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PubMed1991

A genetic transformation system for Streptococcus pyogenes.

An efficient protoplast transformation system for Streptococcus pyogenes has been developed. Efficiencies of up to 7.1 x 10(6) transformants/micrograms DNA were achieved, with transformants recovered on selective media in 24-48 h. The system was characterized as to optimal protoplasting conditions, effective facilitators, dependency on concentration of transforming DNA, plasmid copy number in transformants and stability of transformants. Three isolates of S. pyogenes were used as recipients, and four plasmids were used as the transforming DNA. Growth of S. pyogenes in glycine followed by lysozyme treatment was necessary for optimal protoplast formation. The exact concentrations of these protoplasting agents which were used varied with each isolate tested. Both polyethylene glycol and dextran sulphate were efficient facilitators of transformation, at final concentrations of 10%. An inverse relationship between DNA concentration and efficiency of transformation was shown. The copy number of the AC-1 plasmid in the transformants was shown to be equivalent to that of the wild type S. pyogenes (AC-1) (one or two copies per chromosomal equivalent). Approximately 50% of the AC-1 transformants were stable after one passage on non-selective media, and 100% of those that retained the plasmid were stable for an additional twenty generations. Erythromycin resistance encoded on the AC-1 plasmid was inducible, and transformants with a constitutive mutant of the AC-1 plasmid were detected by growth on selective media. This plasmid may prove useful as a vector as it is readily transformed, expressed, and contains at least three unique restriction sites which could serve as insertion points for cloned DNA.

Culture Media↗

PubMed1997

The hemopexin-type repeats of human vitronectin are recognized by Streptococcus pyogenes.

The specific binding of vitronectin to Streptococcus pyogenes is believed to play an important role in the infection process by mediating adherence of the bacteria to host cells. The domain of vitronectin involved in the interaction with S. pyogenes is unknown. In the present study, we constructed a vitronectin random epitope phage display library, which was used to pan against intact cells of S. pyogenes. Several phage-displayed vitronectin peptides containing a hydrophobic pentapeptide motif within the hemopexin-type repeats were found to bind to streptococci. These data were supported by competition experiments, in which a representative 23-amino acid synthetic vitronectin peptide comprising part of a hemopexin-type repeat inhibited binding of the bacteria to vitronectin, while a control peptide with identical amino acid composition but a scrambled sequence had no effect. Moreover, cells of S. pyogenes were shown to bind to the synthetic peptide as well as to immobilized hemopexin, whose structural homology to the hemopexin-type repeats in the vitronectin molecule has long been underlined. Soluble vitronectin could inhibit streptococcal binding to immobilized hemopexin. These results provide first evidence for a biological role of hemopexin itself and respective repeats in vitronectin in bacterial binding, suggesting that during an infection process these or other hemopexin-type repeat-containing proteins could be potential targets for bacterial attachment and subsequent colonization.

Amino Acid Sequence↗

PubMed2003

Evasion of phagocytosis through cooperation between two ligand-binding regions in Streptococcus pyogenes M protein.

The M protein of Streptococcus pyogenes is a major bacterial virulence factor that confers resistance to phagocytosis. To analyze how M protein allows evasion of phagocytosis, we used the M22 protein, which has features typical of many M proteins and has two well-characterized regions binding human plasma proteins: the hypervariable NH2-terminal region binds C4b-binding protein (C4BP), which inhibits the classical pathway of complement activation; and an adjacent semivariable region binds IgA-Fc. Characterization of chromosomal S. pyogenes mutants demonstrated that each of the ligand-binding regions contributed to phagocytosis resistance, which could be fully explained as cooperation between the two regions. Deposition of complement on S. pyogenes occurred almost exclusively via the classical pathway, even under nonimmune conditions, but was down-regulated by bacteria-bound C4BP, providing an explanation for the ability of bound C4BP to inhibit phagocytosis. Different opsonizing antisera shared the ability to block binding of both C4BP and IgA, suggesting that the two regions in M22 play important roles also under immune conditions, as targets for protective antibodies. These data indicate that M22 and similar M proteins confer resistance to phagocytosis through ability to bind two components of the human immune system.

Amino Acid Sequence↗

PubMed1977

Drug resistance in Streptococcus pyogenes isolated in Japan.

