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PubMed2003

Streptococcus pyogenes isolates with characterized macrolide resistance mechanisms in Spain: in vitro activities of telithromycin and cethromycin.

The in vitro activities of telithromycin and cethromycin (ABT-773) against 412 Streptococcus pyogenes isolates, consecutively collected in 17 Spanish hospitals from different geographical areas, were evaluated and compared with those of erythromycin A, penicillin G, clindamycin and quinupristin-dalfopristin. With a susceptibility testing breakpoint of < or = 1 mg/L for both compounds, 96.1% of isolates were susceptible to telithromycin and 99.8% to cethromycin. Erythromycin non-susceptible isolates (intermediate plus resistant, MIC > or = 0.5 mg/L) comprised 23% of those tested, and were analysed for the genetic basis of their resistance by PCR. Among these isolates (n = 95), 72.6% harboured mef(A), 8.4%, erm(B), and 3.2%, erm(A), as sole macrolide resistance gene, whereas the presence of mef(A) plus erm(A) (11.6%) or mef(A) plus erm(B) (4.2%) was also observed. Both ketolides displayed a significant in vitro activity against S. pyogenes regardless of the macrolide resistance mechanisms. Nevertheless, in the case of telithromycin, 11 out of 19 of the erm(B)-positive isolates (2.7% of total population) exhibited an MIC range of 4-32 mg/L. According to the present results, telithromycin and cethromycin offer a wide coverage against S. pyogenes isolates in a geographic area with a high incidence of resistance to currently used macrolides.

Anti-Bacterial Agents↗

PubMed1987

Comparative analysis of the localization of lipoteichoic acid in Streptococcus agalactiae and Streptococcus pyogenes.

The cellular locations of deacylated lipoteichoic acid (dLTA) and lipoteichoic acid (LTA) were examined in late-exponential-phase cells of a serotype III strain of Streptococcus agalactiae (group B streptococci [GBS]) isolated from an infant with late-onset meningitis and compared with a fresh clinical isolate of Streptococcus pyogenes (group A streptococci [GAS]). LTA and dLTA were found to be associated with the protoplast membranes of both organisms, with only dLTA found in mutanolysin cell wall digests. Both organisms released dLTA during growth, but only the GAS released substantial levels of LTA into the culture medium. However, penicillin treatment (5 micrograms/ml for 60 min) of GBS resulted in the recovery of LTA in cell wall digests as well as in the culture medium. These results suggest that under normal growth conditions, the hydrophobic region (glycolipid) of LTA remains associated with the cytoplasmic membrane of GBS and unavailable for hydrophobic interactions at the cell surface with epithelial cells. In contrast, release of LTA into the environment by the GAS allows the fatty acid moieties to interact with hydrophobic domains on the surface of epithelial cells. These results may help explain the marked differences in the specificity of binding between these two major streptococcal pathogens for human fetal and adult epithelial cells.

Bacterial Adhesion↗

PubMed1993

Isolation of a Streptococcus pyogenes gene locus that directs hyaluronan biosynthesis in acapsular mutants and in heterologous bacteria.

A contiguous 3-kilobase pair region of DNA was isolated from Group A Streptococcus pyogenes (GAS) that can direct hyaluronic acid (HA) capsule biosynthesis in acapsular mutants as well as heterologous bacteria. The DNA was identified by transposon 916 insertional mutagenesis and subcloned into a plasmid shuttle vector. Mutant acapsular GAS or Enterococcus faecalis containing this plasmid, but not vector alone, displayed a mucoid phenotype on agar plates, possessed a capsule as seen by light microscopy, and produced HA in quantities comparable with wild-type GAS. The polysaccharide was shown to be authentic HA based on its recognition by a specific proteoglycan and its degradation by Streptomyces hyaluronate lyase. Escherichia coli with the complementing plasmid also produced HA but at only 10% of the level made by the above cells. E. coli minicell analysis showed that two proteins, 42 and 45 kDa, are expressed by the functional DNA insert. Deletion analysis of the insert in the minicells revealed that the 42-kDa protein is essential for HA production. This is the first demonstration of reconstitution of HA capsule biosynthesis in vivo.

Bacterial Capsules↗

PubMed1980

[T-proteins of Streptococcus pyogenes. I. Communication: Preparation of a serological type specific T1-antigen by ion exchange chromatography and its characterization (author's transl)].

