, P. Nordmann, and P. Courvalin, FEMS Microbiol. Lett. 44:153-160, 1987). A 1.67-kbp NdeI fragment, internal to the ORF from strain DL5, as well as pDL421 hybridized under stringent conditions to DNA from 10 of 10 Tcr strains of C. coli and Campylobacter jejuni from human and animal sources, but not to DNA from Tcs isolates of these two species.

Amino Acid Sequence↗
PubMed1978

Isolation and characterization of a Streptococcus mutans bacteriocin inhibitor from Streptococcus pyogenes.

An inhibitor of Streptococcus mutans strain GS5 bacteriocin was released from a bacteriocin-sensitive strain of S. pyogenes by sonic treatment and partly purified by gel filtration on a Sepharose 6B column. The inhibitory factor was sensitive to heat, trypsin, and periodate and possessed a molecular weight of approximately 93,000. This factor may be the receptor for the S. mutans bacteriocin.

Bacterial Proteins↗
PubMed1992

Expression of Streptococcus mutans gtf genes in Streptococcus milleri.

The Streptococcus mutans glucosyltransferase (GTF) genes gtfB and gtfC were ligated into Escherichia coli-streptococcus shuttle plasmids and introduced into Streptococcus milleri. gtfB transformant KSB8 formed an S. mutans-like rough colony on mitis salivarius agar and expressed an extracellular GTF-I, of 158 kDa, and two cell-bound GTF-Is, of 158 and 135 kDa. gtfC transformant KSC43 formed a semirough colony on mitis salivarius agar and expressed primarily an extracellular GTF-SI, of 146 kDa, and two cell-bound GTF-SIs, of 146 and 152 kDa. The extracellular GTFs from KSB8 and KSC43 were purified and characterized. The two types of GTF also reacted specifically with monoclonal antibodies directed against each enzyme. Both enzymes synthesized significant amounts of oligosaccharides, consisting primarily of alpha-1,6-glucosidic linkages, as well as water-insoluble glucans, containing alpha-1,3-glucosidic linkages. Insoluble-glucan-synthesizing activities of both enzymes were stimulated (three- to sixfold) by the addition of dextran T10 and were inhibited in the presence of 1.5 M ammonium sulfate. The Km(s) for sucrose and the optimal pHs were also similar for both enzymes. However, when the transformants were grown in Todd-Hewitt broth supplemented with sucrose, KSC43 cells, expressing GTF-SI activity, adhered to glass surfaces in vitro, while KSB8 cells, expressing GTF-I activity, did not. These results are discussed relative to the potential role of the gtfB and gftC genes in S. mutans cariogenicity.

Ammonium Sulfate↗
PubMed1997

Pathway for uptake and degradation of X-prolyl tripeptides in Streptococcus mutans VA-29R and Streptococcus sanguis ATCC 10556.

The growth of Streptococcus mutans and Streptococcus sanguis in the oral environment requires that these micro-organisms be able to degrade salivary proteins and to assimilate the resulting peptides as an amino nitrogen source. Our research is aimed at the definition of the proteolytic enzyme systems in these oral streptococci which allow them to utilize such substrates. In the present work, the nature of the hydrolytic activity expressed by S. mutans VA-29R and S. sanguis ATCC 10556 against X-Pro4-nitroanilide and X-Pro-Y tripeptide substrates was investigated. This activity was predominantly associated with a cytoplasmic dipeptidyl peptidase which preferentially catalyzes the release of an N-terminal dipeptide from substrates in which proline is the penultimate residue. These streptococci also possess a second cytoplasmic peptidase, pepD, which catalyzes the hydrolysis of X-Pro dipeptides. We found that Gly-Pro-Ala or Ala-Pro-Gly were transported into the bacterial cells only when an energy source such as glucose was present. Peptide uptake was time-dependent, and selective exodus of peptide-derived amino acids from the bacterial cells occurred during peptide uptake. Results from these studies provide evidence that S. mutans VA-29R and S. sanguis ATCC 10556 possess a pathway for the complete degradation of X-Pro tripeptides. Transport of the peptides into cells prior to hydrolysis provides an efficient way by which all amino acids of a peptide may be obtained at an energy expense equivalent to that associated with the transport of just one amino acid. In light of the abundance of proline in salivary polypeptides, this degradative pathway could be an important component in the proteolytic pathway for salivary polypeptide utilization in these oral streptococci.

