Enterotoxin testing of Escherichia coli causing epidemic infantile enteritis in the U.K.

Three test systems were used to study enterotoxin production by epidemic strains of Escherichia coli from cases of infantile enteritis in well-documented outbreaks in the U.K. The tests used were the Y1-mouse-adrenal-cell test and the Chinese-hamster-ovary-cell (C.H.O.) test for the detection of heat-labile enterotoxin and the infant-mouse test for the detection of heat-stable enterotoxin. All 6 outbreaks had been studied using full serotyping techniques and the results had been published. In each outbreak the epidemiological studies clearly implicated a particular serotype of E. Coli as the epidemic strain and cultures of that serotype were tested for enterotoxin production. Although a control strain validated by other workers was positive in all three systems, the epidemic strains from infantile enteritis were negative. It seems that the three enterotoxin tests used in this study are of little value in recognising strains of E. coli causing epidemics of infantile enteritis in the U.K.