Identification and characterization of heat-stable enterotoxin II-producing Escherichia coli from patients with diarrhea.

Stock strains of Escherichia coli isolated from patients with traveller's diarrhea were examined for production of heat-stable enterotoxin II (STII). Of 400 strains examined, 3 were found to produce STII. The nucleotide sequence of the STII gene of these human strains was shown to be identical to that of porcine strains. Cultured cells of these strains induced fluid accumulation in ligated mouse intestinal loops and the activity was neutralized by anti-STII antiserum. These results suggest that STII-producing enterotoxigenic E. coli can cause human diarrhea.