New vaccine keeps E. coli inside cows

Source of Article:  http://www.sfgate.com/cgi-bin/article.cgi?file=/c/a/2009/07/02/MND818HANH.DTL

 

Thursday, July 2, 2009

While storekeepers were frantically pulling E. coli-tainted cookie dough and beef from their shelves last month, scientists rolled out the country's first cattle vaccine to snuff out the potentially deadly bacteria.

Epitopix LLC, a Minnesota veterinary pharmaceutical company, has received a conditional license from the U.S. Department of Agriculture to market Escherichia coli Bacterial Extract, and the firm plans to release the vaccine to begin inoculating beef cattle in the fall. The vaccine can reduce the prevalence of cattle shedding 0157:H7 - the strain of E. coli responsible for food-borne illnesses - by as much as 85 percent, said scientists who have been testing the product.

E. coli 0157 is carried through cattle feces, although it has also been found in swine and some wildlife, and is estimated to sicken 70,000 people a year, according to the Centers for Disease Control and Prevention.

Experts hail the discovery as a milestone that could go a long way toward wiping out the poisonous microbe that has contaminated everything from spinach and Odwalla juices to Jack in the Box hamburgers and, more recently, Nestle Toll House refrigerated cookie dough. Just this week JBS Swift Beef Co., the largest meat producer in the world, had to expand a recall now totaling 420,000 pounds of beef processed in its Greeley, Colo., plant because of E. coli 0157. So far, 23 people have reported becoming ill from the beef, including two who have suffered kidney failure.

"The vaccine is potentially very exciting," said Michele Jay-Russell, an epidemiologist formerly with the California Department of Public Health who is now a researcher at UC Davis. "Being able to reduce the bacteria will not only have an effect on the beef industry, but on the environment."

The cattle and beef industry - a $1.85 billion-a-year business in California - is also cautiously optimistic.

"While it's still early in the process, we're excited about the prospect of the vaccine," said Matt Byrne, executive vice president of the California Cattlemen's Association. "Beef producers have been very aggressive in reducing incidents. This is the next natural step."

'Major safety milestone'

The industry has invested $27 million since 1993 in beef safety research, said Michelle Rossman of the National Cattlemen's Beef Association.

"We see the vaccine as a major safety milestone," she said. "But we don't see it as a silver bullet - just one more tool."

It is a tool that could be of great use to California, a state that has been particularly rocked by virulent outbreaks of the bacteria.

In 1993, undercooked hamburgers from Jack in the Box, a San Diego-based fast-food restaurant corporation, killed four children and sickened hundreds of other people in the Pacific Northwest. Three years later, E. coli traced to unpasteurized apple juice made at Odwalla's plant in Tulare County in the San Joaquin Valley killed a 16-month-old Colorado girl and infected 66 other people.

Over the last decade, the harmful bacterium has wreaked havoc on the spinach and lettuce fields of California's Central Coast. There have been 20 outbreaks, the most recent in 2006, when bagged spinach killed three people and sickened 205 nationwide.

Jay-Russell, who manages a UC Davis team investigating the 2006 incident, said they've narrowed down the most likely cause of the contamination to either wild pigs infected with 0157 defecating in the fields or to a cattle herd a mile away from the crops that tested positive for the bacteria found in the spinach.

"That's why the vaccine is one more intervention to have," she said. But, she cautioned, "It's not the end-all and be-all, and it doesn't mean everyone can relax."

Less E. coli excreted

Daniel Thomson, a professor of beef production medicine and epidemiology at Kansas State University who has been testing the product for 3 1/2 years, agrees that no vaccine is 100 percent effective. However, he said the numbers are very promising.

The vaccine works by preventing the bacteria, which are not harmful to cattle, from getting to the iron in a cow's intestines.

"Iron is to E. coli what oxygen is to us," Thomson said.

In his last study, Thomson tested 1,300 head of cattle, injecting half of them with the vaccine. Just before slaughter, Thomson and his students took fecal samples of the herd, finding that the vaccinated cattle were 85 percent less likely to excrete E. coli 0157. In the ones that still tested positive, there was a 98 percent reduction in concentration of the bacteria compared with the cattle that were not inoculated.

James Sandstrom, general manager of Epitopix, said his company will continue to supply the USDA with data for the next year, when the conditions of the vaccine's license expires - a routine pathway to full approval. In September and October, the company plans to work with major packing houses and feedlots, including ones in California, to use the product in continuing studies. A price for the vaccine has yet to be set, but Sandstrom expects it to be about $2 a dose.

Thomson said for optimal results, cattle need to be injected with the vaccine three times - when they first get to the feedlot, 21 days later and then 21 days after that. While many cattlemen are excited by the vaccine's potential, some say the three-dose regimen could be a downside.

"It could be the best thing since sliced bread, but only if it's usable," said spokesman Chandler Keys of JBS Swift. Herding cattle through a chute for each injection can be stressful for the animals, he said.

Still, officials of the company, whose tainted meat has sickened people from California to Maine, are looking into the product and have begun talks with Epitopix, Keys said. "Anything we can do to mitigate E. coli from coming into our packing plant, we're interested."

While Epitopix may have the first product of its kind in the United States, others have plans to follow. Bioniche Life Sciences Inc. of Canada is also working on getting a USDA conditional license for a vaccine and hopes to have approval by August or September, said Gary Weber, president of food and safety for the firm's U.S. division.

"I think the U.S. recognizes that this is as much an environmental problem as it is a beef problem," he said. "I think we're at the edge of creating a technology to eradicate 0157 at the source - the cow."

Recent E. coli 0157:H7 contaminations

-- JBS Swift Co. beef, nationwide, June 2009

-- Refrigerated Nestle Toll House cookie dough, nationwide, June 2009

-- Kroger beef, Midwest, July 2008

-- Totino's/Jeno's frozen pizza, November 2007

-- Topps ground beef patties, Midwest, East Coast, October 2007

-- Taco Bell, Northeast, December 2006

-- Fresh bagged spinach, nationwide, October 2006

Source: Centers for Disease Control and Prevention

 

Main Page

setstats            Copyright (C) All rights reserved under FoodHACCP.com

            If you have any comments, please  send your email to info@foodhaccp.com