title: Characterization of Enterohemorrhagic Escherichia coli on Veal Hides and Carcasses.
abstract: Enterohemorrhagic Escherichia coli (EHEC) are Shiga toxin-producing E. coli associated with the most severe forms of foodborne illnesses. The U.S. Department of Agriculture, Food Safety and Inspection Service has identified a higher percentage of non-O157 EHEC compared with E. coli O157:H7-positive samples collected from veal trimmings than from products produced from other cattle slaughter classes. Therefore samples were collected from hides and preevisceration carcasses at five veal processors to assess E. coli O157:H7 and non-O157 EHEC contamination during bob veal and formula-fed veal dressing procedures. E. coli O157:H7 prevalence was measured by culture isolation and found to be on 20.3% of hides and 6.7% of carcasses. In contrast, a non-O157 EHEC molecular screening assay identified 90.3% of hides and 68.2% of carcasses as positive. Only carcass samples were taken forward to culture confirmation and 38.7% yielded one or more non-O157 EHEC isolates. The recovery of an EHEC varied by plant and sample collection date; values ranged from 2.1 to 87.8% among plants and from 4.2 to 64.2% within the same plant. Three plants were resampled after changes were made to sanitary dressing procedures. Between the two collection times at the three plants, hide-to-carcass transfer of E. coli O157:H7 and non-O157 EHEC was significantly reduced. All adulterant EHEC serogroups (O26, O45, O103, O111, O121, and O145) were isolated from veal carcasses as well as four other potentially pathogenic serogroups (O5, O84, O118, and O177). Bob veal was found to have a greater culture prevalence of E. coli O157:H7 and greater positive molecular screens for non-O157 EHEC than formula-fed veal (P < 0.05), but the percentage of culture-confirmed non-O157 EHEC was not different (P > 0.05) between the two types of calves. EHEC-O26, -O111, and -O121 were found more often in bob veal (P < 0.05), whereas EHEC-O103 was found more often in formula-fed veal (P < 0.05).
authors.affiliation: U.S. Department of Agriculture, Agricultural Research Service, U.S. Meat Animal Research Center, P.O. Box 166, State Spur 18D, Clay Center, Nebraska 68933.
authors.forename: Joseph M
authors.initials: JM
authors.lastname: Bosilevac
authors.affiliation: U.S. Department of Agriculture, Agricultural Research Service, U.S. Meat Animal Research Center, P.O. Box 166, State Spur 18D, Clay Center, Nebraska 68933.
authors.forename: Rong
authors.initials: R
authors.lastname: Wang
authors.affiliation: University of Nebraska-Kearney, 2401 11th Avenue, Kearney, Nebraska 68849.
authors.forename: Brandon E
authors.initials: BE
authors.lastname: Luedtke
authors.affiliation: NeoSEEK Laboratory, Neogen Corp., 4131 North 48th Street, Lincoln, Nebraska 68504.
authors.forename: Susanne
authors.initials: S
authors.lastname: Hinkley
authors.affiliation: U.S. Department of Agriculture, Agricultural Research Service, U.S. Meat Animal Research Center, P.O. Box 166, State Spur 18D, Clay Center, Nebraska 68933.
authors.forename: Tommy L
authors.initials: TL
authors.lastname: Wheeler
authors.affiliation: IEH Laboratories and Consulting Group, 15300 Bothell Way N.E., Lake Forest Park, Washington 98155, USA.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Koohmaraie
mesh_terms: D000818:Animals; D002417:Cattle / Q000382:microbiology*; D054324:Enterohemorrhagic Escherichia coli / Q000302:isolation & purification*; D019453:Escherichia coli O157 / Q000302:isolation & purification; D005243:Feces; D008460:Meat; D022621:Shiga Toxin; D054323:Shiga-Toxigenic Escherichia coli / Q000302:isolation & purification
chemical_list: D022621:Shiga Toxin
keywords: Enterohemorrhagic Escherichia coli; Escherichia coli O157:H7; Harvest; Non-O157 Shiga toxin–producing Escherichia coli; Veal