title: Does enteropathogenic Escherichia coli produce heat-labile enterotoxin, heat-stable enterotoxins a or b, or cholera toxin A subunits?
abstract: Although most enteropathogenic Escherichia coli strains do not produce recognized enterotoxins, we wished to examine whether they produce any factors like heat-stable enterotoxin b or cholera toxin active subunits that might be missed by conventional assay methods. E. coli strains E851 (O142) and E2348 (O127) that had caused diarrhea in volunteers were negative for heat-labile enterotoxin and heat-stable enterotoxin a in Chinese hamster ovary cell and suckling mouse assays, failed to cause secretion in ligated small bowel loops from 6- to 8-week-old pigs after 4 to 5 h (used to show heat-stable enterotoxin b), and did not activate adenylate cyclase in pigeon erythrocyte lysates (used to demonstrate cholera toxin A subunit). We conclude that crude, unconcentrated culture filtrates and sonicates do not mimic heat-labile or heat-stable enterotoxins or cholera toxin or its A subunit and that enteropathogenic strains of E. coli probably have yet another mechanism or group of mechanisms by which they cause diarrhea.
mesh_terms: D000818:Animals; D001427:Bacterial Toxins / Q000096:biosynthesis*; D002772:Cholera Toxin / Q000096:biosynthesis; D003967:Diarrhea / Q000382:microbiology*; D004768:Enterotoxins / Q000096:biosynthesis; D004926:Escherichia coli / Q000472:pathogenicity*; D029968:Escherichia coli Proteins; D006801:Humans; D046911:Macromolecular Substances
chemical_list: D001427:Bacterial Toxins; D004768:Enterotoxins; D029968:Escherichia coli Proteins; D046911:Macromolecular Substances; C034151:heat stable toxin (E coli); D002772:Cholera Toxin; C027538:heat-labile enterotoxin, E coli