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PubMed1977

Immunization with dextransucrases, levansucrases, and glycosidic hydrolases from oral streptococci. II. Immunization with glucosyltransferases, fructosyltransferases, and glycosidic hydrolases from oral streptococci in monkeys.

The feasibility of immunizing monkeys with enzymes from oral streptococci in an attempt to reduce dental caries was investigated. Forty rhesus monkeys, Macaca mulatta, were used. Cariogenic streptococci, S mutans, were implanted into all the monkeys' mouths. There was no pathological effect resulting from immunization. Of the 40 animals, 30 retained the implanted flora throughout the experiment; the remaining 10 were reimplanted until the streptococci remained. In six months, gross carious lesions were evident with plaque. Inhibitiors present in the monkey sera after immunization inhibited glucosyltransferase, fructosyltransferase, and neuraminidase activities. It was presumed the inhibitors were antibodies. There was a reduction of 68.6% in the total carious lesions in the animals immunized intraorally with glucosyltransferase, 62.4% reduction in those injected with fructosyltransferase, and 57.4% reduction in total lesions in those immunized with glycosidic hydrolases after 19 months, as compared to the control group. There were no gross lesions apparent in the group immunized with glycosidic hydrolases. It appears that immunization with enzymes significantly reduces carries and is feasible in a primate model.

Animals↗
PubMed1975

[Immunoelectronmicroscopic localization of cell wall antigens in streptococci. II. Localization of the group-specific polysaccharide of group C streptococci with ferritin- and peroxidase-labelled Helix pomatia-agglutinin (author's transl)].

The carbohydrate of the cell wall of group C streptococci is one of the best known group-specific streptococcal antigens with respect to its chemical structure. In the present paper, the ultrastructural location of the carbohydrate was investigated by means of immunoelectronmicroscopic techniques. Besides group-specific antibodies, the specific binding of an agglutinin (protectin Anti-AHP) of the edible snail (Helix pomatia) to structures with terminal N-acetylgalactosamine was used to demonstrate the antigen. The agglutinin was extracted from the albumen gland of the snail and purified by column chromatography. By means of glutardialdehyde it was coupled with ferritin or horesradish peroxidase. The investigations were done on strains of Streptococcus equisimilis and Streptococcus equi. Str. pyogenes (group A streptococci) was used as a control. On whole cells of group C streptococci the carbohydrate was demonstrated on the surface of the triple-layered cell wall. Near the cross-wall the carbohydrate seems to be more concentrated. In the presence of N-acety-D-galactosamine the labelling of the cell wall was inhibited. N-acetyl-D-glucosamine did not have such an effect. On isolated cell walls, both the outer and the inner surface were tagged. This suggests that the group-specific carbohydrate covers the peptidoglycan (mucopeptide) on both sides. The cytoplasmic membrane shows no reaction.

Agglutinins↗
PubMed1975

[Role of anaerobic streptococci in human pathology. Report I. Etiological significance of anaerobic streptococci in chronic tonsillitis].

The authors describe a method of isolation of anaerobic streptococci from the blood. A high seeding efficiency of anaerobic streptococci from the depth of the tonsils (75.1%) and from their surface (59.7%) and also from the blood (36%) pointed to the leading role of these microbes in the etiopathogenesis of chronic tonsillitis. In healthy individuals anaerobic streptococci are revealed (by culture method) on the surface of the tonsils but rarely (6%). Str. micros are the most incident in chronic tonsillitis (in 85.3% of cases-from the depth of the tonsils and in 77.5%-from the surface), whereas Str. anaerobius and Str. intermedius occur in individual cases only (8.4-7.5% and 6.3-15%, respectively). Pure culture of Str. micros was found in 36% of cases. Pathogenetic scheme of development of bacteriemia in chronic tonsillitis and rheumatism is presented. The isolated cultures were found to be resistant to the widely-used antibiotics.

Anti-Bacterial Agents↗
PubMed2004

Oral streptococci exhibit diverse susceptibility to human beta-defensin-2: antimicrobial effects of hBD-2 on oral streptococci.

