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PubMed1989

Molecular characterization of a surface protein antigen gene from serotype c Streptococcus mutans, implicated in dental caries.

The complete nucleotide sequence of the gene for a cell-surface protein antigen (PAc) of Streptococcus mutans MT8148 (serotype c) was determined. The pac gene consisted of 4695 bp and coded for a 170773D protein. The pac gene product contained a putative 38 amino acid signal peptide, resulting in a 166817D mature protein. A potential promoter sequence and a putative Shine-Dalgarno sequence preceded the open reading frame. Two internal repeating amino acid sequences were present in the PAc. One repeating region located in the N-terminal region was rich in alanine, and the other located in the central region was rich in proline. Southern blot analysis under the less stringent condition (allowing up to 35% base mismatch) revealed that the probe covering the proline-rich region hybridized to DNA preparations from strains of Streptococcus cricetus, Streptococcus sobrinus and Streptococcus downei as well as Streptococcus mutans.

Amino Acid Sequence↗
PubMed2005

[Immunization with the fusion protein of GBD of Streptococcus mutans glucan binding protein-A against dental caries in SD rats].

PURPOSE: To observe the effect of immunization with the fusion protein of GBD of Streptococcus mutans glucan binding protein-A against dental caries. METHODS: Purified fusion protein of GBD of Streptococcus mutans glucan binding protein-A was used to immune SD rats by subcutaneous injection route. The rats were fed with Keyes Diet 2000 and infected by S.mutans. The caries level was determined and the result was analyzed by t test. RESULTS: The caries score of SD rats decreased in the group of immunized with GBD fusion protein,P<0.01. CONCLUSION: Immunization with GBD fusion protein resulted in significantly reduced dental caries after infection with S.mutans Ingbritt. Supported by PLA Tenth Five-Year Key Project (01Z089).

Animals↗
PubMed1981

Characterization of the Streptococcus mutans plasmid pva318 cloned into Escherichia coli.

We further characterized the cryptic plasmid pVA318 of Streptococcus mutans. It had a contour length of 5.64 +/- 0.26 kilobases and a guanine-plus-cytosine content of 32 to 34 mol %. Upon cloning the pVA318 plasmid into the vector pBR322 in Escherichia coli, we made the following observations. The expression of tetracycline resistance by HindIII-cloned chimeras, where the insert was in the tetracycline resistance promotor, depended on the orientation of the pVA318 insert. Both HindIII-cloned chimeras segregated from polA(Ts) cells at a nonpermissive temperature. Chimeric molecules cloned with PstI initially showed much instability; the reason for this is unknown, although stable variants were obtained. Both HindIII-cloned variants and a PstI-cloned chimera produced a pVA318-specific protein of approximately 20,000 molecular weight in E. coli minicells. The biological function of this protein is not known; it had no bacteriocin activity against S. mutans or group A Streptococcus indicator strains, and it did not appear in the E. coli periplasm. We constructed a map of pVA318 for restriction endonucleases HindIII, HpaI, PstI, and HaeIII. A previously reported BamHI site in pVA318 did not appear in the pVA318 portion of any of our chimeric clones.

Cloning, Molecular↗
PubMed1990

Caries development in children in relation to the presence of mutans streptococci in dental plaque and of serum antibodies against whole cells and protein antigen I/II of Streptococcus mutans.

Twenty-eight children, aged 0.8-3.8 years, were studied with respect to the presence of mutans streptococci (MS) in dental plaque and the amount and avidity of specific serum IgG and IgM antibodies against whole cells and streptococcal protein antigen I/II (SA I/II) of Streptococcus mutans. The presence or absence of MS in dental plaque at the median age of 1.9 years predicted the caries development during a 2.7-year follow-up period with a sensitivity and specificity of 73 and 92%, respectively. The caries predictive value of a positive finding of MS at this age was as high as 92%. Almost all children had detectable amounts of serum IgG and IgM antibodies against whole cells and SA I/II of S. mutans, irrespective of the presence of detectable levels of this bacterium in dental plaque. These antibodies increased with age. The antibody levels did not differ significantly between children who were MS-negative or MS-positive. However, in MS-free children as well as in the whole study group, total specific and high-avidity antibodies of IgG class against whole cells correlated positively with antibodies against SA I/II. In MS-infected children such an association was observed for IgM but not for IgG antibodies. This different serum antibody profile in MS-negative and -positive children may be related to the mode of immunization with S. mutans.

Analysis of Variance↗
PubMed1975

Periapical destructions caused by experimental pulpal inoculation of Streptococcus mutans in rats.

