Stuart Levy, MD, a leading voice on the dangers of antibiotic overuse in humans and animals, passed away last week after an extended illness.

Levy was a distinguished physician and researcher who taught at Tufts University School of Medicine for nearly 48 years. He also served as director for the Center for Adaptation Genetics and Drug Resistance at Tufts, and was founder and president of the Alliance for Prudent Antibiotic Use, a non-profit organization that promotes appropriate use of antibiotics.

Levy published more than 300 papers and reviews over the course of his career, and authored and edited several books. His 1992 book, The Antibiotic Paradox: How Miracle Drugs are Destroying the Miracle, has been translated into four languages.

Pioneering research

Among his many contributions to the field, Levy conducted pioneering research into antibiotic resistance genes and efflux pumps, two important mechanisms that bacteria use to fight off antibiotics. But he is perhaps most well-known for his groundbreaking research into how low-level use of antibiotics in food animals affects human health, which was chronicled in Maryn McKenna's book, Big Chicken.

In 1974, in a first-of-its-kind study, Levy and colleagues ran an experiment to see whether giving chickens feed with low levels of oxytetracycline would cause changes in the intestinal bacteria of a farm family that was raising the chickens. Within just a few days, they found that tetracycline-resistant bacteria began appearing in the fecal samples of the chickens, and within one week their intestinal flora consisted almost entirely of tetracycline-resistant bacteria. After several weeks, multidrug-resistant bacteria began to appear.

Those finding weren't a surprise. But within 4 months, tetracycline and multidrug-resistant bacteria began to appear in the fecal samples of a control group of chickens given feed without antibiotics. And within 5 months, Levy and his colleagues found tetracycline- and multidrug-resistant bacteria in nearly a third of fecal samples from the farm family.

"The present findings clearly demonstrate…that antibiotic-supplemented feed is a factor contributing to the selection of human resistant strains of bacteria," Levy and his colleagues wrote in The New England Journal of Medicine. "These data speak strongly against the unqualified and unlimited use of drug feeds in animal husbandry and speak for re-evaluation of this form of widespread treatment of animals."

Role model and mentor

Gail Hansen, DVM, a veterinary and public health consultant, said Levy was one of the first scientists to explore the importance of antibiotic stewardship, an issue that would become a focus of his work.

"Dr. Levy was a physician and a pioneer in looking systematically and scientifically at antibiotic resistance in humans and animals….His studies provided some of the first data on the use of antibiotics at low levels in food animals and resistance in bacteria causing disease in people," Hansen said. "He realized that the threat of antibiotic resistance from all uses was collateral damage from the beneficial use of drugs."

Hansen added that Levy also understood the importance of communicating good science to the public, and was a cheerleader for other scientists working on antibiotic resistance and stewardship. "He was a role model, mentor, and friend to so many people who are working to keep antibiotics effective to fight disease," she said.

Levy was frequently honored for his work. In 2012, he received the Abbott-ASM Lifetime Achievement Award from the American Society for Microbiology for his contributions to the microbiological sciences and his decades of research on antibiotic resistance.

In addition to his research on antibiotic resistance, Levy was involved in antibiotic development and was co-founder of Boston-based Paratek Pharmaceuticals, where he helped develop two tetracycline-based antibiotics, saracycline and omadacycline.

"Stuart was a distinguished physician at the forefront of antibiotic development and a dedicated champion for the prudent use of antibiotics," Paratek CEO Evan Loh, MD, said in company press release. "We will greatly miss him."

See also:

Sep 9 Paratek Pharmaceuticals press release

Sep 9, 1976, N Engl J Med study