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PubMed2005

A novel selective medium for isolation of Streptococcus mutans.

The aim of this study was to improve the selective medium of Streptococcus mutans. A new selective medium, designated MS-MUTV, was prepared by adding 10 mg/l valinomycin to the MS-MUT medium previously described. The average recovery of S. mutans was 72.1%, and the growth of S. sobrinus and S. anginousus group was inhibited on MS-MUTV, but allowed on MS-MUT. One hundred and thirty-nine human saliva samples were examined and counted for S. mutans and non-S. mutans colonies. The recovery of S. mutans on MS-MUTV was similar to that on MS-MUT. Eighty-two and 7.9 percent of the saliva samples obtained S. mutans pure cultures, with no bacterial growth on MS-MUTV, respectively. The remaining 10.1% were contaminated with non-S. mutans, with low-level CFU. MS-MUTV is useful for the isolation of S. mutans alone from clinical samples in routine examinations.

Bacteriological Techniques↗

PubMed1991

Identification of monoclonal antibody-binding domains within antigen P1 of Streptococcus mutans and cross-reactivity with related surface antigens of oral streptococci.

Eleven monoclonal antibodies (MAbs) specific for P1, the major protein surface antigen of Streptococcus mutans serotype c, were characterized by Western blot (immunoblot) analysis and by radioimmunoassay using whole bacterial cells. The approximate binding domains of the MAbs were determined by using full-length and truncated P1 polypeptides. The accessibility of these binding sites on the surfaces of intact bacteria was determined by radioimmunoassay. The ability of each MAb to cross-react with related proteins from strains of S. mutans serotypes e and f, S. sanguis, and S. sobrinus serotype g is also reported.

Animals↗

PubMed1986

An improved medium for isolation of Streptococcus mutans.

A medium based upon tryptone, yeast extract, cystine (TYC) agar and incorporating bacitracin and sucrose has been evaluated for selective isolation of Streptococcus mutans. The effect of varying the concentrations of sucrose and bacitracin on the recovery of two standard strains was investigated. Growth of S. mutans NCTC 10449 was significantly inhibited by increasing concentrations of sucrose but was not affected by bacitracin; the reverse was seen with S. sobrinus strain 6715. The best compromise between recovery of the streptococci and growth of other organisms was obtained with a final sucrose concentration of 20% and bacitracin 0.2 units/ml. In comparison with three other selective media, this medium gave the highest recovery rate of standard strains, indicating that it is superior to mitis-salivarius bacitracin (MSB) agar for the recovery of S. mutans from saliva.

Adult↗

PubMed1997

Variations in the predominant cultivable microflora of dental plaque at defined subsites on approximal tooth surfaces in children.

The distribution and composition of the resident microflora were determined in approximal gingival margin plaque from 21 premolars extracted from schoolchildren (mean age 12.0 +/- 1.8 yr). Indigo carmine (5% w v) was used to visualize plaque to facilitate sampling. About 1 mm2 of plaque was removed from sites away from (A), to the side of (S), and below (B) the contact area. Plaque samples were dispersed, serially diluted, and cultured on selective and non-selective agar media. An average of seven to nine species was found at each subsite. Streptococcus and Actinomyces were subdivided on the basis of a range of biochemical tests. The predominant Actinomyces and streptococcal species at most subsites were A. naeslundii and Strep. mitis biovar I. A. naeslundii and A. odontolyticus were isolated more often at subsite B (90.5 and 57.1%, respectively), and A. israelii at subsite S (66.7%) Strep. mitis 1 and Strep. sanguis were found more frequently at subsite S (76.2 and 66.7% respectively), whereas Strep mutans, Strep. sobrinus, Strep. gordonii and Veillonella spp. were recovered most commonly from subsite B (85.7, 33.3, 38.1 and 76.2%, respectively). The isolation frequencies of Strep. mutans and Strep. sobrinus were significantly higher at subsite B (A B p < 0.01 and p < 0.05, respectively). Veillonella spp. were significantly higher at subsites B and S (A < B, p > 0.01; B > S, p < 0.05), while Neisseria spp. were most common at subsite A (A > B. p > 0.03). IgAl protease-producing species were found at each subsite, but they formed only a small proportion of the total Streptococcus population. This study has shown that local variations were evident at different subsites, both with respect to species prevalence and to proportions of each species within each subsite. The population shifts in gingival margin plaque appear to relate to the location of plaque in relation to the most caries-prone site below the contact area B.

