PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Streptococcus pyogenes”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMed1976

[The immunobiology of M-proteins of Streptococcus pyogenes. I. Isolation and purification of M-proteins from group A streptococci (Streptococcus pyogenes) type 1].

Streptococci of group A, type 1, are lysed by use of phage associated lysin, which is characterized as a N-Acetyl-D-glucosaminidase. This enzyme has no proteolytic activity. Type specific protein antigens are isolated and purified by ion exchange chromatography on CM-cellulose and DEAE-cellulose of the crude extract, concentrated by precipitation with ammonium sulfate. The immunization tests are carried out on monkeys and rabbits.

Animals↗
PubMed1975

Transduction of drug resistance to tetracycline, chloramphenicol, macrolides, lincomycin and clindamycin with phages induced from Streptococcus pyogenes.

Strains of Streptococcus pyogenes isolated from pediatric patients with acute infections which were resistant to one or more of the antibiotics, tetracycline (TC), chloramphenicol (CP), macrolide antibiotics (erythromycin, kitasamycin, oleandomycin, josamycin), lincomycin (LCM) and clindamycin (CLM), were used for transduction of drug resistance. These drug-resistant strains were treated with mitomycin C to induce phages and transduction of drug resistance was attempted by means of phages so induced. It was found that transduction of resistance to the above antibiotics was possible. The transductants obtained on TC-containing selective agar plate were resistant to TC alone while those produced on CP- or erythromycin (EM)-containing selective agar plate were resistant to CP, macrolide antibiotics (Mac), LCM and CLM. From this finding, it was inferred that transduction of resistance to TC, CP, Mac, LCM and CLM via phages occurred in two different patterns, i.e., transfer of resistance to TC alone and that of resistance to CP, Mac, LCM and CLM. All of the transductants obtained were found to belong to group A. In T-typing, they were of the same T-12 type as the donor and recipient strains in a majority of cases though some were not typable.

Anti-Bacterial Agents↗
PubMed1978

Interaction between erythromycin and lincomycin in Streptococcus pyogenes.

Ten strains of Streptococcus pyogenes isolated were moderately resistant to erythromycin and highly but paradoxically resistant to lincomycin, and they showed antagonism between the two antibiotics. Another strain was moderately resistant to erythromycin and sensitive to lincomycin, and it showed synergism between the two antibodies.

Dose-Response Relationship, Drug↗
PubMed1979

Immunoelectron microscopic localization of T proteins in the cell wall of Streptococcus pyogenes.

T proteins of Streptococcus pyogenes (group A streptococci) were localized by means of immunochromatographical isolated anti-T-antibodies. For the electron microscopical detection both the direct and the indirect immunoferritin techniques were used. The arrangement of the ferritin particles showed, that the T proteins are evenly distributed on the whole cell surface. They are immediately bound to the outer layer of the cell wall or to only short filaments. On isolated cell walls the T protein was detected only on the outer surface.

Agglutination Tests↗
PubMed1975

Morphological and immunological characteristics of Streptococcus pyogenes, group A, type 50.

Streptococcus pyogenes, group A, type 50, in contrast to other group A streptococci, causes spontaneous disease in mice thereby providing a suitable experimental model for the study of human streptococcosis. Type 50 possesses various peculiar morphological and immunobiological characteristics and under certain conditions forms and extremely thick non-antigenic capsule which seems to interfere with the binding of antibody. This interference is most likely responsible for the difficulties in detecting type 50 streptococci in the tissues of infected mice by immunofluorescent staining. Whereas the surface components (hyaluronic acid, M-antigen) of the type 50 Streptococcus exhibit several uncommon features, the more deeply located cell wall antigens, like peptidoglycan and C-carbohydrate, do not differ in either their chemical constituents or their serological reactions from the comparable components of other group A streptococci.

Animals↗
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↗
PubMed1979

Chemical analysis of changes in membrane composition during growth of Streptococcus pyogenes.

