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PubMed1987

Immunological study of cross-reactive polysaccharide antigens (types a, d, and h) of oral Streptococcus spp. with monoclonal antibodies.

Two monoclonal antibodies against the cross-reactive antigens of S. cricetus (type a) and S. sobrinus (type d) were isolated. Galactose and especially melibiose inhibited the precipitin reaction markedly. Inhibition by melibiose was over 200-fold stronger than that by galactose. This may indicate that galactose-alpha 1, 6-glucose is the predominant antigenic determinant of this cross-reactive antigen. This antigen was also found in S. sobrinus type h strains, but no antigen was found in one type d strain (OMZ176).

Antibodies, Monoclonal↗
PubMed1990

Sialidase activity of the "Streptococcus milleri group" and other viridans group streptococci.

Viridans group streptococci were examined for the production of sialidase (neuraminidase) activity, using the fluorescent substrate 4-methylumbelliferyl-alpha-D-N-acetylneuraminic acid in a simple and rapid (15-min) assay. Sialidase was produced by all strains of Streptococcus oralis and S. intermedius and by a majority of S. mitis strains. S. mutans, S. sobrinus, S. gordonii, S. sanguis, S. vestibularis, S. salivarius, S. anginosus, S. constellatus, "S. parasanguis," and the "tufted fibril group" were uniformly negative. Sialidase production may be a useful characteristic to assist in the identification of viridans group streptococci.

Humans↗
PubMed1994

An in vitro investigation of the cariogenic potential of oral streptococci.

Whilst the importance of the mutans streptococci in the aetiology of dental caries is clear, a number of studies have described caries development in their absence. This investigation aimed to assess the cariogenic potential of Streptococcus gordonii, Strep. sanguis, Strep. vestibularis and Enterococcus faecalis in comparison with Strep. mutans and Strep. sobrinus, using a recently described in vitro model. In the presence of a 146 mM sucrose solution and powdered hydroxyapatite, each species was incubated for 5 h, after which acid anion production, calcium release and change in pH were measured. It was possible to assign each species to one of three groups, with E. faecalis, Strep. gordonii, Strep. sanguis exhibiting low, Strep. vestibularis intermediate, and Strep. mutans and Strep. sobrinus high in vitro cariogenic potential. This assay could be used as a screening test to assess the potential cariogenicity of a range of bacterial species.

Acetates↗
PubMed1985

Cross-reactions between alpha-streptococci and Omniserum, a polyvalent pneumococcal serum, demonstrated by direct immunofluorescence, immunoelectroosmophoresis, and latex agglutination.

In recent years several groups have used serological methods to demonstrate pneumococcal capsular antigens in sputum. In the present study 123 strains of alpha-hemolytic streptococci (including 97 strains from sputum or pharyngeal specimens) were tested for cross-reactions with a polyvalent antipneumococcal serum (Omniserum). Representatives of the following species were included: Streptococcus bovis, S. equinus, S. intermedius, S. lactis, S. milleri, S. mitis, S. mutans, S. sobrinus, S. salivarius, S. sanguis, S. suis, and Aerococcus viridans. Serological reactions were detected by direct immunofluorescence, immunoelectroosmophoresis, and latex agglutination. Fifteen (12%) of the strains gave positive reactions by all three methods. Positive reactions were also observed with another 32 strains (26%) with two of the methods, whereas 37 strains (30%) gave positive reactions by just one technique. Altogether 84 (68%) strains gave positive reactions with one or more of the methods. Latex agglutination gave positive reactions with 26 (21%) strains compared with 57 (46%) in immunofluorescence and 63 (51%) in immunoelectroosmophoresis. Absorption of the antiserum with one alpha-hemolytic strain reduced but did not entirely eliminate the cross-reactions with five tested strains. These findings indicate a potential risk of cross-reactions with polyvalent antipneumococcal serum in tests carried out on sputa or other specimens which may be contaminated with alpha-hemolytic streptococci.