Analysis of Variance↗

PubMed1992

Differentiation of salivary agglutinin-mediated adherence and aggregation of mutans streptococci by use of monoclonal antibodies against the major surface adhesin P1.

The ability to adhere to salivary agglutinin-coated hydroxyapatite beads and to aggregate in the presence of fluid-phase salivary agglutinin was tested by using 25 isolates of mutants streptococci representing eight serotypes. Both adherence and aggregation activity correlated with expression of the Mr-185,000 cell surface antigen P1 on Streptococcus mutans serotype c, e, and f strains. In addition, it was shown that the P1 molecule itself served as the adhesin of S. mutans serotype c, since adherence was significantly inhibited by the presence of recombinant-specified Mr-150,000 P1. The ability of S. sobrinus strains to adhere or aggregate did not correlate with expression of the P1 cross-reactive antigen SpaA. There was also evidence for interaction with salivary agglutinin, as manifested by aggregation but not adherence of S. rattus serotype b, which does not express a P1 cross-reactive antigen. To understand the interaction of P1 with salivary agglutinin at the molecular level, a panel of 11 anti-P1 monoclonal antibodies was tested for inhibitory activity in adherence and aggregation inhibition assays. Overlapping, but not identical, subsets of monoclonal antibodies were found to inhibit adherence and aggregation, indicating that the interactions of P1 with salivary agglutinin which mediate these two phenomena are different. The localization of functional domains of P1 which may mediate the aggregation and adherence reactions is discussed.

Adhesins, Bacterial↗

PubMed1987

Analysis of heart-reactive antibodies induced in rabbits by immunization with Streptococcus mutans.

The induction of antibodies that react with human heart muscle in rabbits immunized with Streptococcus mutans and related organisms has been investigated in order to re-examine the reported antigenic cross-reactivity between the major cell wall protein antigen I/II of S. mutans and heart tissue. Serum from 2 of 8 rabbits hyperimmunized with whole cells of S. mutans, S. sobrinus, S. rattus, or S. mitis, assayed by immunofluorescence and radioimmunoassay, revealed antibodies reactive with sarcolemma that could be attributed to immunization. Antisera raised against several crude and purified antigens of S. mutans did not reveal heart-reactive antibodies, that could be attributed to antigenic similarity between heart and these antigens. An assay designed to detect antibodies that could simultaneously bind to both heart and antigen I/II of S. mutans failed to reveal cross-reactivity due to this antigen, although antibodies separately expressing these binding activities were demonstrable. IgM rheumatoid factor was elevated in several antisera to S. mutans, and could have contributed to some previous observations ascribed to antigenic cross-reactivity between S. mutans and human heart muscle.

Animals↗

PubMed1990

Utilization of mucin by oral Streptococcus species.

The ability of oral Streptococcus strains to utilize oligosaccharide chains in mucin as a source of carbohydrate was studied in batch cultures. Pig gastric mucin, as a substitute of human salivary mucin, was added to chemically defined medium containing no other carbohydrates. Strains of S. mitior attained the highest cell density, while mutans streptococci: S. mutans, S. sobrinus, S. rattus, grew very little in the medium with mucin. S. mitis, S. sanguis, and S. milleri in decreasing order, showed intermediate growth. Mucin breakdown as measured by sugar analyses indicated that oligosaccharide chains were only partially degraded. Every strain produced one or more exoglycosidases potentially involved in hydrolysis of oligosaccharide. The enzyme activities occurred mainly associated with the cells, and very little activity was found in the culture fluids. The relationships between glycosidase activities and growth, or mucin degradation were not always clear.

Animals↗

PubMed1993

Effects of pH, potassium, magnesium, and bacterial growth phase on lysozyme inhibition of glucose fermentation by Streptococcus mutans 10449.

The effects of physiological (saliva and plaque fluid) concentrations of potassium and magnesium and growth phase on lysozyme inhibition of glucose fermentation by S. mutans 10449 were investigated. Glucose fermentations were carried out in a pH-stat at pH 7.0 or 5.5. Cells were at least two times more sensitive to lysozyme in the early-to-middle exponential phase compared with the stationary phase. S. sobrinus 6715 exhibited three-fold greater lysozyme resistance than S. rattus BHT or S. mutans 10449. The concentration of potassium which reduced lysozyme inhibition of S. mutans 10449 fermentation by 50% was 0.2 and 10 mmol/L for stationary and exponential phase cells, respectively. Corresponding values for magnesium were < or = 0.01 and 0.50 mmol/L. Potassium and magnesium exhibited little pH dependence in their reduction of lysozyme inhibition of fermentation by exponential- or stationary-phase S. mutans 10449. The results suggest that: (i) lysozyme interaction with stationary-phase cells involves more non-inhibitory modes than with exponential-phase cells, and (ii) lysozyme may be more effective as an antibacterial agent in saliva than in plaque fluid.

