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PubMed1978

Effects of local immunization with glucosyltransferase fractions from Streptococcus mutans on dental caries in hamsters caused by homologous and heterologous serotypes of Streptococcus mutans.

Seven serotypes of Streptococcus mutans have been identified. The biochemical, genetic, and serological characteristics of these serotypes have indicated that certain serotypes are quite similar, whereas others are quite distinct. The effect of local immunization with glucosyltransferase (GTF) enzymes from serotypes a, c, or g on infection and disease caused by homologous or heterologous cariogenic S. mutans is reported. Organisms with either similar (a and g) or different (c and g) biochemical and serological characteristics were selected for heterologous challenge. NIH white hamsters were injected four times at weekly intervals with GTF prepared by 6 M guanidine-hydrochloride elution from water-insoluble glucan of serotypes a, c, or g, which resulted in enzyme (homologous) inhibitory activity in sera and salivas. After infection of GTF-immunized and sham-immunized groups of hamsters with cariogenic S. mutans of the same serotype as the injected antigen (homologous infection) or with S. mutans of a different serotype from the injected antigen (heterologous infection), the numbers of streptomycin-labeled S. mutans, caries, and lesions were determined. Immunization with GTF preparations from each of the three serotypes resulted in statistically significant reductions in the extent of infection and disease and number of lesions caused by infections with homologous cariogenic S. mutans. Statistically significant reductions in these three parameters were also observed in groups immunized with enzyme from serotype a (strain E49) and challenged with cariogenic serotype g (strain 6715) organisms; or immunized with enzyme from serotype c (strain Ingbritt) and challenged with cariogenic serotype g (strain 6715) organisms; or immunized with enzyme from serotype g (strain 6715) and challenged with cariogenic serotype c (strain Ingbritt) organisms. These studies suggest that soluble antigen preparations containing GTF from one serotype may elicit a protective immune response against infection with cariogenic S. mutans from many or possibly all serotypes.

Animals↗

PubMed1980

Virulence of Streptococcus mutans: restoration of pathogenesis of a glucosyltransferase-defective mutant (C4).

Previous studies have shown that a mutant (designated C4) of Streptococcus mutans 6715 wild type (WT) is defective in glucosyltransferase (GTF)-synthesized insoluble glucan and is avirulent in gnotobiotic rats. This study investigated the factors which would render this mutant virulent in gnotobiotic rats. Microbial analysis of plaque from gnotobiotic rats (45 days old) infected with a mixture of C4 and virulent S. mutans PS-14 (approximately 15,000 C4 organisms to each S. mutans PS-14) yielded higher numbers of C4 organisms than S. mutans PS-14. These animals exhibited significantly lower caries scores than did gnotobiotic rats (age, 45 days) monoassociated with S. mutans PS-14. Similar mixed infection studies using C4 and an avirulent, aggregation-defective mutant of S. mutans 6715 WT (designated UAB 165) which exhibits GTF activity similar to that of the parent strain resulted in plaque consisting almost exclusively of UAB 165 and low caries activity. However, high levels of both C4 and UAB 165 in plaque and high caries activity were observed in gnotobiotic rats infected at weaning with C4 followed by UAB 165 3 days later. When dried S. mutans 6715 WT culture supernatant containing GTF activity was mixed with diet provided rats monoassociated with C4, significant caries activity was observed. Insoluble glucan supplemented in diet did not restore C4 to virulence; however, admixture of suboptimal GTF-rich supernatant with insoluble glucan and C4 resulted in high caries activity in gnotobiotic rats. These results suggest that in vivo restoration of pathogenesis of a GTF-defective mutant of S. mutans can be achieved either by complementation with a mutant defective in aggregation properties or by providing exogenous GTF and glucan from the parent S. mutans 6715 WT.

Animals↗

PubMed1981

Adherence of Streptococcus sanguis clinical isolates to smooth surfaces and interactions of the isolates with Streptococcus mutans glucosyltransferase.

