A Minnesota company made headlines earlier this year by winning conditional license to market a vaccine to reduce the prevalence of E. coli O157:H7 in beef cattle.
Now a graduate student at the University of Saskatchewan is said to have created a vaccine to reduce other types of Shiga-toxin producing E. coli bacteria, or non-0157 STECs. 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. And there have been outbreaks involving 026 and 0111 in the United States.
The breakthrough by student microbiologist David Asper, which the University of Saskatchewan says is soon to be published, still must withstand three to five years of intensive testing in mice and cattle. And further more, like the vaccine already being sold for E. coli O157:H7 by Epitopix LLC, it must gain market acceptance by cattle ranchers to do any good for humans.
But it is somewhat heartening to families who have experienced severe illness or death from E. coli ground beef outbreaks that science continues to work on solutions. Hamburger E. coli outbreaks invariably bring cases of STEC infection that lead to hemolytic uremic syndrome (HUS), a life-threatening disease that can cause renal failure, strokes, brain damage, spinal cord injury, heart problems and hemorrhaging. Children under 5 are the most susceptible and persons over 60 are most likely to die from the poison.
Asper’s vaccine would work by preventing non-O157 STEC organisms from attaching to the intestines of cattle. The bacteria commonly live in the hind guts of cattle without doing them harm. They can contaminate meat during the slaughtering process, when the intestines are nicked or when feces compacted on the animals’ hides spreads to carcasses. The microbes get ground into the meat during the making of hamburger and can survive in the core of the patty if the internal cooking temperature of the hamburger doesn’t reach 160 degrees.
In the U.S., E. coli O157:H7 is banned from ground beef, making it an adulterant. But in one of the many safety gaps that exist in our food safety system, no such classification is given to non-O157:H7 STECs.
Due to improved detection methods, cases of non-O157 E. coli infection are on the rise, increasing the importance of having the second-generation vaccine. “We can protect humans by vaccinating animals before they come in contact with the pathogen. I think that’s very important work that will lead to a lot fewer infections,” Asper said in The Star Phoenix newspaper.
