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ARS Home » Research » Publications at this Location » Publication #112333
Title: HIGH BUT VARIABLE ENTEROHEMORRHAGIC E. COLI (EHEC) O157 FECAL SHEDDING IN PENS OF SLAUGHTER-READY KANSAS AND NEBRASKA BEEF FEEDLOT CATTLE

Author
item Keen, James
item ELDER, ROBERT - FORMER ARS EMPLOYEE

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 3/14/2000
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Objectives (Obj.)--(1) To estimate prevalence of EHEC O157 fecal shedding in finished (slaughter ready) fed beef cattle in representative commercial feedyards in KS & NE.(2)To estimate variation in EHEC O157 fecal shedding of finished cattle in adjoining pens. Design--Prevalence survey. Sample Populations--Obj. (1), 7 large commercial feedyards in western KS (n=3) & central NE (n=4) were recruited in summer 1999. In each feedyard, 30 fresh ground fecal pats were sampled from 2 random steer & heifer show list pens (n=120 samples/feedyard; 840 total samples). Eligible pens had at least 60 head & had been on feed for at least 45 days. Obj. (2), rectal fecal samples were obtained from all finished cattle in 12 adjoining pens of the same feedyard over 3 days in June 1999 (n=455, mean of 38 head/ pen) Procedure--Fecal samples were cultured for EHEC O157. Results--EHEC O157 fecal prevalence was generally high but variable within & between feedyards. Overall prevalence was 237/840 (28.2%; range 0-73%). Heifer & steer prevalence were equal at 119/420. Pen prevalence ranged from 0-93% & 22 of 28 sampled pens had at least 1 positive animal. Fecal shedding varied greatly across the 12 adjacent pens, even between pens with shared fence lines & water sources. Overall prevalence in the 12 pens was 63/455 (13.9%) but ranged from 0-82%. Public health implications--Finished beef feedlot EHEC O157 fecal prevalence was an order of magnitude higher than previously reported; we attribute this to use of sensitive diagnostic methods. These findings suggest that many commercial feedlot cattle presented for slaughter are infected with EHEC O157. High pen-to-pen EHEC O157 prevalence variation implies variable zoonotic risk by pen & suggests that infection status of individuals & pens may be dynamic, unstable & perhaps stochastic.