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PubMed2004

Structure of the putative DNA-binding protein SP_1288 from Streptococcus pyogenes.

The crystal structure of the putative DNA-binding protein SP_1288 (gi/15675166, also listed as gi/28895954) from Streptococcus pyogenes has been determined by X-ray crystallography to a resolution of 2.3 A using anomalous diffraction data at the Se peak wavelength. SP_1288 belongs to a family of proteins whose cellular function is associated with the signal recognition particle; no structural information has been available until now about the members of the family. Crystallographic analysis revealed that the overall fold of SP_1288 consists exclusively of alpha-helices and that 75% of the structure has good similarity to domain 4 of the sigma subunit of RNA polymerase. This suggests its possible involvement in the biochemical function of transcription initiation, which includes interaction with DNA.

Amino Acid Sequence↗
PubMed1993

The serotypes of Streptococcus pyogenes present in Britain during 1980-1990 and their association with disease.

A total of 16,909 cultures of Streptococcus pyogenes (Lancefield group A) isolated in Britain during 1980-90 were examined for T- and M-protein antigens. One or other M antigen was detected in 92.6% of the strains. The numbers of isolates of some serotypes, such as M3 and M12, did not show great variation from year-to-year, whereas there were nationwide epidemics, extending over several years, caused by strains of serotypes M1 and M49. Isolates of serotypes M1 and M3 were associated particularly with invasive disease and fatal infections. Representatives of serotypes M80, M81 and the provisional types PT180, PT1658 and PT5757 were isolated most often from cases of pyoderma. Erythromycin resistance was detected in 30 serotypes but one half of all of the resistant isolates belonged to serotype M4.

Bacteremia↗
PubMed1991

Antitumor action of an acidic glycoprotein (SAGP) from Streptococcus pyogenes in mice.

We have shown that an acidic glycoprotein (SAGP) isolated from a cell-free extract of Streptococcus pyogenes (Su strain) prolonged the life-span of Ehrlich ascites carcinoma (EAC)-bearing mice. The present study shows that the life-span prolonging effect of SAGP in EAC-bearing mice was reduced by whole body X-irradiation before EAC inoculation. SAGP (500 micrograms protein/mouse/day X 4, i.p.) also showed a life-span prolonging effect (T/C (%) = 169) on Meth A fibrosarcoma (Meth A)-bearing mice, but the effect of SAGP was abrogated by an i.p. pretreatment of the host with carrageenan, an antimacrophage agent. The spleen cells from the Meth A-inoculated and SAGP-treated mice were found to have a considerable cytostatic activity by a 3H-thymidine incorporation assay. But the activity disappeared in the presence of carrageenan. These results suggest that the in vivo antitumor effects of SAGP are mediated through its immunomodulating action.

Adjuvants, Immunologic↗
PubMed1996

Epidemiological observations on Streptococcus pyogenes serotype T1 in Uppsala county, Sweden 1989-1995.

During the period 1989-1995, the T-type distribution pattern of Streptococcus pyogenes pharyngeal isolates was compared with the annual incidence of culture-verified S. pyogenes bacteremias in Uppsala county, Sweden. An exceptional increase in the number of S. pyogenes bacteremias was seen in 1994. During the study period, the annual number of blood culture isolates was shown to correlate with the proportion of S. pyogenes serotype T1 among pharyngeal isolates.

Bacteremia↗
PubMed1994

Streptococcus pyogenes type IIa IgG Fc receptor expression is co-ordinately regulated with M protein and streptococcal C5a peptidase.

