The antimicrobial activities of these four chemical combinations were further determined in water containing cattle feces at a ratio of 20:1 (vol/wt). The results revealed that combinations A, B, and C inactivated all three pathogens by more than 5 log CFU/ml within 30 min (Tables (Tables11 to to3).3). Combination D reduced E. coli O157:H7, O26:H11, and O111:NM cell numbers within 30 min by 3.5, 4.9, and 4.6 log CFU/ml, respectively (Tables(Tables 1 1 to to33).