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PubMed1997

Changing epidemiology of invasive Streptococcus pyogenes infections in southern Israel: differences between two ethnic population groups.

BACKGROUND: Two ethnic populations (westernized Jews and Bedouins in transition from semi-nomadic to sedentary life conditions) living in Southern Israel and receiving inpatient services in the only medical facility of the region. OBJECTIVE: To determine whether the incidence and severity of Streptococcus pyogenes infections among Jewish and Bedouin children have changed over the years. STUDY DESIGN: Retrospective (1980 to 1994), population-based. Medical charts of children younger than 15 years of age hospitalized with S. pyogenes bacteremia and/or severe invasive infection were reviewed. Incidence rates of bacteremia among Jewish and Bedouin children were calculated separately. RESULTS: The incidence of S. pyogenes bacteremia was 2.82/100,000 between 1980 and 1984, was 2.58/100,000 between 1985 and 1989 and rose significantly during 1990 through 1994 to 4.82/100,000 (P < 0.01). The observed increment was the result of a significant increase among the Jews, whereas the incidence among the Bedouin population remained relatively stable. Streptococcal toxic shock syndrome was diagnosed in three Jewish patients between 1992 and 1994. No predominance of any particular streptococcal M-type was observed. CONCLUSIONS: The incidence of pediatric S. pyogenes bacteremia has increased in Southern Israel in recent years. This increase has occurred among the Jewish population, among which the first cases of streptococcal toxic shock syndrome have recently occurred. The increased incidence observed is not the result of dissemination of a single virulent streptococcal clone.

Adolescent↗
PubMed1978

Effect of L-form Streptococcus pyogenes and of lipoteichoic acid on human cells in tissue culture.

These studies showed the destruction of growing primary and established human cell lines with a predilection for the group A streptococci by an L-form of Streptococcus pyogenes adapted to grow in isotonic media. Also, this L-form was detected by fluorescent antibody for longer periods of time than by viable count in infected but recovered tissue culture monolayers. Additional studies with human heart cells showed changes in their protein profile and fatty acid content (but not composition) after L-form infection. This report is the first to show that the morphological changes and death of human kidney cells by this viable L-form were mimicked by the structurally different lipoteichoic acids from this organism and its parental streptococcus. These lipoteichoic acids were also equally effective in preventing attachment of S. pyogenes to human cell monolayers, but their deacylation obviated these two activities. Finally, the attachment of the isotonic L-form, as well as the parental streptococcus, to growing human kidney cells suggested that a rigid cell wall is not a prerequisite for host attachment in vitro.

Cell Line↗
PubMed1994

Dual infections with Staphylococcus aureus and Streptococcus pyogenes causing toxic shock syndrome. Possible synergistic effects of toxic shock syndrome toxin 1 and streptococcal pyrogenic exotoxin C.

We describe a 35-year-old woman with clinical, microbiologic, and serologic findings suggesting that the patient developed toxic shock syndrome as a result of dual infections caused by toxin-producing strains of Staphylococcus aureus and Streptococcus pyogenes. Certain aspects of the pathogenesis of this toxin-related syndrome are reviewed.

Adult↗
PubMed1981

Enzyme-linked immunosorbent assay for detection of type A streptococcal exotoxin: kinetics and regulation during growth of Streptococcus pyogenes.

We describe the detection and quantitation of type A streptococcal exotoxin (erythrogenic toxin, streptococcal pyrogenic exotoxin) by an enzyme-linked immunosorbent assay. This sensitive and specific technique detected microgram amounts of type A exotoxin and was useful for studying the kinetics and regulation of type A exotoxin production during the growth of Streptococcus pyogenes NY5. Maximum production of type A exotoxin was observed during the mid-log phase of growth, similar to the production of other streptococcal extracellular products. When S. pyogenes NY5 was grown at 42 degrees C, decreases in both growth and type A exotoxin production were observed. The results obtained when we studied the influence of nutrient additives and metal ions on the production of type A exotoxin led to the conclusion that none of these factors significantly affected type A exotoxin synthesis and that regulation was constitutive.

