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ARS Home » Research » Publications at this Location » Publication #114242
Title: EHEC 0157 FECAL AND HIDE PREVALENCE ARE CORRELATED WITH CARCASS CONTAMINATION IN U.S. BEEF CATTLE

Author
item Keen, James
item ELDER, ROBERT - FORMER ARS EMPLOYEE
item SIRAGUSA, GREGORY - FORMER ARS EMPLOYEE
item Gallagher, Genevieve
item Koohmaraie, Mohammad
item Laegreid, William

Submitted to: International Symposium and Workshop on Shiga Toxin ... Escherichia coli
Publication Type: Abstract Only
Publication Acceptance Date: 8/11/2000
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: The relationship between enterohemorrhagic E. coli O157:H7/non-motile (EHEC O157) fecal or hide prevalence and carcass contamination in U.S. beef cattle has not been evaluated. In July-August 1999, we measured EHEC O157 occurrence in rectal feces, on the brisket hide surface and on three carcass surface sites in samples from 30 single source groups (lots) of fed beef cattle presented for slaughter at four large Midwestern U.S. processing plants. Carcass swab samples obtained were (a) the perineum at pre-evisceration; (b) pooled rump, midline, and brisket swabs post- evisceration (prior to antimicrobial interventions) and (c) pooled rump, midline, and brisket swabs post-processing (in cooler, after all antimicrobial interventions). Overall EHEC O157 prevalence was 28% (91 of 327) in feces and 11% (38 of 355) on hides; carcass prevalence was 43% (148 of 341) at pre-evisceration, 18% (59 of 332) at post-evisceration, and 2% (6 of 330) at post-processing. On a lot basis, 72% had one or more positive fecal samples and 38% had positive hide samples. For carcasses, 87% of lots were positive pre-evisceration, 57% were positive post- evisceration, and 17% were positive post-processing. Lot fecal and hide prevalence were positively correlated with lot carcass contamination incidence (Spearman's rho = 0.58, p =0.001). Five lots had no fecal or hide positive samples yet had up to 75% positive carcass samples, suggesting carcass cross contamination. The higher than expected and interrelated fecal, hide, and carcass EHEC O157 prevalence rates we found justifies concerted live cattle (pre-harvest) and beef processing (post- harvest) prevalence reduction efforts for improved food safety public health.