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At least 19 recordsLinked to original sources
PubMed1960

Immunological studies on a C polysaccharide complex of group A streptococci having a direct toxic effect on connective tissue.

A macromolecular complex of C polysaccharide and peptide derived from Group A streptococcal cells produces a multinodular, remittent, and intermittent lesion of dermal connective tissue following a single intradermal injection. This lesion is greatly modified, both in the gross and microscopically, in rabbits hyperimmunized with a Group A streptococcal vaccine. The immune serum, absorbed to yield only antibodies against C polysaccharide as indicated by agar diffusion techniques, will precipitate and neutralize the toxic material. This neutralization and in vitro precipitation can be inhibited with formamide-isolated C polysaccharide hapten and with N-acetylglucosamine, the primary directive group of this antigen. This clearly demonstrates that antibodies against the group-specific C polysaccharide are responsible for resistance to this toxic material. The immunological and other properties of the toxic C polysaccharide complex, the fact that it is a product of Group A streptococci, the gross and microscopic features of the experimental lesion produced with this substance, and the observations on the chronic course of the experimental lesion, indicate that this toxic material should be investigated as a possible factor in the pathogenesis of the non-suppurative sequelae associated with Group A streptococci.

Animals↗
PubMed1960

Type and group polysaccharides of group D streptococci.

Polysaccharides extracted from cell walls of 4 serological types of Group D streptococci were serologically type-specific. Acid hydrolysates of all 4 contained hexosamine (glucosamine), rhamnose and glucose. A polysaccharide extracted from 2 serological types by either alkaline treatment or mechanical disruption was serologically group-specific. Acid hydrolysates contained glucose and no other single component in comparable amount. The group-specific polysaccharide, which may be of a dextran-like nature, is probably situated wholly or in part at the surface of the streptococcus.

Cell Wall↗
PubMed1961

Studies on the chemical structure of the streptococcal cell wall. I. The identification of a mucopeptide in the cell walls of groups A and A-variant streptococci.

Lysis of trypsinized Group A streptococcal cell walls with phage-associated lysin releases into solution dialyzable and non-dialyzable mucopeptide fractions composed of N-acetylglucosamine, N-acetylmuramic acid and alanine, glutamic acid, lysine, and glycine in addition to the characteristic group-specific carbohydrate. The latter substance contains appreciable amounts of N-acetylmuramic acid and the amino acids as well as N-acetylglucosamine and rhamnose. Hot formamide extraction of the cell walls results in a soluble fraction of group-specific carbohydrate and an insoluble residue. The Group A carbohydrate in this instance is composed of rhamnose and N-acetylglucosamine. The composition of the insoluble residue is similar to that of the mucopeptide fractions released from the cell wall by phage-associated lysin. This residue was shown by electron microscopy to be composed of discrete discs which appear similar in structure to the intact cell wall. The specific carbohydrate obtained by hot formamide extraction of Group A-variant cell walls was composed almost exclusively of rhamnose. The residue fraction was similar to that of Group A. The residue of cell walls extracted with hot formamide is extensively solubilized not only by phage-associated lysin and S. albus enzyme, but also by lysozyme, which has no measurable effect on the intact streptococcal cell wall.

Amino Acids↗
PubMed1962

Studies on the chemical structure of the streptococcal cell wall. II. The composition of group C cell walls and chemical basis for serologic specificity of the carbohydrate moiety.

The trypsinized cell walls of Group C streptococci contain two components, the group-specific carbohydrate and a mucopeptide polymer. Hot formamide extraction of Group C cell walls results in a soluble group-specific carbohydrate fraction and an insoluble mucopeptide residue. This mucopeptide, similar in composition to that of Groups A and A-variant streptococci, contains N-acetylglucosamine, N-acetylmuramic acid, alanine, glutamic acid, lysine, and glycine. It is dissolved by the muralytic enzymes, including lysozyme, which does not attack the whole cell wall. Lysis of the cell wall by phage-associated lysin results in the release of soluble fragments composed of the elements of mucopeptide. Group C carbohydrate extracted with formamide is composed primarily of N-acetylgalactosamine and rhamnose. Serological studies suggest that the specificity of Group C carbohydrate is determined by the N-acetylgalactosamine.

Carbohydrates↗
PubMed1962

Analysis of the experimental lesion of connective tissue produced by a complex of C polysaccharide from group A streptococci. I. In vivo reaction between tissue and toxin.

Specific antibody and a glucosaminidase enzyme react with the serologically active sites on C polysaccharide, and local injection of these reagents will neutralize the toxic effect of C polysaccharide complexes even after an interval of 24 to 72 hours. The cell wall lysins in S. albus filtrate and from phage-lysed Group C streptococci, break down the cell wall structure of Group A streptococci but leave the serological reactive sites of the C polysaccharide intact. These reagents lose much of their ability to neutralize the C polysaccharide toxin when superinjected after an interval of 4 hours following toxin injections. Toxic C polysaccharide cannot be recovered from an injection site by intercellular perfusion of the excised skin area after an interval of 1 to 4 hours following toxin injection. It is concluded that toxic particles of C polysaccharide complexes combine firmly with the dermal tissue of rabbits within 1 to 4 hours following intracutaneous injection. The cell wall lysins neutralize the toxin by reducing the particle size of C polysaccharide complexes. This minimum particle size is required for the initial reaction with tissue and when this has occurred these reagents are no longer able to influence the development of the lesion.

Animals↗
PubMed1962

Variation in the group-specific carbohydrate of group C hemolytic Streptococci.

Certain strains of Group C hemolytic streptococci, termed Group C-intermediate, contain a group-specific carbohydrate antigen which gives a precipitin cross-reaction with A-variant antiserum. The carbohydrate antigens of these strains have a rhamnose:hexosamine ratio ranging from 2.4 to 2.6 whereas the ratio of typical Group C strains varies between 1.1 and 1.7. N-acetylgalactosamine, the major hexosamine in all of these strains is the principle determinant of Group C specificity. The high concentration of rhamnose in the C-intermediate carbohydrate suggests that a portion of the rhamnose oligosaccharide side chains are devoid of terminal N-acetylgalactosamine and thus react with Group A-variant antiserum. This view is supported by the fact that the induced variant enzyme, which destroys A-variant carbohydrate reactivity with the liberation of rhamnose oligosaccharides, has a similar action upon the Group C-intermediate carbohydrate. C-intermediate carbohydrate, after treatment with variant enzyme which removed approximately 25 per cent of the rhamnose, does not react with A-variant antisera.

Carbohydrate Metabolism↗