Streptococcus pyogenes is an important agent of human disease which expresses a variety of proteins and polysaccharides on its surface. Surface molecules M protein and streptococcal C5a peptidase (SCPA) are virulence factors which undergo concurrent phase variation and are under the co-ordinate control of the virR locus. Most opacity factor-positive (OF+) strains of S. pyogenes also express IgG Fc receptor proteins on their surface. These studies were initiated to determine whether the type IIa Fc receptor on the surface of S. pyogenes phase-varies with members of this regulatory circuit. Several methods were applied to M+ and M- variant strains to evaluate this question. (i) Immunoblot assays quantified Fc receptors on whole cells by using human IgG myeloma protein and receptor-specific antibody. M+ strains bound IgG and antibody specific for Fc protein, whereas M- strains did not. (ii) Enzyme-linked immunosorbent assays quantified Fc receptor antigen expression and showed that M+ strains produce more Fc receptor protein than their M- derivatives. (iii) Quantitative RNA dot blots showed that the message for the Fc receptor gene (fcrA) was reduced in M- strains. RNA from M+ strains hybridized to the fcrA probe at a greater dilution than that from their M- counterparts. (iv) Northern hybridization showed that the fcrA transcript is 1200 nucleotides in size and distinct from transcripts for M and SCPA proteins. These data are evidence for the co-ordinate transcriptional control of the Fc receptor, M protein, and SCPA and show that these proteins co-ordinately phase-vary within the same regulatory circuit.

Adhesins, Bacterial↗
PubMed1994

Streptococcus pyogenes type M12 protein shows selective binding to some human immunoglobulin G3 myeloma proteins.

Purified, recombinant M12 protein from Streptococcus pyogenes CS24 has recently been demonstrated to bind human immunoglobulin G3 (IgG3). The binding site for IgG has been localized to an internal peptide encoded by a PvuII fragment of the gene emm12. We have investigated the ability of an isolated recombinant M12 protein consisting of the peptide encoded by the PvuII fragment to bind various monoclonal human IgG3 myeloma proteins representing a number of both Caucasian and Oriental IgG3 Gm(allotypic) phenotypes. Of nine Caucasian IgG3 myeloma proteins, only two bound strongly to the recombinant M12 protein in enzyme-linked immunosorbent assays. The allotypic phenotypes of the reactive proteins were IgG3m(b+)(g-) and IgG3m(b-)(g+). No binding was seen for seven IgG3 myeloma proteins of Oriental origin with G3m(st+)(u-)(b+)(g-), G3m(st-)(u+)(b+)(g-), G3m(st-)(u+)(b-)(g+), and G3m(st-)(u-)(b-)(g+) phenotypes. The binding of human IgG3 to M12 protein seems to be related to features other than its Gm allotypic markers. Selective reactivity of IgG3 myeloma proteins with M12 protein may provide another way to subclassify human IgG3 molecules. The biological significance of the selective reactivity is not known.

Animals↗
PubMed2005

Protective immunity against Streptococcus pyogenes challenge in mice after immunization with fibronectin-binding protein.

BACKGROUND: Surface-associated fibronectin (Fn)-binding proteins of Streptococcus pyogenes play an important role in the bacterial invasion of epithelial cells. We examined the functional domain and protective antigenicity of the Fn-binding protein FbaA. METHODS: To investigate the functional domain of FbaA and its localization on S. pyogenes, a series of recombinant glutathione S-transferase (GST)-truncated FbaA proteins was used for immunofluorescent microscopy, ligand blotting, and Biacore analyses. Mice were immunized with the truncated proteins for the determination of the immunogenic domains that contribute to protection against S. pyogenes infection. RESULTS: Ligand-blotting and Biacore analyses revealed that the FbaA fragments harboring a proline-rich repeat domain (RD), but not the N- and C-terminal regions, possessed Fn-binding activity. Immunofluorescent microscopy findings showed that the N terminus and RD were exposed to external regions, which suggests that the RD serves as a Fn-binding element on live organisms. Specific antibodies were efficiently induced in N terminus- and RD-immunized mice and demonstrated bactericidal activity against S. pyogenes in vitro. FbaA-immunized mice survived significantly longer than GST-immunized mice after infection with serotype M1 and M49 strains expressing FbaA. CONCLUSION: The Fn-binding RD and N terminus of FbaA are potential vaccine candidates for M1 strains of S. pyogenes infection.

Adhesins, Bacterial↗
PubMed1985

Role of fibronectin in attachment of Streptococcus pyogenes and Escherichia coli to human cell lines and isolated oral epithelial cells.

