There is a long-running disagreement between the US and the EU because the EU does not allow the purchase of US poultry since it does not meet EU food standards. Put bluntly, they keep too many chickens in a too small coup, and diseases spread between them as a result on top of the sheer cruelty of it all. To compensate, they give them a lot of antibiotics, which has the effect of creating and spreading resistant superbacteria. At least that's the allegation.