Pressure is mounting on McDonald’s, as well as other large fast food chains, to stop using meat and milk that has been treated with antibiotics. A new online campaign, run by the charity ShareAction, is urging people to email MacDonald’s chief executive in order to get them to pledge to stop buying from farms that excessively use antibiotics.

While the fast food giant has already committed to only using antibiotic-free chicken in their nuggets in the US by the end of 2017, many are saying that this is not enough, and the policy should be extended across all meats and all restaurants around the world. With more than 23,000 Americans dying from antibiotic-resistant infections per year, the threat of moving into a post-antibiotic era is a very real, and very dangerous one.

The heavy use of antibiotics in livestock, where it is given to animals to prevent rather than treat infections, is a major issue globally. It is thought that the overuse of them in animals, which are frequently given the same drugs that we use to treat humans, drives the evolution of bacteria to become resistant to the antibiotics that we rely on. In November 2015, scientists discovered that pigs in China were carrying bacteria resistant to colistin, considered the last line of defense in antibiotics, used when all others fail.

The bacteria was then found to be present in hospitals, before public health bodies reported this year for the first time that colistin-resistant bacteria had been found outside of China. A woman living in Pennsylvania was found to have a urinary tract infection that contained the resistance, a worrying development at a time when many experts now think we may be heading for a post-antibiotic era, as the bacteria are developing these resistances at a rate faster than we are finding alternatives.

And the farming industry plays no small part in this. It is thought that 70 percent of all antibiotics used in the US are given to livestock, while in the UK that figure is somewhere closer to 50 percent, a practice that has previously been described as “excessive and inappropriate.” With McDonald's responsible for buying millions of cattle, pigs, and chickens each year, they have a major impact on the industry, and could make a real difference in driving change within farming.

“The evidence is clear – if we do not curb the routine and excessive use of antibiotics, both in medicine and in livestock production, we face a global public health crisis,” says Emma Rose from the Alliance to Save Our Antibiotics. “McDonald’s has an opportunity to demonstrate global leadership by committing to phase out the routine use of antibiotics entirely – not just limited to chicken in its US market – and doing so would drive up standards across the industry.”

A similar petition has been launched against other fast food joints, such as KFC, in order to pressure them into stopping using antibiotic-fed chicken. With resistances to all known drugs a very real possibility, it will require collective and global action to help prevent.