In a report titled "Chain Reaction IV: Burger Edition," only two hamburger restaurants, California-based Shake Shack and Florida-based BurgerFi, earned A grades based on their public policy of sourcing meat raised without antibiotics.The report was co-authored by Friends of the Earth, the Natural Resources Defense Council, Consumer Reports, Center for Food Safety, FACT: Food Animal Concerns Trust, and the U.S. PIRG Education Fund, all of which were called public interest organizations working to eliminate the routine use of antibiotics in animal agriculture.The restaurants earning A grades both currently serve only beef raised without antibiotics and claims that because the chains are expanding from the small number of current locations, that "their responsible sourcing practices — including serving beef raised without antibiotics — are paying off."The Wendy's chain received a D- grade on the report because in 2018, the chain began to purchase 15 percent of its beef supply from producers that have "reduced the use of one medically important antibiotic, tylosin, by 20 percent."Tylosin, approved and most commonly used for the treatment of shipping fever, falls under the Veterinary Feed Directive though the report gives no details about the stage of production in which the drug is being reduced.Food Safety Inspection Service Acting Deputy Under Secretary Carmen Rottenberg commented on an earlier article published in Consumer Reports, one of the publications behind this report, reminding producers to continue talking about the safety of the U.S. beef supply. Conversation about the carcass by carcass inspection and the robust food safety program, she said, should fill the space rather than allowing the space to be filled with the scare tactic narrative.