Streptococcus sanguis isolated from human dental plaque were grown in Todd-Hewitt broth. Cells were collected by centrifugation and lyophilized after extensive washing with water. The cell-associated glucosyltransferase (GTase) activities of S. sanguis strains were assayed with [14C]sucrose. Strain differences in GTase activity were significant within the same serotype or biotype or both. The ability of S. sanguis cells to adhere to smooth glass surfaces was generally weak, irrespective of significant cell-associated GTase activity synthesizing water-insoluble, gel-like glucans. Resting cells of most S. sanguis strains bound extracellular GTase from Streptococcus mutans strain B13 (serotype d), resulting in the strong adherence of the S. sanguis cells to smooth glass surfaces in the presence of sucrose. Conversely, S. mutans B13 cells also could bind extracellular GTase from some strains of S. sanguis examined. The sucrose-dependent adherence of S. mutans cells was not altered, although S. sanguis strains from which the extracellular GTases were obtained did not produce significant adherence in the presence of sucrose. In view of these findings, it was suggested that S. mutans GTase could affect the adherence of S. sanguis to smooth tooth surfaces in the oral cavity.

Binding Sites↗

PubMed1982

Purification and properties of glucosyltransferase responsible for water-insoluble glucan synthesis from Streptococcus mutans.

A glucosyltransferase responsible for water-insoluble glucan synthesis was purified from the culture fluids of Streptococcus mutans 6715-15 strain by column chromatography on Toyopearl HW-60 and subsequently on hydroxyapatite. The enzyme preparation gave a single band on analysis by polyacrylamide gel electrophoresis. The pH dependency of the activity showed two optimal peaks at 5.8 and 7.3 and the Km values for sucrose were 1.4 and 3.3 mM at the respective optimal pHs. The molecular weight determined by sodium dodecyl sulfate gel electrophoresis was 180,000. Although the enzyme scarcely synthesized water-insoluble and water-soluble glucans from sucrose, water-insoluble glucan formed from sucrose in the presence of dextran T10 consisted of over 93% alpha-1, 3-glucosidic linkage. Analysis of the structure of water-insoluble glucan indicated that the enzyme catalyzed the formation of branch points in alpha-1,6-glucan (dextran) and transferred the glucosyl moiety of sucrose to the C-3 position of the branching glucose residue of dextran. Since this enzyme has not yet been registered, we named it mutansynthetase (EC 2.4.1.?).

Chemical Phenomena↗

PubMed1982

Effects of local immunization with glucosyltransferase on colonization of hamsters by Streptococcus mutans.

Experiments were performed to study the effect of antibody to Streptococcus mutans glucosyltransferase (GTF) on the implantation of these organisms in hamsters. Salivary (immunoglobulin A) and serum (immunoglobulin G) antibodies to GTF and GTF-inhibiting activity were elicited by injection of GTF in Freund complete adjuvant in the salivary gland region. Sham-immunized and GTF-immunized groups were then orally challenged with approximately 10(7), 10(8), or 10(9) colony-forming units of cariogenic S. mutans 6715. The results were evaluated by systematically swabbing molars 4 days and approximately 4 weeks after challenge. In general, fewer GTF-immunized hamsters became infected with S. mutans after challenge with 10(7) or 10(8) organisms than did identically challenged sham-immunized hamsters. Of the animals that did become infected, fewer S. mutans colony-forming units were recovered from GTF-immunized hamsters. These results indicate that the presence of antibody to GTF can diminish the ability of S. mutans to implant in the oral cavity of immunized hamsters.

Animals↗

PubMed1983

Production of monoclonal antibody against a glucosyltransferase of Streptococcus mutans 6715.

A mouse hybrid cell line secreted monoclonal antibody which reacted specifically with Streptococcus mutans 6715 (serotype g) glucosyltransferase (GTase)-synthesizing water-insoluble glucan and inhibited with enzyme reaction. The antibody was cross-reactive with GTase of serotype d but not with GTase of other serotypes of S. mutans when an enzyme-linked immunosorbent assay was used.

Animals↗

PubMed1983

Effects of local immunization of hamsters with glucosyltransferase antigens on infection with Streptococcus sanguis.