We studied the binding of cells of Streptococcus pyogenes and mannose-sensitive Escherichia coli to human fibroblast cell lines and isolated buccal epithelial cells in relation to the cell-associated endogenous or exogenous fibronectin of the host cells. The degree of bacterial binding to cell lines correlated directly with the content of endogenous fibronectin on the surface of the cultured cells, although the correlation was better with S. pyogenes than with E. coli. The addition of exogenous plasma fibronectin to the cell lines or oral epithelial cells enhanced binding of S. pyogenes but suppressed binding of mannose-sensitive E. coli. These findings are consistent with the notion that exogenously acquired fibronectin on the surface of host cells modulates bacterial adherence by providing attachment sites for certain pathogens, such as S. pyogenes, and by blocking receptors for others, such as mannose-sensitive E. coli.

Adhesiveness↗
PubMed2001

Characterization of the domain of fibronectin-binding protein I of Streptococcus pyogenes responsible for elicitation of a protective immune response.

Fibronectin-binding protein I (SfbI) represents a major adhesin of Streptococcus pyogenes. Mice were intranasally immunized with recombinant proteins spanning different portions of SfbI to identify the minimal fragment able to elicit a protective response against a lethal challenge with S. pyogenes. The strongest cellular responses and the highest levels of antigen-specific secretory immunoglobulin A (IgA) were detected in mice immunized with the fibronectin-binding region of SfbI. In contrast, animals vaccinated with a polypeptide spanning the aromatic and proline-rich regions showed the highest titers and fastest IgG response in serum. Vaccination with either SfbI without a membrane anchor and signal peptide or a polypeptide encompassing its fibronectin-binding regions resulted in efficient protection against heterologous challenge (60% and 80%, respectively), whereas the use of a polypeptide lacking this region conferred marginal protection (10%) with respect to the control group (0%). These results demonstrate that the fibronectin-binding region of SfbI is a promising candidate antigen for developing anti-S. pyogenes vaccines.

Adhesins, Bacterial↗
PubMed1998

Fosfomycin reduces CD15s-related antigen expression of Streptococcus pyogenes.

We have previously shown the immunological mimicry of human sialyl-Lewis(x) (CD15s) by a surface antigen of Streptococcus pyogenes. This mimicking surface antigen may act as a ligand to the selectin family and may induce antibody production against CD15s on host cells, suggesting a possible role in the pathogenesis of S. pyogenes. In this study, the effects of antibiotics on the CD15s-related antigen expression of S. pyogenes were examined at a concentration below the MIC (sub-MIC). The amounts of CD15s on the surfaces of S. pyogenes cells and on the surfaces of S. pyogenes biofilms were determined by a whole-cell enzyme-linked immunosorbent assay and by laser scanning fluorescence microscopy, respectively, by using an anti-CD15s monoclonal antibody. At the sub-MICs, fosfomycin (1R,2S-1,2-epoxypropyl phosphonic acid), its enantiomer (1S,2R-1,2-epoxypropyl phosphonic acid), and benzylpenicillin significantly inhibited the CD15s expression of all strains studied. The effects of fosfomycin and its enantiomer on biofilms were also observed by scanning electron microscopy. Incubation of S. pyogenes with the sub-MIC of fosfomycin or its enantiomer, which has no antibacterial activity, reduced the amount of CD15s on the biofilm surface and made it smooth. These results suggest that fosfomycin or its enantiomer might be useful for preventing S. pyogenes adherence to human CD15s receptors and the resulting immunological pathogenicity.

Anti-Bacterial Agents↗
PubMed1994

rRNA gene restriction patterns of Streptococcus pyogenes: epidemiological applications and relation to serotypes.

