title: Enzyme-linked immunosorbent assay for detection of type A streptococcal exotoxin: kinetics and regulation during growth of Streptococcus pyogenes.
abstract: We describe the detection and quantitation of type A streptococcal exotoxin (erythrogenic toxin, streptococcal pyrogenic exotoxin) by an enzyme-linked immunosorbent assay. This sensitive and specific technique detected microgram amounts of type A exotoxin and was useful for studying the kinetics and regulation of type A exotoxin production during the growth of Streptococcus pyogenes NY5. Maximum production of type A exotoxin was observed during the mid-log phase of growth, similar to the production of other streptococcal extracellular products. When S. pyogenes NY5 was grown at 42 degrees C, decreases in both growth and type A exotoxin production were observed. The results obtained when we studied the influence of nutrient additives and metal ions on the production of type A exotoxin led to the conclusion that none of these factors significantly affected type A exotoxin synthesis and that regulation was constitutive.
mesh_terms: D000992:Antitoxins; D001426:Bacterial Proteins; D001427:Bacterial Toxins / Q000096:biosynthesis* / Q000276:immunology / Q000302:isolation & purification; D004797:Enzyme-Linked Immunosorbent Assay; D005098:Exotoxins / Q000096:biosynthesis* / Q000276:immunology / Q000302:isolation & purification; D007700:Kinetics; D008565:Membrane Proteins; D008670:Metals / Q000494:pharmacology; D013297:Streptococcus pyogenes / Q000254:growth & development / Q000378:metabolism*; D013696:Temperature
chemical_list: D000992:Antitoxins; D001426:Bacterial Proteins; D001427:Bacterial Toxins; D005098:Exotoxins; D008565:Membrane Proteins; D008670:Metals; C117980:SpeA protein, Streptococcus pyogenes; C027951:erythrogenic toxin