Infectious diarrhea is a leading cause of morbidity and mortality globally. Worldwide, enteropathogenic bacteria are responsible for one of the most important infectious diseases linked to the food industry, affecting animal welfare with the potential to give rise to public health problems. A total of 445 samples, including 235 domestic cow feces collected from 3 semi-urban community farms, 134 ground beef samples from slaughtered bovine/sheep sources (a Tehran abattoir), and 76 fecal samples from human children (1 to 60 months of age) with acute diarrhea were examined for 12 different genes via a polymerase chain reaction (PCR) approach. Shiga-toxin producing Escherichia coli strains were isolated from 41% of meat, 64%, of cattle feces, and 24% of children’s fecal samples. PCR analysis indicated that 16 samples in total were positive for O157:H7. Also, the 14% of human children and 0.85% of cattle species were Shigella spp. - positive. The most commonly isolated STEC bacteria were from the O146, O112a and O44 serogroups for all 3 sources. Remarkably, none of the STEC strains proved to be from the O145, O111 and O26 serogroups. In conclusion, these observations provide strong evidence that STEC is one of the major causes of diarrhea in developing countries, mainly in children. The panel of assays employed offer simple strategies for the widespread detection and characterization of Diarrheagenic E. coli isolates from a range of sources. DEC detection in this manner facilitates our understanding of their prevalence, clinical characteristics, and epidemiology, and also supports the development of food safety control programs which target all STEC serotypes.

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