The use of rRNA gene restriction fragment length polymorphism analysis (ribotyping) to subtype Streptococcus pyogenes strains was investigated. Sixty-eight S. pyogenes strains, including 17 reference strains and 51 isolates from blood, acute or chronic pharyngitis, and food-borne outbreaks, were characterized by determination of both their rDNA restriction fragment length polymorphism profiles and their serotypes (T and M). Total DNA was cleaved with five selected restriction enzymes and then probed with a digoxigenin-labeled stretch of 1,063 bp hybridizing with 16S rRNA genes. Fifteen and nine distinct patterns were generated with SacI and XhoI, respectively, and five patterns were generated with each of the three additional restriction enzymes. With the combination SacI-XhoI, a total of 21 distinct ribotypes were obtained among the 68 isolates. This number was not increased by the results obtained with the other restriction enzymes. All strains tested were typeable. All isolates from each food-borne outbreak belonged to the same ribotype, and all isolates (pre- and posttreatment) from each child with chronic pharyngitis also belonged to the same ribotype, suggesting antibiotic treatment failures. A discriminatory index was calculated for the 47 isolates which were epidemiologically unrelated, using the Hunter-Gaston formula. This index reached 0.955 when the combination SacI-XhoI was used, showing the good discriminatory power of this typing method. Therefore, ribotyping proved to be a molecular method of interest to subtype S. pyogenes. Moreover, there was some correlation between ribotyping and serotyping, as several ribotypes were related to a unique distinct M serotype.

Child↗
PubMed2002

Prevalence of antimicrobial resistance in Haemophilus influenzae, Streptococcus pneumoniae, Moraxella catarrhalis and Streptococcus pyogenes: results of a multicentre study in Turkey.

The in vitro activities of several antimicrobial agents against clinical isolates of Streptococcus pneumoniae (283), Haemophilus influenzae (272), Moraxella catarrhalis (179) and Streptococcus pyogenes (256) were determined in a multicentre study with the participation of five hospitals from four cities in Turkey. Penicillin resistance in S. pneumoniae was evaluated using the E-test and the remaining agents by disk diffusion. For S. pneumoniae overall 25.8% of the isolates were intermediately and 3.9% were highly resistant to penicillin and resistance to chloramphenicol, azithromycin and trimethoprim/sulphamethoxazole (TMP/SMX) was 3.8, 2.1 and 55.4%, respectively. Seven percent of H. influenzae produced beta-lactamase and all were susceptible to cefotaxime and azithromycin; the highest rate of resistance, 23.5%, was for TMP/SMX. Eighty-one percent of M. catarrhalis isolates produced beta-lactamase, 18.4% were resistant to TMP/SMX and all were susceptible to sulbactam/ampicillin combination. Resistance to chloramphenicol and azithromycin of S. pyogenes was 2.2 and 1.9%, respectively.

Anti-Bacterial Agents↗
PubMed1999

Characteristics in adherence of streptococci and Staphylococcus aureus isolated from various infective skin lesions: serum IgA decreases adherence of Streptococcus pyogenes but not Staphylococcus aureus.

We characterized adherence of streptococci and Staphylococcus aureus strains isolated from various infective skin lesions in terms of hydrophobicity, negative charge, tube adherence, slime production, and influence on adherence to coverslips by plasma and serum immunoglobulins. High hydrophobicity was more frequently observed in Streptococcus pyogenes strains than in Streptococcus agalactiae strains (P < 0.01) and S. aureus strains (P < 0.001) and slime production was more frequently observed in S. agalactiae strains than in S. pyogenes strains (P < 0.05). Serum IgA decreased adherence to coverslips of S. pyogenes strains but not that of S. aureus strains.

Bacterial Adhesion↗
PubMed2004

A rapid increase in macrolide resistance in Streptococcus pyogenes isolated in Poland during 1996-2002.

OBJECTIVES: The aim of this study was to investigate Polish clinical isolates of Streptococcus pyogenes collected during a 7 year period using phenotypic and genotypic techniques. METHODS: A total of 816 isolates of S. pyogenes recovered from 33 medical centres in Poland were tested for their susceptibility to various antimicrobial agents. Erythromycin-resistant isolates were analysed by PFGE, multilocus sequence typing and emm typing methods. RESULTS: The tetracycline resistance rate was high (43%) among all S. pyogenes strains. Ninety-eight (12%) isolates were resistant to erythromycin. A low prevalence of the M phenotype (5.1%) associated with the presence of the mef(A) gene was found. All the isolates of the iMLSB phenotype harboured the erm(TR) gene. Out of the cMLSB isolates, 71.4% and 28.6% carried erm(TR) and erm(B), respectively. All isolates with erm(B) were resistant to telithromycin. PFGE analysis discerned 13 different patterns, A-N, with two predominant PFGE profiles--A (41 isolates) and B (25 isolates)--that in multilocus sequence typing corresponded, respectively, to a novel sequence type (ST) 367 and ST63. Overall, the representatives of these clones accounted for >90% of isolates of the iMLSB phenotype. CONCLUSIONS: A significant increase in erythromycin resistance was observed among clinical S. pyogenes collected in Poland over a 7 year period driven by the spread of two epidemic clones.

