Background and Objective:
Each pathotype of Escherichia coli possesses its own specific virulence factors, which make them significant from both medical and veterinary perspectives. These factors include adhesins, invasins, toxins, and secretion systems. The enterotoxigenic pathotype (ETEC) was the first diarrheagenic pathotype whose pathogenic mechanism was identified between 1959 and 1967, and it was recognized as an independent pathotype. The ability to produce heat-labile toxin (LT), heat-stable toxin (ST), or both, is considered the most important characteristic of the enterotoxigenic pathotype.
Materials and Methods:
In this study, a total of 130 rectal swabs were collected from healthy sheep and goats in Kerman during the spring and summer of 2013. The collected swabs were cultured on selective media to confirm Escherichia coli isolates, which were further verified by biochemical tests. After DNA extraction using the boiling method, the isolates were examined for the presence of LT and ST genes using PCR.
Results:
The findings of this study showed that the prevalence of the enterotoxigenic pathotype was 39.99%, with the frequency of the LTI gene being 27.69% and the frequency of the STI gene being 12.30%.

Conclusion:
This study demonstrated that enterotoxigenic Escherichia coli (ETEC) is present at a considerable frequency in healthy small ruminants in Kerman. The detection of LT and ST genes indicates the potential risk of transmission of these strains to humans. Therefore, regular monitoring and hygienic measures in livestock farms appear to be essential.