Antitoxins↗
PubMed1980

[Immunohistology of the antibody-formation against M-protein of Streptococcus pyogenes in Macaca mulatta (author's transl)].

The immunohistology of the antibody synthesis against M proteins of Streptococcus pyogenes (group A streptococci) was studied in rhesus monkeys (Macaca mulatta). For the immunoelectron microscopic detection of antibody producing cells peroxidase-labelled M protein was used. Cryostat sections of glutaraldehyde-fixed lymphoid organs were incubated with the peroxidase-conjugate followed by 3,3'-diaminobenzidine and H2O2. The labelled tissue sections were further processed for the electron microscopy. Two sites of specific labelling were observed: 1) The cell membrane of lymphocytes and transformed lymphocytes and 2) the endoplasmic reticulum of plasma cells, proplasmocytes and transformed lymphocytes.

Animals↗
PubMed2001

The SpeB virulence factor of Streptococcus pyogenes, a multifunctional secreted and cell surface molecule with strepadhesin, laminin-binding and cysteine protease activity.

The interactions between pathogenic bacteria and the host need to be resolved at the molecular level in order to develop novel vaccines and drugs. We have previously identified strepadhesin, a novel glycoprotein-binding activity in Streptococcus pyogenes, which is regulated by Mga, a regulator of streptococcal virulence factors. We have now identified the protein responsible for the strepadhesin activity and find that (i) strepadhesin activity is carried by SpeB, streptococcal pyrogenic exotoxin with cysteine protease activity; (ii) SpeB carries laminin-binding activity of the bacteria; and (iii) SpeB is not only a secreted molecule but also occurs unexpectedly tightly bound to the bacterial cell surface. Thus, in contrast to the previous view of SpeB as mainly an extracellular protease, it is also present as a streptococcal surface molecule with binding activity to laminin and other glycoproteins.

Adhesins, Bacterial↗
PubMed2003

Primary bacterial pyomyositis associated with septic arthritis caused by Streptococcus pyogenes: a case report.

Pyomyositis is relatively rare in temperate climates. This is the first report of a case of calf pyomyositis associated with septic arthritis of the knee. This case illustrates that pyomyositis should be included in the differential diagnosis of a swollen, tender calf in an emergency setting. The other notable feature of this case is that the infective organism was not the usual Staphylococcus aureus but rather the relatively rarely involved Streptococcus pyogenes.

Adult↗
PubMed2005

Resistance to macrolides, clindamycin and telithromycin in Streptococcus pyogenes isolated in Spain during 2004.

OBJECTIVES: To study the antimicrobial susceptibility and prevalence of the different phenotypes and genotypes of macrolide resistance in group A streptococci isolated in Spain in 2004, and to compare the results with those obtained in 1998 and 2001 using the same methodology and centres. METHODS: A total of 530 unique isolates of Streptococcus pyogenes collected in 21 laboratories from 16 geographic areas (regions) in Spain were used. Antimicrobial susceptibility testing was performed using the agar dilution method. Discs containing erythromycin or clindamycin were used to recognize the phenotypes of macrolide-lincosamide-streptogramin (MLS) resistance. Genes encoding macrolide-lincosamide resistance were detected by PCR. RESULTS: Resistance to erythromycin was 21.7% [95% confidence interval (CI) 16.5-26.3]. The resistance to azithromycin was 21.5%, whereas the resistance to miocamycin and to clindamycin was 6.6% (95% CI 3.0-8.9). Thirty-one (5.8%) of the isolates were resistant to telithromycin. Of the 115 erythromycin-resistant isolates, 67.8% had the M phenotype, representing 14.7% of all the isolates tested. Thirty-five isolates (30.5% of the erythromycin-resistant strains and 6.6% of all the isolates) had the MLS(B) constitutive phenotype. There was a high prevalence of resistance to telithromycin (88.6%) among the 35 strains with the MLS(B) constitutive phenotype. When we compared these results with those from previous studies (1998 and 2001), we found a significant increase in the MLS(B) constitutive phenotype (P < 0.001), and a significant decrease in the M phenotype (P < 0.005) was noted. CONCLUSIONS: The significant increase in the prevalence of resistance to clindamycin and miocamycin, and the prevalence of resistance to telithromycin reached in a short period of time from the introduction of its use, underscore the need for continuous surveillance of antimicrobial resistance in S. pyogenes in Spain.

