“I’ve heard a lot lately about ‘superbugs’ in our food supply. What are they?”
So-called “superbugs” are antibiotic-resistant versions of bacteria that can cause difficult-to-treat illness and infections; as you can imagine, they pose a particular threat to small children, pregnant women, the elderly, and anyone with a compromised immune system.
On June 13, science ministers of the G8 countries met in London and agreed to coordinate a global attack on antibiotic resistance; in a joint statement, they called it “a major health security challenge of the twenty first century.” In the U.S. alone, for instance, the multi-drug-resistant superbug Staphylococcus aureus (MRSA), which initially affected ill people in hospitals, is infecting an increasing number of people in community settings, including healthy athletes and children.
Federal scientists are even finding some antibiotic-resistant superbugs in the contents of supermarket meat cases. In a report published in April, the Environmental Working Group (EWG) analyzed the latest (2011) tests of retail meat conducted by the National Antimicrobial Resistance Monitoring System (NARMS)—an ongoing joint project of the FDA/CVM (Center for Veterinary Medicine), the Centers for Disease Control and Prevention (CDC), and a number of state public health laboratories.
According to EWG’s calculations, the scientists documented antibiotic-resistant foodborne pathogens on 39 percent of chicken breasts, wings, and thighs; 55 percent of ground beef; 69 percent of pork chops; and 81 percent of ground turkey. “In less than a decade,” the EWG report reads, “the proportion of antibiotic-resistant salmonella bacteria found on raw chicken has dramatically increased—from 48 percent in 2002 samples to 74 percent in 2011 samples. About 20 percent of the salmonella microbes detected on chicken samples collected in 2002 were resistant to at least three drugs. By 2011, that number had risen to 45 percent.”
The FDA released a response to the EWG report, cautioning against oversimplification. “It’s especially important to stress that the NARMS report is intended to measure trends in data over several years,” wrote FDA spokesperson Siobhan DeLancey in an email earlier this week. “Results from any one year need to be put into that context. Antimicrobial resistance is a real and serious problem with many causes. FDA is addressing this phenomenon from several angles, including its plan to phase out using antibiotics at low levels to promote growth in food animals.”
As far as the EWG (here’s its rebuttal to the FDA response) and many members of the scientific community are concerned, the FDA isn’t moving fast enough. In the December 2012 issue of BioScience, Marcia Stone wrote, “in the billions of years that they have been on Earth, ubiquitous microbes like Salmonella, among the most pervasive foodborne pathogens around, learned to adapt to almost anything nature can throw at them by commandeering survival genes from their microbial mates and rapidly evolving into new strains.”
According to the American College of Physicians, doctors prescribe more than 133 million courses of antibiotics to non-hospitalized patients each year, and it’s estimated that 50 percent of those prescriptions are unnecessary since they are being prescribed for colds and other viral infections—sometimes at the request of impatient patients. That’s one part of the problem. But of greater consequence are the American industrial producers of meat and poultry (no strangers to the Food, Inc., crowd), who, for decades, have been feeding their animals small daily doses of antibiotics to prevent sickness and accelerate weight gain; more meat in less time reduces production costs. Citing the Pew Campaign on Human Health and Industrial Farming, EWG notes that pharmaceuticals sold for use on food-producing animals account for nearly 80 percent of the American antibiotics market.
These promiscuous misuses and overuses of antibiotics encourage antibiotic-resistant strains of pathogens to develop: When an animal (or human) is given antibiotics, sensitive bacteria are killed, but the resistant ones survive and pass that hardiness along to their offspring as well as to microbes of other species. Anybody else feel as though we’re in a Robin Cook medical thriller? Zombies are so over!
Even if you wouldn’t dream of eating conventionally raised meat and poultry—or any meat and poultry at all—don’t get too complacent. All food, whether conventional or organic, is susceptible to pathogens. Remember that massive recall (39 states) of organic baby spinach back in February? And although it’s been stated that E. coli 0157:H7 doesn’t appear in grass-fed cattle, that turns out not to be true, as James McWilliams reported in Slate in 2010. (That doesn’t mean that consumers are necessarily at equal risk; E. coli contamination is primarily a processing/butchering issue, and grass-fed cattle are generally processed at small facilities instead of large, high-speed industrial plants.)
So, is there any good news? Well, in Marcia Stone’s piece for BioScience, she points out that microbes aren’t all that’s evolving. Science is evolving as well. “New molecular methods such as next-generation sequencing (NGS), coupled with advanced informatics analysis, enable researchers to rapidly identify contaminating pathogens at every step of the food chain—from farms and slaughterhouses to transport, processing facilities, and supermarkets,” she wrote.
To this end, NGS is used in the 100K Pathogen Genome Project at the University of California, Davis, which was started in 2010 to sequence the genetic codes (genomes) of 100,000 strains of important food pathogens and make them available in a free, public database at NIH’s National Center for Biotechnology Information. In May of this year, it announced it had sequenced the genomes of its first ten infectious microorganisms, including strains of Salmonella and Listeria.
In a perfect world, obviously, we would not need this sort of thing. But until we mandate some serious, sweeping changes in large-scale farming practices—and in Washington—it’s imperative that we’re able to quickly pin down the source of an outbreak and prevent further illness.
You’ll notice I was using the editorial “we” there; most of us wouldn’t recognize a genome if we tripped over it. But all this reminded me that almost exactly one year ago, Consumers Union, the advocacy arm of Consumer Reports, released a report on consumer attitudes to the overuse of antibiotics in agriculture. You can make your opinion count at Consumer Union’s NotinMyFood.org. And stay tuned for some tips on smart food-safety practices in the home kitchen.