SEARCH · PubMed Health

Results for “Streptococcus sobrinus”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 415 records · Page 23Linked to original sources

PubMed1990

Proteolytic activity of oral streptococci.

Streptococcus mutans and Streptococcus sobrinus were the least proteolytic of 8 species of oral streptococci while Streptococcus oralis and Streptococcus sanguis were the most proteolytic. Degradation of FITC-BSA was significantly correlated with the hydrolysis of synthetic endopeptidase substrates. As S. oralis strains proliferate in dental plaque in the absence of dietary food their success, in vivo, might be due partially to their greater proteolytic activity compared to other oral streptococci.

Caseins↗

PubMed2004

The influence of biosurfactants released by S. mitis BMS on the adhesion of pioneer strains and cariogenic bacteria.

The influence of Streptococcus mitis BMS biosurfactants on the adhesion of eight pioneer and four cariogenic oral bacterial strains was, for a first screening, examined in a microtiter plate assay. The adhesion to pellicle-coated wells of three cariogenic strains was inhibited >70% by the biosurfactants, while only one pioneer strain showed >70% reduction. The reduction for the other strains did not exceed 50%. Subsequently, adhesion of Streptococcus mutans ATCC 25175 and Streptococcus sobrinus HG 1025, both cariogenic strains, and Actinomyces naeslundii T14V-J1 and Streptococcus oralis J22, two pioneer strains, to biosurfactants-coated enamel with and without a salivary pellicle was studied in a parallel plate flow chamber. A biosurfactants coating to enamel with or without a pellicle caused a reduction in the number of adhering cariogenic organisms, although no such reduction was observed for the pioneer strains. Consequently, it is concluded that S. mitis BMS biosurfactants may play a protective role against adhesion of cariogenic bacteria.

Bacterial Adhesion↗

PubMed1999

Enhanced (+)-catechin transglucosylating activity of Streptococcus mutans GS-5 glucosyltransferase-D due to fructose removal.

The (+)-catechin transglucosylating activities of several glucosyltransferases (GTFs) from the genus Streptococcus were compared. For this purpose, a mixture of four GTFs from Streptococcus sobrinus SL-1 and recombinant GTF-B and GTF-D from Streptococcus mutans GS-5 expressed in Escherichia coli were studied. It was shown that after removal of alpha-glucosidase activity, GTF-D transglucosylated catechin with the highest efficiency. A maximal yield (expressed as the ratio of moles of glucoside formed to moles of catechin initially added) of 90% was observed with 10 mM catechin and 100 mM sucrose (K(m), 13 mM) in 125 mM potassium phosphate, pH 6.0, at 37 degrees C. (1)H and (13)C nuclear magnetic resonance spectroscopy revealed the structures of two catechin glucosides, (+)-catechin-4'-O-alpha-D-glucopyranoside and (+)-catechin-4',7-O-alpha-di-D-glucopyranoside. Fructose accumulation during glucosyl transfer from sucrose to the acceptor competitively inhibited catechin transglucosylation (K(i), 9.3 mM), whereas glucose did not inhibit catechin transglucosylation. The addition of yeasts was studied in order to minimize fructose inhibition by means of fructose removal. For this purpose, the yeasts Pichia pastoris and the mutant Saccharomyces cerevisiae T2-3D were selected because of their inabilities to utilize sucrose. Addition of P. pastoris or S. cerevisiae T2-3D to the standard reaction mixture resulted in a twofold increase in the duration of the maximum GTF-D transglucosylation rate. The addition of the yeasts also stimulated sucrose utilization by GTF-D.

Catechin↗

PubMed1989

[Changes of antibody and splenic plaque forming cell responses to mutans streptococci in the rats infected with S. sobrinus 6715].