Aminopeptidases↗
PubMed2005

Interactions between oral bacteria: inhibition of Streptococcus mutans bacteriocin production by Streptococcus gordonii.

Streptococcus mutans has been recognized as an important etiological agent in human dental caries. Some strains of S. mutans also produce bacteriocins. In this study, we sought to demonstrate that bacteriocin production by S. mutans strains GS5 and BM71 was mediated by quorum sensing, which is dependent on a competence-stimulating peptide (CSP) signaling system encoded by the com genes. We also demonstrated that interactions with some other oral streptococci interfered with S. mutans bacteriocin production both in broth and in biofilms. The inhibition of S. mutans bacteriocin production by oral bacteria was stronger in biofilms than in broth. Using transposon Tn916 mutagenesis, we identified a gene (sgc; named for Streptococcus gordonii challisin) responsible for the inhibition of S. mutans bacteriocin production by S. gordonii Challis. Interruption of the sgc gene in S. gordonii Challis resulted in attenuated inhibition of S. mutans bacteriocin production. The supernatant fluids from the sgc mutant did not inactivate the exogenous S. mutans CSP as did those from the parent strain Challis. S. gordonii Challis did not inactivate bacteriocin produced by S. mutans GS5. Because S. mutans uses quorum sensing to regulate virulence, strategies designed to interfere with these signaling systems may have broad applicability for biological control of this caries-causing organism.

Antibiosis↗
PubMed1979

Essential dependence of smooth surface caries on, and augmentation of fissure caries by, sucrose and Streptococcus mutans infection.

Streptococcus mutans-free Osborne-Mendel rats were used to study the ability of well-characterized S. mutans strains of Bratthall serotypes c, d, and E to form plaque and cause caries when the animals consumed either sucrose- or glucose-containing diets. All of the serotype representatives successfully infected, colonized, and emerged in the oral ecology of animals, independent of the carbohydrate supplementation of the diet. However, the sucrose-containing diet supported higher percentages of S. mutans of all the serotypes in the plaque and greater amounts of plaque on the teeth. Smooth surface caries was essentially S. mutans dependent and sucrose dependent; fissure caries, although it was neither dependent on S. mutans infection nor sucrose consumption, was augmented by both. This sucrose-associated emergence of all three serotype representatives in the plaque flora and their virulence in the production of caries can be ascribed to their production of alkali-solible alpha-(1 yields 3)-rich glucans from sucrose.

Animals↗
PubMed1998

[Study on the adhesion of an endemic strain of Streptococcus mutans serotype C to acquired pellicle. I. A comparison of the methods to extract adhesins from Streptococcus mutans].

The adhesins of S. mutans serotype c endemic strain WD9463A were extracted from culture superant by cold ethol precipitation, or were extracted from cell surface by 0.5 mol/L phosphate buffer, 6 mol/L urea or 2% SDS solution. The composition and adhesive activities of the extracts were compared by SDS-PAGE and bacterial adhesion inhibition experiments. The results showed that the protein composition of the four extracts were similar, and all extracts inhibited the adhesion of the endemic strain dramatically. It indicates that four methods can be used to extract adhesins of S. mutans, but extracting adhesins from culture superant is better than the others.

Adhesins, Bacterial↗
PubMed1998

[Study on the adhesion of an endemic strain of Streptococcus mutans serotype C to acquired pellicle. II. Isolation and extraction of adhesins of an endemic strain of Streptococcus mutans serotype C].

