In 2005 the FDA banned the use of a particular broad-spectrum (meaning effective against a broad range of microbes) antibiotic class—the fluoroquinolones—due to an alarming increase in the rate of resistance to Campylobacter bacteria. Yet, “In recent years, we’ve seen the rate of fluoroquinolone resistance slow, but not drop. With such a ban you would expect a decline in resistance to these drugs,” stated David Love, PhD, lead author of a recent study published in Environmental Science & Technology.
In the study, researchers tested 12 samples of feather meal (yes, they make certain animal feeds from chicken feathers—disgusting, I know), obtained from the United States and China, for antibiotic residues, and pharmaceuticals. They found that all 12 samples had antibiotic residues and 8 of the 12 samples tested positive for the banned fluoroquinolones. They also detected the pain reliever acetaminophen (the active ingredient in Tylenol), the antihistamine diphenhydramine (the active ingredient in Benadryl), and the antidepressant fluoxetine (the active ingredient in Prozac).
“The discovery of certain antibiotics in feather meal strongly suggests the continued use of these drugs, despite the ban put in place in 2005 by the FDA. The continued use of fluoroquinolones and unintended antibiotic contamination of poultry feed may help explain why high rates of fluoroquinolone-resistant Campylobacter continue to be found on commercial poultry meat products over half a decade after the ban,” stated Love.