(Mandy Jansen)With major fast food chains like McDonald’s, Chick fil-A, Chipotle, and Panera all now sourcing at least some meat that wasn’t raised using medically important antibiotics, a coalition of some 50 consumer and health advocacy groups are asking Subway, the fast food chain with the most stores in the U.S., to give drug-free meat a try. Overuse of antibiotics in livestock and by physicians has resulted in the development of bacteria that is now resistant to the drugs created to kill them.