A study of a vaccine for controlling E. coli 0157 in the feces of feedlot cattle has found it was not effective.
The study was conducted with cattle from two commercial feedlots to evaluate to see if the vaccine would reduce the number of E. coli 0157 shed in cattle feces. If the cattle carried E. coli 0157 that had the stx2 toxin gene (which is linked to increased risk of human disease), the vaccine didn’t reduce the level of E. coli 0157 detected on hides or in feces of the animals at any time.
When the stx2 gene was absent, vaccination reduced the number of E. coli 0157 detected in feces and on hides of animals, but only during the feeding period. The reduction was not carried through to shipment and slaughter.
The study also looked at the effectiveness of a direct-fed microbial, but found it also had minimal impact.
“Neither method reduced E. coli 0157 carrying the stx2 gene, thereby putting into question the projected benefits of vaccination on human health,” the Alberta Livestock and Meat Agency, which provided funding for the study, stated in a release.
“With these results, it makes sense for all partners within the beef industry to continue looking for different mitigation strategies,” said Susan Novak, the agency’s executive director of strategic initiatives.