Changes in the structural components of the Streptococcus pyogenes membrane between exponential and early stationary phases of growth are reported. The overall protein composition ranged from 70 to 73% of the dry weight of the membranes, irrespective of the phase of growth from which they were isolated. Amino acid analyses of membranes isolated from streptococci in either the exponential or stationary phase of growth demonstrated that two amino acids, cysteine and tryptophan, were absent. Further analysis of the membrane proteins by sodium dodecyl sulfate-polyacrylamide gradient gel electrophoresis demonstrated that there were proteins unique to a particular phase of growth as well as differences in the amount of specific proteins from the various growth phases. In addition, membranes isolated from exponential-phase cultures contained a higher percentage of peripheral protein than did stationary-phase membranes. There also appeared to be an increase in the amount of outer surface proteins during this growth phase. The phosphorus content of the membranes increased during the stationary phase of growth, whereas the sugar composition remained constant. The only sugar found under various conditions of growth in any of the strains was glucose. Total fatty acid content and the mole percent composition of various fatty acids did not change in the different phases of growth. However, the mole percent composition of fatty acids in the membranes of various group A streptococci did differ between strains. Therefore, these results provide evidence that the composition of membranes of S. pyogenes does not remain constant throughout the growth phases of the culture.

Adenosine Triphosphatases↗
PubMed1978

The cervical lymph nodes in Streptococcus pyogenes, group A, type 50, infection in mice.

Streptococcus pyogenes, group A, type 50, one of the few group A streptococcal types naturally occuring in mice, proved highly virulent in this species after experimental infection. Intranasal infection of 96 mice (Swiss albino, NMRI, and CBA) with this microorganism induced profound reactions in the cervical lymph nodes of 69% of the animals. Histologically, two different forms of reaction were distinguishable. In 61 mice, the lymph nodes exhibited follicular and lymphoplasmacellular hyperplasia and in 9 animals suppurative lymphadenitis was present. The ability of type 50 streptococci to persist in the pharynx of mice, and the similarity of the morphological changes induced by this organism appear to make intranasal murine group A, type 50, streptococcal infection a suitable model for human streptococcal pharyngitis.

Animals↗
PubMed1975

Plasmid-determined resistance to erythromycin: comparison of strains of streptococcus faecalis and streptococcus pyogenes with regard to plasmid hmology and resistance inducibility.

Streptococcus faecalis strains DS-5 and Streptococcus pyogenes strain AC-1 both have a 17 million dalton plasmid that determines resistance to erythromycin, lincomycin, and vernamycin B(alpha). The results of deoxyribonucleic acid-deoxyribonucleic acid hybridization experiments indicate that the two plasmids are about 95% homologous. It was also shown that erythromycin resistance is inducible in AC-1 and constitutive in DS-5.

Drug Resistance, Microbial↗
PubMed1979

The role of M protein in phagocytosis. I. Activity of some enzymes in phagocytic cells during infection with Streptococcus pyogenes in vivo.

The phagocytosis of two type 12 Streptococcus pyogenes strains differing in M protein presence was investigated in vivo. The rate of phagocytosis and the streptococcal viability in phagocytic cells and outside of them was studied simultanously with estimation of enzymatic activity in phagocytic cells. It was observed that M positive strain was phagocytized at lower rate and also exhibited longer viability. Decrease of lactic dehydrogenase and ATP-ase activity in phagocytes of rabbits infected with M+ strain was also detected. These results suggest that M protein disturbs phagocytosis by inhibiting their main metabolic pathway of glycolysis.

Acid Phosphatase↗
PubMed1975

Immunogenicity of ribosomal vaccines isolated from group A, type 14 Streptococcus pyogenes.