The study was undertaken to examine the changes in humoral IgM, IgG and IgA antibodies and splenic plaque forming cell responses against Streptococcus sobrinus 6715 in rats infected with the same mutans streptococci. The serum samples were collected every week for 24 weeks after infection (20 day old, Sprague Dawley rats). Humoral anti-S. sobrinus 6715 IgG and IgA antibodies were determined by an enzyme-linked immunosorbent assay. In the separate experiment, rat splenic IgM, IgG and IgA anti-trinitrophenyl (TNP) conjugated S. sobrinus plaque-forming cell (PFC) responses were also determined from 1 to 12 weeks after the infection. The results obtained were as follows: 1. From 1 to 4 weeks after infection, a slight increase in serum IgG anti-S. sobrinus antibody response was observed in the group of rats infected with S. sobrinus 6715 when compared with the non-infected rat group. However, beyond the 5th week, there was no difference in serum antibody responses between these two groups. 2. Infected rats showed a 2-9 times higher serum anti-S. sobrinus IgA antibody response than those of uninfected rats for 6 weeks after the infection. After this period just as with the IgG response, no difference in the IgA titers was found between these two groups. 3. Splenic IgM, IgG and IgA anti-TNP-S. sobrinus PFC responses showed a remarkable decrease shortly after the infection. These results suggest that the infected rats would gradually acquire oral tolerance to S. sobrinus antigen after the infection.

Animals↗

PubMed1997

Immunogenicity and protective immunity induced by synthetic peptides associated with a catalytic subdomain of mutans group streptococcal glucosyltransferase.

We examined the immunogenicity and induction of protective immunity of two 19-mer sequences (GGY and AND) which overlapped a highly conserved region which has recently been implicated in the enzymatic activity of glucosyltransferases (GTFs) of the mutans group streptococci. These peptides were synthesized as eight-branched constructs on a lysine core. Serum immunoglobulin G (IgG) antibody, induced by subcutaneous (s.c. [salivary gland vicinity]) injection with these peptide constructs, reacted with the inciting antigen, with mutans streptococcal GTFs, and with a 21-mer peptide (CAT) containing an aspartate previously shown to covalently bind sucrose. Several of these antisera also inhibited the ability of Streptococcus sobrinus GTF to synthesize insoluble glucan. Significant levels of salivary IgA antibody were also induced by GGY and AND peptide constructs after s.c. injection. The effect of immunization with the GGY and AND peptide constructs on the cariogenicity of Streptococcus mutans was studied in three experiments by immunization of weanling Sprague-Dawley rats, twice at 7- to 14-day intervals with peptides, S. sobrinus GTF, or phosphate-buffered saline. All rats were then orally infected with S. mutans SJ. After 63-day infection periods, the GGY and AND-injected groups had significant dental caries reductions compared with sham-injected groups in most experiments. These studies support the existence of an additional catalytic subdomain within the sequence defined by the GGY and AND peptides. Furthermore, the epitopes defined in these sequences have significant immunogenicity, can induce immune responses which interfere with GTF-mediated glucan synthesis in vitro, and can protect rats from experimental dental caries.

Amino Acid Sequence↗

PubMed1988

Prevalence of mutans streptococci and lactobacilli in elderly Swedish individuals.

The number of Streptococcus mutans, Streptococcus sobrinus, and lactobacilli in stimulated whole saliva was examined in 149 elderly persons. More than 10(6) CFU/ml of mutans streptococci were found in 57% of the subjects and 85% had more than 10(5) lactobacilli per ml of saliva. There was no difference in the prevalence of mutans streptococci between edentulous and dentate subjects whereas significantly more lactobacilli were detected in denture wearers. S. mutans was most frequent and was found in 72% of the subjects. S. sobrinus, which was carried by 44% of the persons, was found proportionally in more subjects with dentures than in dentate individuals. In most persons with S. sobrinus, S. mutans was also present but in 8% of the subjects only S. sobrinus was detected. The subjects with both S. mutans and S. sobrinus had higher salivary levels of mutans streptococci than individuals with only S. mutans or S. sobrinus.

Aged↗

PubMed1989

Isolation and characterization of the Streptococcus mutans gtfD gene, coding for primer-dependent soluble glucan synthesis.

