This article written by Dr. Reynold Bergen, BCRC Science Director, originally appeared in the November 2020 issue of Canadian Cattlemen magazine and is reprinted on the BCRC Blog with permission of the publisher.
E. coli live in the digestive tracts of warm-blooded animals and birds. Most are harmless, some are beneficial, and some (like E. coli O157:H7) can be very dangerous. E. coli are also involved in antibiotic resistance.
“Extended-spectrum beta-lactamase producing” (or ESBL) E. coli are a major concern in human medicine. These bacteria are resistant to many antibiotics used in both human and veterinary medicine. Ordinary E. coli can cause urinary tract or bloodstream infections in people. They’re usually quite easy to treat with antibiotics. But if ESBL E. coli are responsible, the infection can’t be easily treated with antibiotics, and the illness can be much worse or even fatal.
E. coli rarely causes disease in feedlot cattle. But ESBL E. coli are still a concern, because antibiotic resistance genes are often located on “mobile genetic elements” that bacteria can trade with each other, even with completely unrelated bacteria. So antibiotic resistant BRD bacteria like Mannheimia, Pasteurella or Histophilus can spread their antibiotic resistance genes to each other, or possibly to E. coli. That’s like a border collie developing horns after a day of herding Herefords. Continue reading