The First 30 Years of Shiga Toxin–Producing Escherichia coli in Cattle Production: Preharvest Intervention Strategies

Shiga toxin–producing Escherichia coli (STEC) are the fourth leading cause of bacterialderived foodborne illness in the United States (CDC, 2016). Cattle are recognized as a natural reservoir for STEC, including E. coli O157:H7 (Karmali et al., 2010), and historically, most STEC-induced foodborne illnesses are associated with handling/consuming contaminated or undercooked beef products (White et al., 2016). In 1994, the Food Safety Inspection Service (FSIS) declared E. coli O157:H7 an adulterant in raw ground beef, and in 2011, additional STEC serogroups were declared adulterants (FSIS, 2011). Initial postharvest control measures implemented by the cattle industry to combat STEC were successful; however, to further reduce the incidence of human illness and ensure a safe and wholesome food supply, research into preharvest pathogen reduction and intervention strategies has been pursued (Oliver et al., 2008; Sargeant et al., 2007). Implementation of pathogen-reduction strategies in live cattle has the potential to reduce human illnesses (Rotariu et al., 2012; Smith et al., 2012) by (1) reducing the number of pathogens entering processing plant on/in an animal; (2) reducing horizontal pathogen transfer from infected animals; (3) lowering the pathogenic bacterial burden in the environment and wastewater streams; and (4) reducing the risk to those in direct contact with animals. The current preharvest intervention strategies to reduce the incidence of human STEC illnesses acquired from beef products have been reviewed (Callaway et al., 2013a,b) but will be briefly highlighted and updated herein. A sound management program (described in our previous chapter) in conjunction with preharvest intervention strategies will provide a farm-to-fork approach to reduce the incidence of STEC throughout a cattle operation.