The Action of Chloroform-killed Suspensions of Enteropathogenic Escherichia Coli on Ligated Rabbit-gut Segments

SUMMARY: Suspensions of enteropathogenic Escherichia coli and organisms of the same O-antigen group were tested for ability to cause dilatation of the ligated gut segment of rabbit small intestine. Suspensions treated with penicillin or by disintegration in a Mickle shaker were unsuccessful, since it was impossible to obtain sterile material. Suspensions killed with toluene did not cause dilatation, but chloroform-killed cultures did so when the living culture also gave a positive reaction, whereas chloroform-killed cultures of negative living strains were also negative. Chloroform-killed positive suspensions lost their gut-dilatation effect on keeping; this loss ran parallel to loss of esterase activity, though the esterase was not responsible for the dilatation effect.