This article written by Dr. Reynold Bergen, BCRC Science Director, originally appeared in the November 2016 issue of Canadian Cattlemen magazine and is reprinted on the BCRC Blog with permission of the publisher.
There are between 50,000 and 100,000 different serotypes (strains) of E. coli. Most are harmless, some may be beneficial, but some produce a very dangerous Shiga toxin. Shiga toxigenic E. coli (STEC) can cause vomiting, diarrhea and abdominal pain in people. E. coli O157:H7 is the most well-known STEC, but it is not the only one.
All STEC’s carry at least one stx gene coding for the Shiga toxin, an eae gene coding for a protein that helps E. coli attach to the intestinal surface, and a wzx gene that codes for an “O” antigen. All three of those genes must be present in the E. coli cell for it to be a STEC.
Food safety risks due to E. coli O157:H7 are well known, and the beef industry has made great progress in controlling it. Non-O157 STEC infections are rarer, but in 2011 Continue reading