Half of all raw chicken breasts in the U.S., including organic brands, may contain harmful, antibiotic-resistant “superbug” bacteria, according to research by Consumer Reports. The research, released early Thursday, calls for stricter limits on medicines used on livestock and warns that it may be more difficult to treat people if they become ill after eating contaminated chicken.

In an analysis of more than 300 raw chicken breasts nationwide, Consumer Reports found that more than half of the samples contained fecal contaminants and about half harbored bacteria that is resistant to commonly prescribed antibiotics. Researchers tested for six types of bacteria and found that almost all of the chicken, especially those purchased at your local grocer, contained potentially harmful bacteria. According to Reuters, 49.7 percent of the chicken tested carried bacteria that is resistant to three or more antibiotics.

The fear is that Americans eating this meat will contract an antibiotic-resistant form of Salmonella infection that would make outbreaks almost uncontrollable. Salmonella infections are caused by eating raw or uncooked meat, eggs, or poultry products. Infections usually come about when chicken is undercooked or improperly handled. Officials believe that if cooked correctly, the affected chicken will be safe for consumption. Symptoms include nausea, vomiting, abdominal pain, and diarrhea. According to Mayo Clinic, although most symptoms of Salmonella infection subside after about five days, it could take several months for one’s bowels to return to normal.

Since 2012, there have been at least two multi-state Salmonella outbreaks in the U.S. Just this year, an outbreak linked to Foster Farms in California sickened at least 300 people across 18 states. In all, the U.S. Centers for Disease Control and Prevention (CDC) says that at least 523 people in 29 states have been sickened in Salmonella outbreaks stemming from contaminated chicken, according to Food Safety News. That number could leap to as many as 15,000 if one includes the suspected unreported cases.

Pew Health Group believes that the U.S. Department of Agriculture (USDA) needs to improve its regulation of raw chicken, according to The Hill. “When you have more than 500 people getting sick from chicken, the government policies and the system in place to ensure that that chicken is safe are not working,” said Sandra Eskin, director of the Pew Health Group Food Safety Campaign. “The Food Safety and Inspection Service should go beyond what it is proposing in its recently released ‘Salmonella Action Plan' and do more to target Salmonella, which is responsible for more hospitalizations and deaths than any other bacterium or virus.” Pew suggests establishing new limits for chicken in processing facilities, making unannounced visits to farms and facilities, and regularly updating its standards.

While the Consumer Reports research is troubling, researchers believe that properly cooking poultry to at least 165 degrees will kill the bacteria. They also recommend using separate cutting boards for raw meat to avoid cross-contamination of other foods. For more information on Salmonella and how you can keep yourself safe, visit CDC.gov.