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MP021 Superantigen like gene in human pathogenic Streptococcus dysgalactiae, subsp. equisimilis: Recombinant expression and characterisation of putative streptococcal pyrogenic exotoxin G (SPEGdys)
Wissenschaftliches Programrn 55. DGHM-Tagung 29. September-1. Oktober 2003 in Dresden Abstracts - Poster
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Superantigen like gene in human pathogenic Streptococcus dysgalactiae, subsp, equisimilis: Recombinant expression and characterisation of putative streptococcal pyrogenic exotoxin G (SPEG dye) Sachse, S.1; R6diger, S.1; Seidel, P.~; R6del, J.~; Straube, E}; Gerlach, D.~; Schmidt, 1
1Friedrich-Schiller-University Jena; Institute of Medical Microbiology Streptococcus pyogenes (GAS) cause about 90 percent 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 percent of the human streptococcal diseases like wound infections, otitis media, purulent pharyngitis and also streptococcal toxic shock syndrome. Recently, our group has identified a superantigen like gene, named speG dys in human pathogenic GCS and GGS strains. This showed for the first time, that GCS and GGS are potential producers of superantigens. The sequence of speGdys showed high homology to the gene of SPEG from group A streptococci. Both unprocessed proteins posses a putative signal peptide of 24 amino acids. Additionally, the upstream and downstream regions flanking speG ~ys in GGS strain 39072 were analysed and differences were found in the neighbourhood of speG dys from GGS compared with the region around: speG cAs of GAS. In this report we have cloned speGdys of the GGS strain 39072 in E. coil by using the expression vector pET100. The expressed fusion protein rSPEGdys contained at the N-terminus 36 foreign amino acids coming from the plasmid pET100. The mature protein from which the signal peptide was omitted followed and its sequence started with the amino acids DEI. Our constructed protein rSPEG~ys showed serological cross reactivity to SPEGGAs from GAS demonstrating high similarity between both proteins. But, in contrast to SPEGcAs rSPEG~ys did not show lymphocyte stimulating activity. The absence of biological activity of the recombinant protein is discussed.
Investigation of the deacetylation in the biofilm associated staphylococcal exopolysaccharide PIA Birkenstock, T. 1, G6tz, F. 1 1University of TElbingen; Microbial Genetics Introduction: Previous studies have identified a ~-l.6-1inked Nacetylglucoseamine polymer PIA (Polysaccharide Intercellular Adhesin) as the major component of the extracellular matrix in staphylococcal biofilms (Mack et al. 1996). Structural analyses of PIA have shown that this polysaccharide is partially deacetylated. A corresponding deacetylase, however, has to date not yet been identified. Here, we addressed the question whether IcaB plays a role in the deacetylation of PIA. PIA was extracted from S. carnosus (pTXicaADBC) and S. carnosus (pTXicaADABC) clones (Gerke et al. 1998) and the degree of deacetylation of polysaccharides in both extracts was compared.
http://www.dghm.org
248
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3
v'~N D MI~3.0~x
Superantigen like gene in human pathogenic Streptococcus dysgalactiae, subsp, equisimilis: Recombinant expression and characterisation of putative streptococcal pyrogenic exotoxin G (SPEG dye) Sachse, S.1; R6diger, S.1; Seidel, P.~; R6del, J.~; Straube, E}; Gerlach, D.~; Schmidt, 1
1Friedrich-Schiller-University Jena; Institute of Medical Microbiology Streptococcus pyogenes (GAS) cause about 90 percent 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 percent of the human streptococcal diseases like wound infections, otitis media, purulent pharyngitis and also streptococcal toxic shock syndrome. Recently, our group has identified a superantigen like gene, named speG dys in human pathogenic GCS and GGS strains. This showed for the first time, that GCS and GGS are potential producers of superantigens. The sequence of speGdys showed high homology to the gene of SPEG from group A streptococci. Both unprocessed proteins posses a putative signal peptide of 24 amino acids. Additionally, the upstream and downstream regions flanking speG ~ys in GGS strain 39072 were analysed and differences were found in the neighbourhood of speG dys from GGS compared with the region around: speG cAs of GAS. In this report we have cloned speGdys of the GGS strain 39072 in E. coil by using the expression vector pET100. The expressed fusion protein rSPEGdys contained at the N-terminus 36 foreign amino acids coming from the plasmid pET100. The mature protein from which the signal peptide was omitted followed and its sequence started with the amino acids DEI. Our constructed protein rSPEG~ys showed serological cross reactivity to SPEGGAs from GAS demonstrating high similarity between both proteins. But, in contrast to SPEGcAs rSPEG~ys did not show lymphocyte stimulating activity. The absence of biological activity of the recombinant protein is discussed.
Investigation of the deacetylation in the biofilm associated staphylococcal exopolysaccharide PIA Birkenstock, T. 1, G6tz, F. 1 1University of TElbingen; Microbial Genetics Introduction: Previous studies have identified a ~-l.6-1inked Nacetylglucoseamine polymer PIA (Polysaccharide Intercellular Adhesin) as the major component of the extracellular matrix in staphylococcal biofilms (Mack et al. 1996). Structural analyses of PIA have shown that this polysaccharide is partially deacetylated. A corresponding deacetylase, however, has to date not yet been identified. Here, we addressed the question whether IcaB plays a role in the deacetylation of PIA. PIA was extracted from S. carnosus (pTXicaADBC) and S. carnosus (pTXicaADABC) clones (Gerke et al. 1998) and the degree of deacetylation of polysaccharides in both extracts was compared.
http://www.dghm.org
248