The mouse ligated intestinal loop assay for the studies on enteroinvasive Escherichia coli.

Enteroinvasive Escherichia coli exhibited a positive reaction in the mouse intestinal loop assay except for noninvasive mutant strains. These mean values of fluid weight per gut length of mouse loops inoculated with enteroinvasive E. coli were significantly higher than that given by brain heart infusion broth. Oedema and swelling in all positive loops, increased bacterial cell numbers within intestinal loops were observed.