We examined the antimicrobial effects of human beta-defensin-2 (hBD-2) on 17 species of oral streptococci to investigate the involvement of antimicrobial peptide activity in oral microflora development and the clinical use of the antimicrobial peptide for oral microflora control. Oral streptococci exhibit diverse levels of susceptibility to human beta-defensin-2 (hBD-2). Two major cariogenic bacterial species, Streptococcus mutans ( S. mutans) and S. sobrinus, were found to be susceptible to the peptide, indicating that it is a potential therapeutic agent for preventing dental caries. S. mitis exhibited the lowest susceptibility to the peptide. S. mitis is a major indigenous bacterium in the oral microflora, and our results suggest that it might possess a certain resistance mechanism against hBD-2.

Anti-Infective Agents↗
PubMed1966

The inhibition of streptococci by lactoperoxidase, thiocyanate and hydrogen peroxide. The effect of the inhibitory system on susceptible and resistant strains of group N streptococci.

1. The growth of the lactoperoxidase-sensitive Streptococcus cremoris 972 in a synthetic medium was inhibited by lactoperoxidase and thiocyanate. The glycolysis and oxygen uptake of suspensions of Strep. cremoris 972 in glucose or lactose were also inhibited. The lactoperoxidase-resistant Strep. cremoris 803 was not inhibited under these conditions but was inhibited in the absence of a source of energy. 2. Lactoperoxidase (EC 1.11.1.7), thiocyanate and hydrogen peroxide completely inhibited the hexokinases of non-metabolizing suspensions of both strains. The inhibition was reversible, hexokinase and glycolytic activities of Strep. cremoris 972 being restored by washing the cells free from inhibitor. The aldolase and 6-phosphogluconate-dehydrogenase activities of Strep. cremoris 972 were partially inhibited but several other enzymes were unaffected. 3. The resistance of Strep. cremoris 803 to inhibition was not due to the lack of hydrogen peroxide formation, to the destruction of peroxide, to the inactivation of lactoperoxidase or to the operation of alternative pathways of carbohydrate metabolism. 4. A ;reversal factor', which was partially purified from extracts of Strep. cremoris 803, reversed the inhibition of glycolysis of Strep. cremoris 972. The ;reversal factor' also catalysed the oxidation of NADH(2) in the presence of an intermediate oxidation product of thiocyanate and was therefore termed the NADH(2)-oxidizing enzyme. 5. The NADH(2)-oxidizing enzyme was present in lactoperoxidase-resistant streptococci but was absent from lactoperoxidase-sensitive streptococci.

Carbohydrate Metabolism↗
PubMed1989

Clinical and microbiological evaluation of miocamycin activity against group A beta-hemolytic streptococci in pediatric patients. Three years' incidence of erythromycin-resistant group A streptococci.

The authors have evaluated the incidence of Group A streptococci, and the prevalence of erythromycin-resistant strains in the years 1985/86/87 at the I.C.P. of Milan. The minimum inhibitory concentrations (MICs) for erythromycin, penicillin and miocamycin of 40 erythromycin-resistant strains were also studied (MIC50-MIC90 = 4.5-8, 0.015-0.015, 0.041-0.186 micrograms/ml respectively). A clinical trial with miocamycin vs. erythromycin in the elimination of Group A streptococci (67 patients) showed good and comparable efficacy for both the antibiotics.

Child↗
PubMed1963

THE CELLULAR ANTIGENS OF GROUP A STREPTOCOCCI; IMMUNOELECTROPHORETIC STUDIES OF THE C, M, T, PGP, E4, F, AND E ANTIGENS OF SEROTYPE 17 STREPTOCOCCI.

The immunoelectrophoretic characteristics of the known cellular antigens of serotype 17, Group A streptococci have been presented. These include C, M, T, and polyglycerophosphate. In addition, three hitherto undescribed antigens of serotype 17 have been encountered. The F antigen occurs in most serotype 17 strains, has a faster electrophoretic mobility than M, appears in acid, distilled water, and other extracts of harvested cells, is released from the cells in large quantity into the culture medium during growth when the pH is maintained at 7.3 or over, is probably protein in nature, and may play a minor role in mouse virulence of serotype 17 strains. Its antibodies do not confer bactericidal power on human blood. The E antigen is serotype-specific and is closely associated with the M antigen. The suggestion is made here that E is a part of the M molecule, acquiring independent electrophoretic mobility when separated from the rest of the M molecule by acid hydrolysis and carrying an antigenic determinant serologically distinct from the determinant on the rest of the M molecule. E can be recognized only by immunoelectrophoresis. Its role, if any, in virulence has not been established. The third antigen, E(4), is a non-serotype-specific antigen found in most serological groups and types of hemolytic streptococci. It is serologically related to polyglycerophosphate, but its chemical nature has not been determined. It appears to be unrelated to virulence.