Drug resistance of Streptococcus pyogenes strains isolated during 1974 and 1975 in various districts in Japan were surveyed and compared with an earlier survey of 1970 to 1973. Of 1,021 strains, tetracycline-, macrolide antibiotic-, lincomycin-, and chloramphenicol-resistant strains were demonstrated at frequencies of 80.3, 62.3, 60.8, and 57.9%, respectively. Distinct group resistances to penicillin and aminoglycoside antibiotics could not be identified among the strains examined. It was characteristic that quadruple and triple resistances were manifested among the strains resistant to macrolide antibiotics, lincomycin, tetracycline, and chloramphenicol, and they were confined to the T-type 12. The emergence of multiply resistant streptococcal strains was due mostly to the rapid increase in isolation frequency of macrolide antibiotic- or macrolide antibiotics-lincomycin-resistant strains.

Anti-Bacterial Agents↗

PubMed1989

Epidemiological typing of Streptococcus pyogenes by pyrolysis mass spectrometry.

Strains of Streptococcus pyogenes from an outbreak of infection on a burns unit (15), a collection of routine isolates from another hospital(12) and isolates from a national survey of throat infections in children in the community(4) were examined blind by pyrolysis-mass spectrometry (Py-MS). The outbreak strains (M22 T12) previously found to give identical typing results in conventional tests, formed a closely similar cluster and were distinct from other hospital and community strains. One hospital and one community strain were loosely associated with this cluster. Another cluster comprised six antibiotic-susceptible strains and two community strains. Six strains did not fall within the clusters; four were antibiotic-resistant strains isolated in hospital, one an antibiotic-resistant strain isolated in the community, and one a susceptible hospital strain. Results show that Py-MS is a potentially valuable method for rapid comparison of strains in studies of infection.

Bacterial Typing Techniques↗

PubMed2001

EndoS, a novel secreted protein from Streptococcus pyogenes with endoglycosidase activity on human IgG.

Streptococcus pyogenes is an important human pathogen that selectively interacts with proteins involved in the humoral defense system, such as immunoglobulins and complement factors. In this report we show that S.pyogenes has the ability to hydrolyze the chitobiose core of the asparagine-linked glycan on immuno globulin G (IgG) when bacteria are grown in the presence of human plasma. This activity is associated with the secretion of a novel 108 kDa protein denoted EndoS. EndoS has endoglycosidase activity on purified soluble IgG as well as IgG bound to the bacterial surface. EndoS is required for the activity on IgG, as an isogenic EndoS mutant could not hydrolyze the glycan on IgG. In addition, we show that the secreted streptococcal cysteine proteinase SpeB cleaves IgG in the hinge region in a papain-like manner. This is the first example of an endoglycosidase produced by a bacterial pathogen that selectively hydrolyzes human IgG, and reveals a novel mechanism which may contribute to S.pyogenes pathogenesis.

Amino Acid Sequence↗

PubMed1999

[Erysipelas, cellulitis and other severe Streptococcus pyogenes skin infections].

INCIDENCE AND GRAVITY: Invasive Streptococcus pyogenes infections are a common reason for hospitalization. Serious forms may occur in patients with no known risk factor, including young patients. Inversely, erysipela is observed more readily in the elderly population with a more vulnerable venous system. Disease gravity is related to the high risk of recurrence. For cellulitis, predominantly a disease of young subjects with no past history, severity is related to local extension and development of shock syndrome. Besides the immediate life-threatening situation, functional prognosis may be compromised, depending on the localization of the infection. PATHOGENESIS OF GROUP A STREPTOCOCCAL INFECTIONS: Adherence and invasion properties of group A streptococci, particularly the capsule and protein M, as well as streptococcal toxins cause severe septic and toxinic syndromes. Strains most frequently associated with invasive infections are: biotype 1, serotype M1 and biotype 3, serotype M3. TREATMENT: An antibiotic regimen by intravenous infusion of penicillin G is the gold standard treatment. Clindamycin should be added in case of septic shock. Extensive cellulitis or necrotizing fasciitis requires surgical debridement of the necrotic tissue and intensive care for the shock syndrome.

Cellulitis↗

PubMed1992

[The vir-regulon of Streptococcus pyogenes: coordinate expression of important virulence factors].