The T-protein of Streptococcus pyogenes type 1 was trypsin-extracted and subsequently purified by ion exchange chromatography on CM and DEAE cellulose. Fractionation on CM cellulose by stepwise increase of the pH did not result in separation of type specific material from cross reacting components. The bulk of serologically active material was eluted at pH 5.6. On DEAE cellulose a type specific fraction was eluted with 0.05 m phosphate buffer, pH 8.2. A second fraction eluted with 0.25 m NaCl in the same buffer contained type specific as well as cross reacting material. Molecular weight distributions of type-specific T-protein were studied by gel chromatography on Ultrogel ACA44 and Biogel A 1.5 m. A multiple size subunit structure of T-protein was found and supported by SDS electrophoresis. Molecular weights of fragments serologically active in double diffusion were detected in a range of 37 000 to more than 200 000 Dalton. The isoelectric point was determined as to be pH 4.5. The purified T-protein was found to be free of cystein and of the amino sugars N-acetyl-glucosamine and N-acetyl-muramic acid.

Amino Acids↗

PubMed1991

Streptococcus pyogenes causing toxic-shock-like syndrome and other invasive diseases: clonal diversity and pyrogenic exotoxin expression.

Genetic diversity and relationships among 108 isolates of the bacterium Streptococcus pyogenes recently recovered from patients in the United States with toxic-shock-like syndrome or other invasive diseases were estimated by multilocus enzyme electrophoresis. Thirty-three electrophoretic types (ETs), representing distinctive multilocus clonal genotypes, were identified, but nearly half the disease episodes, including more than two-thirds of the cases of toxic-shock-like syndrome, were caused by strains of two related clones (ET 1 and ET 2). These two clones were also represented by recent pathogenic European isolates. A previous report of a relatively high frequency of expression of exotoxin A among isolates recovered from toxic-shock-like syndrome patients in the United States was confirmed; and the demonstration of this association both within clones and among distantly related clones supports the hypothesis that exotoxin A is a causal factor in pathogenesis of this disease. Near identity of the nucleotide sequences of the exotoxin A structural gene of six isolates of five ETs in diverse phylogenetic lineages was interpreted as evidence that the gene has been horizontally distributed among clones, presumably by bacteriophage-mediated transfer.

Bacterial Proteins↗

PubMed1989

Possible role of Streptococcus pyogenes in mucocutaneous lymph node syndrome. VIII. Immunological tolerance to S. pyogenes-associated antigens seems essential to induction of MCLS.

In our previous studies, we attempted to show that new-born mice infected with an attenuated strain of Streptococcus pyogenes, and exposed to streptococcal antigens approximately one month later, failed to develop a humoral response to those antigens but were able to respond normally to other unrelated antigens. Since such immunological characteristics are identical to those of patients with the mucocutaneous lymph node syndrome (MCLS), the present studies were performed with the aim of assessing the antibody-forming activities of peripheral blood lymphocytes collected from MCLS patients. These lymphocytes were cultured in the presence of pokeweed mitogen, streptolysin-O and streptococcal C-polysaccharide, leading to their refractoriness to S. pyogenes-associated antigens coupled with normal responsiveness to unrelated antigens. The implication of such immunological responsiveness elicited from neonatal exposure to streptococcal antigens is discussed, particularly with reference to the induction of MCLS.

Antibody Formation↗

PubMed2004

Prevalence of the internalization-associated gene prtF1 in a bacterial population of Streptococcus pyogenes isolated from children with acute pharyngotonsillitis before and after antibiotic therapy.

The prevalence of the internalization-associated prtF1 gene was studied in 837 isolates of Streptococcus pyogenes obtained from 713 pediatric patients presenting with acute pharyngotonsillitis before and after antibiotic therapy. Its association with macrolide resistance and with bacteriological treatment failure was determined. The bacterial population isolated from baseline pharyngeal swabs showed an overall prtF1 positivity rate of 33%. A higher prtF1 positivity was found among erythromycin-resistant strains (45%) showing, however, marked differences between the inducible (iMLS), constitutive (cMLS), and efflux pump (M) resistance phenotypes. The prevalence was statistically higher (p < 0.001) in strains belonging to iMLS (84%) and cMLS (67%) phenotypes as compared to the M phenotype (15%). Interestingly, the prevalence of the prtF1 gene was significantly lower (p = 0.04) in strains belonging to M resistance phenotype as compared to erythromycin-susceptible strains (28%). Failed bacterial eradication was demonstrated in 124 patients. The prtF1 positivity rate remained unchanged in strains isolated before and after therapy in patients treated with macrolides (9/54). On the other hand, the positivity rate for the prtF1 gene was significantly higher (p = 0.015) in strains isolated after therapy with beta-lactams (21/70) as compared to baseline isolates (6/70), indicating a differential selection imposed on the organism by these agents. Finally, a high overall eradication rate (88%) of prtF1-positive isolates, belonging to both the erythromycin-susceptible and -resistant phenotypes, was demonstrated following macrolide treatment.

