Abstract
We conducted epidemiological and bacteriological studies of five episodes of food poisoning caused by diarrheagenic Escherichia coli (E. coli) at cookeries in Oita Prefecture, in which the disease-causing bacteria were isolated. There were two cases of enteropathogenic E. coli (EPEC), in which O86a:H27 and O44:H18 were isolated, and three cases of enterotoxigenic E. coli (ETEC), in which heat-stable enterotoxin (ST)-producing O27:H7, ST-producing O153:H10 and heat-labile enterotoxin (LT)-producing O25:HNM (not mobile) were isolated.
When food poisoning arose from school lunches, there were 406 patients, and O44:H18 (EPEC) was isolated from patients' stools and from ramen (cold Chinese noodles in soup). From the result of gene analysis using plasmid profiles and random amplified polymorphic DNA (RAPD) profiles, both pathogens proved to be the same origin. In this case, cell adhesion test and a search for the EPEC adherence factor (EAF) and eae gene were performed without results.
The results of epidemiological studies showed that, compared with EPEC, many patients with food poisoning caused by ETEC tended to have diarrhea more than ten times a day, vomiting and fever more than 38°C. ETEC food poisoning has a longer incubation period.