Streptococcus pyogenes (group A streptococci; GAS) expresses important virulence factors like the antiphagocytic M protein, the complement factor-inactivating C5a peptidase and the immunoglobulin-Fc-binding proteins on its surface. The corresponding emm, scpA, and emm-related (fcrA, ennX) genes are adjacently encoded on the genome. They are coordinately in trans regulated by the positive regulatory VirR factor. The responsible virR gene is also located within this segment of the genome which was called vir-regulon. There are at least three different types of organization of the vir-regulon. A frequently encountered type is the "Large vir-regulon". It comprises from 5' to 3' the following genes: virR, fcrA, a relatively small emm, ennX, and a 4.6 kb version of scpA. Another common type is the "Small vir-regulon", which contains a virR deviating in its 3'-region, a relatively large emm, and a 3.5 kb version of scpA. The "Unusual vir-regulon" is less frequently detected. It closely resembles the small one, but harbors an additional 3 to 4 kb DNA fragment between emm and scpA, occasionally encoding an emm-related gene. The type of vir-regulon encoded by a GAS strain correlates to its serotype, its M class, and its expression of serum opacity factor. The structural genes of the vir-regulon are expressed at a high level during growth in exponential phase, under anaerobiosis, and at body temperature. The sensor molecule which modulates VirR activity according to these environmental conditions has not yet been detected.(ABSTRACT TRUNCATED AT 250 WORDS)

Adhesins, Bacterial↗

PubMed1993

A novel superantigen isolated from pathogenic strains of Streptococcus pyogenes with aminoterminal homology to staphylococcal enterotoxins B and C.

Streptococcus pyogenes (group A Streptococcus) has re-emerged in recent years as a cause of severe human disease. Because extracellular products are involved in streptococcal pathogenesis, we explored the possibility that a disease isolate expresses an uncharacterized superantigen. We screened culture supernatants for superantigen activity with a major histocompatibility complex class II-dependent T cell proliferation assay. Initial fractionation with red dye A chromatography indicated production of a class II-dependent T cell mitogen by a toxic shock-like syndrome (TSLS) strain. The amino terminus of the purified streptococcal superantigen was more homologous to the amino termini of staphylococcal enterotoxins B, C1, and C3 (SEB, SEC1, and SEC3), than to those of pyrogenic exotoxins A, B, C or other streptococcal toxins. The molecule, designated SSA, had the same pattern of class II isotype usage as SEB in T cell proliferation assays. However, it differed in its pattern of human T cell activation, as measured by quantitative polymerase chain reaction with V beta-specific primers. SSA activated human T cells that express V beta 1, 3, 15 with a minor increase of V beta 5.2-bearing cells, whereas SEB activated V beta 3, 12, 15, and 17-bearing T cells. Immunoblot analysis of 75 disease isolates from several localities detected SSA production only in group A streptococci, and found that SSA is apparently confined to only three clonal lineages as defined by multilocus enzyme electrophoresis typing. Isolates of one of these lineages, (electrophoretic type 2) are strongly associated with TSLS. The data identify SSA as a novel streptococcal superantigen that appears to be more related structurally to staphylococcal enterotoxins than to streptococcal exotoxins. Because abundant SSA production is apparently confined to only three streptococcal clonal lineages, the data also suggest that the SSA gene has only recently been acquired by S. pyogenes.

Amino Acid Sequence↗

PubMedDate not supplied

Prevalence of Streptococcus pyogenes as an oropharynx colonizer in children attending daycare: a comparative study of different regions in Brazil.

UNLABELLED: Thirty percent of acute pharyngotonsillitis is caused by Streptococcus pyogenes, which increased the risk of glomerulonephritis and rheumatic fever. Children attending daycare centers have a higher incidence of these infections. AIM: to identify and compare the prevalence of Streptococcus pyogenes in the oropharynx of children who are enrolled and who are not enrolled in daycare centers in different regions of Brazil. MATERIALS AND METHODS: A prospective study of two hundred children from Sao Paulo/SP and Porto Velho/RO. Children from each city were divided into two groups: those attending, and those not attending daycare centers. Swabs of the oropharynx were taken for bacteriological culture and identification. RESULTS: The prevalence of Streptococcus pyogenes in the Sao Paulo groups were 8% and 2% for daycare and control groups, which was statistically significant (p=0.02). The prevalence in children from Porto Velho/RO was 24% and 16% for daycare and control groups, which was statistically significant (p=0.015). Statistical analysis also showed a significant difference between the corresponding groups in the two locations (p<0.01). CONCLUSION: These results show that daycare attendance is a risk factor for oropharyngeal streptococcal colonization; this was seen in different populations, but was statistically significance in only one of the two samples.

Brazil↗

PubMed1998

[Neonatal Streptococcus pyogenes meningitis and sagittal sinus thrombosis: case report].

We report a case of Streptococcus pyogenes meningitis in a 18 days year-old-girl with clinical course complicated by sagittal sinus thrombosis. Some aspects of the pathogenesis, treatment and follow-up of the disease are discussed. The world increase of serious streptococcal infections in the last 10 years, probably will become neonatal Streptococcus pyogenes meningitis more frequent in the future and it is important to be alert for the precocious diagnosis and the possible complications of that potentially lethal infection.

