21 October 2008

3 minute read

North America

Bioniche Life Sciences Inc. on Friday announced that the results of a large-scale commercial beef feedlot study with the company's E. coli O157 vaccine have been published in Foodborne Pathogens and Disease (Vol. 5, Number 5, 2008), a peer-reviewed scientific journal.

The article is entitled, "A Two-Dose Regimen of a Vaccine Against Escherichia coli O157:H7 Type III Secreted Proteins Reduced Environmental Transmission of the Agent in a Large-Scale Commercial Beef Feedlot Clinical Trial" (David R. Smith, Rodney A. Moxley, Robert E. Peterson, Terry J. Klopfestein, Galen E. Erickson, and Sharon L. Clowser).

In the research, vaccine was administered to all cattle within treated pens at arrival processing and again at routine re-processing. Pens of cattle were sampled for four test periods - one week after the second dose of vaccine and every three weeks thereafter. Test samples were taken from seven ropes per pen hung overnight from the feed-bunk neck-rail (the ROPES method). The study involved 20,556 cattle, held in 140 pens at 19 feedlots, over the period between February and October of 2004. Vaccinated pens of cattle were less likely to test ROPES-positive (OR=0.59, p=0.004).

Because ROPES testing identifies organisms in the mouth of cattle, and its outcome is proven to be both associated with presence of the organism in the pen environment and correlated with the prevalence of fecal shedding, the researchers concluded that the two-dose vaccine regimen reduces the probability for environmental transmission of E. coli O157:H7 within commercial cattle feeding systems.

"This is further peer-reviewed evidence of the efficacy of the Bioniche E. coli O157 vaccine," said Dragan Rogan, Vice-President, Animal Health Research & Development at Bioniche Life Sciences Inc. "Although this successful study was conducted using a two-dose regimen, it is important to note that the initial regulatory approval for the vaccine will be based upon a three-dose regimen. The ultimate goal of the vaccine is the maximum possible reduction of the prevalence of the E. coli bacterium in cattle environments, from which it contaminates water, produce or meat and harms people."

Recent E. coli O157:H7 outbreaks include one in North Bay, Ontario, Canada, where there are 15 lab-confirmed cases of human illness and another 78 under investigation as of this week. The illnesses are connected to a Harvey's Restaurant outlet in that community. Another recent outbreak involves iceberg lettuce, with 50 people made ill in Michigan, Illinois and Canada starting in early September, 2008.

An estimated 100,000 cases of human infection with the E. coli O157:H7 organism are reported each year in North America. Two to seven per cent of those people develop hemolytic uremic syndrome (HUS), a disease characterized by kidney failure (in recent outbreaks, this percentage has risen to as high as 16 percent). Five percent of HUS patients die, many of them children and senior citizens, whose kidneys are more sensitive to damage.

In addition to being infected by contaminated food or water, individuals can become infected from E. coli O157:H7 by visiting animal exhibits. Petting zoos, fairs, and agricultural exhibits provide many possible routes of transmission for E. coli. Direct animal contact (e.g., feces, fur, saliva) is the obvious route, but contact with contaminated products (e.g., hand-rails, sawdust, shavings, soiled clothing or shoes) can also lead to human infection.

TheCattleSite News Desk