The effects of immunization with antigens of the Streptococcus mutans glucosyltransferase (GTF) complex on oral challenge with two Streptococcus sanguis strains (H7PR3 and 34) in hamsters were studied. Antisera to S. mutans GTF complex were able to inhibit one-third (strain H7PR3) to one-half (strain 34) of the S. sanguis GTF activity which could be inhibited when these S. sanguis GTFs were incubated with antisera to S. sanguis GTF. Washed, intact cells of strains H7PR3 and 34 were able to remove a significant amount of enzyme inhibitory activity and immunoglobulin G antibody activity from antisera to S. mutans GTF. These results established the existence of an antigenic relationship between S. sanguis and S. mutans GTFs. The effect of injection of S. mutans strain 6715 GTF or phosphate-buffered saline, incorporated into complete Freund adjuvant, on oral challenge with S. sanguis was compared in 243 hamsters in nine experiments. Salivary and serum GTF inhibitory activity was present in all GTF-injected animals before challenge. After a 2- or 3-day challenge with S. sanguis H7PR3 (seven experiments) or 34 (two experiments), fewer bacteria were recovered from GTF-injected hamsters in every experiment. Significant differences were observed in six of the nine experiments. During the 7- to 21-day period after challenge, 33% of the phosphate-buffered saline-injected sham group (group I) still had S. sanguis recoverable from the molar surfaces, whereas only 19% of the S. mutans GTF-injected group (group II) remained infected with S. sanguis (P less than 0.01). These results suggest that immunization with GTF from S. mutans may influence the colonization potential of S. sanguis in the oral cavity.

Animals↗

PubMed1985

Mapping of a cloned glucosyltransferase gene in Streptococcus mutans.

A cloned glucosyltransferase (gtfA) fragment, inserted adjacent to an erythromycin resistance (Eryr) marker in plasmid pVA891, was used in transformation experiments to determine the genetic location of gftA on the Streptococcus mutans chromosome. Eryr (gftA) cotransformed with a methionine (Met+) marker at a frequency of approximately 23%, whereas cotransfer with a number of other markers was not observed. The number of Met+ transformants was approximately 50-fold greater than the number of Eryr transformants. Furthermore, over 20% of the Eryr transformants were always Met+, whereas less than 1% of the Met+ transformants were Eryr, indicating the extreme asymmetrical cotransfer of these markers. The results indicate that S. mutans genes can be mapped by this procedure.

Chromosome Mapping↗

PubMed1985

Purification and characterization of a primer-independent glucosyltransferase from Streptococcus mutans 6715-13 mutant 27.

Affinity chromatography on Sephadex G-50 and subsequent ion-exchange chromatography on Trisacryl-M-DEAE were used to purify the glucosyltransferase (GTF) enzymes produced by mutant 27 of Streptococcus mutans 6715-13. Complete separation of three types of GTF, including a primer-independent GTF capable of synthesizing a slightly branched, water-soluble glucan (GTF-S), was obtained. The characteristics of this primer-independent GTF-S were compared with those of the normally occurring primer-dependent GTF-S. The Km for sucrose was easily obtained for each enzyme (10(-2) M), but the Km for dextran could only be determined for the primer-dependent GTF-S (5 X 10(-7) M for clinical dextran of molecular weight 60,000 to 90,000). The primer-independent GTF-S did not respond catalytically to the presence of either clinical dextran or the highly branched, water-soluble glucan produced by primer-dependent GTF-S, although it was capable of binding these polysaccharides at a noncatalytic site and of responding to the low-molecular-weight acceptor 1-O-methyl-alpha-D-glucopyranoside. The water-soluble glucan product of primer-independent GTF-S was a superior priming glucan for primer-dependent GTF enzymes as compared with the glucan product of primer-dependent GTF-S. The presence of primer-independent GTF-S in reaction mixtures stimulated glucan synthesis by primer-dependent GTF-S and by GTF synthesizing water-insoluble glucan by at least 10-fold, whereas the presence of similar amounts of primer-dependent GTF-S had no effect on synthesis by GTF synthesizing water-insoluble glucan. Primer-independent GTF-S appears to be a potent source of priming glucan for the primer-dependent GTF enzymes. Its possession of a noncatalytic binding site for glucan, the first observed for the GTF of S. mutans, suggests that it may also serve as a glucan receptor on the S. mutans cell surface.

Carbon Radioisotopes↗

PubMed1986

Cloning of a Streptococcus mutans glucosyltransferase gene coding for insoluble glucan synthesis.

