Sources of Escherichia coli deposited on beef during breaking of carcasses carrying few E. coli at two packing plants

► At beef packing plant I, most E. coli on cuts originated from workers' gloves. ► At plant I, most of the few E. coli on trimmings originated from conveyor belts. ► At plant II, chilling reduced E. coli numbers on beef carcasses by 2 log units. ► At plant II, most E. coli on both cuts and trimmings originated from the conveyor belt.