Production of heat-labile or heat-stable enterotoxins by strains of Escherichia coli belonging to serogroups O44, O114, and O128.

Strains of Escherichia coli which belong to enteropathogenic serogroups usually fail to produce heat-labile or heat-stable enterotoxins. However, 1 of 34 strains of E. coli O44, 9 of 45 strains of E. coli O114, and 18 of 82 strains of E. coli O128 produced heat-labile or heat-stable enterotoxins. Most enterotoxigenic isolates were from tropical or developing countries; all three enterotoxigenic strains isolated in Britain were from patients returned from abroad. Enterotoxigenic strains were of many different flagellar types. Certain enterotoxigenic strains of E. coli O114 and O128 possessed colonization factor antigen I.