Acute Disease↗

PubMedDate not supplied

Morphological alterations of Staphylococcus aureus and Streptococcus pyogenes exposed to cefdinir, a new oral broad-spectrum cephalosporin.

Affinity for penicillin-binding proteins (PBPs) and the morphological alteration of Staphylococcus aureus 209-P JC and Streptococcus pyogenes C-203 exposed to cefdinir were studied. Although cefdinir was bactericidal against both strains, the extent of the decrease in colony-forming units (CFU) was similar in a fairly wide range of concentrations. Transmission electron microscopy of S. aureus 209-P JC revealed that cefdinir induced thickening of the cross wall and frequent cell lysis at low concentrations. The lytic sites were seen at the site of septum formation. In S. pyogenes C-203, cefdinir induced thickening of the peripheral wall and cross wall, and protoplast-like cells were observed during the incubation period. Cefdinir showed high affinity for all PBPs of S. aureus 209-P JC and S. pyogenes C-203. The drastic changes in the morphology of S. aureus and S. pyogenes were caused by binding of cefdinir to all PBPs.

Bacterial Proteins↗

PubMed1992

Mother-to-infant vertical transmission and cross-colonization of Streptococcus pyogenes confirmed by DNA restriction fragment length polymorphism analysis.

Restriction fragment length polymorphism (RFLP) analysis of total DNA and of ribosomal DNA (rDNA) regions (ribotyping) were used to document Streptococcus pyogenes vertical mother-to-infant transmission and to investigate the spread of S. pyogenes in an obstetric unit. Two isolates from a newborn, two isolates from his mother (patient 1), and two isolates from two other mothers (patients 2 and 3) were studied. RFLP of total DNA, both after HindIII and PvuII digestions and ethidium bromide staining, gave indistinguishable patterns for the strains isolated from the neonate, his mother, and patient 2. Strains from patient 3 and six unrelated strains studied for comparison showed different patterns. In our system, ribotyping was less discriminative than total DNA RFLP analysis. DNA RFLP analysis therefore provides a valuable molecular tool for studying S. pyogenes epidemiology.

Adult↗

PubMed1989

Septic shock and acute respiratory distress syndrome after salpingitis caused by Streptococcus pyogenes group A.

A 32-year-old woman with acute salpingitis had signs and symptoms of sepsis, with hypotension, renal failure, acute respiratory distress syndrome, and disseminated intravascular coagulation. Streptococcus pyogenes group A was grown from blood cultures taken at the onset of illness, and salpingitis was confirmed at laparotomy. The patient recovered after appropriate antimicrobial and intensive supportive therapy.

Adult↗

PubMed2003

Survey of emm gene sequences from pharyngeal Streptococcus pyogenes isolates collected in Spain and their relationship with erythromycin susceptibility.

We conducted a nationwide survey of the variable 5' emm (M protein gene) sequences from 614 pharyngeal Streptococcus pyogenes isolates susceptible (299 isolates) and resistant (315 isolates) to erythromycin that were isolated in Spain from 1996 to 1999. Almost 98% of these isolates had emm sequences in agreement with previously recorded M antigen association. We only identified a new 5' emm sequence in 17 isolates. Nine different emm types accounted for 85% of the S. pyogenes isolates susceptible to erythromycin. By contrast, only 3 emm types accounted for 70% of the erythromycin-resistant isolates. Further characterization of these isolates by ribotyping and pulsed-field gel electrophoresis indicated that high frequency of erythromycin resistance in Spain is due to few clones.

Anti-Bacterial Agents↗

PubMed2002

Antimicrobial resistance amongst isolates of Streptococcus pyogenes and Staphylococcus aureus in the PROTEKT antimicrobial surveillance programme during 1999-2000.

