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PubMed1976

Chemical and immunological properties of the type f polysaccharide antigen of Streptococcus mutans.

The type-specific cell wall polysaccharide antigen was extracted, purified, and characterized from type f Streptococcus mutans strain OMZ175 and MT557. The antigen was extracted from lyophilized cells with 5% trichloroacetic acid at 85 C for 15 min or saline at 120 C for 30 min. The trichloroacetic acid antigen was chromatographically separated into three antigenic fractions on a diethylaminoethyl-Sephadex A-25 column. Antigen 1 (Ag1P), which was specific for type f antiserum, was further purified by passing through carboxymethyl-Sephadex C-25 and Sephadex G-200 columns. It was a polysaccharide composed of 49% rhamnose and 47% glucose. No reaction was obtained with anti-polyglycerophosphate (PGP) serum. Antigen 2 was reactive with both type f and PGP antisera and contained significant amounts of protein and phosphorus. Antigen 3 was reactive only with PGP antiserum and had no type specificity. The polysaccharide antigen gave a single precipitin band against type-specific antiserum on immunodiffusion and immunoelectrophoresis. The presence of alpha-1,6-glucosidic linkages was indicated by a 90% inhibition of the precipitin reaction by isomaltose and alpha-methyl-D-glucopyranoside, adsorption to and release from a concanavalin A-Sepharose column, and reaction with an S. mutans (type e) glucan antiserum. This antiserum was used to show that the type f polysaccharide antigen did not contain free glucan. An analysis of the antigen released from the antigen-glucan antiserum complex showed the presence of rhamnose and glucose. This released antigen also reacted with an f antiserum, which did not react with commercial dextran. The results show that the type f polysaccharide antigen is the first of those S. mutans type-specific polysaccharides identified to be immunologically related to an S. mutans glucan.

Antigens, Bacterial↗
PubMed2005

Vectors that facilitate the replacement of transcriptional lacZ fusions in Streptococcus mutans and Bacillus subtilis with fusions to gfp or gusA.

Plasmid vectors have been constructed for Streptococcus mutans and Bacillus subtilis that make possible rapid replacement of the widely used reporter gene lacZ (encoding beta-galactosidase) with either gfp (encoding green fluorescent protein) or gusA (encoding beta-glucuronidase). The lacZ-->gfp replacement vectors greatly facilitate the analysis of the spatial location of gene expression in biofilms of S. mutans and in sporulating B. subtilis. The lacZ-->gusA replacement vectors facilitate the comparison of two promoters within the same organism. A vector is also described that enables gusA to be replaced with gfp in B. subtilis.

Bacillus subtilis↗
PubMed1986

Serum and salivary antibody responses in rats orally immunized with Streptococcus mutans carbohydrate protein conjugate associated with liposomes.

In this study we describe the preparation of a Streptococcus mutans vaccine consisting of a purified polysaccharide antigen, derived from S. mutans OMZ175 serotype f, covalently coupled through reductive amination to a previously isolated 74,000-molecular-weight (74K) cell wall protein which interacts with saliva proteins (74K-SR). We also investigated the local and systemic immune response to the poly-74K-SR conjugate after oral administration of the conjugate associated with liposomes. Intragastric administration of liposome-associated poly-74K-SR conjugate in rats produced a local immunoglobulin A (IgA) response directed against the polysaccharide and the cell surface protein, whereas liposome-associated polysaccharide was unable to induce any detectable local IgA response. The antigenicity of the polysaccharide in the conjugate was not affected by the coupling reaction, while that of the cell surface protein was reduced. We showed that the immunogenicity of S. mutans polysaccharide could be improved by chemical coupling with a carrier cell surface protein. If such a conjugate were orally administered with liposomes it could constitute a potential vaccine against dental caries.

Administration, Oral↗
PubMed1977

Infective endocarditis caused by Streptococcus mutans.

