The case of the Dutch farmer, although isolated, placed that assumption in question. A panel of experts recommended banning the most widely used animal antibiotic, Tylosin phosphate, along with Virginiamycin, Bacitracin Zinc and Spiramycin because they are similar enough to drugs used in human medicine to fear that resistance could be passed across the species barrier through gene transfer. A spokesman for the European Commission, the EU executive body, said the experts could not prove that the widespread use of the drugs would cause antibiotic resistance in humans, but they could not disprove it either. Since the animal antibiotics concentrate in the gut, which is removed before carcasses are sent to market, the risk of the drugs getting into the human food chain was thought to be nonexistent. Mr. Kiely said.
Experts acknowledge that the evidence for the prosecution is slender.
The antibiotics ban could lead to another trade problem with the United States, with which the EU already is in conflict over its refusal to admit imports of hormone-treated beef. The commission's scientific steering committee, which is looking at the whole question of drug-resistant bacteria, will vote in December on the proposed ban, which could go into effect on Jan. 1. Mr. Kiely said it was important to advance solid scientific reasons for imposing a ban. Without them, the EU would be open to a challenge in the World Trade Organization, as it has been in the case of hormones in beef. The experts' recommendation does not apply to the use of the antibiotics for the treatment of animal diseases, but to their routine use in feeds.