The pattern of susceptibility to a range of antimicrobials was tested for 1485 isolates of Streptococcus pyogenes and 1547 isolates of Staphylococcus aureus included in the international PROTEKT (Prospective Resistant Organism Tracking and Epidemiology for the Ketolide Telithromycin) surveillance study (1999-2000). Overall, almost 10% of S. pyogenes isolates were erythromycin A resistant. There was a wide heterogeneity of resistance, with high levels of macrolide resistance in Poland (42%), Hong Kong (28%), Italy (25%), Portugal (24%) and Spain (21%), and no macrolide resistance in Indonesia, Austria, Belgium, the Netherlands or the UK. Using NCCLS tentative breakpoints, 97.6% of isolates were susceptible to telithromycin, with MIC(90) < or = 0.015 mg/L in most regions. Resistance among S. pyogenes to the beta-lactams (MIC(90) < or = 0.12 mg/L for all except cefaclor) and fluoroquinolones was not detected. Macrolide resistance was present among the S. aureus isolates, and as with S. pyogenes, there was a wide heterogeneity of resistance, with lower rates in Australia, Indonesia, Hungary, Austria, Germany, the Netherlands, Portugal, Sweden and Switzerland. Methicillin-resistant isolates were resistant to the beta-lactams and the macrolides. Resistance to telithromycin was detected in methicillin-resistant isolates in Latin and North America, Asia and Europe. Telithromycin resistance was non-existent or low (MIC(90 )range 0.06-0.25 mg/L) in Australia, Indonesia, Hungary, Austria, Germany, the Netherlands, Portugal, Sweden and Switzerland. Regardless of methicillin susceptibility, resistance to linezolid, teicoplanin or vancomycin was not apparent globally.

Anti-Bacterial Agents↗

PubMed1992

Fibronectin-binding protein of Streptococcus pyogenes: sequence of the binding domain involved in adherence of streptococci to epithelial cells.

The sequence of the fibronectin-binding domain of the fibronectin-binding protein of Streptococcus pyogenes (Sfb protein) was determined, and its role in streptococcal adherence was investigated by use of an Sfb fusion protein in adherence studies. A 1-kb DNA fragment coding for the binding domain of Sfb protein was cloned into the expression vector pEX31 to produce an Sfb fusion protein consisting of the N-terminal part of MS2 polymerase and a C-terminal fragment of the streptococcal protein. Induction of the vector promoter resulted in hyperexpression of fibronectin-binding fusion protein in the cytoplasm of the recombinant Escherichia coli cells. Sequence determination of the cloned 1-kb fragment revealed an in-frame reading frame for a 268-amino-acid peptide composed of a 37-amino-acid sequence which is completely repeated three times and incompletely repeated a fourth time. Cloning of one repeat into pEX31 resulted in expression of small fusion peptides that show fibronectin-binding activity, indicating that one repeat contains at least one binding domain. Each repeat exhibits two charged domains and shows high homology with the 38-amino-acid D3 repeat of the fibronectin-binding protein of Staphylococcus aureus. Sequence comparison with other streptococcal ligand-binding surface proteins, including M protein, failed to reveal significant homology, which suggests that Sfb protein represents a novel type of functional protein in S. pyogenes. The Sfb fusion protein isolated from the cytoplasm of recombinant cells was purified by fast protein liquid chromatography. It showed a strong competitive inhibition of fibronectin binding to S. pyogenes and of the adherence of bacteria to cultured epithelial cells. In contrast, purified streptococcal lipoteichoic acid showed only a weak inhibition of fibronectin binding and streptococcal adherence. These results demonstrate that Sfb protein is directly involved in the fibronectin-mediated adherence of S. pyogenes to epithelial cells.

Amino Acid Sequence↗

PubMed1995

DNA fingerprinting of Streptococcus pyogenes from patients with recurrent pharyngotonsillitis by means of random amplified Polymorphic DNA analysis.

In recent years, several DNA fingerprinting methods have been tried for the epidemiological investigation of Streptococcus pyogenes isolates. We chose the Random Amplified Polymorphic DNA (RAPD) method for the typing of pre- and post-antibiotic treatment S. pyogenes isolates obtained from 14 patients with pharyngotonsillitis. Isolates from 4 patients had been collected 10 years earlier than from the others. Hence epidemiological connections between the strains were unlikely. Both pre- and post-antibiotic treatment isolates showed identical RAPD patterns, indicating that recurrences in these patients had been caused by homologous strains of S. pyogenes. It was possible by means of RAPD to differentiate between 12 different T-types and occasionally between clones of the same serotype of S. pyogenes. The RAPD method is an easier alternative to traditional DNA-typing techniques and provides quick results with minimal technical complexity.

Bacterial Typing Techniques↗

PubMed2003

Streptococcus pyogenes recruits collagen via surface-bound fibronectin: a novel colonization and immune evasion mechanism.

