TABLE 2.

Prevalence of E. coli O157:H7 in feedlot cattle during the final phase of finishing

Collection	No. of animals sampled	No. of positive samplesa
1	788	314
2	788	265
3	476	206
4	197	39
5	100	28
6	35	15

^aPositive samples were samples that contained E. coli O157:H7 with the eae, stx₁, and stx₂ virulence genes. This E. coli O157:H7 genotype was targeted as it was the most common genotype identified during the first two sample collections and the purpose of this study was to gain insight into persistent shedding of E. coli O157:H7.