Walmart Pork Products Containing Superbugs Resistant to Critically Important Antibiotics Discovered

Testing has revealed the presence of bacteria resistant to multiple antibiotics in pork products sold at Walmart stores in the eastern U.S., according to a report.

Research conducted by non-profit World Animal Protection (WAP) identified several strains of bacteria in the meat, 80 percent of which were resistant to at least one antibiotic. Furthermore, the report found that 37 percent of the bacteria in the Walmart samples were resistant to three or more classes of antibiotics—and nearly 10 percent were resistant to six classes.

Worryingly, the report found that 27 percent of the resistant bacteria in the Walmart samples would be unaffected by antibiotics categorized as "Highest Priority Critically Important Antimicrobials" (HPCIAs) by the World Health Organization (WHO). HPCIAs are antibiotics used when there are few or no alternatives to treat people with serious bacterial infections.

According to the report, antibiotic-resistant bacteria—commonly referred to as "superbugs"—pose a threat to "all human life." Meanwhile, the WHO recently described antimicrobial resistance as an "increasingly serious threat to global public health that requires action across all government sectors and society."

The Centers for Disease Control and Prevention estimates that more than 2.8 million antibiotic-resistant infections occur in the U.S. every year, leading to the death of over 35,000 people. And a United Nations report concluded that by 2050, superbugs could kill 10 million people globally every year by 2050 if no action is taken to combat the problem.

However, the researchers say that not enough is being done to address the overuse of antibiotics, which is contributing to the rise of superbugs that can enter the food chain and environment.

One of the main drivers of this rise is that the drugs are vastly overused in animal agriculture.

"Seventy percent of the world's antibiotics are use on farmed animals," Alesia Soltanpanah, Executive Director of WAP U.S., told Newsweek. "And when you use antibiotics on farmed animals as a preventative rather than to treat the animal when it's sick, then it's an overuse of antibiotics.

"There has not been a great progress in the development of new antibiotics over the last 50 years," she said. "So we are not keeping up with the new bugs that keep cropping up, such as swine flu, etcetera."

Use of antibiotics as growth promoters in animal feed and water is no longer allowed in the U.S., however, the drugs are still routinely used to prevent the spread of disease, especially in low-welfare standard factory farms where animals are kept confined in overcrowded environments.

The report notes that these kinds of farms provide the perfect conditions for infections to spread. Instead of providing a better environment for pigs and other animals, producers are overusing antibiotics to stop stressed or injured animals getting sick.

"[Pigs] are crammed into small barren cages and it creates a lot of stress. They're in 'gestation crates' where they cannot move," Soltanpanah said. "Pigs are highly intelligent animals and they're very family oriented. Just the same as humans, they get sick when stressed out. So the only way that you can raise these pigs in these kinds of conditions and not have them all die off—which would cut profitability—is to feed them antibiotics."

In the latest report, the researchers focused on pork sold by two well-known retail chains in the U.S.—a country with one of the highest per capita rates of meat consumption in the word.

pig farm
Pigs at a farm near Osage, Iowa. Scott Olson/Getty Images

In total, WAP tested 80 pork samples purchased from several Walmart stores in the mid-Atlantic region and another 80 from outlets belonging to a competing national retail chain. They were tested in 32 batches of five samples.

The samples were then analyzed by researchers at Texas Tech University for the presence of bacteria that are commonly found in pigs and pork: E. coli, Salmonella, Enterococcus, and Listeria. Any bacteria identified was then tested for resistance to antibiotics.

The results revealed that the pork sold in both chains had a similar overall presence of bacteria in their batches, although more than half of the antibiotic-resistant strains (60 percent) were from Walmart's pork samples. Overall, the researchers made a number of key findings.

The report states:

  • The scientists identified a total of 51 bacteria isolates from the batches including:
    • Enterococcus in 27 batches;
    • E. coli in 14 batches;
    • Salmonella in six batches, and;
    • Listeria in four batches.
  • Batches of samples from Walmart were far more likely to contain a detectable presence of two or more of the bacteria in a single batch than the other chain, and all batches that tested positive for three or more bacteria were obtained at Walmart.
  • Antibiotic susceptibility testing conducted by the laboratory revealed that 41 of the 51 bacteria isolated from the pork samples were resistant to at least one class of medically important antibiotics. Twenty-one of the bacteria were multi-drug-resistant, meaning they were resistant to three or more classes, with three being resistant to six classes of medically important antibiotics.
  • The majority of multi-drug-resistant strains were isolated from Walmart sample batches, including all strains resistant to four or more drug classes. All seven strains resistant to HPCIA's were in Walmart samples.

