Basic microbiology and the principle of natural selection dictate that antibiotic use will tend to spur bacteria to become resistant to antibiotics. This fact underlays growing concern about the public health effects of the 29 million pounds of antibiotics sold annually for animal agriculture, weighing in at over four times the tonnage sold for use in treating sick humans. The U.S. Food and Drug Administration (FDA), tasked with protecting public health, has taken a lax stance on the use of antibiotics in livestock or poultry feed, refusing to place binding regulations on producers that would limit their antibiotic use. Despite rising problems with antibiotic resistance linked to antibiotic use in food animals, and the fact that most antibiotics given to livestock are used for growth promotion, rather to than to treat illness, making their use unnecessary, the FDA has asked that industry to make voluntary reductions and, and essentially, to self-regulate.
Three years ago food safety and public health advocates began to recognize that another sector of agriculture—the corn ethanol industry—also played a role in antibiotic misuse. Many ethanol producers routinely add antibiotics such as penicillin and erythromycin (both important for human health) and virginiamycin and tylosin (both have analogues used to treat humans) to the tanks where they mix corn mash with warm water to ferment ethanol. Bacterial outbreaks are common in ethanol plants (the bacteria like the warm, moist conditions and the corn sugar), and can lead to yield (and therefore profit) losses. Antibiotics help keep bacterial counts low, but fuel isn’t the only product that leaves ethanol plants. Producers also sell what is known as “distillers grains” (DGS), the nutrient-rich, leftover corn mash, to cattle, dairy, swine and poultry producers for use as a livestock feed. In 2008 the FDA found antibiotic residues in DGS samples taken from ethanol plants across the country, results that have been confirmed by subsequent studies.
As with antibiotics added directly to livestock feed, 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. Companies marketing these antibiotics, and the ethanol producers using them, are therefore doing so unlawfully; and the FDA is violating federal code in not regulating them.
For life-threatening bacterial infections in humans, there are no alternatives to antibiotics. Once resistant bacteria develop from antibiotic misuse, we have forever lost the corresponding tools needed to treat bacterial illness. As with non-therapeutic antibiotic use in livestock, however, ethanol production does not require antibiotics. Effective, cost-competitive antimicrobial alternatives are readily available to producers. In fact, many ethanol producers have already begun to substitute these products for antibiotics. Given these alternatives, and the very real threat antibiotic misuse poses to public health, there is no good argument for their continued use.
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