STUDY after study has shown that feeding antibiotics to livestock as growth promoters leads to antibiotic-resistance appearing in bacteria in the animals, and eventually in bacteria that cause diseases in people. It has always been assumed that this was because the drugs allowed naturally resistant strains to flourish, or evolve over time. Now, astonishingly, it has been found that the crude antibiotics fed to farm animals for decades actually include resistance genes.
The feed-grade antibiotic avoparcin made by the Swiss firm Roche contains DNA from the bacteria used to produce it, including intact copies of a cluster of three genes…