The gtfB gene coding for a glucosyltransferase (GTF) activity of Streptococcus mutans GS-5 was isolated on a 15.4-kilobase DNA fragment by using a lambda L47.1 gene library. The activity was catalyzed by gene products of 150 and 145 kilodaltons which reacted with antibodies directed against both soluble and insoluble glucan-synthesizing GTFs. The enzyme present in crude Escherichia coli extracts synthesized both soluble and insoluble glucans. The enzyme was partially purified from lysates of the lambda DS-76 clone and synthesized both types of glucans in a primer-independent fashion. In addition, the purified enzyme exhibited a pI of approximately 5.0. Southern blot analysis indicated that the cloned GTF gene represented a contiguous nucleotide sequence on the strain GS-5 chromosome. Furthermore, evidence for the existence of a distinct gene sharing partial homology with gtfB was also obtained. The gtfB gene was subcloned into plasmid pACYC184 into E. coli and exhibited GTF activity when carried on GS-5 inserts as small as 5 kilobases. The approximate location of the GTF promoter and the direction of gene transcription were also determined. The cloned enzyme was not secreted through the cytoplasmic membrane of E. coli, since most of the activity was found in the cytoplasm and, in lesser amounts, associated with the cytoplasmic membrane. The gtfB gene was insertionally inactivated by introducing a gene fragment coding for erythromycin resistance into the GTF coding region. After transformation of strain GS-5 with the altered gene, transformants defective in insoluble glucan synthesis were identified. These results indicate that the gtfB gene codes for a GTF involved in insoluble glucan synthesis in strain GS-5.

Base Sequence↗

PubMed1987

Oral immunization of humans with Streptococcus sobrinus glucosyltransferase.

The effect of oral administration of glucosyltransferase (GTF) from Streptococcus sobrinus 6715 on levels of immunoglobulin A (IgA) antibody to GTF in parotid saliva and on the number of indigenous Streptococcus mutans in the whole saliva was studied in young adult males. GTF combined with aluminum phosphate (AP) was administered in capsules to 14 subjects, while sodium phosphate buffer combined with AP was administered in the same way to 11 control subjects. Thirteen administrations were given during the first immunization regimen, and five administrations, approximately 3 months later, constituted the second immunization regimen. All subjects were given professional dental prophylaxis immediately prior to each immunization. Each subject served as his own control by using antibody and bacterial data collected prior to antigen administration for comparison. After the first immunization regimen, the GTF vaccine group exhibited a significantly higher distribution (P less than 0.05) of normalized parotid saliva IgA antibody elevations than observed in the placebo group. Between the first and second immunization regimens a significant increase (P less than 0.05) in parotid salivary anti-GTF activity also occurred in the GTF vaccine but not the placebo group. No significant differences between these two groups were observed on any occasion when serum IgG or IgA antibody to GTF was analyzed. Comparison of the group mean log ratios (post- to prevaccine administration) of S. mutans to total streptococci in whole saliva revealed that the GTF vaccine group values were always lower than those of the placebo group. These differences reached significance (P less than 0.01) on three of the last four sampling occasions (days 21, 35, and 42) following initiation of the first immunization regimen. The mean log ratios of the GTF vaccine group were also lower than those of the placebo group after the second immunization regimen but did not reach significance. These data indicate that oral administration of GTF from the mutans streptococci has the potential to elicit a salivary IgA antibody response when combined with an aluminum-based adjuvant and that this response can interfere with the reaccumulation of indigenous S. mutans following dental prophylaxis.

Administration, Oral↗

PubMed1987

Monoclonal antibodies to the extracellular glucosyltransferases from Streptococcus sobrinus 6715.

Murine monoclonal antibodies (MAbs) were raised against the glucosyltransferases (GTFs) of Streptococcus sobrinus 6715. The antibody panels included MAbs raised against the primer-independent, soluble product enzyme (GTF-Si) which did not cross-react with other GTFs, as well as MAbs raised against the primer-dependent, soluble product enzyme (GTF-Sd) which recognized both GTF-Si and GTF-Sd, thus indicating that these catalytically distinct enzymes share epitopes. MAbs raised against GTF-I recognized several forms of GTF-I and did not cross-react with the GTF-S enzymes. None of the MAbs recognized the major glucan-binding protein of S. sobrinus. Two MAbs inhibited glucan synthesis, one blocking primer synthesis by GTF-Si by 89% and the second inhibiting that by GTF-I by 92%.

Antibodies, Bacterial↗

PubMed1987

Molecular cloning and characterization of the glucosyltransferase C gene (gtfC) from Streptococcus mutans LM7.

