|
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
Stacy Finz, Chronicle Staff Writer
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
|