Members of the viridans group of streptococci are the commonest causes of bacterial endocarditis. However, Streptococcus mutans, a member of this group associated with dental caries which might be expected to be commonly associated with endocarditis, has only rarely been reported. This is possibly because of difficulties in isolation and identification. Differing blood culture media may affect the chances of isolation of these organisms, and, though brain-heart infusion, thiol, tryptic soy, and glucose-brain infusion broths have all proved satisfactory, subcultures may require increased CO2 concentrations for growth. Plemorphism in the resultant colonies and in the individual organisms may give rise to a hazardous misinterpretation of this appearance as contamination. Strep. mutans and the similarly penicillin sensitive Strep. bovis may be differentiated from the penicillin resistant enterococci by their lincomycin sensitivity and intolerance of 6-3 per cent sodium chloride. Precise differentiation of streptococci in bacterial endocarditis is of value both epidemiologically and in the management of the disease.

Adult↗
PubMed1991

Effect of immune bovine milk on Streptococcus mutans in human dental plaque.

The use of a mouthrinse of bovine milk containing antibodies to Streptococcus mutans resulted in an initial reduction in the numbers of recoverable Strep. mutans in a group of 9 individuals. Ten volunteers who used control bovine milk that contained no antibody activity to Strep. mutans had variable levels of plaque Strep. mutans. In addition, after culture on Mitis Salivarius and Gold's agar, the plaque Strep. mutans from subjects who used the immune bovine milk rinse formed smaller colonies than those from pre-treatment plaque and from all plaque samples of subjects who used the control rinse.

Adult↗
PubMed1987

Utilization of a mini-mu transposon to construct defined mutants in Streptococcus mutans.

The gtfB gene coding for glucosyltransferase-I (GTF-I) activity previously isolated from Streptococcus mutans GS-5 was insertionally inactivated with the newly constructed transposon MudE in an Escherichia coli background. Insertion of MudE into various regions of the gtfB gene led to inactivation of GTF-I activity. The altered gene was introduced back into S. mutans GS-5 by transformation and produced mutants defective in insoluble glucan synthesis as well as the ability to colonize smooth surfaces in the presence of sucrose. Therefore, the MudE transposon can be utilized to produce specific mutants in oral streptococci as well as in other transformable Gram-positive bacteria expressing an erythromycin-resistance marker.

DNA Restriction Enzymes↗
PubMed1977

New method for the isolation of Streptococcus mutans and its differentiation from other oral streptococci.

A new, improved agar medium for the isolation of Streptococcus mutans, the etiological agent of dental caries, was developed. In contrast to mitis-salivarius agar, this medium not only recovers a greater number of S. mutans strains from most oral specimens but, because of its mannitol and sorbitol content, it also facilitates the differentiation of S. mutans from other oral streptococci, e.g., S. salivarius, S. mitis, and S. sanguis, which do not grow or produce scanty growth only after 10 days of incubation. The medium is easy to prepare because of its simple and unique composition, is characterized by the presence of an acid indicator, and can be utilized under aerobic and anaerobic conditions as well. The medium cannot be used to distinguish among the eight serotypes, a to g and SL-1, of S. mutans. Mannitol-utilizing bacteria such as streptococci (e.g., S. faecalis) and other microorganisms (e.g., Staphylococcus aureus) are able to grow on this medium and can be distinguished from S. mutans by their unique colony morphology.

Aerobiosis↗
PubMed1977

Microcapsules on Streptococcus mutans serotypes by electron microscopy.

Extracellular microcapsules have been demonstrated on cells of most serotypes of Streptococcus mutans by electron microscopy, using bacterial strains of the various serotypes and peroxidase labeled or unlabeled immune serum. A correlation was noted between the amount of capsular substance on the strains of S mutans examined and degree of antigenicity as expressed by the indirect fluorescent antibody (FA) title. A serotype d strain was shown to lose both antigenicity as determined by the FA reaction and capsular material as seen by electron microscopy with repeated in vitro passage. When 10% unheated rabbit serum was added to the medium, antigenicity and capsular material were restored.

