EN
Aim of the study: The study was conducted to assess the molecular relationship of verotoxigenic E. coli (VTEC) isolated from cattle slaughtered in abattoirs in the eastern part of Poland. Materials and Methods: A total of 50 non-O157 VTEC strains isolated from bovine hides and the corresponding carcasses were tested with the pulsed field gel electrophoresis (PFGE) method. Results and discussion: The XbaI restriction analysis enabled the clustering of the isolates into 19 PFGE profiles. Seven of them contained more than two strains with two groups of 8 isolates each. Furthermore, three profiles grouped two isolates and the remaining nine PFGE types were represented by only one strain. The PFGE results were analyzed in relation to identified VTEC serotypes (O186:H16, O185:H7, O181:H49, O177:H25, O175:H21, O174:H2, O153:H25, O153:H2, O148:H8, O139:H19, O117:H4, O91:HNT, O84:H28, O36:H19, O21:H25, O2:H6, O2:H32, ONT:H34) and presence of their virulence genes. It was found that strains of the same PFGE type were usually of the same serotype and possessed the same pathogenic markers. The most numerous profile was represented by eight isolates: all of these strains were identified as O2:H32 serotype and had the same virulence genes – vtx2 and vtx2e. Furthermore, the majority of the PFGE profiles grouped the strains isolated during the same day. PFGE analysis revealed that among the isolates obtained from hides and the corresponding carcasses five pairs of strains had an identical molecular profile. The present study provided valuable information concerning the molecular characterization of VTEC isolated from cattle at the slaughter level. The results reflected a low genetic diversity among VTEC isolates tested and may suggest a common source of contamination within the abattoir.