Novel vaccine reduces prevalence and shedding of Escherichia coli O157:H7 in cattle.

Escherichia coli O157:H7 is a food-borne pathogen that causes severe hemorrhagic colitis and hemolytic uremic syndrome (HUS) in humans. The gastrointestinal tract of cattle is the main reservoir for E. coli O157:H7, making cattle feces a possible direct and indirect source of exposure for humans. According to the CDC, shiga-toxin producing E.coli 0157 causes an estimated 73,000 illnesses annually in the United States, resulting in over 2,000 hospitalizations and 60 deaths (Frenzen et. al, 2005). Interventions used to reduce shedding of this microorganism will lower contamination of the environment. A recently developed vaccine that targets Gram-negative bacteria's ability to acquire iron may be a practical intervention strategy for reducing the prevalence of this pathogenic microorganism. Therefore, the purpose of the study was to evaluate the efficacy of a vaccine containing outer membrane siderophore receptor and porin (SRP) proteins in reducing fecal prevalence and shedding of E. coli O157:H7 in cattle.