Fluorescent Antibody Technique↗
PubMed1993

Identification of Streptococcus mutans antigen D as the HPr component of the sugar-phosphotransferase transport system.

Extraction of Streptococcus mutans with the detergents HECAMEG and lauroyl sarcosinate preferentially extracted antigen D, previously identified as a low molecular mass wall-associated protein. Western blotting with specific antisera was used to demonstrate that this antigen is the HPr component of the sugar-phosphotransferase transport system. Non-denaturing electrophoresis indicated that HECAMEG selectively extracted only one of the two forms of HPr. It is suggested that this form of HPr may have a specific cell surface location.

Antigens, Bacterial↗
PubMed1991

Synthesis and antibacterial activities of 4-hydroxy-o-phenylphenol and 3,6-diallyl-4-hydroxy-o-phenylphenol against a cariogenic bacterium Streptococcus mutans OMZ 176.

For the purpose of survey of the antibacterial activity against a cariogenic bacterium Streptococcus mutans OMZ 176 with the introduction of hydroxyl and allyl groups to o-phenylphenol (Fig. 2, 1), 4-hydroxy-o-phenylphenol (2), and 3,6-diallyl-4-hydroxy-o-phenylphenol (4) were synthesized, successively. The synthesized compounds, 2 and 4 showed more potent antibacterial activity than the starting material, 1. The hydroxyl group was supposed to the essential element for the antibacterial activity and the introduction of allyl group to phenolic ring to be another element to increase the activity.

Allyl Compounds↗
PubMed2000

Characterization of the gtfB and gtfC promoters from Streptococcus mutans GS-5.

We have characterized the promoter regions of the gtfB and gtfC genes from Streptococcus mutans GS-5. Using a plasmid-based reporter system, we discovered that the gtfC promoter is an order of magnitude stronger than the gtfB promoter. In addition, we found that a variety of growth conditions failed to affect or discriminate between the expression of the two promoters. Only during the various phases of growth could we demonstrate significant changes in expression. We conclude that gtfB and gtfC promoters are coordinately expressed.

Base Sequence↗
PubMed1985

In-vitro inhibition of glucosyltransferase from the dental plaque bacterium Streptococcus mutans by common beverages and food extracts.

Some fruit juices and beverages inhibit the glucosyltransferases of Streptococcus mutans. Inhibition by cocoa, coffee and tea was due partly to gelatin-precipitable tannins and partly to components that exhibited properties of monomeric polyphenols. Charcoal treatment removed all inhibitory activity. Catechin, a known constituent of these beverages, was an effective inhibitor of the enzymes. The effects of the fruit juices were attributable mainly to the inhibition of the glucosyltransferases by the endogenous fructose and glucose. The findings show that naturally-occurring constituents of foods can inhibit extracellular polysaccharide formation from sucrose. Such constituents may play a role in regulating dental plaque formation in vivo and, thereby, may have long-term effects on the development of dental caries.

Beverages↗
PubMed1996

Irreversible paraben inhibition of glycolysis by Streptococcus mutans GS-5.

Parabens were found to inhibit irreversibly glycolysis by the cariogenic dental plaque bacterium Streptococcus mutans GS-5 and to decrease the capacity of the bacterium to lower the pH in dense cell suspensions containing excess glucose. The hierarchy of effectiveness was butyl > propyl > ethyl > methyl paraben. Results of studies of the nature of glycolytic inhibition by butyl paraben indicated that it could act at millimolar concentrations as an irreversible inhibitor of the phosphotransferase system for sugar uptake and was lethal for the bacterium at these same levels. Butyl paraben acted also as a reversible inhibitor of the F-ATPase of the organism. Overall, it appeared that the lethal actions of parabens can be interpreted at least in part as due to irreversible damage to key enzymes, such as those of the phosphotransferase system.

