A total of 70 enteropathogenic Escherichia coli (EPEC) strains belonging to 11 serogroups, isolated from infantile diarrhoea in Tehran, Iran, were tested for the production of verocytotoxin (VT), enterotoxin, and also for their adherence to HeLa cells. In total 55 (78.5%) strains were either VT (32 strains) or enterotoxin (23 strains) producers, and of these 8 strains produced both VT and enterotoxins. 57 (81.4%) strains showed either Localized (LA) or Diffuse adherence (DA) or both types of adhesion (LA/DA) on HeLa cells, with strains showing LA/DA in the same preparations being dominant (32 strains), followed by those showing LA (14 strains) and DA (11 strains). Among adherent EPEC, 26 (37.1%) strains belonging to the serogroups 020, 086, 0119, 0125, 0126, 0127 and 0128 also produced VT. These findings suggest that production of VT and enterotoxin is an important factor in the pathogenesis of EPEC diarrhoea in Iran and that the combination of adherence and production of toxins is a common feature of EPEC strains which cause diarrhoea in this country.

The incidence of shigellae was measured in 445 children with diarrhoea in Sanandaj, Kordestan, and 715 in Tehran during a 1-year study. 18 (4%) patients in Sanandaj and 41 (5.7%) patients in Tehran were positive for various shigella species. Sh. boydii (7 strains) and Sh. sonnei (25 strains) were the commonest species in Sanandaj and Tehran respectively. Among the isolates from Sanandaj the highest resistance was to tetracycline (55.5%), whereas in Tehran it was to sulfamethoxazole/trimethoprim (68.3%).