On May 11, 2012, Representatives Edward J. Markey (D-MA) and Louise M. Slaughter (D-NY: the only microbiologist in Congress) wrote a letter to the Food and Drug Administration (FDA) asking several questions about the FDA’s stance on reducing the number of antibiotic-resistant bacteria linked to food animals.
Food Poisoning Bulletin has talked to several experts about this topic, including Tyler Smith of Johns Hopkins Center for a Livable Future. Scientists and physicians are concerned about the connection between routine sub-therapeutic use of antibiotics in farm animals and the increasing threat of antibiotic-resistant bacteria.
The letter the Congresspersons sent to the FDA asks about the link between ethanol byproducts used in animal feed and antibiotic-resistant bacteria. It was prompted by a report issued by the Institute for Agriculture and Trade Policy (IATF), which recently investigated the “FDA’s failure to regulate antibiotic sales to the ethanol industry,” according to that agency.
Their new report, Bugs in the System, How the FDA Fails to Regulate Antibiotics in Ethanol Production, states that the FDA has “taken a lax stance on the use of antibiotics in livestock and poultry feed, refusing to place binding regulations on producers that would limit their antibiotic use.” While it’s not well known, ethanol producers routinely add antibiotics to the tanks used to ferment ethanol from corn.
Bacteria love sugar, and the corn mash that produces ethanol is the perfect medium for their growth. Antibiotics prevent that bacterial growth, but they end up in a byproduct of ethanol called “distillers grains”, or DGS, that is fed to farm animals. DGS is just another way that farm animals ingest low, or sub-therapeutic, doses of antibiotics that are important to human health.
According to the report,
“the FDA has not restricted the marketing or use of antibiotics in ethanol production, nor have they prohibited or limited sales of DGS that are contaminated with antibiotic residues. The FDA has ruled, however, that antibiotics used in ethanol production should be treated as food additives, and thus require FDA approval before they can be used. This IATP report shows that the FDA has not enforced its own ruling.”
The letter asks the FDA five questions; the representatives want an answer by June 1, 2012.
- Why hasn’t the FDA published the full results of the 2008 survey of antibiotic residues in DGS?
- Did the information collected by the FDA in its surveys of antibiotic residues in DGS suggest that drug contamination may pose a risk to animals used for human consumption?
- Does the FDA believe that the presence of antibiotics in DGS used for livestock feed post a similar public health concern as the impact of directly using antibiotic drugs to promote livestock growth?
- What is the FDA doing to ensure that ethanol producers are complying with Food Additive Regulations?
- Why did the FDA choose to ban the use of DGS contaminated with the antibiotic, virginiamycin, in laying hens, but not in other food-producing animals?
We’ll report on the FDA’s response. That agency did conduct a survey of distillers grains for antibiotic residues and published those results in a 2009 report. They found that “4 of the 46 samples were quantifiable in the laboratory for antibiotics.” Each sample contained a total of five antibiotic residues, including virginiamycin, erythromycin, and penicillin.
The IATF’s report recommends that the FDA should ban the sale of unapproved antibiotics to ethanol producers, that antibiotic manufacturers should stop marketing antibiotics to the ethanol industry, and that the ethanol industry should voluntarily stop using antibiotics and start using alternatives for bacterial control in corn mash, with the assistance of the USDA, DOE and other agencies.