Investors’ fast food coalition against antibiotics is urging U.S. food companies like McDonald’s Corp, Denny’s Corp, and Sanderson Farms Inc to stop buying or producing meat raised with medically important drugs.

Members of the Interfaith Center on Corporate Responsibility (ICCR) have filed shareholder resolutions at each of the companies, ICCR said in a statement on Thursday.

If the resolutions are not successfully challenged by the companies, they will come up for vote at the companies’ next shareholders meetings.

ICCR members, alongside other campaigners, have had previous success in convincing most U.S. chicken producers to stop using medically important antibiotics.

Scientists and public health experts for years have warned that the regular use of antibiotics to promote growth and prevent illness in healthy farm animals contributes to the development and spread of drug-resistant superbugs that can infect people.

The World Health Organization earlier this year recommended that meat producers end such practices.

Fast-food chain McDonald’s USA last year shifted to chicken raised without medically important antibiotics. The latest shareholder resolution, sponsored by the Congregation of Benedictine Sisters of Boerne, Texas, calls on McDonald’s Corp to adopt a similar sourcing policy for beef or pork.

Adopting such a policy would move McDonald’s closer to rivals Chipotle Mexican Grill Inc and Panera Bread Co, which serve chicken, pork and beef from animals raised without antibiotics important to human health.