Surface proteins of S. mutans WD9463 A(c) were separated by DEAE-Sephadex A25 Chromatography and Sepharose C1-6B Chromatography. The adhesins were distinguished by bacterial adhesin inhibition experiment and were identified by PAGE, SDS-PAGE, IEP-PAGE, immunol diffusion test, GTF activity test and annalization of the sorts of amino acid. The results showed P1, two proteins with molecular weight of 117 kD and 127 kD and two proteins with GTF activity could inhibit the adhesion effectively. On the other hand, another kind of GTF could improve the adhesion of the strain. These indicated that S. mutans may be many kinds of adhesins.

Adhesins, Bacterial↗
PubMed1992

Reduced nicotinamide adenine dinucleotide oxidase involvement in defense against oxygen toxicity of Streptococcus mutans.

The growth inhibition of the Streptococcus mutans group, including Streptococcus mutans, Streptococcus cricetus, Streptococcus rattus and Streptococcus sobrinus, on glucose by oxygen and the properties of reduced nicotinamide adenine dinucleotide (NADH) oxidase induced by oxygen, using a representative oxygen-tolerant strain, were examined. The growth response to oxygen varied among strains and correlated with the level of NADH oxidase activity in the cell extract. The induced synthesis of NADH oxidase as well as superoxide dismutase was affected by oxygen tension and energy sources. The induced NADH oxidase involved at least two types, major H2O-forming NADH oxidase and minor H2O2-forming NADH oxidase activity. In the presence of a scavenger of H2O2, pyruvate, the growth inhibition by oxygen in an oxygen-sensitive strain (GS5) was protected but not in another oxygen-sensitive strain (MT8148). The high level of induced H2O-forming NADH oxidase activity protected against oxygen toxicity.

Aerobiosis↗
PubMed1998

Mutacin production by Streptococcus mutans may promote transmission of bacteria from mother to child.

The production of bacteriocin-like inhibitory substances, mutacins, by mutans streptococci varies among isolates. To find if the degree of mutacin activity of an isolate was related to its transmission between mother and her child, 19 mothers and their 18-month- to 3-year-old children were sampled for their oral mutans streptococci. In addition, the stability of mutacin activity was studied with isolates from the mothers and with isolates from five unrelated 5-year-old children in 5- to 7-year follow-up studies. A total of 145 oral mutans streptococcal isolates were serotyped by immunodiffusion, ribotyped, and mutacin typed by the stab culture technique. Mutacin was produced by 88% of the strains against more than 1 of the 14 indicator strains, representing mutans streptococci, Streptococcus sanguis, Streptococcus salivarius, Streptococcus oralis, Streptococcus gordonii, and Streptococcus pyogenes. Streptococcus mutans isolates showed more inhibitory activity than did Streptococcus sobrinus isolates. Identical ribotypes had similar mutacin activity profiles within a subject, initially and in the follow-up studies, in all but two cases. The mothers harbored a total of 37 different mutans streptococcal ribotypes. Six children were negative for mutans streptococci. Transmission was probable in 9 of 20 mother-child pairs on the basis of the presence of identical strains, as determined by ribotyping and bacteriocin (mutacin) typing. S. mutans strains shared between a mother and her child showed a broader spectrum of inhibitory activity than did nontransmitted strains. In conclusion, the mutacin activity of clinical isolates is reasonably stable, and this virulence factor seems to be of clinical importance in early colonization by S. mutans.

Adolescent↗
PubMed1990

Incidence of bacteriocinogeny among fresh isolates of Streptococcus mutans.

Among 139 Streptococcus mutans fresh isolates tested, using the deferred-antagonism test and Streptococcus sanguis Ny 101 as the indicator strain, we observed that the frequency of detection of inhibition zones was reduced by 19% (from 53 to 34%) when arginine (1%) was used in the overlay agar. Among pigmented strains, the frequency of mutacin-like production was 70%. The frequency with which inhibition zones were detected varied from 7 to 91%, depending on the indicator strain used. These results indicate that the ability to detect the presence of mutacin-like substances varies widely and is dependent to a great extent on the methodology used.

Adult↗
PubMed1985

Cloned gtfA gene of Streptococcus mutans LM7 alters glucan synthesis in Streptococcus sanguis.