Analysis of Variance↗

PubMed1985

Inhibition of ecological emergence of mutans streptococci naturally transmitted between rats and consequent caries inhibition by Streptococcus salivarius TOVE-R infection.

The ability of Streptococcus salivarius strain TOVE-R to inhibit the ecological emergence of virulent representatives of the most prevalent human mutans streptococci on the teeth of specific pathogen-free Osborne-Mendel rats was studied. Rats which were infected by TOVE-R, or either S. mutans 10449S or S. sobrinus 6715-13WT, or uninfected were transiently co-caged so as to allow natural fecal transfer of organisms due to coprophagy. The infectants were differentially recovered from swabs of the teeth over the time course of the experiments and from sonified teeth at termination. Data were expressed on both relative (percentage) and absolute (CFU) bases. Initial oral colonization of rats by TOVE-R inhibited the ecological emergence of fecally transmitted S. mutans 10449S and S. sobrinus 6715-13WT. There was a generally inverse relationship between the percentages and absolute numbers of TOVE-R and the mutans streptococci on the teeth, which strongly suggested their competition for tooth sites. Absolute numbers of total recoverable flora from the teeth upon sonification were correlated with caries scores, thus suggesting that total recoverable flora counts substantially reflect cavitation status. TOVE-R itself induced no apparent caries activity and its transmission to rats already infected by 10449S or its colonization of rats before 10449S infection inhibition caries induction by this S. mutans strain; similar anticaries effects were not statistically significant for TOVE-R against 6715-13WT in these experiments. These data on the inhibition of the ecological emergence of the mutans streptococci supplement the already reported ability of TOVE-R to preempt initial colonization of teeth and partially displace the colonization of teeth by the mutans streptococci.

Animals↗

PubMed1991

Conservation of the gene encoding streptococcal antigen I/II in oral streptococci.

The spaP gene of Streptococcus mutans serotype c encodes a major cell surface protein, streptococcal antigen (SA) I/II, with an Mr of 185,000, that is thought to be involved in bacterial adhesion to teeth. Proteins with significant amino acid sequence homology to SA I/II have also been found in S. sobrinus and S. sanguis. The objectives of this study were to investigate the conservation of the spaP gene in the mutans groups of streptococci and to determine whether homologous genes were present in other species of alpha-hemolytic streptococci. DNA extracted from representative strains of 19 streptococcal species was examined by Southern hybridization and partial DNA sequence analysis. A series of five overlapping DNA probes from the spaP gene were amplified by the polymerase chain reaction and used in the Southern hybridizations. The entire gene was found to be well conserved in all strains of S. mutans serotypes c, e, and f investigated. A probe from the 3' region of the gene, which encodes residues 857 to 1207 of the SA I/II protein, hybridized with DNA from a number of mutans streptococci, as well as with DNA from nonmutans alpha-hemolytic streptococci. Conservation within this region was further demonstrated by sequencing gene fragments of two strains of S. intermedius and S. oralis. The results show that some regions of the spaP gene are highly conserved not only in the mutans group of streptococci but also in other nonmutans alpha-hemolytic streptococci. This suggests that a family of cell surface proteins which, by analogy with the 185,000-Mr SA I/II of S. mutans, could be involved in bacterial adhesion might exist.

Amino Acid Sequence↗

PubMed1991

Isolation of a human T cell line specific for a streptococcal cell surface antigen.

A streptococcal cell surface antigen of Mr 185,000 (SAI/II) expressed by Streptococcus mutans has previously been well characterised. A T cell line specific for native SAI/II has been isolated from peripheral blood mononuclear cells (PBMC) of a naturally sensitised normal individual. This line has been maintained in culture for several months and was shown to be highly specific, not only for different preparations of native antigen but also for recombinant SAI/II protein. It did not respond to a homologous antigen SpaA (Mr 210,000), extracted from Strep. sobrinus. The phenotype of the line was CD3+ CD4+ CD8- TcR alpha beta +. HLA typing and inhibition studies showed that the response was restricted by both DR and DP encoded class II.

Antibodies, Monoclonal↗

PubMed1998

Streptococcal histone-like protein: primary structure of hlpA and protein binding to lipoteichoic acid and epithelial cells.