Cross Reactions↗
PubMed2001

Nucleotide sequence and molecular characterization of a dextranase gene from Streptococcus downei.

DNA fragments encoding the Streptococcus downei dextranase were amplified by PCR and inverse PCR based on a comparison of the dextranase gene (dex) sequences from S. sobrinus, S. mutans, and S. salivarius, and the complete nucleotide sequence of the S. downei dex was determined. An open reading frame (ORF) of dex was 3,891 bp long. It encoded a dextranase protein (Dex) consisting of 1,297 amino acids with a molecular mass of 139,743 Da and an isoelectric point of 4.49. The deduced amino acid sequence of S. downei Dex had homology to those of S. sobrinus, S. mutans and S. salivanus Dex in the conserved region (made of about 540 amino acid residues). DNA hybridization analysis showed that a dex DNA probe of S. downei hybridized to the chromosomal DNA of S. sobrinus as well as that of S. downei, but did not to other species of mutans streptococci. The C terminus of the S. downei Dex had a membrane-anchor region which has been reported as a common structure of C termini of both the S. mutans and S. sobrinus Dex. The recombinant plasmid which harbored the dex ORF of S. downei produced a recombinant Dex enzyme in Escherichia coli cells. The analysis of the recombinant enzyme on SDS-PAGE containing blue dextran showed multiple active forms as well as dextranases of S. mutans, S. sobrinus and S. salivarius.

Amino Acid Sequence↗
PubMed1991

["In vitro" study of the bacteriocinogenic capacity of Streptococcus mutans].

In our paper the bacteriocinogen ability of some subspecies of Streptococci mutans has been studied. We have obtained a production percentage of 50%. That production ability was bigger for subspecies mutans than sobrinus in a significative way, who strength the increasing differences between these microorganisms. A brief revision of the role that bacteriocins look like to play in oral ecologist equilibrium and their feasible utilization in dental caries prevention has been done.

Bacteriocins↗
PubMed1990

[Microflora around the bracket by direct bonding system].

The purpose of the present study is to clarify the influence of microflora in plaque of the brackets edge by direct bonding system and the cause of caries that is induced around the bracket during orthodontic treatment. The subjects were selected from the patients undergoing direct bonded orthodontic treatment and from the non-orthodontic patients. They were divided into four groups: those having no orthodontic treatment (control group), those having no caries around the bracket (group A) and those having caries around the bracket (groups B and C). Sample plaques were collected from the initial tooth surface with control group, from the tooth surface around the bracket with group A, from the carious cavity around the bracket with group B and from the non-carious tooth surface around the bracket with group C. The isolation rates of microflora in dental plaque of the four groups were compared, and the following conclusions were obtained. 1. Group A had almost same level with control group as to the proportion of each bacterium examined by shape and gram stain of microbiota. Group B had higher level of gram positive cocci than the other groups. 2. Group A and control group had no difference as to the isolation rates of genera Streptococcus, Actinomyces and Lactobacillus. 3. Group A had low level of S. mutans, was the same as control group. 4. The isolation rate of each genus: 1) The isolation rate of genus Streptococcus was almost same in groups A, C and control group. Group B had higher than the other groups. 2) The isolation rate of genus Actinomyces was the highest in all groups. 3) The isolation rate of genus Lactobacillus was exceedingly low. 4) Groups B and C had significantly higher level of S. mutans group than group A and control group. Group B had significantly lower level of S. mitior than group A and control group. 5. All four groups showed high level of biotype I, and biotype IV was observed in groups B and C. Biotype I was identified as S. mutans serotype c, biotype IV was observed as S. sobrinus serotype d.

Actinomyces↗
PubMed1991

A scheme for the identification of viridans streptococci.

