Abstract:Escherichia coli O26 was isolated and identified form a slaughter plant in order to investigate its contamination of E. coli O26. According to USDA detection method, samples were enriched with immunomagnetic separation (IMS) after selective enrichment, and then isolated and purified with selective chromogenic mRainbow agar. Subsequently, the suspected colonies were screened and chose to test the O antigen by PCR and followed by the serum agglutination test. The virulence genes (stx1, stx2, eae and hly) of positive isolations were detected by multiplex PCR. The results showed that only one strain from 120 samples was identified as E. coli O26, however the four virulence genes were found negative. Our results indicated that the E. coli O26 contamination existed in this slaughter house, but these positive bacterium strains did not carry virulence genes.