title: Dietary interactions and interventions affecting Escherichia coli O157 colonization and shedding in cattle.
abstract: Escherichia coli O157 is an important foodborne pathogen affecting human health and the beef cattle industry. Contamination of carcasses at slaughter is correlated to the prevalence of E. coli O157 in cattle feces. Many associations have been made between dietary factors and E. coli O157 prevalence in cattle feces. Preharvest interventions, such as diet management, could reduce the fecal prevalence and diminish the impact of this adulterant. Dietary influences, including grain type and processing method, forage quality, and distillers grains have all been associated with E. coli O157 prevalence. In addition, several plant compounds, including phenolic acids and essential oils, have been proposed as in-feed intervention strategies. The specific mechanisms responsible for increased or decreased E. coli O157 shedding or survival are not known but are often attributed to changes in hindgut ecology induced by diet types. Some interventions may have a direct bacterial effect. Frequently, results of studies are conflicting or not repeatable, which speaks to the complexity of the hindgut ecosystem, variation in animal feed utilization, and variation within feed products. Still, understanding specific mechanisms, driven by diet influences, responsible for E. coli O157 shedding will aid in the development and implementation of better and practical preharvest intervention strategies.
authors.affiliation: Department of Diagnostic Medicine and Pathobiology, Kansas State University, Manhattan, Kansas 66503-8663, USA.
authors.forename: Megan E
authors.initials: ME
authors.lastname: Jacob
authors.forename: Todd R
authors.initials: TR
authors.lastname: Callaway
authors.forename: T G
authors.initials: TG
authors.lastname: Nagaraja
mesh_terms: D000821:Animal Feed / Q000009:adverse effects; D000822:Animal Husbandry / Q000379:methods; D000818:Animals; D057138:Bacterial Shedding; D002417:Cattle / Q000382:microbiology*; D004032:Diet / Q000009:adverse effects / Q000662:veterinary*; D002523:Edible Grain / Q000009:adverse effects; D004927:Escherichia coli Infections / Q000382:microbiology / Q000517:prevention & control; D019453:Escherichia coli O157 / Q000302:isolation & purification / Q000502:physiology*; D005243:Feces / Q000382:microbiology; D005511:Food Handling; D005516:Food Microbiology; D005517:Foodborne Diseases / Q000517:prevention & control; D054884:Host-Pathogen Interactions; D006801:Humans