Female↗

PubMed2000

[Streptococcus pyogenes: in vitro susceptibility and role of beta-lactamase producing bacteria in the persistence of streptococcal pharyngotonsillitis].

OBJECTIVE: To assess the frequency of association between Streptococcus pyogenes and beta-lactamase-producing-bacteria in the pharyngotonsillitis and the evaluate the in vitro susceptibility. DESIGN: Prospective, descriptive, transverse study. SETTING: The present study was carried out in the Health Center Dr. José Castro Villagrana, in Tlalpan, México, D.F., from Juanary, 1996 to February 1999. PARTICIPANTS: In three hundred and ninety four patients with pharyngotonsillitis diagnosis we isolated the same number of Streptococcus pyogenes, and possible beta-lactamase-producing-bacteria. RESULTS: In 180 patients (45.7%) we isolated at least one possible beta-lactamase-producing-bacteria. Of these, in 138 patients (35%) were confirmed the enzyme presence. In total, we isolated 218 possible beta-lactamase-producing bacteria, and 152 (69.7%) were beta-lactamase positive. We found no significant change in the in vitro susceptibility of group A Streptococcus to penicillin, but erythromycin resistance is relatively common, approximately 10% in this study. CONCLUSIONS: Streptococcus pyogenes was uniformly susceptible to all penicillins and cephalosporins in vitro. Erythromycin treatment should not be promoted as first-line therapy because the consequent increase of bacterial resistance could create difficulty in treating penicillin-allergic patients. Because of the poor activity of trimetoprimsulfametoxazol, this drug no longer can be considered the drug of choice for the management of group A Streptococcal infections.

Adolescent↗

PubMed1996

[Epidemiologic surveillance of streptococcus pyogenes resistances to macrolides and lincosamides].

With the changing face of modern medicine and increased use of new antimicrobial compounds against Streptococcus pyogenes, as macrolides, in recent years more strains developed new resistance to macrolides and lincosamides. This is of interest because some scientists believe that the new antibiotics policies possibly influence the rate of resistance in Streptococcus pyogenes: the pattern of resistance to macrolides is complex and involving cross or co-resistance with chemically unrelated or related agents, as lincosamides. To obtain current epidemiological data on antimicrobial resistance of Streptococcus pyogenes, we performed an year surveillance study: the rate of resistance to erythromycin was from 4% in October 1994 to 55% in December 1995, and in the same time clarithromycin was from 0% to 46% and clindamycin from 0% to 32%.

English Abstract↗

PubMed1994

[Streptococcus pyogenes toxic shock. A clinical case].

Toxic shock-like syndrome (TSLS) due to Streptococcus pyogenes has been recently reported in both children and adults. This syndrome is characterized by hypotension or shock, fever, multiorgan system involvement and death in 30 to 60% of patients. This syndrome closely resembles the more frequent staphylococcal TSLS. Only one case of TSLS caused by streptococcus has been reported, up to now, in our Country. We describe a second case of fatal streptococcus pyogenes TSLS in a 64-year-old man, in which the site of infection was in the soft tissues. The illness was characterized by rapid progression of shock, erythematous rash, multisystem organ involvement and finally death. Clinicians must be aware of the presentation of this disease as its incidence appears to be increasing.

Humans↗

PubMed1990

[Induction and functional analysis of gamma delta TCR-bearing T cells from human tonsil by Streptococcus pyogenes stimulation].

The killer cell characteristics of gamma delta TCR-bearing T cells induced from human tonsil by streptococcus pyogenes stimulation were examined. Immunohistologic staining of tonsil showed that gamma delta TCR-bearing T cells were mainly located in the interfollicular area connected with stratified squamous epithelium. Streptococcus pyogenes could induce the proliferation of gamma delta TCR-bearing T cells from tonsil in the presence of low-dose of IL-2. This streptococcus pyogenes-induced gamma delta TCR-bearing T cell proliferation was likely to be independent on the IL-2/IL-2R system since an obvious inhibition was not observed with anti-IL-2 and anti-IL-2R mAbs. More importantly, these gamma delta TCR-bearing T cells exhibited cell-mediated cytotoxic activity in a 4 hr 51 Cr-release assay. In addition, immunocytochemical staining revealed that these cells contained a killer protein perforin. These results demonstrate that gamma delta TCR-bearing T cells from tonsil exhibit typical killer cell characteristics. These data also suggest that gamma delta TCR-bearing T cells in human tonsil may play a cytotoxic role in protecting the integrity of tonsil from infection.