Anti-Bacterial Agents↗
PubMed1996

Antigenic epitope mapping of the M24 protein of Streptococcus pyogenes: implications for serodiagnosis of rheumatic fever.

Rheumatic fever continues to be a significant problem in Australian Aboriginal communities and developing countries worldwide. Early diagnosis could facilitate the institution of penicillin prophylaxis resulting in the prevention of recurrences of rheumatic fever. An overlapping biotinylated peptide bank of 82 peptides, based on the known sequence of Streptococcus pyogenes M24 protein, was used in a standard enzyme immunoassay. A total of 82 sera were tested from both aboriginal and non-aboriginal subjects with clinically proven rheumatic fever, rheumatic heart disease and matched controls. Two peptides with significant sequence homology at the C-terminal end were found to be discriminatory between aboriginal cases and controls. It is proposed that these peptides could be the basis of a serological test for rheumatic fever.

Adult↗
PubMed2000

In vitro activity of propolis against Streptococcus pyogenes.

Propolis, a multifunctional substance used by bees to maintain the safety of their hives, is popular for its therapeutic potential against some micro-organisms. Ethanolic extracts of two propolis specimens, collected from different areas within a region in the north-west of Italy, were examined to evaluate their antimicrobial activity against 46 Streptococcus pyogenes strains. By both agar dilution and agar diffusion methods, the minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) were </= 234 microg ml-1, corresponding to a one in 512 dilution of the 12% (w/v) extracts. One of the two propolis samples was more active and this extract was shown to be richer in the flavonoids pinocembrin and galangin using HPLC. Therefore, with a simple microbiological assay technique, in particular the agar dilution method, it was possible to standardize the analysis of propolis samples to identify the quality parameters of this natural product before use for medical treatment.

Child↗
PubMed1999

Nationwide survey in Italy of treatment of Streptococcus pyogenes pharyngitis in children: influence of macrolide resistance on clinical and microbiological outcomes. Artemis-Italy Study Group.

Throat swab specimens were obtained from 3,227 children with symptoms of acute pharyngotonsillitis. After 14 to 21 days, a second throat swab specimen was obtained at a follow-up visit. Over 42% of the 934 strains of Streptococcus pyogenes isolated in the primary study were resistant to erythromycin, azithromycin, and clarithromycin. Eradication rates among the 668 patients who entered the follow-up study were as follows: 84.1%, penicillin recipients; 82.7%, cephalosporin recipients; and 71.7%, macrolide recipients. Among patients treated with macrolides, the eradication rate was approximately 80% when the infecting organisms were erythromycin-susceptible and approximately 60% when they were erythromycin-resistant. These results indicate substantial in vitro macrolide resistance among Italian isolates of S. pyogenes. However, at least for a minor self-limiting condition such as acute S. pyogenes pharyngitis, our findings point to a limited overall correlation between in vitro susceptibility (to penicillins, cephalosporins, or macrolides) and eradication in patients treated with these drugs and an even weaker correlation between in vitro resistance (to macrolides) and noneradication in patients receiving macrolide therapy.

Adolescent↗
PubMed2004

Antimicrobial susceptibility of Streptococcus pneumoniae, Streptococcus pyogenes and Haemophilus influenzae collected from patients across the USA, in 2001-2002, as part of the PROTEKT US study.