The development of pulpal and periapical changes in rat molars was studied after inoculation of Streptococcus mutans (GS-5) into the pulp chamber. Before injection into the pulp Streptococcus mutans was cultured on a special collagen substrate and "trained" to break down collagen. The destruction of the alveolar bone periapically could be demonstrated both roentgenologically and histopathologically. Large numbers of inflammatory cells in the pulp chamber and the periapical area, as well as carious dentin, were present. The pulpally inoculated bacteria could also be recovered from the systemic blood. The identity between the pulpally inoculated bacteria and the bacteria recovered from the blood was proved by gel precipitation.

Alveolar Process↗
PubMed2006

Multilevel control of competence development and stress tolerance in Streptococcus mutans UA159.

Genetic competence appears to be important in establishment of biofilms and tolerance of environmental insults. We report here that the development of competence is controlled at multiple levels in a complex network that includes two signal-transducing two-component systems (TCS). Using Streptococcus mutans strain UA159, we demonstrate that the histidine kinase CiaH, but not the response regulator CiaR, causes a dramatic decrease in biofilm formation and in transformation efficiency. Inactivation of comE or comD had no effect on stress tolerance, but transformability of the mutants was poor and was not restored by addition of competence-stimulating peptide (CSP). Horse serum (HS) or bovine serum albumin (BSA) had no impact on transformability of any strains. Interestingly, though, the presence of HS or BSA in combination with CSP was required for efficient induction of comD, comX, and comYA, and induction was dependent on ComDE and CiaH, but not CiaR. Inactivation of comC, encoding CSP, had no impact on transformation, and CiaH was shown to be required for optimal comC expression. This study reveals that S. mutans integrates multiple environmental signals through CiaHR and ComDE to coordinate induction of com genes and that CiaH can exert its influence through CiaR and as-yet-unidentified regulators. The results highlight critical differences in the role and regulation of CiaRH and com genes in different S. mutans isolates and between S. mutans and Streptococcus pneumoniae, indicating that substantial divergence in the role and regulation of TCS and competence genes has occurred in streptococci.

Bacterial Proteins↗
PubMed2001

Quaternary structure and metal ion requirement of family II pyrophosphatases from Bacillus subtilis, Streptococcus gordonii, and Streptococcus mutans.

Pyrophosphatase (PPase) from Bacillus subtilis has recently been found to be the first example of a family II soluble PPase with a unique requirement for Mn2+. In the present work, we cloned and overexpressed in Escherichia coli putative genes for two more family II PPases (from Streptococcus mutans and Streptococcus gordonii), isolated the recombinant proteins, and showed them to be highly specific and active PPases (catalytic constants of 1700-3300 s(-)1 at 25 degrees C in comparison with 200-400 s(-)1 for family I). All three family II PPases were found to be dimeric manganese metalloenzymes, dissociating into much less active monomers upon removal of Mn2+. The dimers were found to have one high affinity manganese-specific site (K(d) of 0.2-3 nm for Mn2+ and 10-80 microm for Mg2+) and two or three moderate affinity sites (K(d) approximately 1 mm for both cations) per subunit. Mn2+ binding to the high affinity site, which occurs with a half-time of less than 10 s at 1.5 mm Mn2+, dramatically shifts the monomer <--> dimer equilibrium in the direction of the dimer, further activates the dimer, and allows substantial activity (60-180 s(-)1) against calcium pyrophosphate, a potent inhibitor of family I PPases.

Bacillus subtilis↗
PubMed2006

[Study on the genetic diversity within the extended-V region of the surface protein of Streptococcus mutans].

PURPOSE: The purpose of this study was to investigate the genicity of the extended- variable region (V+) of surface proteins of Streptococcus mutans (S. mutans, serotype c,f) and provide some genetic informations on the molecular structure of S. mutans surface protein. METHODS: 7 standard strains and 110 clinical isolates of S.mutans were selected.The bacterial DNA was extracted and the extended-V region (srV+ 1384-2514 bp) was amplified using polymerase chain reaction (PCR). The genetic diversity of srV+ was assessed by using restriction fragment length polymorphism (RFLP) with restriction endonuclease DdeI. RESULTS: The results showed that five different patterns (A,B,C,D,E) of the PCR-RFLP among the 117 strains were reveled by DdeI. The ration of the genotype A and B were the most among the strains, C followed by genotype, the D and E were 1 and 3 strains per genotype, respectively.OMZ175 (serotype f) belonged to B genotype. CONCLUSIONS: The study supported that the extended-variable region (srV+) of the surface proteins of Streptococcus mutans have diversity. There are five patterns of genotypings. The most genotypings were p1-like,spaP /sr-like and pac-like.

