Infectious E. coli strains that have become resistant to antibiotics are being linked to a rise in hard-to-treat urinary tract infections, reports The Atlantic.

Two recently published studies in Oxford Journals (Food-Borne Origins of Escherichia coli Causing Extraintestinal Infections) and by the Centers for Diseases Control (Chicken as Reservoir for Extraintestinal Pathogenic Escherichia coli in Humans, Canada) cite the source of the untreatable bacterial infections as poultry. The studies, says The Atlantic, "found close genetic matches between resistant E. coli collected from human patients and resistant strains found on chicken or turkey sold in supermarkets or collected from birds being slaughtered."

Americans eat more chicken than any other type of meat—8.6 billion are raised just for meat in the U.S. annually. Chickens, like all conventionally raised livestock in the U.S., are routinely fed antibiotics. Eighty percent of the nation's antibiotics are fed to animals to increase size and weight and to ward off the potential for infections common in crammed, unsanitary and disease-prone factory farms. Chickens live in some of the harshest conditions—crammed in cages with 4-5 other birds so tiny that none of them can even spread a single wing.

The steady diet of antibiotics has given rise to a number of infections, like E. coli and MRSA that do not respond to conventional antibiotic treatments, causing physicians to prescribe heavier antibiotics with more serious side effects and risks. From Maryn McKenna's article in The Atlantic: "Investigators began to sort out two things. They became convinced that the resistance pattern could be traced back to animal antibiotic use, because resistance genes in the bacteria causing human infections matched genes found in bacteria on conventionally raised meat. And they began to understand that E. coli's complexity would make this new resistance problem a difficult one to solve. The strains that cross to humans via poultry meat "don't establish themselves as big, successful lineages" of bacteria that would be easy to target, Johnson said. "But collectively they can cause a lot of infections, because there are just so many of them and they're so diverse."

Even the World Health Organization recently vocalized concern over what could become a 'post-antibiotic era' where a scraped knee could lead to death if an untreatable infection arises. Scientists and advocacy groups have been urging the FDA for tighter regulations on antibiotics in livestock feed. Recently the FDA dismissed petitions targeting some of the more widely used antibiotics while enforcing restrictions on cephalosporin, a less commonly used class of antibiotics.

Keep in touch with Jill on Twitter @jillettinger

Image: antaean