Cattle water troughs as reservoirs of Escherichia coli O157

Environmental survival of Escherichia coli O157 may play an important role in the persistence and dissemination of this organism on farms. The surviva l of culturable and infectious E, coli O157 was studied using microcosms si mulating cattle mater troughs. Culturable E, coli O157 survived for at leas t 245 days in the microcosm sediments. Furthermore, E, coli O157 strains su rviving more than 6 months in contaminated microcosms were infectious to a group of 10-week-old calves. Fecal excretion of E, coli O157 by these calve s persisted for 87 days after challenge. Water trough sediments contaminate d with feces from cattle excreting E, coli O157 may serve as a long-term re servoir of this organism on farms and a source of infection for cattle.