Most hamburger is contaminated with bacteria, and a lot of those bugs have superpowers.

That's the conclusion of a new study from Consumer Reports, which found that out of 300 samples from stores across the country, bacteria linked to fecal contamination was detected in nearly every package.

Researchers found that 18 percent of ground beef from conventionally-raised cows that are fed antibiotics contained E. coli and other bacteria resistant to resistant to three or more classes of antibiotics used in human medicine.

Organic, grass-fed beef raised without antibiotics scored better, with just 9 percent containing antibiotic-resistant bacteria. The report recommends buying sustainably raised beef when possible.

Critics from the meat industry said the findings about superbugs was "misleading and alarmist," because resistant bacteria detected rarely cause foodborne illness.

Overall 20 percent of the samples contained C. perfringens, which the Centers for Disease Control says causes up to a million food poisoning cases each year, and 10 percent of the samples were contaminated with a strain of Staphylococcus aureus that makes people sick.

Food safety advocates recommend cooking beef of all kinds at a temperature of 160 degrees Fahrenheit to kill off bacteria.

Read More:

• How Safe Is Your Ground Beef? (Consumer Reports)
• Ground Beef Contains Dangerous Bacteria, Study Finds (Time)
• Consumer Reports' Ground Beef Study Elicits Differing Interpretations (Food Safety News)
• Bacteria In Ground Beef Dangerous Or Natural? Depends On Point Of View, Apparently (Food Politics)