Battlefront Shifts in Fight Against Beef E coli Outbreaks
The Centers for Disease Control and Prevention (CDC) estimates about 73,480 people are infected each year with E. coli O157:H7, resulting in 600 deaths. Contaminated beef is a leading source of these illnesses and the chronic nature of beef E. coli outbreaks and recalls remains a constant focus of attention among regulators and industry.
Already since December 24, more than 1 million pounds of beef products have been recalled because they had potential to be contaminated with E. coli O157:H7.
Separate stories this week by USA Today reporter Elizabeth Weise and by Scott Canon of the Kansas City Star highlight an important trend in the battle: Intervention at the farm and feedlot level to reduce levels of the bacteria in animals’ guts and hides before they reach slaughter.
“The theory is that animals are carrying higher levels of E. coli during the summer months, and sometimes they may overwhelm the systems in place to control pathogen contamination in (processing) plants,” said James Marsden, a professor of food safety and security at Kansas State University.
As the USA Today story noted, new interventions are intended to flatten out the curve between winter months when less bacteria is entering the system and the April-September period when cattle shed higher concentrations of E. coli O157:H7 and external temperatures are more suitable for the pathogens to cluster.
Each new method, it is hoped, might take down the incidence of E. coli O157:H7 by a factor of 100. Together they could substantially lower the toll inflicted by the disease, which can cause cramps, bloody diarrhea, kidney failure and death. More than 5 percent of infections lead to life-threatening hemolytic uremic syndrome (HUS) or thrombotic thrombocytopenic purpura (TTP).
What follows is a quick run-down on some of the methods being employed to reduce the overall universe of E. coli O157:H7 in cattle:
- Phages: Cattle walk through a car-wash-like spray of bacteria-eating viruses called phages. These viruses are harmless to humans and have been successfully used to kill a spotting bacteria on tomatoes and peppers in agricultures.
- Probiotics: Basically these are bacterial cultures much like those in yogurt, given to cattle in their feed. They’re called “competitive exclusion” cultures because they out-compete the bad bacteria and exclude them in the animals’ guts. The challenge to these is that they are hard to consistenting administer in large feedlot conditions.
- Diet: Research in Texas, Kansas and Idaho has shown that switching cattle from grain to a more expensive diet of high quality hay before slaughter may lower E. coli O157:H7 rates, though the findings have not always been consistent.
- Vaccine: Cargill Meat Solutions is in the midst of an active vaccination program in 100,000 cattle that will reach slaughter this spring. At an estimated cost of $3 to $10 per animal, vaccination against E. coli appears to have the potential to dramatically hinder the population of E. coli in the guts of cattle. A Minnesota-made vaccine called Epitopix already is in trial in the U.S. and Canada has its own E. coli vaccine that could possibly gain approval in the U.S.
From an epidemiologic standpoint, it’s clear that these pre-slaughter interventions lower the E. coli O157:H7 burden in the cattle, says Guy Loneragan, a professor of animal science and expert in O157:H7 in cattle at West Texas A&M University in Canyon, Texas.
Tags: Cattle E coli, E. coli lawyer