A glucosyltransferase (GTF) gene, designated gtfC, was cloned from Streptococcus mutans LM7. Its gene product was detected by screening a bacteriophage lambda library with rabbit antiserum raised against S. mutans LM7 extracellular proteins. DNA isolated from the immunopositive recombinant phage revealed two S. mutans chromosomal EcoRI fragment inserts, 8.1 and 4.7 kilobase pairs in size. Escherichia coli minicell analyses revealed the approximate position and direction of transcription of the gtfC gene. The gene product was determined to be a polypeptide of about 150 kilodaltons which synthesized a water-soluble glucan. Restriction endonuclease mapping and DNA hybridization indicated a repeated region of DNA corresponding to a portion of the coding region of gtfC immediately downstream from the intact gtfC locus on the chromosome. A 300-base-pair gtfC-specific probe showed that the gene and the putative duplicated sequence were present in S. mutans serotypes c, e, and f, but not in other related oral streptococci which had GTF activity. In addition, the gtfC determinant displayed homology to sequences corresponding to the carboxy-terminal coding region of a gene (gtfB) encoding a GTF activity that synthesized water-insoluble glucans. These data suggest that at least one class of GTF genes may be present in multiple copies in S. mutans and, further, that GTF genes may contain conserved sequences internal to their coding regions.

Chromosome Mapping↗

PubMed1990

Size and subdomain architecture of the glucan-binding domain of sucrose:3-alpha-D-glucosyltransferase from Streptococcus sobrinus.

Mild trypsin proteolysis of Streptococcus sobrinus sucrose:3-alpha-D-glucosyltransferase (GTF-I) reduced most of the enzyme to small products but left a few large fragments undigested. The digest had no glucosyl transfer activity, but several digestion products had an affinity for glucan equivalent to that of the native enzyme. The glucan-binding fragments ranged in size from 17 to 60 kilodaltons (kDa), with a particularly prominent 42-kDa fragment. The largest of these (60 kDa) appears to be the full extent of the domain since it increases in abundance when the enzyme is protected with glucan during proteolysis. The presence of smaller fragments with glucan-binding function and intact tertiary structure indicates that the full domain must be built on glucan-binding subdomains. Among the range of glucan-binding fragments, only the 42-kDa segment could be satisfactorily purified. It was subjected to N-terminal sequence analysis and, because of some ambiguity, was also subjected to chymotrypsin digestion and sequence of several chymotryptic peptides. The sequence data established that the 42-kDa domain fragment is initiated approximately two-thirds into the 170-kDa enzyme in a region previously identified as a segment of the gene that includes the glucan-binding domain (J. J. Ferretti, M. L. Gilpin, and R. R. B. Russell, J. Bacteriol. 169:4271-4278, 1987). The site is approximately 60 kDa from the C terminus and covers a region characterized by extensive amino acid sequence repeats. The data are discussed in the context of the size range of the glucan-binding fragments and subdomain architecture of the full glucan-binding domain.

Amino Acid Sequence↗

PubMed1990

Analysis of the Streptococcus downei gtfS gene, which specifies a glucosyltransferase that synthesizes soluble glucans.

The complete nucleotide sequence was determined for the Streptococcus downei (previously Streptococcus sobrinus) MFe28 gtfS gene which specifies a glucosyltransferase (GTF-S) producing water-soluble glucan. A single open reading frame which encodes a mature protein with a molecular weight of 147,408 (1,328 amino acids) and a putative signal peptide 36 or 37 amino acids in length was detected. GTF-S shares extensive sequence similarity with GTF-I (gtfI) from S. downei and GTF-I (gtfB) and GTF-SI (gtfC) from Streptococcus mutans. GTF-S contains a highly conserved enzymatic domain and C-terminal repeated sequences which appear to be involved in glucan binding. Comparison of the deduced GTF-S protein sequence with other sequenced GTF genes of mutans streptococci revealed that these C-terminal repeats occurred in all cases, although the patterns of repeated sequences varied with respect to each other and to the glucan-binding protein of S. mutans. GTF-S contains four C-terminal repeat sequences ranging from 49 to 51 amino acids in length and a partial repeat of 13 amino acids. Nuclear magnetic resonance analysis of the glucan produced by GTF-S revealed that the product consisted of more than 90% alpha-1,6-linked glucosyl residues.

Amino Acid Sequence↗

PubMed1991

Cloning of a Streptococcus sobrinus gtf gene that encodes a glucosyltransferase which produces a high-molecular-weight water-soluble glucan.