DNA, Bacterial↗
PubMedDate not supplied

[Streptococcus mutans: its relation to cariogenic activity].

This research was carried out with the purpose of learning about relationship between degree of infection by Streptococcus mutans in saliva and prevalence of caries and further incidence in a one year term. A total of 931 children aged 2-3 years of Havana City and Sancti Spiritus Province, and 10 different series of school children aged 6-12 years of both provinces, with a total of 848 children, were studied. A direct significant relationship between degree of infection by S. mutans and prevalence of caries (percentage of affected children and co/COPD index) was found in the groups under study. Likewise, in the relationship between previous degree of infection and incidence of caries, differences were significative in children aged 2-3 years and in six of the 10 series of school children, with a correlation (r) of 0.216. It is analyzed that despite that degree of infection by Streptococcus mutans is the parameter with higher correlation with cariogenic activity, its predictive value is not enough by itself, therefore, a joint valuation with other parameters also related to cariogenic activity is required, in order to be able to reach necessary validity in the prognosis.

Child↗
PubMed1989

Water-soluble glucans from Streptococcus mutans strain Ing-Britt as an energy source for bacterial growth.

Two fractions of water-soluble glucans with different molecular weight were produced by Streptococcus mutans IB. The larger glucan had a molecular weight of about 40,000. The molecular weight of the small glucan was estimated to be 4,100 by gel filtration chromatography and by biochemical methods. These glucans were tested for their ability to initiate and support growth of S. mutans IB and Streptococcus sanguis 903. S. sanguis 903 could grow with the low molecular weight glucan at a reduced rate compared with glucose. S. mutans IB could not utilize any of the glucans. No endo- or exo-glucanase activities could be detected in culture supernatants of any of the strains. In addition to maltose S. sanguis 903 could also utilize maltotriose, maltopentaose and maltoheptaose for growth while S. mutans IB could not grow with maltopentaose or maltoheptaose.

Chromatography, Gel↗
PubMed1973

Structure and immunological specificity of the Streptococcus mutans group b cell wall antigen.

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.

Agglutination Tests↗
PubMed1976

Inhibition of Streptococcus mutans strains by different mitis-salivarius agar preparations.

Several Streptococcus mutans strains were markedly inhibited by mitis-salivarius agar manufactured by Baltimore Biological Laboratories, but little, if any, inhibition was noted using Difco Laboratories' mitis-salivarius agar. Supplementation of the basic medium with sucrose and bacitracin for specific selection of S. mutans resulted in suppression of representative S. mutans type a strains regardless of manufacturer.

Agar↗
PubMed2004

[Preliminary study on gene related to acid tolerance of Streptococcus mutans].

OBJECTIVE: To construct an acid-sensitive mutant of Streptococcus mutans (S. mutans) by transposon mutagenesis and to find a new gene related to the acid tolerance of S. mutans. METHODS: The transposon Tn917 was delivered into S. mutans UA159 by the temperature-sensitive plasmid pTV1-OK bearing Tn917 and transposition of Tn917 was induced after incubation at non-permissive temperature (42 degrees C). Transposants harboring Tn917 in the chromosome were screened for the selection of mutant that had diminished growth at low pH. Southern analysis was performed with EcoRI (no cut within Tn917) digests of S. mutans UA159 and the selected aid-sensitive mutant, with DIG-labeled probe of 4.3 kb KpnI fragment of pTV1-OK containing Tn917. Genetic backcross experiment was performed by transforming the genome of the mutant to another S. mutans strain MT8148 to determine the linkage of Tn917 insertion to the change of phenotype (acid-sensitivity). Comparison of the abilities to grow at low pH, the glycolytic pH drop and killing pH values were done between the acid-sensitive mutant and the parent strain. The asymmetric PCR method was used to obtain the fragment flanking Tn917 and the PCR products were cloned to pMD18-T vector for sequencing. RESULTS: One mutant that showed no growth at pH 5.0 was isolated from 2 316 transposants and was named as b23. Southern analysis and genetic backcross experiment confirmed the linkage between single Tn917 insertion into the chromosome and the phenotypic change (acid sensitive). b23 was less acid tolerant than UA159 in that it showed poorer growth at low pH and higher glycolytic pH minimum and higher killing pH. BLAST results indicated that Tn917 inserted into the genome of S. mutans UA159 at the site of 996 123 bp. CONCLUSION: An acid-sensitive mutant of S. mutans was successfully constructed and a new gene that is responsible for the acid tolerance in S. mutans UA159 was revealed.