This study aimed to characterize matrix assembly mechanisms on the surface of the human pathogen Streptococcus pyogenes. Among 125 S. pyogenes isolates, 61% were able to recruit collagen type IV via surface-bound fibronectin. Streptococcus gordonii expressing the fibronectin-binding repeat domain of S. pyogenes SfbI protein was equally potent in recruiting collagen, indicating that this domain was sufficient to promote fibronectin-mediated collagen recruitment. Electron microscopic analysis of streptococci revealed that fibronectin-mediated collagen recruitment led to matrix deposition on and between streptococcal cells, which induced the formation of large bacterial aggregates. Furthermore, collagen-recruiting streptococci were able to colonize collagen fibres and were protected from adhering to human polymorphonuclear cells in the presence of opsonizing antibodies. Fibronectin-mediated collagen recruitment thus represents a novel aggregation, colonization and immune evasion mechanism of S. pyogenes.

Adhesins, Bacterial↗

PubMed1989

[Verification of the preparation of Streptococcus pyogenes str. A1 96/50 based on the results of growth properties of media].

For tests of the growth properties of media Czechoslovak standards prescribe a culture of the Streptococcus pyogenes strain Str. A1 96/50 which must be shaken with sea sand and diluted with a gelatin solution. The author found that shaking the culture with sea sand usually reduces significantly (P less than 0.05) the number of colonies in agar medium, as compared with a culture which did not have this treatment. The author also found that there is no significant difference (P greater than 0.05) in the number of colonies when the culture is diluted with a gelatin solution or isotonic sodium chloride solution. He proved that there is no significant difference (P greater than 0.05) in the scatter of the number of colonies in agar when the culture is shaken with sea sand or if it is diluted with a gelatin solution, as compared with a culture not shaken with sand or diluted with sodium chloride solution.

Bacteriological Techniques↗

PubMed1999

A Streptococcus pyogenes outbreak caused by an unusual serotype of low virulence: the value of typing techniques in outbreak investigations.

OBJECTIVES: To investigate and stop the spread of an outbreak of Streptococcus pyogenes infection in a district general hospital, involving 19 patients and two nurses over a 20-day period. METHODS: All suspected persons were investigated using conventional bacteriological techniques, followed by M, T and exotoxin gene-typing of the isolates in a national reference laboratory. RESULTS: 11 patients and both nurses were associated with the acute surgical ward on one floor of the hospital. They were infected with serotype M 9/T B3264, a strain with apparently low virulence, which has not been previously associated with outbreaks. Two other patients on the same floor each had different types and there were two clusters of another S. pyogenes serotype on other floors, each involving two patients. Two (unrelated) patients yielded other types of S. pyogenes. The patients were not seriously ill but had some delay in wound healing. CONCLUSIONS: The value of typing the isolates of S. pyogenes in this outbreak was in defining which patients were involved. No added value could be ascribed to the exotoxin gene-typing results.

Adult↗

PubMed1988

Pathogenicity of capsulate and non-capsulate members of Bacteroides fragilis and B. melaninogenicus groups in mixed infection with Escherichia coli and Streptococcus pyogenes.

The relationships between capsulate and non-capsulate Bacteroides fragilis strains and Escherichia coli, and between capsulate and non-capsulate strains of the B. melaninogenicus group and Streptococcus pyogenes, were studied in a subcutaneous abscess model in mice. Selective antimicrobial agents directed against either aerobic or anaerobic bacteria were used alone or in combination to explore the effect of eradication of one component of the mixed infection. Single agent therapy effective against both aerobic and anaerobic flora was also employed. Single therapy of mixed infection directed at the elimination of only one organism (S. pyogenes, E. coli or Bacteroides sp.) caused significant reductions in the numbers of sensitive organisms and also smaller yet significant decreases in the numbers of insensitive organisms. However, the abscesses were not eliminated after such therapy. Combination therapy or use of a single agent (cefoxitin) directed against the aerobic and anaerobic components of the infection was more effective. Non-capsulate Bacteroides spp. became capsulate after passage in mice mixed with either S. pyogenes or E. coli. Therapy directed at the elimination of S. pyogenes and E. coli did not prevent the emergence of capsulate Bacteroides spp. These data demonstrate the synergy between all members of the B. fragilis group and E. coli and between the B. melaninogenicus group and S. pyogenes, and reiterate the need to direct antimicrobial therapy at the eradication of the aerobic and anaerobic components of mixed infections.

Abscess↗