Meat, poultry, and shrimp from animals raised without antibiotics are less likely to harbor multidrug-resistant “superbug” bacteria than those that are conventionally produced, according to a sweeping new analysis by Consumer Reports.

The findings, reported in the magazine’s latest issue, are based on a review of in-depth studies conducted over the past three years by Consumer Reports’ Food Safety and Sustainability Center of bacterial contamination in four different types of primarily raw and uncooked meat.

Hundreds of packages of meat, poultry, and shrimp were methodically tested for bacteria and antibiotic resistance and analyzed by an expert team of scientists and statisticians.

In most cases, the researchers found lower levels of “superbug” contamination in meat from animals not treated with antibiotics than in those raised using conventional methods. For example, ground beef raised from conventionally raised cows was twice as likely as that from those raised without antibiotics to carry superbugs.

About 80 percent of the antibiotics sold in the U.S. are given to animals raised for food — including hogs, cattle, chickens, and turkeys — making the practice a key driver of drug-resistant infections not only in animals, but also in humans, studies show. Food and Drug Administration data show that more than 32 million pounds of antibiotics were sold for use in food animals in the U.S. in 2013 — up 17 percent from 2009.

“Eliminating routine antibiotic use is an important step in protecting the effectiveness of these medicines for future generation,” said Urvashi Rangan, executive director of the Food Safety and Sustainability Center at Consumer Reports. “Using drugs to promote growth and to compensate for hygiene problems puts everyone at risk.”

Using data from the Centers for Disease Control and Prevention, Consumer Reports calculated 20 percent of people sickened by an antibiotic-resistant bug get it from their food. At least 2 million Americans fall victim to antibiotic-resistant infections every year; 23,000 die, according to the CDC.

The magazine’s editors urged consumers to steer clear of conventionally raised food products. Chipotle and Panera have nearly eliminated antibiotics from their supply chain while four other restaurants — McDonald’s, Chick fil-A, Dunkin Donuts, and Subway — are reducing antibiotic use in the meat and/or poultry they serve.

“Consumers can choose meat and poultry raised without antibiotics both at the supermarket and when they are eating out,” Rangan said.