McDonalds Corp. announced this week that over the next two years it plans to phase out the use of some antibiotics in chicken that it serves.

Overuse of antibiotics can result in stronger, more resistant "superbug" bacteria and render treatments ineffective over time.

The U.S. Centers for Disease Control links 23,000 deaths, as well as $20 billion in added health care costs, to sickness from to antibiotic-resistant bacteria each year.

Many commercial meat producers use low doses of antibiotics to promote growth and prevent the kinds of infections that are more likely to crop up in industrial conditions.

"Our customers want food that they feel great about eating – all the way from the farm to the restaurant – and these moves take a step toward better delivering on those expectations," McDonald's U.S President Mike Andres said in a statement.

The company will continue to use meat from chicken treated with animal antibiotics known as ionophores, a practice that fast food chains Chipotle and Panera has already banned.

Sustainability advocates cheered the company's announcement, but warn that current regulations don't go far enough to curb antibiotic use.

"Voluntary measures are not enough. It's past time for the FDA to force the meat industry to eliminate its use of harmful antibiotics though enforceable, non-voluntary regulation," said Wenonah Hauter, executive director of Food & Water Watch, in a release following McDonald's announcement.

McDonalds is one of the biggest chicken buyers in the U.S., purchasing up to 4 percent of the country's 39 billion pounds of chicken consumed last year.

Read More:

• McDonald's USA To Phase Out Human Antibiotics From Chicken Supply (Reuters)
• Your Mcnuggets: Soon Without A Side Of Antibiotics (Wired)
• McDonald's Is Finally Phasing Out Antibiotics in Chicken. Thank Chipotle. (Slate)