Anti-Biotic Free Meat Places in Rome?
If this is a medical condition that has to be stricktly kept, the answer is: there is no such place - or you can never be sure. For such beat, it has to be organic and though there are butchers in Rome where you can buy organic meat and cook it yourself, there is no restaurant serving it I am aware of - and even an organic restaurant wouldn't be a guarantee.
I just returned from several weeks in Rome, eating at restaurants/trattorias every day. Not one had meat w/o additives/antibiotics. Wine and bread are available in markets as "biologico" products. But additive/antibiotic/pesticide-free meat and veggies at dinner or lunch have not made it on to Roman menus anywhere to my knowledge.
The Margutta near P. Popolo has organic offerings but the restaurant is strictly vegetarian.