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PubMedDate not supplied

[Frequency of genes speA, speB, and speC in Streptococcus pyogenes strains and the identification of the infective agent by polymerase chain reaction].

In cultures of S. pyogenes isolated from patients and carriers in different territories of the Russian Federation the genes of erythorogenic toxins A, B and C (speA, speB and specC) were detected. The possibility of the identification of S. pyogenes by means of PCR on the basis of primers to erythrogenic toxin B was determined. Gene speB was detected in all S. pyogenes cultures under study and proved to be species specific. Genes speA and speC were detected, respectively, in 29.4% and 9.35% of the S. pyogenes cultures under study. A test system for the identification of S. pyogenes on the basis of primers to gene speB was developed. The prospects for the detection of genes speA and speC for intraspecific typing of this infective agent were evaluated.

Bacterial Proteins↗

PubMedDate not supplied

[The M-protein heterogeneity of Streptococcus pyogenes strains isolated from clinically healthy and ill children in an organized collective].

The study of the kinetic curves of the lysis of group A S. pyogenes cell-walls (cells), serovars 29 and 12 M, variants M+ and M-; with endo-N-acetyl-muramidase revealed that the kinetics of the lysis of virulent and avirulent strains was different: variant M- was lyzed faster than M+. This difference in the cell-wall lysis of both variants made it possible to use this method for the identification of M+ and M- states of the strains. 18 group A S. pyogenes cultures were studied. The cultures isolated from healthy and sick children in an organized group belonged to variants both M+ and M-. The pepsin fragments of M-proteins of group A S. pyogenes, type M 1, isolated in dynamics from a carrier and a patient, were studied. Their amino acid compositions were studied, and differences between them were established. The data thus obtained indicate that heterogeneity is characteristic of both the surface structure of streptococci and the individual components of their surface, in particular, M-protein.

Amino Acids↗

PubMed1994

[Enzyme immunoassay test system for detection of antibodies to Streptococcus pyogenes group-specific A polysaccharide in blood droplets on paper].

An enzyme immunoassay-based test system has been developed to assess the level of specific antibodies to A polysaccharide which permits analysis of material (droplets of native sera or blood eluate) collected on filter paper. Special variants of the test system permit separate detection of IgA, IgG, and IgM antibodies. The test system is fit for clinical and epidemiologic studies.

Adolescent↗

PubMed1993

[The return of severe infections caused by Streptococcus pyogenes].

Two patients with severe group A streptococcal infection associated with a toxic shock-like syndrome are described. Both isolates produced the pyrogenic exotoxin B. Since 1987 there have been many reports of these severe streptococcal infections. In order to know the incidence in the Netherlands, isolates from patients with severe streptococcal infection have to be serotyped (types of M-protein) and tested for streptococcal toxin production, and serum antibody levels have to be determined.

Adolescent↗

PubMed1989

[Hydrophobic quality and the level of surface proteins in the cell wall of cultures of Streptococcus pyogenes isolated from clinically healthy children from an organized collective].

The Str. pyogenes cultures isolated from clinically healthy children were found to have different hydrophobic properties and quantities of surface cell wall proteins, and to exhibit pronounced variability in these signs in time. Most studied cultures lacked a correlation between their hydrophobic properties and the quantity of surface proteins of the cell wall.

Absorption↗

PubMed1980

Production of group C streptococcus phage-associated lysin and the preparation of Streptococcus pyogenes protoplast membranes.

Optimum conditions of pH, temperature and multiplicity of bacteriophage infection for the production of phage-associated lysin from Group C streptococci were defined. Lysin obtained by the optimum method was used to make protoplast membranes of Group A type 12 streptococci. These membranes consistently contained very low concentrations of rhamnose, indicating minimal cell wall contamination. The development of such a reproducible technique for the preparation of protoplast membranes will permit more meaningful studies on the involvement of these membranes in the pathogenesis of acute post-streptococcal glomerulonephritis.

Bacteriolysis↗

PubMed1996

Immune response to Streptococcus pyogenes and the susceptibility to psoriasis.