In addition to its role in the nucleoid, the histone-like protein (HlpA) of Streptococcus pyogenes is believed to act as a fortuitous virulence factor in delayed sequelae by binding to heparan sulfate-proteoglycans in the extracellular matrix of target organs and acting as a nidus for in situ immune complex formation. To further characterize this protein, the hlpA genes were cloned from S. pyogenes, S. gordonii, S. mutans, and S. sobrinus, using PCR amplification, and sequenced. The encoded HlpA protein of S. pyogenes has 91 amino acids, a predicted molecular mass of 9,647 Da, an isoelectric point of 9.81, and 90% to 95% sequence identity with HlpA of several oral streptococci. The consensus sequence of streptococcal HlpA has 69% identity with the consensus sequence of the histone-like HB protein of Bacillus species. Oral viridans group streptococci, growing in chemically defined medium at pH 6.8, released HlpA into the milieu during stationary phase as a result of limited cell lysis. HlpA was not released by these bacteria when grown at pH 6.0 or below. S. pyogenes did not release HlpA during growth in vitro; however, analyses of sera from 155 pharyngitis patients revealed a strong correlation (P < 0.0017) between the production of antibodies to HlpA and antibodies to streptolysin O, indicating that the histone-like protein is released by group A streptococci growing in vivo. Extracellular HlpA formed soluble complexes with lipoteichoic acid in vitro and bound readily to heparan sulfate on HEp-2 cell surfaces. These results support a potential role for HlpA in the pathogenesis of streptococcus-induced tissue inflammation.

Amino Acid Sequence↗

PubMed1991

The presence of two forms of the phosphocarrier protein HPr of the phosphoenolpyruvate:sugar phosphotransferase system in streptococci.

The protein, HPr, a necessary component of the phosphoenolpyruvate phosphotransferase system (PTS) in bacteria, was purified from Streptococcus salivarius by column chromatography. The purified preparation gave only one band when analyzed by sodium dodecylsulfate gel electrophoresis or by isoelectric focusing in polyacrylamide gel (pI = 4.85). However, electrophoresis in Tris-containing buffers under non-denaturing conditions revealed 2 bands that could be phosphorylated by PEP in the presence of enzyme I of the PTS or by ATP with the HPr kinase. Homogeneous preparations of these 2 forms could be obtained by preparative electrophoresis. Each preparation exhibited only 1 band when analyzed by electrophoresis under non-denaturing conditions, indicating that the doublet observed before preparative electrophoresis was not an electrophoretic artefact. The electrophoretic mobility of each protein was not modified following heat-treatment at 100 degrees C for 20 min or storage at -40 degrees C for several months. Both HPr proteins catalyzed in vitro the PEP-dependent phosphorylation of glucose, but at a rate slightly lower than that observed with a preparation of HPr containing both forms of the protein. Both forms were also able to transfer the phosphate group from PEP to the other specific PTS proteins known in S salivarius. Rabbit polyclonal antibodies directed against each form reacted with both proteins. The presence of the 2 forms of HPr was detected in fresh cellular extracts of S salivarius; however, their intracellular ratio varied according to growth conditions. A doublet was also found in many other streptococcal species tested (S mutans, S sobrinus, S sanguis, S thermophilus, S bovis, S rattus) and also in L lactis.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1976

Serological and genetic examination of some nontypical Streptococcus mutans strains.

Thirty-four strains of Streptococcus mutans whose antigenic or genetic positions were unclear or unknown with respect to the serological scheme of Bratthall (1970) and Perch et al. (1974), or the genetic (deoxyribonucleic acid base sequence homology) scheme of Coykendall were analyzed to clarify their relationship to previously well-characterized strains. Strain OMZ175 of the "new" serotype f was genetically homologous with strains of S. mutans subsp. mutans. Strains of the "new" serotype g were homologous with serotype d strains (S. mutans subsp. sobrinus). Strains isolated from wild rats constituted a new genetic group but carried the c antigen. Thus, strains within a "genospecies" (subspecies) of S. mutans may not always carry a unique or characteristic antigen. We suggest that the existence of multiple serotypes within subspecies represents antigenic variation and adaptations to hosts.

Animals↗

PubMed1988

Immunological properties of the primer-independent glucosyltransferase of Streptococcus mutans serotypes d and g.

