title: Temperature-dependent variation in the synthesis of group-specific carbohydrate by streptococcal variant strains. I. Immunochemical studies.
abstract: A temperature-dependent alteration in the synthesis of the group-specific polysaccharide was found to occur in two "variant" streptococcal strains, A-486-Var and C 121/46/4. These strains synthesize a polysaccharide with variant immunochemical characteristics when grown at 37 degrees C. However, when these organisms are grown at lower temperatures, 22 degrees C, an enhanced synthesis of Group A carbohydrate occurs. Other variant strains show no appreciable alteration of the cell wall carbohydrate composition when grown at lower temperatures. Studies on an intermediate strain show that this organism has a propensity for the synthesis of a polysaccharide with higher glucosamine content and enhanced Group A serological reactivity when grown at 22 degrees C. Immunochemical studies performed on the carbohydrates produced by the A-486-Var at various temperatures revealed that the appearance of Group A serological reactivity at lower temperatures is due to the additional synthesis of a polysaccharide with Group A specificity along with the continued synthesis of a variant carbohydrate. This finding contrasts with data obtained on the carbohydrate produced by the intermediate organisms that appears to consist predominently of one molecule bearing dual A and variant antigenic determinants.
mesh_terms: D000818:Animals; D000942:Antigens, Bacterial; D002241:Carbohydrates / Q000096:biosynthesis*; D002473:Cell Wall / Q000276:immunology / Q000378:metabolism; D003429:Cross Reactions; D003470:Culture Media; D000939:Epitopes; D005559:Formamides; D005612:Freeze Drying; D014644:Genetic Variation; D005944:Glucosamine / Q000032:analysis; D007106:Immune Sera; D005779:Immunodiffusion; D011135:Polysaccharides, Bacterial / Q000096:biosynthesis / Q000302:isolation & purification; D011233:Precipitin Tests; D011817:Rabbits / Q000276:immunology; D012210:Rhamnose / Q000032:analysis; D013297:Streptococcus pyogenes / Q000254:growth & development / Q000276:immunology* / Q000378:metabolism; D013696:Temperature
chemical_list: D000942:Antigens, Bacterial; D002241:Carbohydrates; D003470:Culture Media; D000939:Epitopes; D005559:Formamides; D007106:Immune Sera; D011135:Polysaccharides, Bacterial; D005944:Glucosamine; D012210:Rhamnose