Diarrhea is a common cause posing significant economic losses in sheep farming, primarily caused by various infectious pathogens, among which Escherichia coli is one of the key etiological agents. However, limited data exist on the antimicrobial resistance profiles and virulence-associated factors of E. coli isolated from diarrheic sheep in Ningxia, China. In this study, a total of 32 fecal samples were collected from diarrheic sheep at farms in Ningxia to investigate the resistance phenotypes and virulence gene profiles of E. coli. The 16S rRNA gene amplification and phylogenetic analysis were used to identify bacterial isolates. E. coli recovered from 59.4% (19/32) of the samples. Antimicrobial susceptibility was determined by the disk diffusion method, antibiotics include β-lactams, quinolones, aminoglycosides, tetracyclines, polymyxins, and sulfonamides. The eaeH gene was detected in all isolates (19/19); several strains also harbored virulence genes associated with enteroaggregative (EAEC), enteropathogenic (EPEC) and enterohemorrhagic (EHEC) E. coli. Antimicrobial susceptibility revealed that all isolates were resistant to ampicillin and trimethoprim-sulfamethoxazole. In conclusion, these findings indicate a high prevalence of virulence traits and multidrug resistance among the ovine E. coli isolates from Ningxia, underscoring the urgent need to strengthen antimicrobial stewardship and pathogen surveillance in the region.

To Cite This Article: Wang J, Zhu Z, Zhang X, Zhao Y, Yu Y, Guo Y, Wang P, Qu W and Li K, 2026. Phylogenetic and molecular insights into antimicrobial resistance and virulence determinants of ovine escherichia coli in ningxia, china. Pak Vet J. http://dx.doi.org/10.29261/pakvetj/2026.037