Animals↗
PubMed2006

Molecular epidemiology of macrolide resistance in beta-haemolytic streptococci of Lancefield groups A, B, C and G and evidence for a new mef element in group G streptococci that carries allelic variants of mef and msr(D).

OBJECTIVES: To study the molecular mechanisms of erythromycin resistance in beta-haemolytic streptococci of Lancefield groups A, B, C and G. METHODS: Erythromycin-resistant clinical isolates from North East Scotland were collected over 2 years. Resistance phenotypes were determined by disc diffusion and MICs by Etest. Resistance genes mef, msr(D), erm(B) and erm(TR) were identified by PCR and mef and msr(D) were sequenced. RESULTS: Erythromycin resistance prevalence was 1.9% in group A streptococci (31 of 1625), 4.3% in group B (53 of 1233), 3.8% in group C (18 of 479) and 6.2% in group G (64 of 1034). The numbers of resistant isolates available were 26, 42, 9 and 52 in each group respectively. The majority of resistant isolates in groups A (57.7%, 15 of 26), B (88.1%, 37 of 42) and G (90.4%, 47 of 52) were MLS(B). The contribution of M phenotype was significant in groups C (77.8%, 7 of 9) and A (42.3%, 11 of 26). Group A isolates carried mef(A) and group B carried mef(E) exclusively. A mef sequence distinct from mef(A) and mef(E) was identified in group G and was associated with a new msr(D) sequence. These sequence variants appear to be part of a new genetic element that is inserted in the comEC gene. A bimodal distribution of erythromycin MICs was noted in erm(TR) isolates. CONCLUSIONS: The results demonstrate significant differences in the mechanisms of macrolide resistance amongst different Lancefield groups in the same geographical area. New sequences show that resistance mechanisms are still evolving.

Alleles↗
PubMed1997

Viridans streptococci in blood cultures. Can we see any patterns of species related to patient category? Review of 229 cases of positive cultures with viridans streptococci.

We present a review of 229 blood cultures with viridans streptococci collected during a period of eight and a half years from 1986 to 1994 at a teaching hospital in Sweden. The clinical significance of the growth of viridans streptococci is always uncertain, since these bacteria can be contaminants from the skin flora. Growth in more than one culture bottle strengthens the clinical value of the finding. The question was whether species identification might also help in the assessment of the clinical relevance of the finding. The results show that Streptococcus mitis occurs significantly more frequently in blood cultures from the departments dealing with cancer patients. Even with polymicrobial growth in blood cultures, S. mitis should be considered a pathogen of clinical relevance, not a contaminant.

Blood↗
PubMed2001

[Long-term observations on type distribution of clinical isolates of beta-hemolytic streptococci in Sapporo. II. Type distribution of Group B streptococci during the fifteen-year period between 1985 and 1999].

During the fifteen-year period between 1985 and 1999, a total of 1,985 strains of Group B Streptococci isolated in Sapporo City General Hospital were classified by agglutination method. The results were summarized as follows: 1. Type distribution of 1,513 isolates of group B streptococci in and after 1992 when type NT6 and type JM9 were started to be typed for the first time was as follows; according to rate isolation it was in the order of type NT6 (412 strains 27.3%), JM9 (257 17.0%), III (220 14.5%), Ia (182 12.0%), following IV, Ib, V and II. 2. As for proportion of origin-materials of isolates, vaginal discharge was 49.5%, urine 26.8%, throat swab 6.8%, sputum 6.6%, pus or exudate 4.2%, blood or spinal fluid 1.8% and stomach contents was 1.3%. A proportion of vagina-origin strains went up to 55% in the second half (1992-1999) from 23% in the first half (1985-1991). 3. In type distribution of isolates in terms of origin-materials, the proportion of type III was significant by high in the stomach contents and blood and spinal fluid. Proportion of type Ia was significant by high in the sputum or throat swab. 4. Thirteen out of 28 strains (46.4%) from newborns were type III; 3 out of 4 (75.0%) from spinal fluid, 5 out of 10 (50.0%) from blood, 5 out of 13 (35.7%) from stomach contents.