Streptococcus mutans LM7 (Bratthall serotype e) chromosomal DNA was partially digested with EcoRI and ligated into the positive-selection plasmid vector pOP203(A2+). The ligation mixture was transformed into Escherichia coli, and transformants were selected for tetracycline resistance. Recombinant-bearing clones were screened for their ability to ferment raffinose, using the procedure of Robeson et al. (J. Bacteriol. 153:211-221, 1983). One raffinose-fermenting clone was isolated and found to contain a plasmid with an insert consisting of four EcoRI fragments totalling approximately 10.3 kilobases (kb). This strain was capable of growth on defined medium plus raffinose or sucrose and generated reducing sugars from a sucrose substrate. Southern hybridization analysis of the four EcoRI fragments revealed homology not only to S. mutans LM7 chromosomal DNA but also to S. mutans serotypes b, c, and f. Subcloning of this fragment array into a streptococcal E. coli shuttle vector indicated that a 2.4-kb EcoRI fragment was essential for sucrase activity. E. coli minicell experiments revealed a gene product of 55 kilodaltons. These data along with restriction endonuclease analysis and Southern hybridizations suggested that the cloned S. mutans LM7 gene was closely related to the gtfA gene cloned by Robeson et al. from S. mutans PS13 (Bratthall serotype c). The shuttle plasmid containing the 2.4-kb fragment was transformed into Streptococcus sanguis, which subsequently displayed increased sucrase activity in both intracellular and extracellular fractions. Elevated levels of synthesis of alcohol-insoluble and water-insoluble glucans were observed with crude extracellular fractions of the S. sanguis strain bearing the 2.4-kb fragment. An isolate cured of the shuttle plasmid plus the 2.4-kb fragment displayed wild-type S. sanguis glucan synthesis. In S. sanguis, this gtfA allele may play a role in glucan synthesis by interacting with extant high-molecular-weight glucosyltransferases.

Cloning, Molecular↗
PubMed2006

[Assessment of gene associated with Streptococcus mutans biofilm formation].

Streptococcus mutans, the primary etiological agent of human dental caries and an obligate biofilm-forming bacterium, has developed a variety of mechanisms to colonize the tooth surface. Oral transmission of S. mutans through contact between mother and child is thought to be one of the risks of developing dental caries. In this study, I surveyed oral transmission frequency of S. mutans from mother to a 3-year-old child. In 19 (10.9%) of 174 mother-child pairs, S. mutans was isolated from both mother and chihld. The identities of genomic DNA from S. mutans in 5 (45.5%) of the 11 mother-child pairs were presented. Among those, the biofilms formed by S. mutans 3 c and 4 c, respectively, which had high and low ability of biofilm formation, were examined by confocal laser scanning microscopy (CLSM). Microscopic analysis revealed that the volume of biofilm formation in 3 c was higher than that in 4 c biofilm in the bottom. Furthermore, DNA microarrays were used to study the gene expression profiles of 3 c and 4 c biofilms. In this paper we describe that about 3.8% of genes showed differential expression; about 2.2% of genes were activated and about 1.6% were repressed in 3 c biofilm compared with 4 c biofilm. The present study suggests that biofilm gene expression is strongly associated with differential biofilm formation. Our identification of biofilm-involved genes points to mechanisms of the virulence of S. mutans and provides a first foothold for studying the natural history of S. mutans infections in mother and child.

Biofilms↗
PubMed1984

Penicillin-induced lysis of Streptococcus mutans.

Treatment of Streptococcus mutans GS-5 cells with concentrations of penicillin G within a relatively narrow range resulted in substantial lysis. This penicillin-induced lysis was dependent upon cell density and pH of the lysis medium. Other oral streptococci (Streptococcus sobrinus, Streptococcus rattus, and Streptococcus cricetus) also demonstrated substantial levels of penicillin-induced lysis under appropriate conditions. Lesser degrees of lysis were seen in a related organism, Streptococcus ferus.

Dose-Response Relationship, Drug↗