Wired have an article on this, and it highlights the likelihood of farms being a major contributor to antibiotic resistance.
Outside of experimental conditions, it’s never been possible to prove that this antibiotic given to that animal gave rise to this bacterium that ended up in that human. But this new work dives so deeply into the genomics of bacterial adaptation in food animals and humans, it proves the link that ag would rather deny.
Among the many strains they found was one known as H22, which was present on chicken meat and in people, and carried genetic markers indicating it had occupied the guts of poultry first, and then adapted to humans.