Anti-Bacterial Agents↗
PubMed2000

[Streptococcus pyogenes: penicillin and erythromycin susceptibility in the cities of Neuquen and Cipolletti].

Penicillin resistance has not yet been detected in Streptococcus pyogenes. However macrolide-resistant streptococci have emerged in several countries. Only low rates of erythromycin-resistant S. pyogenes were reported in Argentina, with the exception of a 11.1% observed in Mendoza. The aim of the present study was to determine the susceptibility to penicillin and to erythromycin of 251 consecutive clinically-significant isolates of S. pyogenes obtained from four centers of Cipolletti and Neuquén during the period April-December 1998. The double disk test with erythromycin and clindamycin disks was employed as a screening method to detect ERY-resistant streptococci and to determine the phenotype of macrolide resistance. Disk diffusion was also employed for determining penicillin susceptibility. Macrolide-resistant isolates were also tested for penicillin, ceftriaxone, erythromycin, clindamycin and azithromycin susceptibility by the agar dilution method. Additionally they were also tested for erythromycin susceptibility by E-test (AB Biodisk, Solna, Sweden). All streptococci studied were susceptible to penicillin and thirty of them (12.0%) were resistant to erythromycin. All these resistant isolates were also resistant to azithromycin but susceptible to ceftriaxone and clindamycin. They showed the phenotype M (probably efflux-mediated mechanism) and the MICs of erythromycin ranged between 8 and 16 micrograms/ml. According to these results we conclude that in spite of universal susceptibility to penicillin in S. pyogenes, macrolide resistance is a matter of concern in Neuquén and Cipolletti. At least in those cities it appears to be necessary to routinely perform macrolide susceptibility tests in beta-hemolytic streptococci.

Anti-Bacterial Agents↗
PubMed2004

Macrolide-resistant genes of Streptococcus pyogenes isolated from the upper respiratory tract by polymerase chain reaction.

The growing number of macrolide-resistant strains of Streptococcus pyogenes is an increasing problem worldwide. This study evaluated 300 clinical isolates obtained from the upper respiratory tract. Minimal inhibitory concentrations (MICs) of erythromycin (EM), azithromycin (AZM), and clindamycin (CLDM), serotypes, and macrolide resistance genes of mefA, ermB, and ermTR were determined. The genetic relationship of EM-resistant and susceptible strains were also analyzed by pulsed-field gel electrophoresis (PFGE). Twenty-nine (9.7%) EM-resistant S. pyogenes were identified. Of the 29 strains showing resistance to EM, 22 isolates (7.3%, MIC 3.13-12.5 microg/ml) expressed the mefA gene. The predominant serotypes among the mefA-positive isolates were T12, emm9 or T25, emm75-1. The two isolates (0.1%) that possessed the ermB gene were highly resistant to EM (MIC > 100 microg/ml). The remaining five strains (1.6%) possessed the ermTR gene (MIC 3.13-100 microg/ml). Restriction fragment polymorphism analyzed by pulsed-field gel electrophoresis (PFGE) by SmaI and ApaI digestions showed several clones among the mefA-positive S. pyogenes. Our findings suggest that the mefA gene is the predominant mechanism for macrolide resistance and that this gene is horizontally transmitted among M phenotype strains of S. pyogenes. Consequently, macrolides would not be the first drug of choice for treatment of tonsillitis and other S. pyogenes-related diseases. Physicians and researchers need to take into consideration the macrolide resistance of some strains of S. pyogenes.

Adolescent↗