A collection of strains representing all the currently recognised species of oral or viridans streptococci (Streptococcus sanguis, S. parasanguis, S. gordonii, S. oralis, S. mitis, S. salivarius, S. vestibularis, S. anginosus, S. constellatus, s. intermedius, S. mutans and S. sobrinus) were tested for the production of a range of glycosidase activities with 4-methylumbelliferyl-linked fluorogenic substrates, and for reactions in a range of conventional fermentation and hydrolytic tests. The resulting biochemical scheme, consisting of 14 tests, enabled the differentiation of all these species and distinguished three biotypes within S. sanguis. The scheme reported here represents an improvement over currently available schemes for the identification of viridans streptococci.

Culture Media↗
PubMed1990

[Oral Streptococci - a scheme for the identification of Streptococcus mutans].

A reliable simple scheme for the rapid identification of certain species of oral streptococci has been developed and compared with biochemical and physiological results of 45 well known clinical isolates and stock strains. Moreover, a method for the determination of H2O2 production was tested. With selected reactions as for instance acid formation in mannitol and raffinose broth, hydrolysis of arginine and esculin, the production of peroxidase, and the resistance of bacitracin the species S. rattus, S. sobrinus, S. mutans, S. cricetus, S. ferus, S. milleri, S. mitis, S. sanguis, S. mitior, and S. salivarius were differentiated.

Animals↗
PubMed1978

Electron-microscopic demonstration of Streptococcus mutans in 5-day-old experimental dental plaque using immunohistochemistry.

The present work described the distribution of horseradish peroxidase reaction product obtained after immunohistochemical staining of consecutive ultra-thin sections of 5-day-old experimental dental plaques using differently absorbed anti-S.mutans sobrinus, anti-S.mutans mutans, and normal rabbit lambda-globulins. It was found that an in situ identification of S.mutans subspecies sobrinus could be obtained using thoroughly absorbed anti-S.mutans sobrinus gamma-globulins and consecutive sections. The anti-S.mutans mutans gamma-globulins were after tests on pure cultures of several oral bacteria found to cross-react with S.milleri. Furthermore, crude and absorbed normal rabbit gamma-globulins were observed to contain antibodies that cross-reacted with several plaque microorganisms.

Bacteriological Techniques↗
PubMed2002

Genetic studies on reference strains of mutans streptococci.

Twenty four reference strains (serotype a-h) belonging to the mutans group of streptococci were compared for DNA fragment patterns of rDNA after treatment with Hind III. It was shown that Streptococcus cricetus (serotype a), S. rattus (serotype b), and S. downei (serotype h) reveals comparatively homogeneous patterns while S. mutans (serotype c, e and f) exhibits differences between the different serotypes as well as within single serotypes. S. sobrinus had an intermediary diversity. These data support the previous findings that S. mutans is heterogeneous at the serological, biochemical and genetical level.

Animals↗
PubMed2006

Viridans streptococci isolated by culture from blood of cancer patients: clinical and microbiologic analysis of 50 cases.

Clinical and microbiologic studies of 50 cases of viridans streptococcal bacteremia in cancer patients were performed. The bacteria were identified to species level by sequencing analysis of the 16S rRNA gene. At least nine Streptococcus spp. were found, including S. mitis (25 strains, 50.0% of 50); currently unnamed Streptococcus spp. (11 strains); S. parasanguis (five strains); S. anginosus (three strains); S. salivarius (two strains); and one strain each of S. gordonii, S. sanguis, S. sobrinus, and S. vestibularis. There were no S. oralis strains. Among 11 antibiotics of nine classes tested, no resistance to vancomycin, linezolid, or quinupristin-dalfopristin was seen. Resistance to penicillin (MIC, 4 to 12 mug/ml) was noted only among S. mitis strains (28.0%, 7/25) and not non-S. mitis strains (0/25) (P = 0.004). Significantly more S. mitis strains than non-S. mitis strains were resistant to fluoroquinolones and to > or =3 classes of antibiotics. Isolation of quinolone-resistant organisms was associated with the prior usage of quinolones (P = 0.002). Quantitative blood cultures showed that the strains resistant to levofloxacin or gatifloxacin were associated with higher colony counts than were their corresponding nonresistant strains. The young and elderly patients also had higher levels of bacteremia caused predominantly by S. mitis. Septic shock was present in 17 (34.0% of 50) patients, and 13 of those cases were caused by S. mitis (P = 0.007). These results suggest that S. mitis is the most common cause of viridans streptococcal bacteremia in cancer patients and is more resistant to antibiotics than other species.

