cow and calves walking in a field

​Certain strains of Escherichia coli

​Certain strains of Escherichia coli are pathogenic, such as O157:H7. This strain produces toxins that can be a cause of food-borne illness through consumption of contaminated food (e.g. undercooked ground beef). Image courtesy of USDA

cattle about to eat out of a bunk

Cattle are major reservoirs for Escherichia coli O157. It is not in great abundance in the rumen but the asymptomatic colonization by E. coli O157 in the lower gut of cattle can be associated with diet. Many studies have revealed that wet distiller’s grain diets have a higher prevalence of E. coli O157. Image courtesy of Liquid Feeds

microscopic colorized image of bacteria

Recent studies suggested that E. coli O157:H7 has an unusual tolerance against some environmental stresses, such as acidic and dry conditions, compared with other types of E. coli. Image courtesy of Extension 

four cattle looking at the camera with the herd behind them

Since the gastrointestinal tract of cattle is an identified reservoir of this pathogen, contamination of food and water by bovine feces is the most common route of transmitting E. coli O157:H7 to humans. Image courtesy of NEOGEN Europe