Why was extra-label use of fluoroquinolones and glycopeptides banned in 1997?

• A. It increased antibiotic residues in edible tissues
• B. It reduced the efficacy of vaccines
• C. It did not affect pathogen resistance
• D. It could increase drug-resistant zoonotic pathogens at slaughter

Answer: (D)

Preventing the spread of antibiotic-resistant bacteria from food animals to people is the key idea. Extra-label use means giving a drug outside its approved species, dose, or indication. Fluoroquinolones and glycopeptides are critical for treating human infections, so using them beyond labeled guidelines increases the selective pressure on bacteria living in animals. This can lead to resistant strains that contaminate meat during slaughter and reach humans through the food supply, making infections harder to treat. While residue concerns exist, the central public health rationale for the ban is to reduce the chance that drug-resistant, zoonotic pathogens at slaughter could be introduced into people.