Abstract

Background: The zoonotic pathogen Escherichia coli O157: H7, known as enterohemorrhagic E. coli (EHEC), is a public health concern associated with acute gastrointestinal diseases and hemolytic uremic syndrome (HUS). The primary reservoirs of EHEC are ruminants, including cattle and, potentially, sheep. However, data on EHEC prevalence and antimicrobial resistance in Jordanian sheep are scarce.
Aim: This study aimed to examine the prevalence of EHEC and to assess antibacterial resistance patterns in non-EHEC E. coli isolates from Awasi sheep in Central Jordan.
Methods: Rectal swabs from 198 sheep were collected and analyzed using conventional bacteriological methods and polymerase chain reaction (PCR) for genotypic confirmation of EHEC. The sample size was calculated using an anticipated prevalence of 5%, a confidence level of 95%, and a precision of 3%. Antimicrobial susceptibility testing was performed using the disc diffusion method for ciprofloxacin, ampicillin, and erythromycin, with findings interpreted according to standards.
Results: None of the 198 EHEC isolates were identified among the 198 samples. However, 18 samples (9%) contained non-EHEC E. coli isolates, all of which exhibited resistance to at least one antibiotic. Notably, all isolates (100%) showed resistance to ampicillin, 94.4% to erythromycin, and 5.6% were ciprofloxacin-resistant. No significant variations in prevalence were found between sampling sites (p=0.78).
Conclusion: The absence of EHEC in local sheep suggests that they are not a primary source of this pathogen in Jordan. However, the observed antimicrobial resistance in non-EHEC isolates highlights the need for stringent sanitary practices and antimicrobial stewardship to mitigate public health risks. Seasonal and age-related variations should be explored in future longitudinal studies.

Key words: E. coli, O157:H7, antimicrobial resistance, zoonotic pathogens, Awasi sheep, Jordan