According to a report, most hamburger chains receive an "F" of antibiotics

A joint report from six consumer and environmental groups ranked the top 25 fast food chains on the use of antibiotics in the hamburgers that they sell. Bad news for 22 of them: they were unsuccessful.

Restaurants that have failed include McDonald's, Burger King, Sonic, Jack In The Box, Hardee's, Whataburger, Carl's Jr., White Castle, The Burger Grill Habit, Fuddruckers and In-N-Out Burger.

The overuse of antibiotics in animals is accelerating the proliferation of bacteria resistant to these drugs, according to the World Health Organization, which considers antibiotic resistance as "one of the biggest threats to the health, food security and development in the world ". According to the Centers for Disease Control, 2 million Americans contract an infection each year, 23,000 of which result in death.

The report, Chain Reaction, was produced in cooperation with Consumer Reports, the Center for Food Safety, the US PIRG Education Trust, Trust Animal Concerns Trust, Friends of the Earth, and the Natural Resources Defense Council.

More than 70% of the medically important antibiotics sold in the US are for food animals, "the report says. "Many meat producers routinely give these drugs to animals that are not sick, either to promote faster growth or to prevent diseases caused by production practices on industrial farms."

Only two chains, Shake Shack and BurgerFi, received the grade A for the supply of high meat without antibiotics. Wendy's received a minus D after buying 15% of its beef from suppliers who use less tylosin, a key antibiotic.

A survey conducted by Consumer Reports in 2018 found that 59% of those surveyed preferred to eat in restaurants serving meat from animals raised without antibiotics.

A spokesman for McDonald's said USA today that the company will announce a new global policy on antibiotics by the end of this year.