Articles in this document:
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Alta.
scientists develop new tools in E.coli battle
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E. coli
vaccine for cows approved by feds; expert cautions bacteria risk remains
Alta. scientists
develop new tools in E.coli battle
Margaret Munro , Canwest News
Service -
Published: Monday, October 27, 2008
Scientists have two new weapons against deadly E. coli
bacteria - a vaccine to prevent cattle from shedding the microbe in the first
place, and a technique for mopping up E. coli's
toxins when people do get infected.
Researchers at the University of Alberta say they have
developed "inhibitors" that should be able to grab onto and
neutralize the potent toxins released by E. coli that contaminated the drinking
water supply in Walkerton, Ont., in 2000 and has been making headlines again
this month after an outbreak in the Ontario city of North Bay.
It was also announced Monday that a vaccine against the
microbe is now available for use on Canadian beef and dairy cows. The vaccine,
which grew out of research at the
"Cows carry E. coli O157: H7 but they don't get sick.
Where the disease comes from is people encountering contaminated food or water,
usually from cow feces," said UBC microbiologist Brett Finlay in a
statement. "If we block the colonization of cows by O157, we basically
decrease the number that humans are exposed to, and thus, dropping the disease
levels in humans."
Seven people died and more than 2,000 became ill after
Walkerton's water supply was contaminated with E. coli that was traced back to
cattle manure from a local farm.
The microbe is in the headlines again this month after an
outbreak in
Research in Finlay's lab led to the vaccine, called Econiche. It is produced by the biopharmaceutical company Bioniche Life Sciences Inc., which announced Monday the
vaccine has received full licensing approval from the Canadian Food Inspection
Agency.
The Edmonton-led team has taken a different approach, going
after the toxins released by microbes that can cause severe, and in some cases
lethal, organ damage in people who ingest contaminated meat, vegetables or
water.
The inhibitors are designed to grab onto and neutralize
bacterial toxins before they are released into the bloodstream, the
Source: Canwest News Service
canada.com
E. coli vaccine for
cows approved by feds; expert cautions bacteria risk remains
By Joshua Clipperton, The Canadian Press
Mon Oct 27, 2008
Via Yahoo! News
Bioniche Life Sciences Inc. (TSX:BNC) announced Monday that the Canadian Food Inspection
Agency has approved the vaccine Econiche to help
reduce the proliferation of E. coli O157:H7 in cattle, in turn decreasing the
risk of the bacteria spreading to humans.
It's the same strain linked to an ongoing outbreak at a
The strain also claimed seven lives and made 2,500 people
ill when it entered Walkerton's water supply in 2000.
The E. coli strain targeted by the vaccine reproduces in the
intestines of cattle, but doesn't harm the animals.
If contaminated manure seeps into drinking water or comes
into contact with food, it can have a devastating effect on humans, Bioniche CEO Graeme McRae said in an interview.
"A cow can produce billions of (E. coli) bacteria per
gram of manure, but it only takes five bacteria or eight bacteria to kill a
human. It's a huge public health hazard," McRae said.
"We are sitting on the cusp of maybe being able to
prevent situations like
A CFIA spokeswoman confirmed Monday the vaccine received
approval last week.
Although the new vaccine could help protect the public from
E. coli outbreaks, the lead investigator of the Walkerton Health Study
cautioned that commercial and residential food handlers still have to be
careful.
"I'm not sure that any one solution will do it all, and
I certainly think people still have to be very careful with their food
practices," said Dr. Bill Clark of the London Health Sciences Centre in
It's estimated that between 10 and 30 per cent of cattle
herds have animals carrying the deadly strain, added
In Walkerton, 30 per cent of people who became seriously ill
had an increased risk of developing high blood pressure or severe kidney
damage, he said.
"I think (the vaccine) is a step forward in the sense
that it's an attempt to go back to where the reservoir is, to where (an E. coli
outbreak) begins."
The vaccine - which required eight years and $20 million of
research to develop - will be produced at the company's facility in
Cattle will require three separate immunizations at a total
cost of about $10 per animal, the company said.
The vaccine attacks the proteins that help the deadly E.
coli strain to reproduce in a cow's intestines, McRae said.
"If the bacteria arrive in the intestine and can't
colonize, then if you vaccinated (an entire herd), the chances are you'd reduce
(the bacteria) down to a negligible amount," he said.
Although most forms of E. coli don't harm humans, the
O157:H7 strain seems to be transferring genetic information to other forms of
the bacteria, making the process by which the vaccine attacks the strain
important, McRae said.
"By blocking the attachment proteins, as the bacteria
are changing and the DNA is being forwarded to new bacteria, it seems like the
attachment process is the same," he said.
Clinical testing of the vaccine included more than 30,000
cattle, the company said.
In an average year without a major outbreak of E. coli,
between 1,100 and 1,600 Canadians are sickened by the O157:H7 strain,
The real number is likely at least double that because of
cases that go unreported, he added.
"Potentially the impact (of the vaccine) could be
major, and it will be interesting with the test of time how this strategy
works."
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