Monoclonal antibodies directed against type 12 Group A streptococcal cell wall antigens cross-react with nuclei and cytoplasm of cells from skin and synovium from controls, uninvolved skin of psoriatics and psoriatic plaques. Patients with psoriasis had high serum titres of antibody against the M12 (C-region) streptococcal antigen compared to controls. An abnormal immune response directed against a "self' antigen after initiation by Group A streptococcal infection may play an important role in the exacerbation or development of psoriasis.

Antibodies, Monoclonal↗

PubMed1997

Conversion of M serotype 24 of Streptococcus pyogenes to M serotypes 5 and 18: effect on resistance to phagocytosis and adhesion to host cells.

In this study, we utilized recombinant strains expressing the M5 and M18 proteins and M- mutants of group A streptococci to compare the abilities of these M proteins to confer resistance to phagocytosis and to mediate adhesion to host cells. The data indicate that the M5 and M18 proteins can confer resistance to phagocytosis, that fibrinogen is required for this resistance, and that these M proteins can mediate adhesion to HEp-2 cells.

Antigens, Bacterial↗

PubMed1975

Complex surveillance of Streptococcus pyogenes. II. Resistance in human blood and bactericidal activity receptors of field and collection streptococci.

A comparative study of a series of 31 epidemic streptococci and 36 collection M protein producers showed no statistically significant difference in their resistance in human blood. Even highly resistant field strains did not produce M protein (as the main bactericidal activity receptor) under laboratory conditions, however, although under natural conditions they left an anti-M response in the exposed population. Streptococcal resistance is not generally associated with M protein, but is influenced by another factor.

Antibodies, Bacterial↗

PubMed1994

[Toxic shock syndrome caused by Streptococcus pyogenes].

Necrotizing fasciitis and myositis due to Lancefield group A beta-haemolytic streptococcal infection is a medical emergency. Survival depends on aggressive early wound management as well as high-dose intravenous antibiotics. We report about a 28-year-old man with fulminant necrotizing fasciitis and myositis of his right arm, in whom many features of the toxic shock syndrome were present, including profound hypotension and renal failure. After extensive surgical debridement with amputation of his arm in combination with high-dose intravenous penicillin G the patient recovered from this serious infection.

Adult↗

PubMed1993

[Pharyngo-tonsillitis and necrosing submaxillary adenitis caused by Streptococcus pyogenes associated with toxic shock syndrome in children from Mexico City].

We report on six previously healthy children between nine months and nine years old, who suffered streptococcal faringoamigdalitis and cervical adenitis with scarlet fever and toxic shock syndrome; four of them died in a fulminant course and two survived. These patients behave similarly to others reported from United States of America, England and Australia, and in similar way these clinical entity could be due to bacterial pyrogenic exotoxins according to the clinical fulminant course.

Child↗

PubMed1976

Characterization of the antibiotic resistance plasmid ERL1 from Streptococcus pyogenes.

The streptococcal plasmid ERL1 determining inducible resistance to erythromycin, lincomycin, and staphylomycin S was isolated by dye-buoyant density centrifugation and shown to have a molecular weight of about 17.5 Mdal, as revealed by sedimentation through neutral sucrose gradients. In SM60 cells entering the stationary phase its covalently closed circular form was present to the extent of 5 copies per chromosomal genome equivalent, ERL1 was subject to the DNA restriction and modification mechanism discovered in strain 56188. It did not appear to exercise restriction of phage DNA but mediated a partial release of the restricted growth of A25.

DNA, Bacterial↗

PubMed2002

Erythromycin-resistant pharyngeal isolates of Streptococcus pyogenes recovered in Italy.

Three classes of macrolide resistance phenotypes and three different erythromycin resistance determinants were found among 127 erythromycin-resistant group A streptococcal (GAS) isolates recovered from 355 (35.8%) pediatric pharyngitis patients in Rome, Italy. According to emm and sof sequence typing results, erythromycin-resistant isolates comprised 11 different clonal types. Remarkably, 126 of the 127 macrolide-resistant isolates were serum opacity factor (sof) gene positive. These data suggest a strong association between macrolide resistance and the presence of sof among GAS isolates recovered from Italian pediatric pharyngitis patients.

