Virulence of group A streptococci in fertile hens eggs is mainly effected by M protein and streptolysin O

Schmidt, Karl‐Hermann; Gerlach, Dieter; Gubbe, Knut; Geyer, Angelika; Birch-Hirschfeld, Eckhard; Straube, Eberhard; Podbielski, Andreas

doi:10.1078/1438-4221-00102

“…We show here that human pathogenic GCS and GGS strains can carry superantigen genes. This implicates that GCS and GGS have potential tools like GAS to resist host defence mechanisms like M protein and streptolysin O [11,22,23,28] and may be potential producers of some superantigen. Expression studies of SPEG in such strains are in progress.…”

Section: Discussionmentioning

confidence: 97%

Superantigen-like gene(s) in human pathogenicStreptococcus dysgalactiae, subsp.equisimilis: genomic localisation of the gene encoding streptococcal pyrogenic exotoxin G (speG^dys)

Sachse

¹

,

Seidel

²

,

Gerlach

³

et al. 2002

FEMS Immunology &Amp; Medical Microbiology

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Streptococcus pyogenes (GAS) causes about 90% of streptococcal human infections while group C (GCS) and G (GGS) streptococci can be pathogenic for different mammalians. Especially the human pathogenic GCS and GGS, Streptococcus dysgalactiae, subsp. equisimilis, account for 5-8% of the human streptococcal diseases like wound infections, otitis media, purulent pharyngitis and also streptococcal toxic shock syndrome. A defined superantigen so far was not identified in GCS and GGS strains. In the present investigation we screened DNA of GCS and GGS human isolates for the presence of genes for streptococcal pyrogenic exotoxins (spe) by hybridisation with probes that stand for the GAS genes speA, speC, speZ (smeZ), speH, speG, speI, speJ and ssa. In many GCS and GGS strains we found positive reactions with the probes speG, speJ and ssa, but not with the probes for the remaining genes under investigation. PCR amplification with subsequent sequence analysis of the PCR fragments revealed only the presence of the gene speG in GCS and GGS strains, while no DNA fragments specific for speJ and ssa could be amplified. Additionally, the upstream and downstream regions flanking speG in GGS strain 39072 were sequenced. Remarkable differences were found in the neighbourhood of speG between GAS and GGS sequences. Downstream of speG we identified in strain GGS 39072 two new open reading frames encoding proteins with no similarity to protein sequences accessible in the databases so far. In the compared GAS strains SF370 and MGAS8232, this segment, apart from some small fragments, had been deleted. Our analysis suggests that a gene transfer from GGS to GAS has preceded following deletion of the two genes orf1 and orf2 in GAS.

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“…We show here that human pathogenic GCS and GGS strains can carry superantigen genes. This implicates that GCS and GGS have potential tools like GAS to resist host defence mechanisms like M protein and streptolysin O [11,22,23,28] and may be potential producers of some superantigen. Expression studies of SPEG in such strains are in progress.…”

Section: Discussionmentioning

confidence: 98%

Superantigen-like gene(s) in human pathogenic Streptococcus dysgalactiae, subsp. equisimilis: genomic localisation of the gene encoding streptococcal pyrogenic exotoxin G (speGdys)

Sachse

2002

FEMS Immunology and Medical Microbiology

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Streptococcus pyogenes (GAS) causes about 90% of streptococcal human infections while group C (GCS) and G (GGS) streptococci can be pathogenic for different mammalians. Especially the human pathogenic GCS and GGS, Streptococcus dysgalactiae, subsp. equisimilis, account for 5-8% of the human streptococcal diseases like wound infections, otitis media, purulent pharyngitis and also streptococcal toxic shock syndrome. A defined superantigen so far was not identified in GCS and GGS strains. In the present investigation we screened DNA of GCS and GGS human isolates for the presence of genes for streptococcal pyrogenic exotoxins (spe) by hybridisation with probes that stand for the GAS genes speA, speC, speZ (smeZ), speH, speG, speI, speJ and ssa. In many GCS and GGS strains we found positive reactions with the probes speG, speJ and ssa, but not with the probes for the remaining genes under investigation. PCR amplification with subsequent sequence analysis of the PCR fragments revealed only the presence of the gene speG in GCS and GGS strains, while no DNA fragments specific for speJ and ssa could be amplified. Additionally, the upstream and downstream regions flanking speG in GGS strain 39072 were sequenced. Remarkable differences were found in the neighbourhood of speG between GAS and GGS sequences. Downstream of speG we identified in strain GGS 39072 two new open reading frames encoding proteins with no similarity to protein sequences accessible in the databases so far. In the compared GAS strains SF370 and MGAS8232, this segment, apart from some small fragments, had been deleted. Our analysis suggests that a gene transfer from GGS to GAS has preceded following deletion of the two genes orf1 and orf2 in GAS.

