There’s a “simple explanation for why eating a hamburger can now make you seriously ill,” wrote Eric Schlosser in Fast Food Nation: The Dark Side of the All-American Meal. “There is shit in the meat.”

A new Consumer Reports investigation suggests things haven’t changed much since the publication of Schlosser’s 2001 blockbuster. The team tested 300 packages of ground beef, bought from more than 100 grocery, big-box, and natural food stores in 26 cities nationwide. The result:

    All 458 pounds of beef we examined contained bacteria that signified fecal contamination (enterococcus and/or non-toxin-producing E. coli), which can cause blood or urinary tract infections.

But not all burger meat is created equal. The researchers also compared the bacterial load of beef from conventionally raised cows (181 samples) to that of their no-antibiotic, grass fed, and organic peers (116 samples total), grouped under the heading “more sustainably produced.” Here’s what they found:

The bacterial implications of beef production practices really emerged when the researchers tested the bacterial strains for resistance to antibiotics. Nearly a fifth of conventional ground beef carried bacteria resistant to three or more classes of antibiotics—more than double the number found in the “more sustainably produced” samples, and triple that found in samples from cows raised outdoors on grass.