A ribosomal preparation isolated from group A, type 14 Streptococcus pyogenes protected mice against a challenge of 1,000 mean lethal doses. Optimal immunization consisted of subcutaneous administration of 326 mug of protein with Freund incomplete adjuvant. Animals immunized with higher or lower antigen concentrations showed decreased survival. Freund incomplete adjuvant was necessary to insure optimum immunization. Immunochemical studies showed no M protein or C carbohydrate present in the ribosomal preparation. Mice optimally immunized with the type 14 ribosomal preparation were protected against heterologous challenge with M types 2, 5, 8, and 12. Protein-free ribonucleic acid extracts isolated from the type 14 ribosomal preparation did not protect mice against homologous challenge. But ribonucleic acid-free protein extracts showed 100% protection in mice after homologous challenge.

Animals↗
PubMed1976

Defective synthesis of lipid intermediates for peptidoglycan formation in a stabilized L-form of Streptococcus pyogenes.

Membrane preparations obtained from a stabilized L-form of Streptococcus pyogenes are incapable of synthesizing peptidoglycan from uridine-5'-diphospho-N-acetyl-D-muramyl-L-Ala-D-iso-Glu-L-Lys-D-Ala-D-Ala and uridine-5'-diphospho-N-acetyl-D-glucosamine, in contrast with similar preparations from the parental streptococcus. Furthermore, 50-fold higher levels of lipid intermediates which serve as membrane-bound substrates for peptidoglycan synthesis are synthesized in reaction mixtures containing streptococcal membranes than with similar preparations from the L-form. These observations suggest that the inability of this stabilized L-form to form a cell wall in vivo lies, at least in part, in its failure to synthesize significant quantities of the lipid substrates for peptidoglycan synthesis.

Adenosine Triphosphate↗
PubMed1978

Hemolytic mutants of group A Streptococcus pyogenes.

Hemolytic mutants of Lancefield strain SS-95 and ATCC 19615 Streptococcus pyogenes were produced by treatment with N-methyl-N'-nitro-N-nitrosoguanidine. These mutants contained the same levels of streptolysin O, nicotinamide adenine dinucleotidase, deoxyribonuclease, and hyaluronidase. The mutants were deficient in streptolysin S, as was the naturally occurring nonhemolytic Lowry strain. The mutants retained their pathogenicity for mice and, when reisolated from the dead animals, produced the mutant hemolytic pattern.

Animals↗
PubMed2025

Temporal and geographical lineage dynamics of invasive Streptococcus pyogenes in Australia from 2011 to 2023: a retrospective, multicentre, clinical and genomic epidemiology study.