Child↗

PubMed2025

Streptococcus pyogenes EVs induce the alternative inflammasome via caspase-4/-5 in human monocytes.

The sensing of Gram-negative Extracellular Vesicles (EVs) by the innate immune system has been extensively studied in the past decade. In contrast, recognition of Gram-positive EVs by innate immune cells remains poorly understood. Comparative genome-wide transcriptional analysis in human monocytes uncovered that S. pyogenes EVs induce proinflammatory signatures that are markedly distinct from those of their parental cells. Among the 209 genes exclusively upregulated by EVs, caspase-5 prompted us to study inflammasome signaling pathways in depth. We show that lipoteichoic acid (LTA), a structural component of Gram-positive bacterial membranes present on EVs from S. pyogenes and other Gram-positive species, is sensed by TLR2 which triggers the alternative inflammasome composed of NLRP3 and the inflammatory caspases-4/-5 to mount an IL-1β response without inducing cell death. For S. pyogenes, we identify TLR8 as a sensor to mediate caspase-4/-5-dependent IL-1β secretion. Notably, inflammasome activation by intact bacteria is independent of the global virulence regulator CovS in monocytes. Overall, our study highlights a new role for TLR2 and caspase-4/-5 in the recognition of Gram-positive EVs in human monocytes.

Humans↗

PubMed1979

Isolation of type-specific antibody to streptococcus pyogenes by affinity chromatography.

Rabbit type-specific opsonic antibodies to type 1 and type 12 streptococci were isolated by affinity chromatography on immobilized phage-enzyme extract. They were tested by precipitation in gel, bactericidal test and radioimmunoassay. Only type-specific activities were demonstrated. These activities were distributed homogeneously according to avidity. No suggestion of opsonizing and precipitating activities being separable from each other was found. These highly purified rabbit antibodies were marked by radioiodination and used to titrate human anti-M antibodies by competition. These marked antibodies were also used for the study of type-specific antigenic determinants on streptococcal antigens.

Animals↗

PubMed1969

Effect of incubation temperature on T-agglutination typing of Streptococcus pyogenes.

The temperature of incubation affected the typability of beta-hemolytic group A streptococci by T-agglutination tests. When strains could not be typed after routine incubation at 30 C, they were incubated at 22 to 25 C, and nearly a 10% increase in typability was achieved. The clinical source of the strains was related to their typability. Incubation at the lower temperature was required for successful typing of higher percentages of strains from the skin and other clinical sources than from the throat. Sixty per cent of the skin strains were represented by six serotypes. Of these, 53% of the strains required incubation at 22 to 25 C before they could be typed.

Agglutination Tests↗

PubMed2004

Genetic and phenotypic characterization of resistance to macrolides in Streptococcus pyogenes from Argentina.

Five hundred and seventy-eight strains of group A streptococci (GAS) isolated mostly from paediatric pharyngeal swabs were tested to evaluate their susceptibility to erythromycin. Resistant strains were then tested for their MICs to erythromycin and clindamycin, their phenotype of resistance to macrolides-lincosamides-streptogramin (MLS(B)) and for the presence of macrolide resistance genes. The rate of resistance to erythromycin was 8.2%. Constitutive, inducible and M phenotypes of resistance were detected in 2.1, 2.1 and 95.8% of resistant strains, respectively. All M phenotypes harboured the mefA gene, whereas constitutive and inducible phenotypes had ermB and ermTR genes, respectively.

Drug Resistance, Bacterial↗

PubMed2001

Expression of the major heat shock proteins DnaK and GroEL in Streptococcus pyogenes: a comparison to Enterococcus faecalis and Staphylococcus aureus.

One of the outstanding problems in the field of heat shock response has been to elucidate the mechanism underlying the induction of heat shock proteins (HSPs). In this work, we initiate an analysis of the expression of heat shock groEL and dnaK genes and their promoters in S. pyogenes. The synthesis of total cellular proteins was studied upon transfer of a log-phase culture from 37 degrees C to 42 degrees C by performing 5-min pulse-labeling experiments with (35)S-Met. The heat shock responses in the pathogenic Gram-positive cocci, Enterococcus faecalis and Staphylococcus aureus, were also analyzed.

Bacterial Proteins↗