BACKGROUND: The PROTEKT US (Prospective Resistant Organism Tracking and Epidemiology for the Ketolide Telithromycin in the United States) surveillance programme was started in 2000, to chart the emergence and spread of antimicrobial resistance among isolates of Streptococcus pneumoniae, Streptococcus pyogenes and Haemophilus influenzae from across the USA. METHODS: In 2001-2002 (Year 2 of PROTEKT US) 242 centres from 46 states and the territory of Puerto Rico submitted a total of 10 012 S. pneumoniae, 4508 S. pyogenes and 3296 H. influenzae isolates from community-acquired respiratory tract infections (CARTIs). Susceptibility testing was performed and interpreted using NCCLS methodology and criteria. RESULTS: Overall, 35.4% of S. pneumoniae were non-susceptible to penicillin (14.2% intermediate, MIC 0.12-1 mg/L; 21.2% resistant, MIC > or =2 mg/L) and 27.9% were resistant to erythromycin (MIC > or =1 mg/L) (0.2% intermediate, MIC 0.5 mg/L). A total of 105 (1.0%) isolates were resistant to levofloxacin (MIC > or =8 mg/L). More than 99.2% of isolates were susceptible to telithromycin (MIC < or =1 mg/L) irrespective of penicillin and/or erythromycin resistance. All S. pyogenes isolates were susceptible to penicillin (MIC < or =0.12 mg/L) and 5.7% were resistant to erythromycin (MIC > or =1 mg/L) (0.3% intermediate, MIC 0.5 mg/L). The MIC90 of telithromycin for S. pyogenes was 0.03 mg/L. A total of 27.5% of H. influenzae isolates were beta-lactamase producers. Overall, 27.8% were resistant (MIC > or =4 mg/L) and 1.1% were intermediate to ampicillin (MIC 2 mg/L). A total of 96.3% of H. influenzae isolates were susceptible to telithromycin (MIC < or =4 mg/L). CONCLUSIONS: Antimicrobial resistance continues to be a problem in the USA. The ketolide telithromycin continues to show high activity against common CARTI pathogens, including those resistant to beta-lactams and macrolides.

Anti-Infective Agents↗
PubMed2006

Illustration of a common framework for relating multiple typing methods by application to macrolide-resistant Streptococcus pyogenes.

The studies that correlate the results obtained by different typing methodologies rely solely on qualitative comparisons of the groups defined by each methodology. We propose a framework of measures for the quantitative assessment of correspondences between different typing methods as a first step to the global mapping of type equivalences. A collection of 325 macrolide-resistant Streptococcus pyogenes isolates associated with pharyngitis cases in Portugal was used to benchmark the proposed measures. All isolates were characterized by macrolide resistance phenotyping, T serotyping, emm sequence typing, and pulsed-field gel electrophoresis (PFGE), using SmaI or Cfr9I and SfiI. A subset of 41 isolates, representing each PFGE cluster, was also characterized by multilocus sequence typing (MLST). The application of Adjusted Rand and Wallace indices allowed the evaluation of the strength and the directionality of the correspondences between the various typing methods and showed that if PFGE or MLST data are available one can confidently predict the emm type (Wallace coefficients of 0.952 for both methods). In contrast, emm typing was a poor predictor of PFGE cluster or MLST sequence type (Wallace coefficients of 0.803 and 0.655, respectively). This was confirmed by the analysis of the larger data set available from http://spyogenes.mlst.net and underscores the necessity of performing PFGE or MLST to unambiguously define clones in S. pyogenes.

Anti-Bacterial Agents↗
PubMed2004

Streptococcus pyogenes and Lactobacillus rhamnosus differentially induce maturation and production of Th1-type cytokines and chemokines in human monocyte-derived dendritic cells.

Dendritic cells (DCs) are the most efficient antigen-presenting cells and thus, have a major role in regulating host immune responses. In the present study, we have analyzed the ability of Gram-positive, pathogenic Streptococcus pyogenes and nonpathogenic Lactobacillus rhamnosus to induce the maturation of human monocyte-derived DCs. Stimulation of DCs with S. pyogenes resulted in strong expression of DC costimulatory molecules CD80, CD83, and CD86 accompanied with a T helper cell type 1 (Th1) cytokine and chemokine response. S. pyogenes also induced interleukin (IL)-2 and IL-12 production at mRNA and protein levels. In addition, IL-23 and IL-27 subunits p40, p19, p28, and EBI3 were induced at mRNA level. In contrast, L. rhamnosus-stimulated DCs showed only moderate expression of costimulatory molecules and produced low levels of cytokines and chemokines. Furthermore, no production of IL-2 or IL-12 family cytokines was detected. Bacteria-induced DC maturation and especially cytokine and chemokine production were reduced when bacteria were heat-inactivated. Our results show that human monocyte-derived DCs respond differently to different Gram-positive bacteria. Although pathogenic S. pyogenes induced a strong Th1-type response, stimulation with nonpathogenic L. rhamnosus resulted in development of semi-mature DCs characterized by moderate expression of costimulatory molecules and low cytokine production.