Cytotoxicity, Immunologic↗

PubMed1964

ELECTROPHORETIC SEPARATION OF CONSTITUENTS OF PARTIALLY PURIFIED M PROTEIN OF STREPTOCOCCUS PYOGENES.

Pierce, William A., Jr. (Tulane University, New Orleans, La.). Electrophoretic separation of constituents of partially purified M protein of Streptococcus pyogenes. J. Bacteriol. 88:912-921. 1964.-Partially purified M protein of a group A, type 12 strain of Streptococcus pyogenes was studied by use of chemical, electrophoretic, and immunological techniques. It was demonstrated in immunodiffusion tests that the antigen contains multiple precipitating components. The type-specific antigen was identified, and evidence was presented that, in some instances at least, the cross-reactions observed between this type 12 M protein and heterologous antisera in immunodiffusion tests involve contaminating antigens rather than the component which precipitates with adsorbed homologous-typing antiserum. In passive hemagglutination tests where M protein was adsorbed to tanned sheep erythrocytes, it was found that antisera suitably adsorbed to show good specificity in capillary precipitin tests nevertheless still contain cross-reactive antibodies which are detectable by this more sensitive technique. Electrophoresis on starch paste separates some of the components of partially purified M protein, so that a fraction can be obtained which has fewer precipitating antigens, as determined in immunodiffusion tests, and which is less cross-reactive in passive hemagglutination tests with heterologous unadsorbed antistreptococcal antisera.

Animals↗

PubMed2004

Intranasal vaccination with streptococcal fibronectin binding protein Sfb1 fails to prevent growth and dissemination of Streptococcus pyogenes in a murine skin infection model.

Fibronectin binding protein F1 (Sfb1) of Streptococcus pyogenes (group A streptococcus [GAS]) is a well-characterized adhesin that has been shown to induce protection in mice against a lethal intranasal GAS challenge after intranasal immunization with cholera toxin B subunit (CTB) as adjuvant. With a murine skin infection model, we have shown that Sfb1/CTB vaccination neither elicits opsonizing antibodies nor prevents systemic bacterial growth and dissemination to internal organs after a subcutaneous GAS challenge. These results indicate that an Sfb1-based vaccine should be complemented with additional protective antigens in order to be used in areas such as the tropical north of Australia, where the skin is the primary route of entry for invasive streptococcal diseases.

Adhesins, Bacterial↗

PubMed2004

Epidemiology of diseases caused by Streptococcus pyogenes in Serbia during a nine-year period (1991-1999).

BACKGROUND & OBJECTIVES: Streptococcus pyogenes (group A Streptococcus - GAS) is an important human pathogen which causes a variety of diseases, including tonsillopharyngitis, scarlet fever and rheumatic fever. It is important to understand the changes in epidemiology of the diseases caused by the pathogen for improved control of such infections. Hence, the aim of the present study was to carry out an epidemiological analysis of GAS infections in Serbia in a 9-yr period (1991-1999) and evaluation of susceptibility of GAS isolates obtained during the same period to penicillin and erythromycin. METHODS: Occurrence of tonsillopharyngitis, scarlatina and rheumatic fever was analyzed and GAS carrier status in healthy children was examined over a 9-yr period from 1991 to 1999. Susceptibility to penicillin and erythromycin was determined for 1657 GAS isolates obtained from patients diagnosed with pharyngitis or scarlet fever and 512 isolates from healthy carriers. M-type antigen was also determined in these isolates. RESULTS: The average incidences of tonsillopharyngitis and scarlet fever were 76.2 and 30.8 per cent respectively. A total of 166 cases of rheumatic fever were registered. Per cent of carriers varied from 5.5 to 11.4 per cent over the study period. Predominating M serotypes among GAS isolates tested were M1, M3, M4, M6, M11, M12 and M18, depending on the source of clinical material and period of isolation. Antimicrobial susceptibility testing showed susceptibility to penicillin in all isolates tested and resistance to erythromycin in 2.41 per cent of the isolates. INTERPRETATION & CONCLUSION: Although the fluctuations in incidence were noted during the nine-year period, the incidence of streptococcal tonsillopharyngitis is low but with a steady raise in Serbia. No significant changes in the incidence of scarlet fever and rheumatic fever were noted. Susceptibility to penicillin remained unchanged, but the number or erythromycin resistant strains have increased.

Adolescent↗