Genes, Bacterial↗
PubMed1994

Differential localization of the Streptococcus mutans GS-5 fructan hydrolase enzyme, FruA.

Streptococcus mutans GS-5 synthesizes an exo-beta-D-fructosidase, FruA, capable of degrading levans, inulins, sucrose and raffinose, with the greatest activity on levans. A previous analysis of the deduced amino acid sequence of the FruA protein revealed the presence of a C-terminus with an LPXTGX membrane sorting sequence and membrane spanning domain, characteristic of many Gram-positive cocci surface proteins. Here it is demonstrated that FruA, which had been previously shown to exist almost exclusively as an extracellular enzyme, can be detected in significant proportions at the surface of S. mutans cells. Moreover, growth of S. mutans GS-5 at steady state in continuous culture at pH values of 7.0, 6.0, or 5.0 revealed that the amount of cell-associated enzyme increased with decreasing pH values, such that roughly 50% of the total fructanase activity of pH 5.0-grown organisms was cell-associated. This result was confirmed using anti-recombinant-FruA antisera in Western blotting of culture supernate and cell-associated enzyme preparations from chemostat-grown cells. Incubation of S. mutans at pH values of 5.0, 6.0 or 7.0 in buffered media yielded results similar to those observed in the chemostat experiments. The release of FruA from S. mutans was also shown to be inhibitable by copper, which is known to interfere with the release of the surface adhesin, P1, from intact cells and protoplasts of S. mutans. These data provide evidence for a unique post-translational mechanism for the regulation of the catabolism of polysaccharides by bacteria.(ABSTRACT TRUNCATED AT 250 WORDS)

Bacterial Outer Membrane Proteins↗
PubMed1991

Incorporation of fatty acids by Streptococcus mutans.

In a series of investigations into the cariogenicity of Streptococcus mutans, we studied the incorporation of exogenous fatty acids with reference to glucosyltransferase secretion and membrane fatty acid changes. When cells were grown with different fatty acids, both saturated and unsaturated fatty acids were readily incorporated into the membrane lipids and were biotransformed and elongated preferentially to the longer 16- and 18-carbon-chain fatty acids. This incorporation and chain-elongation led to significant changes in fatty acids composition. By adding fatty acids to the medium, it was possible to appropriately modify the degree of unsaturation and the relative ratio between specific fatty acids in the membrane lipids of S. mutans.

Fatty Acids↗
PubMed1984

Glucose-sucrose-potassium tellurite-bacitracin agar, an alternative to mitis salivarius-bacitracin agar for enumeration of Streptococcus mutans.

An agar medium for selective recovery and enumeration of Streptococcus mutans was developed as an alternative to mitis salivarius-bacitracin (MSB) agar. Combinations of dyes, antibiotics, and tellurite were added to a nonselective medium which, because of its sucrose content, allowed easy recognition of S. mutans colonies. Candle jar incubation for 2 days, by comparison with anaerobic incubation, reduced background flora but did not diminish S. mutans recoveries from clinical samples. Quantitative comparisons were made of the simultaneous recoveries of a number of authentic S. mutans serotype representatives and fresh clinical isolates, using various glucose-sucrose-potassium tellurite-bacitracin (GSTB) formulations and mitis salivarius, MSB, and blood agars. Mitis salivarius counts were not detectably different from blood counts, but counts on MSB were distinctly lower. A formulation of the new medium containing 5% glucose 5% sucrose, 0.001% potassium tellurite, 0.3 U of bacitracin per ml (hence GSTB), and 2% agar gave recoveries nearly equal to those on mitis salivarius agar and much greater than those on MSB. The medium yielded readily recognized S. mutans colonies and facilitated detection of intracellular polysaccharide formers upon flooding with I2 reagent. Freshly isolated serotype c, E, and f colonies could often be distinguished from serotype d and g colonies, a distinction made reliable by testing for intracellular polysaccharide. A study of 300 salivary samples revealed GSTB to give significantly higher recoveries than MSB. About 72% of all samples were substantially underestimated for S. mutans with MSB, and 6.7% of samples were falsely negative for S. mutans with MSB. Recovery of background flora on GSTB was as low or lower than on MSB, and both types of agar could be stored for at least 9 weeks without notable change of selectivity. Thus, GSTB agar appears to be simple and reliable to use and requires no anaerobic incubation. Caution is voiced about interpretation of data previously reported which evaluated S. mutans on MSB agar.

Agar↗