The majority of foodborne illness outbreaks caused by antibiotic-resistant pathogens on record have occurred in the past thirteen years, according to a new report released by the Center for Science in the Public Interest on Wednesday.

The analysis found that between 1973 and 2011 there were 55 antibiotic-resistant outbreaks, 34 (58 percent) of which occurred since the year 2000. Dairy products, ground beef, and poultry were identified as the source of half of those. Salmonella was the most common culprit. Overall, 56 percent of the pathogens identified were resistant to five or more antibiotics.

“Antibiotic resistance isn’t a hypothetical problem,” said CSPI food safety research associate Susan Vaughn Grooters. “Real people are getting really sick from antibiotic-resistant pathogens in our food supply.”

In a press release highlighting the report, Reps. Louise Slaughter (D-NY) and Rosa DeLauro (D-CT) called for stronger action from the government in tackling antibiotic resistance issues.

“How many more outbreaks will it take before the USDA and the FDA take this problem seriously?” Slaughter asked in the release. “We have evidence that the practice of overusing antibiotics in food-animals is ruining these drugs’ effectiveness, and every day that the government stands idly by, we move closer to the nightmare scenario where routine infections can no longer be cured with antibiotic treatment.”

Slaughter, the only microbiologist serving in Congress, is the primary sponsor of the Preservation of Antibiotics for Medical Treatment Act (PAMTA), which would require that eight major classes of antibiotics be limited to only treat sick animals, not to be used subtherapeutically. DeLauro is a cosponsor of the legislation.

“It is clear that antibiotic-resistant strains of Salmonella present a very real risk to the public health,” Delauro said. “I urge the USDA to expeditiously review the petition that CSPI submitted more than two years ago and protect the public health from the clear risk of antibiotic-resistant foodborne pathogens.”

In May 2011, CSPI petitioned USDA to declare antibiotic-resistant Salmonella as an adulterant, which would make it illegal in meat products. USDA has not yet responded to the petition.