Anti-Bacterial Agents↗
PubMed1989

Production and partial characterization of the extracellular polysaccharides from oral Streptococcus salivarius.

The production of polysaccharides from sucrose by extracellular enzymes from oral Streptococcus salivarius isolates and the physico-chemical properties of water-insoluble products (IPs) were investigated. Extracellular enzymes from all the 18 strains tested produced insoluble alpha-D-glucans (IGs) as well as soluble beta-D-fructans, and formed adhering deposits on glass. Generally, the IPs (mostly IGs) of S. salivarius strains differed from the S. sobrinus IPs by (a) containing significant proportions of alpha-D-(1----4)-, in addition to alpha-D-(1----3)- and alpha-D-(1----6)-glucosyl linkages, and much higher proportions of alpha-D-(1----3) than alpha-D-(1----6) linkages, (b) being more susceptible to hydrolysis by mutanase than by dextranase, (c) possessing low or no streptococcal cell-agglutinating ability, and (d) showing weaker adhesion to a glass surface. The degree of the polysaccharide adherence differed greatly among the S. salivarius strains and, therefore, they were divided into three groups of adherence producers; heavy, moderate, and slight. The IPs of the three groups contained, generally in descending order, a higher proportion of higher-molecular-weight fractions, and consisted of higher proportions of IG containing higher proportions of -(1----6)-alpha-D and -(1----4)-alpha-D glucosyl linkages and (1----3,6) branches, but showed higher susceptibility to hydrolysis by mutanase as well as dextranase. Thus, the production and the properties of extracellular insoluble alpha-D-glucans from sucrose differ considerably between oral S. salivarius and cariogenic S. sobrinus.

Agglutination↗
PubMed1989

[Cariogenicity of polydextrose and refined polydextrose as a substrate].

Polydextrose is a randomly bonded condensation polymer of glucose, containing minor amounts of bound sorbitol and citric acid. This material has been developed for a reduced-calorie bulking, bodying or texturizing agent in the manufacture of low-calorie foods. The effect of polydextrose or refined preparation which has been eliminated saccharides under molecular weight of 500 in polydextrose, on cariogenicities of Streptococcus mutans group (serotype a-g) and certain oral microorganisms was studied. Some of S. mutans strains (serotype c and f) metabolized polydextrose at a low level and produced 20% lactic acid as compared with glucose. It did not serve as a substrate for plaque formation and cellular aggregation of S. mutans group and did not utilized water-insoluble glucan synthesis by glucosyltransferase from S. mutans PS-14 (c) or S. sobrinus 6715 (g). In the adherence experiment using polydextrose, heat killed cells of S. mutans labelled with 3H and GTase, the amount of cells that adhered to the smooth surface was almost 0. Further, polydextrose inhibited sucrose dependent water-insoluble glucan synthesis. The case of refined polydextrose was not utilized for the growth, acid production, cellular aggregation and plaque formation of Streptococcus mutans group (serotype a-g). Refined polydextrose also did not produce lactic acid by certain oral microorganisms. It did not serve as a substrate for water-insoluble glucan synthesis and cellular adherence by GTase from S. mutans PS-14 (c) or S. sobrinus 6715 (g). Further, refined polydextrose inhibited sucrose dependent cellular adherence by GTase from S. mutans PS-14(c). SPF SD rats infected with S. sobrinus 6715 were fed a diet containing 20% refined polydextrose or 20% sucrose for 48 days. A significantly (p less than 0.01) lower caries score (mean +/- SE, 4.74 +/- 0.86) was observed in the rats fed a diet containing refined polydextrose than the control (31.17 +/- 0.33). Also, the value of caries score of rats fed a diet containing the refined polydextrose was almost equal as that of the rats fed a diet containing cornstarch only.