The gtf gene coding for glucosyltransferase (GTF), which produces a water-soluble glucan, was cloned from Streptococcus sobrinus OMZ176 (serotype d) into plasmid vector pBR322. This gene was expressed in Escherichia coli, and the product was purified to near homogeneity. The antigenicity of recombinant GTF (rGTF) was examined with the antisera raised against purified GTF P1, P2, P3, and P4 obtained from S. sobrinus AHT (serotype g). The rGTF reacted only with anti-GTF P1 serum in a Western blot (immunoblot) analysis. The rGTF closely resembled GTF P1 in its molecular mass, Km value for sucrose, optimal pH, primer dependency, and immunological properties. The high-molecular-weight, water-soluble glucan produced by the rGTF also resembled that of GTF P1, which is the most efficient primer donor for primer-dependent, water-insoluble glucan synthesis. Properties of the rGTF were also compared with those of rGTFS, which was purified from E. coli carrying the gtfS gene isolated from Streptococcus downei (previously S. sobrinus serotype h) MFe28. Both rGTF and rGTFS synthesized water-soluble glucan from sucrose without primer dextran, but their characteristics in Km values for sucrose, optimal pHs, and polymer sizes of the glucan were different. Furthermore, the gtf gene did not hybridize with the gtfS gene in a Southern blot analysis. These results showed that rGTF is similar to S. sobrinus AHT GTF P1 but distinct from rGTFS that has been previously purified from E. coli carrying the gtfS gene.

Amino Acid Sequence↗

PubMed1991

Sucrose-promoted accumulation of growing glucosyltransferase variants of Streptococcus gordonii on hydroxyapatite surfaces.

Streptococcus gordonii exhibits a phase variation involving expression of high (Spp+) or low (Spp-) glucosyltransferase activity. The related bacterial accumulation on hydroxyapatite (HA) and saliva-coated HA surfaces was examined and found to be significant. Spp+ cells growing anaerobically in a defined medium utilize about 30% of the glucose available from sucrose to make insoluble glucans. These glucans formed cohesive masses on HA beads, which contained 80 to 90% of the total bacteria. The bacterial polymer mass had a volume of about 40 microns3 and contained more than 5 x 10(10) viable cells per cm3. In the absence of sucrose, the beads were saturated by 1 x 10(8) to 2 x 10(8) Spp+ cells. Spp- bacteria, which make 30-fold less glucan than do Spp+ bacteria, did not accumulate on surfaces in numbers significantly above the saturation level of 1 x 10(8) to 2 x 10(8) cells in the presence or absence of sucrose. Insoluble glucan synthesized by Spp+ cells from sucrose also enabled these bacteria to accumulate on saliva-coated HA seven times more effectively than the Spp- cells and 10 times more effectively than the Spp+ cells grown in medium without sucrose.

Culture Media↗

PubMed1991

Oral passive immunization against dental caries in rats by use of hen egg yolk antibodies specific for cell-associated glucosyltransferase of Streptococcus mutans.

The effect of polyclonal egg yolk immunoglobulin G antibodies (yIgG) raised against whole cells, cell-free (CF) glucosyltransferase (GTase), or cell-associated (CA) GTase of serotype c Streptococcus mutans was examined in terms of in vitro inhibition of virulence-related factors of S. mutans and protection of S. mutans-infected rats against the development of dental caries. Hens (18 weeks old) were immunized with formalin-treated whole cells, purified CF-GTase, or CA-GTase together with Freund's complete adjuvant. In addition, yIgG to surface protein antigen was used in some in vitro experiments for comparison with other antibodies. yIgG was purified by ammonium sulfate precipitation followed by DEAE-Sephacel column chromatography or fractional precipitation with ethanol. Purified yIgG was found to be a 220-kDa protein, which was dissociated into heavy and light chains upon addition of 2-mercaptoethanol. yIgG to whole cells and surface protein antigen gave a heavy aggregation of S. mutans organisms, while yIgG to CF- and CA-GTase specifically inhibited the enzymatic activity of the respective GTase. yIgG to CA-GTase and whole cells was found to clearly suppress the adherence of S. mutans cells to a glass surface. Specific-pathogen-free Sprague-Dawley rats that had been infected heavily and repeatedly with S. mutans and fed diet no. 2000 developed severe dental caries, while rats fed diet 2000 containing greater than or equal to 0.1% yIgG to CA-GTase showed a statistically significant reduction in dental plaque accumulation and caries development. Administration of yIgG to CF-GTase and whole cells failed to protect against caries. These results clearly suggest that yIgG to S. mutants CA-GTase specifically inhibited a virulence factor of this organism, i.e., insoluble glucan-synthesizing CA-GTase, resulting in a significant reduction in the development of dental caries.

Administration, Oral↗