Characterization of verotoxigenic Escherichia coli (VTEC) isolates from faeces of small ruminants and environmental samples in southern Jordan.

This study was conducted to determine the prevalence rate of VTEC in slaughtered sheep and goats and to evaluate the contamination rate of VTEC in slaughterhouses and butchers' shops in southern Jordan. 201 E. coli isolates from animals' faecal samples and 33 E. coli isolates from slaughterhouse/butcher shop samples were characterized by multiplex PCR (mPCR) reaction for detection of stx1, stx2, eae A and E-hly A virulent genes. Twenty-six virulent E. coli isolates were characterized by mPCR to seven different virulent patterns: stx1, stx1+stx2, stx1+eae A, stx1+E-hly A, stx1+eae A+E-hly A, eae A and E-hly A. It was found that VTEC comprised 6.4% and 21% of the total E. coli isolates from slaughtered small ruminants and slaughterhouses/ butchers' shops, respectively. The VTEC comprised 76.2% of the virulent isolates. The proportion of stx1:stx1+stx2 patterns was 19:1. It was found that the characterized complex VTEC (containing eae A and/or E-hly A) possessed three virulence patterns, including (VTEC) stx1 +eae A, (VTEC/EHEC) stx1 +E-hly A and (VTEC/EHEC) stx1 +eae A +E-hly A in percentages of 30%, 25% and 10%, respectively, in relation to the total VTEC isolates. Only two VTEC isolates were characterized as E. coli O157 and O26 serotypes, as highly pathogenic strains. Each of the O157 and O26 VTEC isolates was in a percentage of 0.4% in relation to the total E. coli isolates with virulent patterns stx1, eae A and E-hly A. The rest of the VTEC isolates were non-O157 VTEC. The antibiotic sensitivity test showed that the isolated VTEC was highly sensitive to gentamicin and co-trimoxazole and highly resistant to tetracycline and ampicillin.