Newsweek contacted Walmart for comment regarding the findings of the report but the company did not immediately reply.

"It's not uncommon to find these [bacteria,]" Soltanpanah said. "[But] I think the amount and the type of superbugs that were resistant to antibiotics was very surprising to us.

"The presence of multi-drug-resistant bacteria on pork products illustrates the role the pork supply chain plays in the global health crisis caused by antibiotic-resistant bacteria," she said in a statement. "The fact that pork purchased from several Walmart stores, one of the nation's largest retailers, contains bacteria resistant to antibiotics critically important to human health is particularly alarming and should raise concerns for all Walmart customers."

The latest report follows on from another paper published by WAP in 2018 that found bacteria resistant to antibiotics in samples sold by major supermarkets in Spain, Thailand and Brazil. Some of the samples from Brazil were purchased at Walmart stores.

Soltanpanah said WAP has previously been in contact with Walmart about these results but she claims that the company was "not responsive" to the concerns raised regarding its suppliers. Meanwhile, WAP say that the second retailer has committed to strengthening animal welfare policies for its pork suppliers, including working towards a commitment to completely eliminate the use of gestation crates for breeding sows. It has not been named in the report as a result of these commitments.

WAP says that Walmart is "lagging behind the times," noting that the company has not yet made a time-bound commitment to phase out the use of gestation crates in its supply chain, despite the fact that several of its competitors have—including Target, Costco and Kroger.

"By requiring higher welfare practices of all its pork suppliers, starting with a definitive timeline to end the use of gestation crates, Walmart can help eliminate the overuse of antibiotics to protect pigs and their customers," Soltanpanah said. "In fact, 88 percent of Walmart customers surveyed agreed that supermarkets have a responsibility to ensure that pigs are treated well, and 78 percent would be more inclined to shop at a retailer that planned to eliminate cages from its pork supply."

WAP is calling on global supermarkets to improve the lives of pigs by only sourcing pork from high-welfare farms—ones in which the animals can live in groups with room to move and freedom to express their natural behaviors.

"What we're asking retailers and producers to do is to raise them in more natural settings, and more natural settings leads to less illness," Soltanpanah said. "It's been proven in many studies, if you can raise them in group settings where they're able to socialize, able to be in straw—which is a natural element for pigs to play in—or have toys or things for them to interact with, they're much less stressed and they're much less likely to get sick. And therefore the antibiotic use goes way down. And you know what? The pigs are happier, it's less cruel and you're going to get a better product in the end."

Concluding, the researchers said: "There is an opportunity for the pig industry to responsibly reduce antibiotics while improving animal welfare practices: better for pigs, people and the planet."

In a statement provided to Newsweek Walmart said: "At Walmart and Sam's Club we are committed to providing our customers with access to safe, affordable, and sustainable food as well as promoting the humane treatment of animals. We only accept fresh pork from animals raised under the standards of the National Pork Board's (NPB's) Pork Quality Assurance (PQA) Plus Program."

"We value our relationships with U.S. pork producers who are dedicated to providing the highest in quality and safety through practices that promote animal well-being. Our priority is to advance humane treatment of farm animals in accordance with 5 Freedoms of Animal Welfare," the statement read.

The company said that by the end of 2018, 100 percent of its pork suppliers had implemented video cameras in order to monitor production.

"Additionally, as the world's largest grocer, we are committed to playing a leading role in upholding food safety laws and regulations applicable to our global businesses, and to providing access to safe, high-quality foods.To reduce food-safety-related risk in our supply chain, we require all private-brand suppliers and select categories of national-brand suppliers to achieve certification to one of the Global Food Safety Initiative's internationally recognized food safety standards, which often exceed applicable regulatory requirements," Walmart said.

This article was updated to include comments from Walmart.