A new online campaign has urged fast food giant McDonald's to impose a global ban on products from animals treated with antibiotics. The campaign, which was initiated by charity ShareAction, is looking to fight the rise of dangerous, drug-resistant bacteria.

Scientists believe that treating livestock with antibiotics will lead to a rise in drug-resistant superbug infections that is said to have killed at least 23,000 Americans a year and represents a significant threat to global public health. Customers of McDonald's — the world's biggest fast food chain — have been requested to email CEO Steve Easterbrook putting forward their concern.

The group, which promotes socially responsible investing, wants the fast food chain to stop using chicken, beef, pork and dairy products that have been given antibiotics in all of its 30,000 stores globally. More than 70 percent of all antibiotics used in the United States and half of those used in the United Kingdom are given to livestock, ShareAction said.

"We hope this action will encourage McDonald's to supersize their ambition," ShareAction CEO Catherine Howarth said, according to Reuters.

Last week, the fast food chain stopped using poultry treated with antibiotics - but only in its U.S. restaurants.

McDonald's told Reuters that it was too early to set a timeline for phasing out the use of all meat and milk products from animals treated with antibiotics.

"We continue to regularly review this issue," the statement said.