CANADA: U of S student develops new E. coli vaccine

19.oct.09
Star Phoenix
Anne Marie Hickey

Food and water around the world could soon become safer for human
consumption, thanks to a new cattle vaccine created by University of
Saskatchewan graduate student David Asper.
The veterinary microbiology student's work -- soon to be published -- is
premised on the idea that humans can be protected from harmful bacteria
by vaccinating cattle that are the source of the bacteria.
Asper's work builds on groundbreaking research by his supervisor, Andrew
Potter, director of the Vaccine and Infectious Disease
Organization-International Vaccine Centre, which led to the first cattle
vaccine against E. coli O157 -- the leading cause of "hamburger
disease." The vaccine prevents the bacteria from attaching to the
animal's intestines and from colonizing, cutting the disease off at the
source.
"The E. coli O157 vaccine is the first of its kind worldwide and is
expected to significantly lessen the amount of E. coli O157 present in
food products and also in the environment," said Potter.
These Shiga toxin-producing E.coli -- or STEC for short -- produce
infections that can range from very mild to severe or even
life-threatening.
What Asper has been able to do is create a vaccine prototype to protect
cattle against a number of non-O157 STEC bacteria that are responsible
for human outbreaks of disease around the world.
"David has broadened the scope of the work we've done, and I think the
impact is large," said Potter. "He essentially created this vaccine on
his own."
Though E. coli O157 is the most prevalent STEC bacteria in North
America, others are more dominant around the world. In Europe, O26 is
the most common. In South America, it is O111.
"One place where this could make a huge difference is Argentina," said
Asper. "They have 10 times the cases of renal failure than we do in
Canada. This vaccine could reduce sickness and deaths caused by E. coli
by a large amount."