BACKGROUND: Defining the temporal dynamics of invasive Streptococcus pyogenes (group A Streptococcus) and differences between hyperendemic and lower-incidence regions provides crucial insights into pathogen evolution and, in turn, informs preventive measures. We aimed to examine the clinical and temporal lineage dynamics of S pyogenes across different disease settings in Australia to improve understanding of drivers of pathogen diversity. METHODS: In this retrospective, multicentre, clinical and genomic epidemiology study, we identified cases of invasive S pyogenes infection from normally sterile sites between Jan 1, 2011, and Feb 28, 2023. Data were collected from five hospital networks across low-incidence regions in temperate southeast Australia and the hyperendemic, tropical, and largely remote Top End of the Northern Territory of Australia. The crude incidence rate ratio (IRR) of bloodstream S pyogenes infection comparing the Top End and southeast Australia and in First Nations people compared with non-First Nations people was estimated by quasi-Poisson regression. We estimated odds ratios (ORs) of intensive care unit (ICU) admission, in-hospital mortality, and 30-day mortality for the Top End versus southeast Australia using logistic regression. Retrieved and successfully sequenced isolates were assigned lineages at whole-genome resolution. Temporal trends in the composition of co-circulating lineages were compared between the two regions. We used an S pyogenes-specific multistrain simulated transmission model to examine the relationship between host population-specific parameters and observed pathogen lineage dynamics. The prevalence of accessory genes (those present in 5-95% of all genomes) was compared across geographies and temporal periods to investigate genomic drivers of diversity. FINDINGS: We identified 500 cases of invasive S pyogenes infection in patients in the Top End and 495 cases in patients in southeast Australia. The crude IRR of bloodstream infection for the Top End compared with southeast Australia was 5·97 (95% CI 4·61-7·73) across the entire study period; in the Top End, infection disproportionately affected First Nations people compared with non-First Nations people (5·41, 4·28-6·89). The odds of in-hospital mortality (OR 0·43, 95% CI 0·26-0·70), 30-day mortality (0·38, 0·23-0·63), and ICU admission (0·42, 0·30-0·59) were lower in the Top End than in southeast Australia. Longitudinal lineage analysis of 642 S pyogenes genomes identified waves of replacement with distinct lineages in the Top End, whereas southeast Australia had a small number of dominant lineages that persisted and cycled in frequency. The transmission model qualitatively reproduced a similar pattern of replacement with distinct lineages when using a high transmission rate, small population size, and high levels of human movement-characteristics similar to those of communities in the hyperendemic Top End. Using a lower transmission rate, larger population size, and lower levels of migration similar to those of communities in urbanised southeast Australia, the transmission model qualitatively reproduced a pattern of dominant lineages that cycled in frequency. Despite distinct circulating lineages, the prevalence of accessory genes in the bacterial population was maintained across geographies and temporal periods. INTERPRETATION: In a hyperendemic setting, the replacement of distinct S pyogenes lineages occurred in waves, which could be linked to the disproportionate burden of disease and sparse human population in this setting. The maintenance of bacterial gene frequency could be consistent with multilocus selection. These findings suggest that lineage-specific interventions-such as vaccines under development-should consider disease setting and, without broad cross-protection, might lead to lineage replacement. FUNDING: National Health and Medical Research Council, and Leducq Foundation.

Humans↗
PubMed1978

Isolation and characterization of a Streptococcus mutans bacteriocin inhibitor from Streptococcus pyogenes.

An inhibitor of Streptococcus mutans strain GS5 bacteriocin was released from a bacteriocin-sensitive strain of S. pyogenes by sonic treatment and partly purified by gel filtration on a Sepharose 6B column. The inhibitory factor was sensitive to heat, trypsin, and periodate and possessed a molecular weight of approximately 93,000. This factor may be the receptor for the S. mutans bacteriocin.

Bacterial Proteins↗
PubMed1975

In vitro sensitivity of hemophilus influenzae and streptococcus pyogenes to co-trimoxazole.

The invitro testing of Hemophilus influenzae and Streptococcus pyogenes for co-trimoxazole sensitivity requires certain "defined" media that have to be free of inhibitory substances. The use of Columbia agar base with Fildes extract for H. influenzae or of blood agar for S. pyogenes may produce "false-resistant" strains. The addition of thymidine phosphorylases in the form of gentlylysed horse blood (2 to 10%) does not remove all inhibitors in those tests, especially where "undefined" agar bases are used, and results in scanty growth of H. influenzae; the addition of more than 2% results in dark plates, making reading of sensitivities difficult. Fildes agar for testing H. influenzae may be made with enriched sheep or horse blood if the proper "defined" agar base is used. The use of Wellcotest or DST (Oxoid) agar is recommended with Fildes extract for H. influenzae or with blood for S. pyogenes for in vitro testing for co-trimoxazole sensitivity. The addition of thymidine phosphorylase in the form of 2% lysed horse blood does not interfere with reading. However, it results in scanty growth of H. influenzae. Proper inoculation of plates is important. The growth on the plates should be light, dense, but not confluent. Heavy growth may render some strains "false-resistant" even when defined media are used. Our results indicate that many of the previously reported resistant strains of H. influenzae and S. pyogenes may have been "false-resistant" because of the use of "undefined" media. We believe that, in view of our results, respiratory infections may be treated with co-trimoxazole until bacteriologic studies prove that this treatment is contraindicated, since H. influenzae and S. pyogenes are usually found sensitive in vitro under proper conditions.

Animals↗