Serotypes of Escherichia coli that hybridized with DNA probes for genes encoding Shiga-like toxin I, Shiga-like toxin II, and serogroup O157 enterhemorrhagic E. coli fimbriae isolated from adults with diarrhea in Thailand.

Escherichia coli strains isolated from adults with diarrhea in Bangkok, Thailand, were examined for hybridization with DNA probes for genes that code for Shiga-like toxin (SLT)-I, SLT-II, and serogroup O157 enterhemorrhagic E. coli (EHEC) fimbriae. Seven isolates that hybridized with the SLT-I, SLT-II, and O157 EHEC fimbria probes and produced verocytotoxin (VT; group A) were isolated from two patients with diarrhea. Two strains that hybridized with only the SLT-II probe and the O157 EHEC fimbria probe and were VT+ (group B) were isolated from two patients with diarrhea, 7 strains that hybridized with only the SLT-II probe and were VT+ (group C) were isolated from two patients with diarrhea, and 26 strains that hybridized with only the O157 EHEC fimbria probe and were VT- (group D) were isolated from four patients with diarrhea. Seven strains in group A had serotypes O2:H1 (n = 1), O110:H19 (n = 1), and Ont:H8 (n = 5); 2 strains in group B were O112ab:H21 (n = 1) and O113:H21 (n = 1); 7 strains in group C were O6:H28 (n = 1), O22:H16 (n = 1), O52:H25 (n = 1), O112ab:H21 (n = 1), OR:H45 (n = 2), and OR:H11 (n = 1); and 26 strains in group D were O76:H7 (n = 18), O146:H3 (n = 2), O146:H10 (n = 1), O146:Hnt (n = 1), OR:H16 (n = 1), Ont:H2 (n = 1), Ont:H8 (n = 1) and Ont:H16 (n = 1). In Thailand, E. coli strains that hybridized with SLT-I, SLT-II, and O157 EHEC fimbria probes were of a variety of serotypes, none of which were O157:H7.