Outbreaks of Food Poisoning Caused by Enterotoxigenic Escherichia coli and Detection of Heat-Labile Enterotoxin in Stools by an Enzyme-Linked Immunosorbent Assay

Abstract

In 1983, 3 outbreaks of food poisoning caused by enterotoxigenic Escherichia coli (ETEC) occurred in Osaka. The causative agent of all the outbreaks was ETEC O6: H16 that produced both LT and ST. In 1 of the outbreaks, ETEC was isolated from the water (well water) in caterer where incriminated food was made. The outbreak may be occurred because ETEC in water transmitted the food.
ELISA was utilized to detect LT directly in stool specimens obtained from patients. LT was detected 18 of the 22 (81.8%), 7 of the 27 (25.9%), 2 of the 16 (12.5%) stool specimens obtained from patients within 4 days, 5 to 9 days, 11 and 12 days after infection, respectively. The detection rate of LT in stool specimens was high in early stage of disease. The highest amount of LT was 40 ng/g in stool specimens obtained from 2 patients within 4 days after infection. These results suggest that ELISA can be used to detect LT in stool without or before bacterial isolation, and it is a useful method to diagnose the infection caused by LT-producing ETEC rapidly.