22 burger chains given "F" over antibiotics -- only 2 get "A" rating

Twenty-two of the top 25 U.S. burger chains -- including McDonald's, Burger King, White Castle and Five Guys -- received a failing grade in a review assessing their practices and policies on antibiotics use in their beef products. Only two chains were given an "A" rating.The scores were published Wednesday in a report called "Chain Reaction IV: Burger Edition," which was produced by the Center for Food Safety, Consumer Reports, Food Animal Concerns Trust, U.S. PIRG Education Fund, Friends of the