Animals↗
PubMed1982

Physiology of "mutans-like" Streptococcus ferus from wild rats.

Strains of Streptococcus ferus isolated from the oral cavities of wild rodents inhabiting sucrose-rich and sucrose-poor environments have many traits in common with the "mutans" streptococci. Thus, S. ferus HD3 and 8S1, like cariogenic S. sobrinus 6715-13, from adherent, alpha (1 leads to 3) glucopyranosyl-glucose linkage-rich, plaquelike deposits in vitro and in vivo through the action of constitutive glucosyltransferase(s) enzymes on sucrose, produce and degrade intracellular polysaccharide, produce short-chain fatty acids from the catabolism of mono- and disaccharides, carry the c antigen of S. mutans, and penetrate, persist, and proliferate in a sucrose-augmented fashion in the oral cavities of specific-pathogen-free rodent caries models. However, unlike infection with common S. mutans, infection with tested S. ferus strains does not cause caries. This avirulence appeared to result more from the reduced aciduricity of S. ferus than from differences in glucosyltransferase complements. Studies showed that despite generally similar growth rates and extracellular glucan syntheses, the acidogenic metabolism of S. ferus was more inhibited by declining environmental pH than was cariogenic S. sobrinus 6715-13 and that, in vitro, less hydroxyapatite was solubilized by S. ferus metabolic end products. The physiology of these S. ferus strains demonstrated that, in addition to plaque formation and acid production, acid tolerance was crucial to the carious process.

Agglutination↗
PubMed1993

Interaction of the salivary glycoprotein EP-GP with the bacterium Streptococcus salivarius HB.

The interaction of the human salivary glycoprotein EP-GP with a number of oral bacterial species, following incubation with human whole saliva, has been investigated. EP-GP could be detected with a specific monoclonal antibody, by means of ELISA or by electrophoresis in combination with Western Transfer. The results indicated that EP-GP is bound only by Streptococcus salivarius, and not by the other tested strains of bacteria, Actinomyces viscosus, A. naeslundii, Actinobacillus actinomycetemcomitans, Bacteroides fragilis, S. gordonii, S. oralis, S. sanguis, S. mitis, S. mutans, S. sobrinus, S. rattus, S. constellatus, and S. anginosus. Binding of EP-GP to S. salivarius is mediated by a protein-protein interaction, which was found to be pH-dependent with a maximum binding between pH 5 and 6. For further characterization of the binding of EP-GP to S. salivarius, four mutants were tested, each of them lacking different cell wall antigens. EP-GP was bound to all mutants in amounts comparable with the wildtype, in spite of the different surface antigen compositions. We were able to identify a 27-kD EP-GP binding protein, by extraction of S. salivarius-cell wall antigens and electrophoretic techniques. In addition to EP-GP, S. salivarius also bound two other salivary proteins, namely, secretory IgA and low-molecular-weight mucin (MG-2).

Animals↗
PubMed1997

[Effects of specific antibodies against the cell surface protein P1 of streptococcus mutans MT 6R upon adhered streptococci].

The sera and saliva were obtained from BALB/C mice by injection of the cell surface protein P1 and Freud's adjuvant. High antibody titers were showed in the sera and saliva by an enzyme-linked immunosorbent assay. The cells of S. mutans (serotype c, e and f) adhered on saliva-coated hydroxyapatite could be detached by the antibodies of the protein P1 of S. mutans MT 6R including in the sera and saliva (P < 0.05), but the antibodies had no influence on the cells of S. cricetus AHT, S. sobrinus OMZ176, S. sobrinus 6715 and S. rattus BHT (P > 0.05).

Animals↗