Two glucosyltransferase genes from Streptococcus mutans GS-5, gtfB and gtfC, have been previously isolated and sequenced in this laboratory. In the present communication a third gtf gene, gtfD, was isolated and characterized. Isolation of the gene involved a novel procedure utilizing the integration plasmid pVA891. A peptide expressed by the 1.7-kilobase DNA fragment from strain NHS1 (containing deletions in both the gtfB and gtfC genes) was initially identified in a pUC18 clone bank with antiglucosyltransferase antibodies. This fragment was integrated into the GS-5 chromosome following ligation into pVA891 and transformation, yielding strain DP2. The vector together with one complete and one incomplete copy of the gtfD gene was removed from the chromosome of strain DP2 following EcoRI digestion, religation, and transformation of E. coli HB101. The resultant plasmid, pNH4, expressed glucosyltransferase S (GTF-S) activity. The enzyme was purified to near homogeneity and was shown to synthesize water-soluble glucan exclusively in a primer-dependent manner. The molecular mass (155 kilodaltons) and the kinetic parameters of the purified enzyme were similar to those observed for the GTF-S enzyme previously purified from culture fluids of strain GS-5. Insertional inactivation of the gtfD gene indicated that this gene is not required for in vitro sucrose-dependent adherence to smooth surfaces. Furthermore, inactivation of the gtfD gene in a gtfC gtfB mutant indicated that three distinct gtf genes involved in glucan formation are present on the S. mutans GS-5 chromosome. Southern blot analysis further suggested that the gtfD gene does not share demonstrable homology with the gtf genes from Streptococcus sanguis or Streptococcus sobrinus.

Cloning, Molecular↗

PubMed1989

Acidogenesis by oral streptococci at different pH values.

Streptococcus mutans is known to be one of the most cariogenic oral microorganisms. Recently, organisms classified as S. mutans have been shown to be genotypically heterogeneous and to form at least six separate species. In this study, differences in acid production between the mutans streptococci and Streptococcus sanguis were investigated at pH values from 5.0 to 7.0. While all of the species investigated were able to produce acids, Streptococcus sobrinus was found to be significantly more acidogenic than the others. S. sobrinus was capable of sustained acid production at pH levels below 6.0, while acid production by other species ceased or was strongly inhibited. These results indicate that S. sobrinus deserves more attention as a potentially cariogenic microorganism.

Acids↗

PubMed1989

Salivary levels of putative cariogenic organisms in patients with eating disorders.

The present study examined the hypothesis that women with eating disorders associated with a history of chronic vomiting can be characterized by a salivary flora with high levels of aciduric organisms, such as, mutans streptococci, lactobacilli and yeast. Three groups of female subjects were studied: vomiting bulimics (G1; n = 14), and comparison groups selected for high Streptococcus mutans (G2; n = 13), and low S. mutans levels (G3; n = 12). The prevalence and levels of mutans streptococci, lactobacilli and yeast tended to be higher in bulimics than in non-bulimics. The bulimics had significantly higher levels and higher prevalence of Streptococcus sobrinus than the non-bulimics. A high S. sobrinus colonization may be a marker for a history of vomiting in bulimia.

Bulimia↗

PubMed1991

Dental caries and mutans streptococci in selected groups of urban and native Indian schoolchildren in Mexico.

Two groups of Mexican children aged 12-14 yr were examined for dental caries and salivary mutans streptococci counts. One hundred lived in Mexico City and 100 belonged to a native Mazahua Indian population. The prevalence of caries, diagnosed according to WHO, was 90% in Mexico City and 82% in the Indian community. Mean DMFT was 5.98 and 3.57 respectively. Saliva samples were analyzed for mutans streptococci by the "Strip mutans" method. Further identification of the biotype/serotype was done. Mutans streptococci were found in 95% of the urban children and 75% of the Indians. There was a statistically significant difference in the prevalence of mutans streptococci between the city and the rural samples. Streptococcus mutans was more frequently found than Streptococcus sobrinus.

Adolescent↗

PubMed1990

Characterization of the product of the gtfS gene of Streptococcus downei, a primer-independent enzyme synthesizing oligo-isomaltosaccharides.

The gtfS gene, coding for a glucosyltransferase which synthesizes water-soluble glucan and previously cloned from Streptococcus downei strain MFe28 (mutans serotype h) into a bacteriophage vector, was subcloned into a plasmid vector. The gtfS gene products expressed in Escherichia coli were compared to the primer-independent, oligo-isomaltosaccharide synthase in Streptococcus sobrinus strain AHT (mutans serotype g) and shown to resemble it closely in molecular mass, isoelectric point, immunological properties, optimum pH and Km values. The glucans produced from sucrose by the gtfS gene products are alpha-1,6-linked linear oligo-isomaltosaccharides without any branching sites. A similar gtfS gene was also detected on chromosomal DNA from S. sobrinus strain AHT.

Blotting, Western↗

PubMed1991

Combined effects of Zn(2+)-chlorhexidine and Zn(2+)-cetylpyridinium chloride on caries incidence in partially desalivated rats.

