Isolation and Characterization of Verocytotoxin-Producing Escherichia coli O157 Strains from Dutch Cattle and Sheep

Abstract

In the periods from July to November 1995 and 1996, fecal samples from Dutch cattle and sheep were collected at the main slaughterhouses of The Netherlands, located at different geographic sites. The samples were examined for the presence of verocytotoxin (VT)-producingEscherichia coli (VTEC) of serogroup O157. E. coli O157 strains could be isolated from 57 (10.6%) of 540 adult cattle, 2 (0.5%) of 397 veal calves, 2 (3.8%) of 52 ewes, and 2 (4.1%) of 49 lambs. Immunomagnetic separation with O157-specific-antibody-coated beads appeared to be significantly more sensitive than conventional plating for detection of the organism in feces. With the exception of two isolates from adult cattle which appeared to be negative for VT genes, all animal isolates were positive for both VT (VT1 and/or VT2) and E. coliattaching-and-effacing gene sequences, and therefore, they were regarded as potential human pathogens. Although genomic typing by pulsed-field gel electrophoresis revealed a wide variety of distinct restriction patterns, comparison of the 63 animal isolates with 33 fecal O157 VTEC strains previously isolated from humans with the diarrhea-associated form of the hemolytic-uremic syndrome by their phage types and VT genotypes showed a marked similarity between animal and human isolates: 30 (90.9%) of the 33 human isolates appeared to be of E. coli O157 strain types also isolated from cattle and sheep. It was concluded that Dutch cattle and sheep are an important reservoir of E. coli O157 strains that are potentially pathogenic for humans.

High numbers of Shiga toxin-producing found in bovine faeces collected at slaughter in Japan

“…In contrast, O157:H7 has rapidly spread into dairy and beef farms worldwide since this serotype was first described in 1983 [12], although the route of transmission is unclear. Recent reports described O157:H7/-infection rates in slaughtered cattle and/or cows at 1.3-28% in the United States [42,43], 16.1-16.6% in Italy [44], 10.6% in The Netherlands [45], 4.0-4.7% in England [8,13], 0.2% in France [36] and 1.6-8.1% in Japan [5]. According to these reports, although these differences are likely due to differences in culture methods, remarkable differences were found in the rates of recovery of O157:H7 isolates for slaughtered animals in various geographic areas.…”

Shiga toxin‐producingEscherichia coliO157 in feedlot cattle and Norwegian rats from a large‐scale farm

“…This result corresponds with findings in the UK (Chapman et al 1993) and Italy (Conedera et al 1997), where the incidence of STEC O157 in cattle at slaughter was 4% and 3·6%, respectively. A higher incidence was recorded in the Netherlands (Heuvelink et al 1998). In Germany, on the other hand, the incidence of STEC O157 in slaughtered cattle was very low (Montenegro et al 1990;Richter et al 1997).…”

Risk Factors for the Presence of High-Level Shedders ofEscherichia coliO157 on Scottish Farms

“…Calves born in the spring are weaned in autumn at the time of housing. From weaning until 12 months of age, calves are believed to be a major risk group for shedding VTEC O157 (18,39,43). Higher prevalences have been detected for calves after weaning (11,16,56).…”