Abstract
This investigation was done to study the possibility of enterotoxin production by local isolates of the bacterium Morganella morganii .Specimen were obtained from infantile diarrhoeal patients of ages 2 years or less in Mosul City .418 stool specimen were collected, 4.54% of which were Morganella morganii (about 19 isolates).Suckling mice assay was depended in detecting heat stable enterotoxin producing strains. It was shown that 42.1% of the strains were producers. On the other hand Delayed rabbit skin permeability assay, Rabbit ligated ileum and the enlargments of mouse thymus were done to study heat labile enterotoxin. Results revealed that 36.84% of isolates were producers. Finally, to determine the nature of effect of enterotoxins on intestinal cells a comparison was made on histological section and control animals. No variations were noticed between untreated and negative animals. However, great differences were noted between intestinal tissue of positive suckling mice and others .A destroyed villi layer was noted with the appearance of red corpuscles. Therefore, we conclude that the enterotoxin is cytotoxic to the intestine.