The effects of Zn2+ combined with either chlorhexidine or cetylpyridinium chloride (CPC) on caries incidence in partially desalivated rats were investigated. Seven groups of 12 animals each received topical applications for 20 s with a saturated swab (0.2 ml) of the following aqueous solutions twice daily on weekdays (10 a.m. and 3 p.m.) and once daily during weekends (12 a.m.) for 5 wk: deionized water (placebo); 40 mM zinc acetate; 2.2 mM chlorhexidine diacetate; 4.4 mM CPC; 40 mM zinc acetate and 2.2 mM chlorhexidine diacetate; 40 mM zinc acetate and 4.4 mM CPC; and 20 mM NaF (positive control). Coronal caries was scored by the method of Keyes. All treatments except CPC alone resulted in significantly (P less than 0.05, ANOVA) less smooth-surface caries than did the placebo. NaF treatment resulted in significantly less smooth-surface caries than did Zn2+, chlorhexidine, CPC, and Zn(2+)-CPC. The inclusion of zinc ions did not significantly increase the caries-inhibitory efficacy of chlorhexidine (CH). The combination of Zn(2+)-CPC decreased smooth-surface scores significantly more than did CPC alone. Significant differences in sulcal-surface caries were not observed among the groups. Zn(2+)-CPC suppressed the Streptococcus sobrinus counts significantly more than did the separate agents. Animals treated with Zn(2+)-CH harbored the lowest populations of S. sobrinus.

Acetates↗

PubMed2004

Molecular interactions of surface protein peptides of Streptococcus gordonii with human salivary components.

Oral streptococci play a large role in dental biofilm formation, and several types interact as early colonizers with the enamel salivary pellicle to form the primary biofilm, as well as to incorporate other bacteria on tooth surfaces. Interactions of surface molecules of individual streptococci with the salivary pellicle on the tooth surface have an influence on the etiological properties of an oral biofilm. To elucidate the molecular interactions of streptococci with salivary components, binding between surface protein (SspB and PAg) peptides of Streptococcus gordonii and Streptococcus sobrinus were investigated by utilizing BIAcore biosensor technology. The analogous peptide [change of T at position 400 to K in SspB(390-402), resulting in the SspB(390-T400K-402) peptide] from S. gordonii showed the greatest response for binding to salivary components and inhibited the binding of Streptococcus sanguis by more than 50% in a competitive inhibition assay in a comparison with other SspB and PAg peptides. This peptide also bound to the high-molecular-weight protein complex of salivary components and the agglutinin (gp340/DMBT1) peptide (scavenger receptor cysteine-rich domain peptide 2 [SRCRP 2]). In addition, the SspB(390-T400K-402) peptide was visualized by two surface positive charges in connection with the positively charged residues, in which lysine was a key residue for binding. Therefore, the region containing lysine may have binding activity in S. gordonii and S. sanguis, and the SRCRP 2 region may function as a receptor for the binding. These findings may provide useful information regarding the molecular mechanism of early biofilm formation by streptococci on tooth surfaces.

Adhesins, Bacterial↗

PubMed1997

Effects of a hydrogenated isomaltooligosaccharide mixture on glucan synthesis and on caries development in rats.

The caries inhibitory effect of the hydrogenated derivative of an isomaltooligosaccharides mixture (IMO-H) was examined in vitro and in vivo experiments. IMO-H could not be used as a substrate for the crude glucosyltransferases (GTases) of Streptococcus sobrinus 6715 to synthesize water-insoluble glucan. Moreover, it not only significantly inhibited the synthesis of water-insoluble glucan from sucrose, but also the sucrose-dependent adherence of these growing cells the glass surfaces. In the in vivo experiment, the addition of IMO-H to a sucrose-containing diet resulted in significant reduction of caries development in specific-pathogen-free (SPF) rats infected with S. sobrinus 6715.

Animals↗

PubMed1994

[3 different methods for evaluating Streptococcus mutans in the saliva].