Food Preservatives↗
PubMed1981

Enhanced transmembrane proton conductance in Streptococcus mutans GS-5 due to ionophores and fluoride.

The uptake of protons by intact cells of Streptococcus mutans GS-5 was measured directly by assessing the pH increase in lightly buffered cell suspensions as protons moved across the plasma membrane after acid pulses. The barrier function of the cell membrane for protons was disrupted completely by 5% (vol/vol) butanol. This function was compromised severely by the ionophores valinomycin and gramicidin and by the uncoupler carbonylcyanide-m-chlorophenyl hydrazone. Proton conduction across the membrane was also enhanced by fluoride. It appeared that HF traversed the membrane and acted as a carrier. Once in the relatively alkaline cytoplasm, HF dissociated to yield F- and H+, which acted to acidify the cytoplasm and reduced the pH difference across the membrane.

Carbonyl Cyanide m-Chlorophenyl Hydrazone↗
PubMed1995

Characterization of the dextranase gene (dex) of Streptococcus mutans and its recombinant product in an Escherichia coli host.

The gene (dex), which encodes the Streptococcus mutans dextranase (Dex), was cloned in Escherichia coli. The E. coli host harboring a recombinant plasmid (pSD2) containing an 8-kb BamHI insert produced a Dex protein of 133 kDa as well as smaller enzymes of 118, 104, and 88 kDa. The Dex produced by the recombinant E. coli was apparently located in the cytoplasmic fraction, not in the periplasmic nor the extracellular fractions. Subcloning and deletion analysis of pSD2 showed that the structural gene of Dex was encoded by a 4-kb BamHI-SalI fragment. The fragment also contained the dex promoter which was effective in the E. coli cell.

Cloning, Molecular↗
PubMed1978

Colonization of teeth in humans by Streptococcus mutans as related to its concentration in saliva and host age.

The relationship of the salivary concentration of Streptococcus mutans and host age to the colonization of this organism on erupting teeth was studied in humans. Plaques were obtained from fissures and buccal surfaces of erupting permanent first and second molars of children 6 to 7 and 11 to 14 years old, respectively. In subjects of both age groups with salivary S. mutans concentrations below 5 x 10(2) colony-forming units per ml, the organism was detected on only a few of the tooth surfaces; at concentrations of 5 x 10(2) to 4.9 x 10(4) colony-forming units per ml more than half of the surfaces and at concentrations of 5 x 10(4) colony-forming units per ml or higher most of the surfaces were colonized by S. mutans. The frequency of detection and concentration of S. mutans in plaque as well as its concentration in saliva were higher in the case of the older children. However, when younger and older children with similar salivary S. mutans concentrations were compared, S. mutans was more frequently isolated from plaque from older children only in the case of children with below 5 x 10(2) colony-forming units per ml of saliva. Eleven of the 64 children studied had low or undetectable S. mutans levels in plaque and saliva. The salivary S. mutans levels of the parents of these children were lower than those of parents of a group of children with normal oral S. mutans levels.

Adolescent↗
PubMed1992

Characterization of an exo-beta-D-fructosidase from Streptococcus mutans Ingbritt.

An extracellular enzyme beta-D-fructosidase was purified from the culture supernatant of Streptococcus mutans Ingbritt and characterized. The molecular weight of the enzyme was 127,000 as determined by SDS-polyacrylamide gel electrophoresis. The enzyme was specific for levan which mainly consists of beta-(2,6)-linked D-fructose and was also able to hydrolyze inulin, sucrose and raffinose at the activities of 13, 9 and 5% of that hydrolyzing levan, respectively. The pH optima for levan, inulin and sucrose were approximately 5.5, 6.0 and 5.0, respectively. The enzyme was optimally reactive at 55 C for levan. The enzyme was inhibited by Fe3+, Hg2+ and Zn2+ and not by either anionic or non-ionic detergents. Paper chromatographic analysis revealed that the enzyme attacked levan by an exo-type mechanism.

Chromatography, Gel↗