Cell Differentiation↗
PubMed2000

The extracellular hyaluronidase gene (hylA) of Streptococcus pyogenes.

Group A streptococci produce an extracellular hyaluronidase (hyaluronate lyase) which may be associated with the spread of the organism during infection. The gene for this hyaluronidase (hylA) encodes an 868 amino acid protein with a molecular size of 99636 Da. Cleavage of the proposed signal peptide results in an extracellular protein of 95941 Da. Comparison with other bacterial hyaluronidases indicates strong similarities to the genes from Streptococcus pneumoniae, Streptococcus agalactiae and Staphylococcus aureus. A region internal to the hylA gene was amplified from all 175 strains of Streptococcus pyogenes tested suggesting a widespread distribution of the gene.

DNA, Bacterial↗
PubMedDate not supplied

Post-antibiotic effects of ofloxacin on Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus, and Streptococcus pyogenes.

A viable counting technique was used to determine the post-antibiotic effect (PAE) of ofloxacin against four bacterial species, treated with either once of four times the minimum inhibitory concentration for 1 or 3 h. Similar to the results obtained previously with ciprofloxacin, ofloxacin gave PAE values with Escherichia coli, Staphylococcus aureus, and Streptococcus pyogenes. Cell division of Klebsiella pneumoniae was inhibited on removal of ofloxacin, but no clear PAE was demonstrated with this species because once replication recommenced, the mean generation times of drug-treated cultures were much shorter than those of untreated controls. Therefore, although the results obtained with ciprofloxacin and ofloxacin imply a consistency of PAE for 4-quinolones within a species, the response to DNA damage induced by 4-quinolones is multifaceted and species dependent. 4-quinolones inhibit both DNA replication and cell division, whilst at the same time stimulating DNA repair pathways. Thus, in some cases PAEs result from an increased post-treatment lag phase which may be followed by nearly normal multiplication, whereas in other cases a long lag may be followed by abnormally rapid cell division, with the generation times of treated cultures being shorter than those of corresponding drug-free controls. The PAE of a drug-induced lag may thus be masked by rapid cell division once growth resumes.

Colony Count, Microbial↗
PubMed2005

Ketolide resistance in Streptococcus pyogenes correlates with the degree of rRNA dimethylation by Erm.

Macrolide and ketolide antibiotics inhibit protein synthesis on the bacterial ribosome. Resistance to these antibiotics is conferred by dimethylation at 23S rRNA nucleotide A2058 within the ribosomal binding site. This form of resistance is encoded by erm dimethyltransferase genes, and is found in many pathogenic bacteria. Clinical isolates of Streptococcus pneumoniae with constitutive erm(B) and Streptococcus pyogenes with constitutive erm(A) subtype (TR) are resistant to macrolides, but remain susceptible to ketolides such as telithromycin. Paradoxically, some strains of S. pyogenes that possess an identical erm(B) gene are clinically resistant to ketolides as well as macrolides. Here we explore the molecular basis for the differences in these streptococcal strains using mass spectrometry to determine the methylation status of their rRNAs. We find a correlation between the levels of A2058-dimethylation and ketolide resistance, and dimethylation is greatest in S. pyogenes strains expressing erm(B). In constitutive erm strains that are ketolide-sensitive, appreciable proportions of the rRNA remain monomethylated. Incubation of these strains with subinhibitory amounts of the macrolide erythromycin increases the proportion of dimethylated A2058 (in a manner comparable with inducible erm strains) and reduces ketolide susceptibility. The designation 'constitutive' should thus be applied with some reservation for most streptococcal erm strains. One strain worthy of the constitutive designation is S. pyogenes isolate KuoR21, which has lost part of the regulatory region upstream of erm(B). In S. pyogenes KuoR21, nucleotide A2058 is fully dimethylated under all growth conditions, and this strain displays the highest resistance to telithromycin (MIC > 64 microg ml-1).

Amino Acid Sequence↗