Researchers collected 184 samples of chicken labeled organic, raised without antibiotics, kosher, and conventional from grocery stores in the New York City area. Kosher chickens had the highest levels of antibiotic-resistant E. coli, at 78% of the samples tested. About 60% of certified-organic and “raised without antibiotics” harbored the bacteria. Conventional chicken had the lowest rate of contamination, at 55%—still pretty high. Keep in mind that the study only looked at a small sample size in a certain area, so we can’t generalize the findings to the rest of the country. Still, the results point to systemic problems with chicken production, says Keeve Nachman, PhD, program director of the Food Production & Public Health Program at Johns Hopkins University’s Center for a Livable Future. “It’s a long continuum from the production of an animal to what you pick up at the store,” he says, “and, there are a lot of opportunities for cross-contamination.” For one, chicken processors typically handle all types of chicken. “After poultry processors handle conventional chickens, the facility has to be cleaned prior to production of organic chicken,” Nachman says. But if the facility isn’t cleaned well, there are lots of chances for your organic chicken to wind up with nonorganic bugs. Furthermore, organic chickens can receive antibiotics while in the shell and on the first day after they hatch, according to organic guidelines, which can contribute to antibiotic resistance. In fact, the study found that about 10% of the E. coli strains found on both organic and nonorganic samples were resistant to gentamicin, a common antibiotic in eggs and newborn chickens.But this shouldn’t deter you from organic meat, Nachman says. “Organic and antibiotic-free chickens are still better for surrounding communities,” he says, “and studies like this can distract from the hazards that conventional farms really pose.” (Check out these10 Good Reasons To Buy Organic for more proof.) To avoid bacteria, cook your chicken (no matter what kind) to an internal temperature of 165ºF. And keep raw chicken separate from raw vegetables and other foods you don’t intend to cook. More from Prevention: 100 Cleanest Packaged Foods