Researchers at the Tufts School of Medicine in October released a review study that urges the U.S. government to adopt stricter regulations on farmers' use of non−therapeutic antibiotics on food animals and fish farming in order to reduce antibiotic resistance, according to a Nov. 15 Tufts Now press release.
The review study, published in the journal Clinical Microbiology Reviews, cites numerous recent studies illustrating animal−to−human spread of antibiotic−resistant bacteria and argues for further restrictions on non−therapeutic antibiotics in animals used for food.
"Antibiotic resistance is rapidly making many of our precious antibiotics useless," co−author of the study Stuart Levy, professor of molecular biology and microbiology and director of the Center for Adaptation Genetics and Drug Resistance at the Tufts School of Medicine, said in an email to the Daily.
"Action is needed on all fronts … to help preserve the antibiotics that we currently have, because few new ones are appearing on the horizon," he said.
In the study, Levy and co−author Bonnie Marshall argue that antibiotic−fed farm animals become a "factory" for resistant bacteria, which can spread to humans through direct contact or indirectly, through food, water and the use of animal waste in farming.
The potential spread of resistant bacteria to humans makes antibiotics aimed at food animals "societal drugs," according to Levy.
"This body of research supports tighter regulation of antibiotic use in animals so as to safeguard and keep antibiotics effective in the treatment of human disease," Levy said. "Research into alternative methods of rearing and treating animals to reduce disease and decrease the need for antibiotics is important."
The study also dispels fears that further bans on antibiotic use will greatly increase the cost of farming, pointing to European countries such as Denmark that experienced only nominal increases in farming costs after banning the use of non−therapeutic antimicrobial agents on food animals.
Levy, who orchestrated the first study of antibiotic use on farm animals in 1976, noted that recently the Food and Drug Administration has tightened their restrictions on antibiotic use.
"This is definitely a step in the right direction, but is still a long way from the complete bans that were instituted in parts of Europe over a decade ago," Levy said. "I am still hopeful that tighter regulations will occur in this country as well, and that continuous low−dose treatment of animals will be eliminated entirely."
While the study focuses primarily on the dangers of non−therapeutic antibiotic use in food animals, it acknowledges that irresponsible antibiotic use among humans remains a major contributor to antibiotic resistance.
"There is no doubt that human misuse and overuse of antibiotics are large contributors to resistance, particularly in relation to bacteria associated with human infection," the study states. "Interventions in medical settings and the community are clearly needed to preserve the efficacy of antibiotics."
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