Adult↗
PubMed1991

Virulent human strains of group G streptococci express a C5a peptidase enzyme similar to that produced by group A streptococci.

Specific proteolytic destruction of the human chemotaxin, C5a, is a property of group A and B streptococcal pathogens. Here we show that virulent group G streptococci from human sources also express C5a peptidase activity. The enzyme responsible for this activity is approximately the same size as and is antigenically similar to that produced by group A streptococci. On the basis of Southern hybridization analysis with an internal fragment of the group A C5a peptidase gene (scpA) as a probe, a copy of this gene was found in the genome of all group G human isolates tested. Comparison of partial restriction maps of scpA and scpG revealed significant similarity between the two genes. Group G strains isolated from dogs and cows were found to lack C5a peptidase activity and did not hybridize to the scpA-specific probe. The association of this activity with three streptococcal species suggests that elimination of phagocyte chemotactic attractants is a more universal virulence mechanism than originally anticipated.

Adhesins, Bacterial↗
PubMed1993

The association of mutans streptococci and non-mutans streptococci capable of acidogenesis at a low pH with dental caries on enamel and root surfaces.

Coronal dental plaque from each of 12 caries-positive subjects (Group I) was pooled from "white spot" tooth surface areas and, separately, from sound surface areas; sound surface areas in each of 18 caries-free subjects (Group II) were sampled similarly. Two samples, one consisting of material from a root-surface lesion and another of plaque from a sound root-surface area, were obtained from each of another 10 subjects (Group III). The samples from Groups I and II were evaluated for: (1) pH-lowering potential in vitro with dispersed plaque suspensions, excess glucose supply, and a 60-minute test; (2) the levels of mutans streptococci (MS) and lactobacilli; and (3) the distribution of the predominant non-mutans streptococci (non-MS) according to their final pH in glucose broth; only microbial analysis was done for the Group III samples. The levels of the MS were generally positively associated with caries. A weaker positive association was found for the levels of those non-MS capable of acidogenesis at low pH (final pH < 4.4). The latter generally far outnumbered the MS in all types of samples. The levels of lactobacilli were nearly always very low. The pH-lowering potential (final pH and pH drop rate) was higher for plaque from "white spot" areas than for plaque from sound surface areas (Group I). The samples from caries-free subjects (Group II), however, exhibited a pH-lowering potential which was not significantly different from that of both types of samples from the caries-active subjects (Group I).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1983

Chlorhexidine for prevention of neonatal colonization with group B streptococci. I. In vitro effect of chlorhexidine on group B streptococci.

Forty-three strains of group B streptococci (GBS) of types Ia, Ib, II and III were tested for susceptibility to chlorhexidine in concentrations ranging from 256 to 0.25 mg/l using the agar and tube dilution methods. The strains showed minimum inhibitory concentration (MIC) values ranging from 0.5 to 1 mg/l. Serum added to the test medium (50%) increased the MIC values to 4-8 mg/l, while amniotic fluid (50%) had almost no effect, increasing the values to 1-2 mg/l. The minimum bactericidal concentration (MBC) ranged from 1 to 5 mg/l. The killing kinetics were related to the concentration of chlorhexidine and the length of exposure. For example, at a concentration of 63 mg/l, 7 h were required for a bactericidal effect in broth, as compared to 1 h at 500 mg/l chlorhexidine. 200 mg/l chlordexidine had no effect on the adherence of two GBS strains to vaginal epithelial cells, and no effect on the phagocytosis of GBS with mouse peritoneal macrophages.

Bacteriolysis↗
PubMed1983

Chlorhexidine for prevention of neonatal colonization with group B streptococci. II. Chlorhexidine concentrations and recovery of group B streptococci following vaginal washing in pregnant women.