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“…S. pyogenes strains used in this study are depicted in Table 1. A streptococcal pyrogenic exotoxin B (SPE-B)-negative S. pyogenes mutant 1579 was derived from strain 634 (M49 CS101) (14,21), and a streptolysin O (SLO)-negative mutant A468 (T17) was derived from strain 3413 (M1 38541) (20). As control strains E. faecalis (H1A, Minneapolis), Staphylococcus aureus (SA1, H Mi 1, Giessen), and Escherichia coli OP50 were used.…”

Section: Methodsmentioning

confidence: 99%

Hydrogen Peroxide-Mediated Killing ofCaenorhabditis elegansbyStreptococcus pyogenes

Jansen

¹

,

Bolm

²

,

Balling

³

et al. 2002

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Caenorhabditis elegans is currently introduced as a new, facile, and cheap model organism to study the pathogenesis of gram-negative bacteria such as Pseudomonas aeruginosa and Salmonella enterica serovar Typhimurium. The mechanisms of killing involve either diffusible exotoxins or infection-like processes. Recently, it was shown that also some gram-positive bacteria kill C. elegans, although the precise mechanisms of killing remained open. We examined C. elegans as a pathogenesis model for the gram-positive bacterium Streptococcus pyogenes, a major human pathogen capable of causing a wide spectrum of diseases. We demonstrate that S. pyogenes kills C. elegans, both on solid and in liquid medium. Unlike P. aeruginosa and S. enterica serovar Typhimurium, the killing by S. pyogenes is solely mediated by hydrogen peroxide. Killing required live streptococci; the killing capacity depends on the amount of hydrogen peroxide produced, and killing can be inhibited by catalase. Major exotoxins of S. pyogenes are not involved in the killing process as confirmed by using specific toxin inhibitors and knockout mutants. Moreover, no accumulation of S. pyogenes in C. elegans is observed, which excludes the involvement of infection-like processes. Preliminary results show that S. pneumoniae can also kill C. elegans by hydrogen peroxide production. Hydrogen peroxide-mediated killing might represent a common mechanism by which gram-positive, catalase-negative pathogens kill C. elegans.Streptococcus pyogenes is a major human pathogen, causing a wide spectrum of pyogenic infections such as tonsillitis, pharyngitis, scarlet fever, and skin inflammation. The organism can also invade tissues and cells and cause life-threatening diseases such as necrotizing fasciitis and toxic shock syndrome. Untreated infections can lead to serious postinfection complications in the form of rheumatic heart disease and glomerulonephritis in predisposed individuals (22). The pathogenesis of streptococci is so complex that the infections caused by these organisms and their sequelae have not been completely understood. Bacterial factors, host factors, and an abnormal immune response determine the outcome of the infection. One of the difficulties in understanding the streptococcus-host interaction is the lack of a suitable animal model. Recently a mouse model of invasive streptococcal infections has been developed (16), but there remains a great need for new animal models to understand streptococcal pathogenesis.Ausubel and coworkers have introduced Caenorhabditis elegans as a new, facile, and cheap model organism to study the pathogenesis of the gram-negative bacteria Pseudomonas aeruginosa (5,15,(23)(24)(25)27) and Salmonella enterica serovar Typhimurium (1, 2, 13), and Garsin et al. showed that the gram-positive bacteria Enterococcus faecalis and Streptococcus pneumoniae kill C. elegans (8). Hodgkin et al. demonstrated that the genetically amenable nematode C. elegans is ideally suited to identify host factors (12).We examined C. elegans as a pathogenes...

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Virulence of group A streptococci in fertile hens eggs is mainly effected by M protein and streptolysin O

Cited by 6 publications

References 38 publications

Superantigen-like gene(s) in human pathogenicStreptococcus dysgalactiae, subsp.equisimilis: genomic localisation of the gene encoding streptococcal pyrogenic exotoxin G (speG^dys)

Superantigen-like gene(s) in human pathogenicStreptococcus dysgalactiae, subsp.equisimilis: genomic localisation of the gene encoding streptococcal pyrogenic exotoxin G (speG^dys)

Superantigen-like gene(s) in human pathogenic Streptococcus dysgalactiae, subsp. equisimilis: genomic localisation of the gene encoding streptococcal pyrogenic exotoxin G (speGdys)

Hydrogen Peroxide-Mediated Killing ofCaenorhabditis elegansbyStreptococcus pyogenes

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Virulence of group A streptococci in fertile hens eggs is mainly effected by M protein and streptolysin O

Cited by 6 publications

References 38 publications

Superantigen-like gene(s) in human pathogenicStreptococcus dysgalactiae, subsp.equisimilis: genomic localisation of the gene encoding streptococcal pyrogenic exotoxin G (speGdys)

Superantigen-like gene(s) in human pathogenicStreptococcus dysgalactiae, subsp.equisimilis: genomic localisation of the gene encoding streptococcal pyrogenic exotoxin G (speGdys)

Superantigen-like gene(s) in human pathogenic Streptococcus dysgalactiae, subsp. equisimilis: genomic localisation of the gene encoding streptococcal pyrogenic exotoxin G (speGdys)

Hydrogen Peroxide-Mediated Killing ofCaenorhabditis elegansbyStreptococcus pyogenes

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Product

Resources

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Superantigen-like gene(s) in human pathogenicStreptococcus dysgalactiae, subsp.equisimilis: genomic localisation of the gene encoding streptococcal pyrogenic exotoxin G (speG^dys)

Superantigen-like gene(s) in human pathogenicStreptococcus dysgalactiae, subsp.equisimilis: genomic localisation of the gene encoding streptococcal pyrogenic exotoxin G (speG^dys)