Streptococcus mutans serotype g secretes at least three kinds of glucosyltransferase with different enzymological and immunological properties. One of them is a primer-independent enzyme and seems to be the source of primer for the others, both of which are primer-dependent enzymes. Recently, we purified the primer-independent enzyme, the third glucosyltransferase in this group from S. mutans strain AHT-k serotype g. In the present study, we examined the specificity of the antiserum against the primer-independent glucosyltransferase using extracellular culture-conditioned fluids of many strains of the various serotypes of S. mutans. The antiserum cross-reacted with the extracellular culture fluids from strains of serotypes d and a, in addition to serotype g, but not with those of other serotypes, indicating that the primer-independent glucosyltransferase is secreted by the S. sobrinus and S. cricetus, but not by S. mutans and S. rattus. The antiserum did not completely inhibit the activity of the enzyme, even at more than twofold antibody excess, determined by indirect precipitation with immobilized staphylococcal protein A.

Animals↗

PubMed1987

Mutans streptococci, lactobacilli and caries prevalence in 11- and 12-year-old Icelandic children.

Since the caries prevalence has not declined in Iceland as it has in other European countries, it was of interest to study the presence of cariogenic bacteria in Icelandic children. The prevalence of salivary mutans streptococci and lactobacilli was examined in 217 11- and 12-yr-old Icelandic children and was related to their caries prevalence. In 2% of the children mutans streptococci were not found whereas 31% and 35% of the 11-yr-olds and 12-yr-olds respectively carried more than 10(6) CFU per ml saliva. Lactobacilli were not detected in 8% of the children whereas 28% of the 11-yr-olds and 23% of the 12-yr-olds had more than 10(5) CFU per ml saliva. The mean caries prevalence (DFS), initial caries included, for 11-yr-olds was 21.6 and for 12-yr-olds 28.8. Both mutans streptococci and lactobacilli were significantly correlated to each other as well as to caries prevalence. An increased number of these microorganisms, especially the mutans streptococci, were associated with an increased DFS. Children with high salivary counts of mutans streptococci and lactobacilli showed four times higher DFS than children with low numbers. The magnitude of salivary cariogenic bacteria as well as caries prevalence was found to resemble the situation in Sweden 10 yr ago. S. mutans (serotype c/e/f) was carried by all mutans streptococci positive children. S. sobrinus (serotype d/g) was found in 60 children (30.2%). Children with both S. mutans and S. sobrinus had significantly higher salivary counts of mutans streptococci and lactobacilli as well as caries prevalence than children with only S. mutans.

Child↗

PubMed2004

Isopanduratin A from Kaempferia pandurata as an active antibacterial agent against cariogenic Streptococcus mutans.

An antibacterial compound active against Streptococcus mutans was isolated from Kaempferia pandurata and identified as isopanduratin A using 1H NMR, 13C NMR and EI-MS. The minimum inhibitory concentration (MIC) of isopanduratin A was 4 mg/l which was much lower than that of some other natural anticariogenic agents such as sanguinarine (12 mg/l), green tea extract and carvacrol (125 mg/l), thymol (250 mg/l) and isoeugenol and eucalyptol (500 mg/l). The bactericidal test showed that isopanduratin A completely inactivated S. mutans at 20 mg/l in 1 min. Significant inhibitory activity of isopanduratin A was also observed against S. sobrinus, S. sanguinis and S. salivarius with an MIC of 4 mg/l. Damage to the cell membrane and cell wall of S. mutans by isopanduratin A was shown using transmission electron microscopy (TEM). These results suggest that isopanduratin A could be employed as a potential antibacterial agent for preventing dental caries.

Anti-Bacterial Agents↗

PubMed1988

Immune properties of glucosyltransferases from S. sobrinus.

GTF activity was separated into water-insoluble (GTF-I) and water-soluble (GTF-S) polyglucan-synthesizing enzymes. Each preparation demonstrated a single band on 6% SDS PAGE. Only water-insoluble or water-soluble polyglucan was synthesized by the respective enzyme preparation. Rats were immunized, on Days 1 and 14, with either GTF-I or GTF-S in adjuvant. Animals were bled 13, 35 and 54 days after the initial immunization. Individual antisera were tested against either the GTF-I or the GTF-S for inhibition of radioactive glucose incorporation into glucan, and in gel diffusion, and by Western transfer analyses. The respective antisera reacted with the homologous, but not the heterologous enzyme in gel diffusion and Western transfer. GTF-I activity was not inhibited by antibody to GTF-S, but antibody to GTF-I inhibited GTF-I by 68%. GTF-S was inhibited by more than 60% by each of 3 anti-GTF-S sera. Only one anti-GTF-I serum inhibited GTF-S at as much as a modest 30% level. These data support the antigenic and functional distinctiveness of the GTF enzymes of S. sobrinus 6715.

Animals↗