RESULTS of a newly released Consumer Reports study suggest that U.S. ground beef from conventionally raised animals is twice as likely to contain "superbugs" as grass-fed or organic beef.

Meat industry stakeholders, on the other hand, are touting the study's confirmation that pathogenic bacteria rarely are found in meat.

For the study, Consumer Reports tested 300 packages of ground beef — a total of 458 lb. — from 103 grocery, big-box and natural food stores in 26 cities across the country. Additionally, different varieties of ground beef were tested, including conventionally raised, grass-fed and organic.

Samples were tested for the presence of five common types of bacteria found on beef: Clostridium perfringens, Escherichia coli (including O157 and six other toxin-producing strains), enterococcus, salmonella and Staphylococcus aureus.

Results showed that 18% of the beef samples from conventionally raised cows contained "dangerous superbugs" resistant to three or more classes of antibiotics used to treat illness in humans, compared with just 9% of beef from samples that were called "sustainably" produced.

The North American Meat Institute (NAMI), however, said the bacteria identified in the Consumer Reports testing are types that rarely cause foodborne illness. Bacteria such as S. aureus, enterococcus and generic E. coli are commonly found in the environment and are not considered pathogenic bacteria.

"The real headline here is the bacteria that Consumer Reports doesn't report finding in their testing: Shiga toxin-producing E. coli and salmonella, which are the foodborne bacteria of greatest public health concern in beef," NAMI vice president of scientific affairs Dr. Betsy Booren said in response to the findings.

Bacteria occur naturally on all raw food products, from beef to blueberries, so finding certain types on some foods in a grocery store is not surprising and should not be concerning, Booren said.

"As an industry, our number-one priority is producing the safest meat and poultry possible, and this is done by focusing attention on bacteria that are most likely to make people sick, particularly Shiga toxin-producing E. coli and salmonella," she said. "It is telling that Consumer Reports did not highlight finding these bacteria on products they tested, which is a strong indication of the overall safety of beef."

NAMI pointed out that U.S. meat companies produce billions of pounds of ground beef annually, and the U.S. Department of Agriculture's Food Safety & Inspection Service (FSIS) routinely samples the product in meat plants for E. coli O157:H7. FSIS data show that E. coli O157:H7 occurs at a rate of less than one-tenth of 1% in ground beef products, NAMI noted.

USDA has found other Shiga toxin-producing E. coli strains in only 15 raw ground beef components so far this year. Any product that tests positive cannot enter the marketplace. FSIS also tests for salmonella, with a positive rate of less than 1% in 2015.

In addition to FSIS testing, NAMI said the industry regularly tests for these pathogens independently to ensure that safe products are being produced.

Alarmist, misleading

NAMI said while the study's results make clear the safety of beef, Consumer Reports' claims about antibiotic resistance and its prevalence in products from different production methods is far less clear.

"Antibiotic resistance is common in nature; it has been found in permafrost that has been untouched by humans and animals. Its presence in bacteria is expected," the group noted. "What is most important to know is whether certain pathogenic bacteria are resistant to certain types of antibiotics, but Consumer Reports has not specified this information in the materials shared with the industry."

According to NAMI, the Food & Drug Administration has said that it is inaccurate and alarmist to define bacteria resistant to one or even a few antimicrobials as "superbugs" if these same bacteria are still treatable by other commonly used antibiotics. This is especially misleading when speaking of bacteria that do not cause foodborne disease and have natural resistances, such as enterococcus.

"Just because a bacterium is resistant to one, two or even three antibiotics doesn't necessarily make it a superbug," Booren explained. "Superbugs are bacteria that are no longer treatable with antibiotics. The important aspect to look at isn't the resistance itself but whether that resistance is a public health danger."

NAMI referenced a National Antimicrobial Resistance Monitoring System report showing that about 80% of human salmonella isolates are not resistant to any of the tested antibiotics — a finding that has not changed in the past 10 years. Additionally, resistance to ceftriaxone, azithromycin and quinolones — three important drugs used to treat human salmonella isolates — remains below 3%.

Salmonella multi-drug resistance (resistant to three or more classes of antibiotics) in human, cattle and chicken isolates has not changed (at about 10%) in the last decade, NAMI noted.

Both Consumer Reports and NAMI agreed that consumers should cook all ground beef — whether conventional, organic or grass fed — to 160 degrees F. NAMI said any bacteria, antibiotic resistant or not, are killed when cooked to the recommended temperature.

"Consumers are urged to use a meat thermometer to confirm doneness and properly store products before and after cooking since bacteria can multiply at temperatures above 40 degrees F," NAMI said.

Volume:87 Issue:d3