Three different methods for detection and count of Streptococcus mutans in saliva have been compared with a microbiological method in order to estimate their efficacy and practicality. The study has been carried out on fifty children of six-eleven years old. The first method (stamp method) derives from that of Kohler and Bratthall, improved on the sampling, without saliva stimulation and, hence, more rapid. Furthermore, using a tongue depressor with a shovel-like extremity, we can either restrict the area where the grown colonies must be counted, avoiding any mistake, and stamp the spatula in the centre of the plate, not in the border, as the original method described, pressing it with the same force in every part, so that almost all the saliva collected can be plated on the Streptococcus mutans selective medium. As stated by this method, a tongue depressor is pressed first on the subject's tongue, then on a plate containing the medium. After incubation, the Streptococcus mutans colonies are counted on the plate's area limited by the stamp of the extremity of the spatula. According to Emilson we can also discriminate Streptococcus mutans and Streptococcus sobrinus colonies. The second method is a "strip mutans test" (Dentocult): saliva is stimulated making the subject chew a piece of paraffin and then it is collected passing a plastic spatula for ten times on the child's tongue. The spatula is introduced into a tube containing a liquid medium selective for Streptococcus mutans and then incubated.(ABSTRACT TRUNCATED AT 250 WORDS)

Bacteriological Techniques↗

PubMed1988

C31G, a new agent for oral use with potent antimicrobial and antiadherence properties.

C31G, an equimolar mixture of alkyl dimethyl glycine and alkyl dimethyl amine oxide, was evaluated for antimicrobial and antiadherence properties. The efficacy of C31G, its two components, and several commercial mouth rinses was determined in assays measuring inhibition of glycolysis, inhibition of bacterial adherence, and MICs. Inhibition of glycolysis was determined by using a saliva sediment model, with glycolytic activity expressed as the change in pH relative to that of a control. Adherence studies were undertaken with Streptococcus sobrinus 6715 to measure inhibition of adherence to nichrome wires. MICs were determined against selected microorganisms by standard methods. C31G demonstrated broad-spectrum antimicrobial properties, with activity against both gram-positive and gram-negative organisms and Candida albicans, a yeast. C31G inhibited both glycolysis by salivary bacteria and adherence of Streptococcus strains to wire mesh. C31G was more effective in the assays conducted than any commercial formulation tested and was as effective as chlorhexidine. A synergistic effect was demonstrated between the individual components of C31G, and no loss of activity was noted when it was formulated into a mouth rinse vehicle.

Anti-Bacterial Agents↗

PubMed1990

Arginine catabolism by strains of oral streptococci.

Arginine catabolism via the arginine deiminase pathway was found in Streptococcus sanguis 903. Citrulline and ornithine were released from resting cells incubated with arginine, arginine-containing peptides, or saliva. Maximum arginine catabolism by resting cells of S. sanguis 903 was found in the pH range 7-8 and at 45-48 degrees C. Arginine deiminase activity was found in the cytoplasm and in the cell-wall extract of this strain, while ornithine carbamoyltransferase activity was found in the cytoplasm and in extracts of cell walls and cytoplasmic membranes. Streptococcus mutans GS-5 and Streptococcus sobrinus strains OMZ 176 and 6715 could release arginine from salivary peptides but were incapable of significant arginine catabolism.

Arginine↗

PubMed1992

Adherence of oral streptococci to salivary glycoproteins.

We used an overlay method to study the ability of human salivary glycoproteins to serve as receptors for several strains of streptococci that colonize the oral cavity. Parotid and submandibular-sublingual salivas were collected as ductal secretions, separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and transferred to nitrocellulose membranes. The resulting blots were overlaid with [35S]methionine-labeled bacteria, and salivary components to which the bacteria bound were detected by autoradiography. Potential glycoprotein receptors were identified for 8 of the 16 strains tested. In three cases (Streptococcus sanguis 72-40 and 804 and Streptococcus sobrinus OMZ176), highly specific interactions with a single salivary component were detected. Removal of sialic acid residues from the low-molecular-weight salivary mucin prevented adherence of one of these strains (S. sanguis 72-40), suggesting that this saccharide either mediates binding or is a critical component of the receptor site. In the remaining five strains (Streptococcus gordonii G9B and 10558, S. sanguis 10556, and Streptococcus oralis 10557 and 72-41), interactions with multiple salivary components, including the low-molecular-weight salivary mucin, highly glycosylated proline-rich glycoproteins, and alpha-amylase, were detected. These results suggest that some oral streptococci can bind specifically to certain of the salivary glycoproteins. The interactions identified may play an important role in governing bacterial adherence and clearance within the oral cavity.

Bacterial Adhesion↗