The fecal specimens of patients suffered from acute diarrhea, were examined during the period from December 1979 to January 1982.
Enterotoxigenic Escherichia coli strains were isolated from 24 (2.2%) cases. Two out of the 24 patients were cases which have been infected in abroad and one was thought to be a contagious case with the family that was a traveller listed above. Other 21 cases had no contact with oversea travellers. Serotype of 21 enterotoxigenic Escherichia colistrains were distributed to 13 0 serogroups. The commonly isolated were 0 148 and 0 6. The cases with ST only producing strain were most frequently found (16 cases 76.2%). The cases with both LT and ST producing strain and case with LT only producing strain were 5 (23.8%) and 1 (4.8%), respectively. From one patient, ST only and both LT-ST producing strains were isolated simultaneously. Indole negative strains which produce ST and serotyped 0 148: H ut were found from 4 individual cases.