The effect of a single washing of the urogenital tract with 0.5 g/l chlorhexidine was studied in 6 women in weeks 38-40 of pregnancy, among whom 5 were carriers of group B streptococci in urethra and/or cervix. The chlorhexidine concentrations varied between 25 and 200 mg/l during the first hour after washing in 5 of the 6 women, whereas one patient showed concentrations below 25 mg/l. With the exception of one patient, all individuals showed concentrations less than 25 mg/l at 3-24 h after washing. A clear suppression of the number of colony-forming units of GBS was already apparent after 60 min and was still evident 6 h after chlorhexidine washing.

Carrier State↗
PubMed1951

Studies on non-hemolytic streptococci isolated from the respiratory tract of man; the antigenic basis for type specific reactions with streptococcus salivarius and non-levan-forming streptococci.

The type specific immunological properties of certain non-hemolytic streptococci, including Str. salivarius type I and type II, present in the respiratory tract of human beings appear to be dependent upon the presence of capsular polysaccharides. The levans formed from sucrose by Str. salivarius (encapsulated S cells or non-encapsulated R variants), or by cell-free enzymes derived from these microorganisms, are indistinguishable immunologically and show no evidence of type specificity. Such levans appear to be immunologically distinct from and unrelated to the capsular polysaccharides of the microorganisms which produce them.

Fructans↗
PubMed1952

Preparation and properties of a protein (R antigen) occurring in streptococci of group A, type 28 and in certain streptococci of other serological groups.

A group A, type 28 protein antigen, resistant to tryptic digestion and previously considered to be a type-specific substance, was purified and its chemical and immunological properties studied. This protein lacks the characteristic properties of a type-specific M antigen since it is apparently unrelated to virulence and does not induce the formation of protective antibodies although precipitins are readily produced. It is designated the R antigen. The R antigen in addition to occurring in "type 28" group A strains also occurs in some strains of streptococci of other serological groups. Protective antibodies, distinct from precipitins for the R antigen, are present in "type 28" antibacterial sera. The antigens responsible for protection have not been identified, and it is possible that several different types may be included among strains designated as type 28 on the basis of the R antigen. The purified R antigen is phosphorus-free and has a sulphur content of 1.04 per cent. In the ultraviolet a maximum absorption was obtained at a wave length of 280 mmicro and a minimum at 254 mmicro. Electrophoretically the R antigen was found to be 95 per cent homogeneous at most pH values, but at pH 4.6 the main peak separated into two peaks of approximately equal areas, both containing serologically active material. The interpretation of this finding is at present uncertain. The isoelectric pH was at 4.5 in sodium acetate buffer of 0.1 ionic strength. The purified R antigen sedimented in the ultracentrifuge as a single boundary.

Antibodies↗
PubMed2001

[Long-term observations on type distribution of clinical isolated of beta-hemolytic streptococci in Sapporo. I. T-type distribution of group A hemolytic streptococci during the thirty one-year period between 1969 and 1999].

During the thirty one-year period between 1969 and 1999, a total of 6,876 strains of group A streptococci isolated in Sapporo City General Hospital were classified by T-agglutination method. This research consisted of 5,866 strains of scarlet fever-patients (scarlet fever-strains), 450 of child-patients (child-strains), 141 of adult-patients (adult-strains) and 409 strains of the indistinct. The results were summarized as follows: 1. Total of 6,866 strains were classified to sixteen kinds of T-types such as T12 (44.1%), T4 (21.7%), T1 (9.2%), T6 (4.4%), T3 (2.8%), T22 (2.1%), T18 (1.9%), T28 (1.6%) & others. This pattern of type distribution, three prevailing types of T12/T4/T1, have been reported in other areas generally. But original increase of isolation rates of strains of some T-types as T6, for example, also appeared in Sapporo. 2. Long-term observations demonstrated that the isolation rates of individual T-type, especially T4 or T1, had been forming a small epidemic-wave having a 4 to 8 year-interval and these of type T3 or type T6 on the other hand were repeating sudden prevalence every several years. 3. The isolation rates of type T12 or type T4 in scarlet fever-strains, were significantly higher than in child-strains or adult-strains. It was shown that Type T1 was distributed widely irrespective of patient-group and age-group. It was also characteristic to be distributed to many T-types in adult-strains.

Adult↗