Researchers say the chicken industry is making strides in using fewer antibiotics. Beef and pork, not so much.

Restaurants are doing better when it comes to reducing antibiotics used in the meat they serve.

However, more than half of the eating establishments surveyed by a coalition of consumer, environmental, and health organizations are still receiving failing grades.

The restaurant antibiotics scorecard was released today in the coalition’s second annual Chain Reaction report.

The group used responses from the top 25 restaurant chains in the United States as well as public information to come up with the grades.

Officials at the organization said the issue is an important one since more than 70 percent of medically important antibiotics sold in the United States are used on livestock.

They said 96 percent of those drugs are added to feed and water often given to animals that aren’t sick.

They said the overuse of these antibiotics is a prime reason why antibiotic-resistant infections are increasing.

Officials at the Centers for Disease Control and Prevention (CDC) estimate that 2 million Americans are infected with these so-called “superbugs” every year. At least 23,000 of those infected die.

“We don’t have much time to fix this and we don’t have much choice,” Lena Brook, food policy advocate at the Natural Resources Defense Council (NRDC), told Healthline.

Read more: Investors tell major food chains to cut antibiotics from meat »

There was good news and bad news in Tuesday’s report.

On the positive side, coalition officials said, there are twice as many restaurants responding to public pleas to serve meat from animals that ingested a reduced about of antibiotics.

Nine of these chains received a passing grade of at least a “D,” double last year’s number.

In addition, officials said chicken meat suppliers have improved their policies regarding antibiotics.

On the negative side, beef and pork suppliers have not made such great strides, officials said.

In addition, 16 of the 25 restaurants surveyed still received failing “F” grades for their antibiotics programs.

The highest marks went to Panera and Chipotle. They were the only two companies receiving “A” grades. It’s the second year in a row both were given the top mark.

Brook said these two restaurants have been leaders in the antibiotics cause for almost a decade. She said both companies have built brands around quality products that aren’t reliant on antibiotics.

“They realized the seriousness of the issue early on,” Brook said.

Officials at Panera said they will continue this commitment. They noted they introduced deli turkey produced without antibiotics this month.

“We’re proud to have led the way on antibiotic reduction for over a decade, and continue to push ourselves to new milestones,” Sara Burnett, Panera’s director of wellness and food policy, told Healthline in an email comment.

Officials at Chipotle noted they have served meat free of antibiotics for years.

“We are pleased that surveys such as this bring more attention to issues of antibiotic use in livestock production and hope more restaurants will follow our lead in this area,” said Chris Arnold, communications director at Chipotle, in an email to Healthline.

Coalition officials also praised McDonald’s, which raised its mark to a “C-plus” after ending its antibiotics program in its chicken products.

Subway was the most improved, leaping from an “F” grade last year to a “B” this year. Last fall, the company announced it would end its use of antibiotics in its meat and poultry by 2025.

Read more: Antibiotics used in livestock pose risk to children’s health »

Some of the nation’s best-known restaurants were part of the group that received an “F” grade.

Among them were Applebee’s, Olive Garden, Denny’s, Burger King, Jack in the Box, and Dairy Queen.

Dunkin’ Donuts was downgraded to an “F” this year after coalition officials said the company weakened its publically stated antibiotics policy.

The most puzzling restaurant in this group to coalition officials is KFC.

The restaurant’s product is almost exclusively chicken, the part of the industry that has made the greatest strides.

Brook said chickens don’t have as long a lifespan as livestock, so it’s easier to forego antibiotics.

She added that chicken suppliers such as Foster Farms and Tyson have upgraded their antibiotics policies.

Brook noted that Taco Bell and Pizza Hut, which are owned by the same company as KFC, had improved scores this year.

In addition, Chick-fil-A, a main competitor, was given a “B” on this year’s scorecard.

“So, I can’t say what is holding KFC back,” Brook said. “They are a real laggard at this point.”

In an email response to Healthline, KFC officials said the company is currently reviewing its antibiotics program and the viability of its suppliers to go beyond federal guidelines.

“By 2017, antibiotics important in human medicine will only be used to maintain chicken health, and only under the supervision and prescription of a licensed veterinarian,” the KFC statement said.

Read more: Weakening antibiotics could result in 6,300 more infection-related deaths every year »

Brook said there is no reason to believe a lack of antibiotics in farm animals will hurt the quality of restaurant food or the restaurant chains’ bottom line.

She said there are no studies that show meat produced without antibiotics tastes any different.

She added it’s not known yet whether these new policies will prompt restaurants to raise their prices on these type of meals.

Brook said it seems apparent that companies can adopt these policies and still turn a profit since so many of them are doing just that right now.

“I think it shows that this is not only possible, it’s profitable,” she said.

Brook said she expects animal antibiotic use to continue to dwindle due to consumer demands. She hopes the beef and pork industry will catch up soon with the chicken market.

“There is change on the horizon. It’s just not happening as quickly in those industries,” she said.