Fueling Resistance? Antibiotics in Ethanol Production
The epidemic of antibiotic resistance globally poses a severe threat to human and animal health. Deaths and infections caused by “superbugs,” which are unresponsive to treatment with multiple antibiotics, are the human face of this problem.
The use and overuse of antibiotics is a key driver of resistance in hospitals as well as on farms. For instance, the best available estimates are that about 84 percent of all antimicrobials in the U.S. are used in agriculture.
Lately, there have been reports of a new and heretofore unrecognized source of unregulated antibiotic use: the ethanol industry.
For decades, ethanol producers have added antibiotics to the ethanol fermentation process to control bacterial outbreaks, and for most of that time, they have claimed the antibiotics dissipate or are rendered inactive during production. But in 2008, the Food and Drug Administration (FDA) began testing dried distillers grains—the nutrient-rich residue sold as livestock feed that is a co-product of ethanol production—for antibiotic residues. The test results came back positive for erythromycin, tylosin (a similar macrolide antibiotic that may also spur cross-resistance to erythromycin) and virginiamycin (a streptogramin antibiotic with an important human analogue, Synercid), which doctors also depend on for treating sick patients.
The National Academies of Science, among many others, have called for an end to the indiscriminate and unnecessary use of antibiotics. In addition, the FDA recently told Congress that it supports a ban on non-therapeutic use of antibiotics in the raising of food animals. The ethanol industry—along with the livestock sector and other industrial users—needs to move quickly as a sector to end the use of antibiotics. Luckily, there are existing alternatives to antibiotics use for controlling bacteria and many ethanol producers are already putting these alternatives into practice. In this report, IATP looks at the implications of antibiotic use in ethanol production and points the way toward an antibiotic-free ethanol industry