PREVALENCE OF E. COLI O157:H7 ON HIDES AND IN FECES OF FEEDLOT CATTLE OVER TIME

The specific objectives of these experiments are to determine the prevalence of E. coli O157:H7 on the hides and in the feces of feedlot cattle in the same pens over time and to determine or estimate the number of cattle shedding E. coli O157:H7 that are necessary to contaminate the hides of over 50% of the animals in the pen. Pulsed-field gel electrophoresis (PFGE) fingerprinting will be used to match the E. coli O157:H7 isolates from hides with those of feces. This analysis will allow, within the limits of PFGE, determination of the source of E. coli O157:H7 hide isolates.