A One Health Perspective on Antimicrobial Resistance

Thursday, November 16, 2017

During the 2017 Annual Fall Conference, the Class of 1963 Distinguished Lectureship featured Laura H. Kahn, MD, MPH, MPP, FACP. Kahn shared her research on One Health and the growing problem of antimicrobial resistance in “A One Health Perspective on Antimicrobial Resistance.”

Kahn has spent years investigating the history, science and politics behind the issue of antimicrobial resistance. Her analysis includes looking at antibiotic use, antimicrobial resistance, history of the bans on low dose antibiotics, livestock production, healthcare costs, global antimicrobial resistance, environmental antimicrobial resistance, and antibiotic research and development issues.

“The concept of One Health is that human, animal, and environmental health are linked,” Kahn said. “Because they are linked, it is critical to analyze One Health and address it in an interdisciplinary way.

“Medicine and agriculture are critical to the functioning of society. Both have become increasingly specialized. Both are technologically driven. Antibiotics are the foundation of modern medicine. Without antibiotics many treatments would not be possible. For example, elective surgeries, cancer chemotherapies, and immunosuppressive therapies for autoimmune diseases are simply too risky to do if the risk for infection becomes too high. Likewise, agriculture and the food security it provides are the foundation of civilization itself. Global climate change jeopardizes agriculture and food security. You can’t grow crops or food animals if the climate is too hot or if there is a drought. You can’t be healthy if you’re starving. Many diseases, i.e., Ebola, Zika, SARS, etc., are emerging and spreading because of widespread deforestation, environmental degradation, and bushmeat consumption, which are all linked to food security. The use of antibiotics is intimately involved with food security. In livestock we use antibiotics for growth, prevention and treatment. In humans we use antibiotics for prevention and treatment. All uses—all uses lead to antibiotic resistance.”

According to Kahn, Congress has spent decades debating the risks of growth promoting antibiotics. They consistently concluded that more data was needed but never appropriated funding to get more data. Each side—human medicine and agriculture—blames the other side for antibiotic resistance.

“There is a no evidence that vancomycin resistance (VRE) came from U.S. livestock even though VRE is a huge problem in human hospitals. When we look at antibiotic resistance, we’re looking at genes, just snippets of the DNA in an organism. What we need is to sequence the entire genome of an organism to be able to look at the epidemiology of vancomycin resistance. Genetic analyses suggest that the vancomycin resistance precursor came not from livestock but from dogs. Dogs are sharing our food, our beds, and our children hug and kiss them. Yet, these animals are ignored in the antimicrobial resistance debate. They are not on any surveillance system anywhere and yet they are intimately involved in our lives—they are beloved members of our family.”

Kahn continued to say that discoveries in the microbiome (i.e. gut microbes) are making researchers rethink how we approach health and disease.

“The human microbiome project has shown that our bodies harbor many microbes and that animals have microbiomes, too. When it comes to food animal microbiomes, some are positively correlated with growth while others are negatively correlated. More studies are needed to improve our understanding of these relationships. Bacteriophages (or phages) could theoretically target the unwanted microbes.

“Phages are bacteria’s natural foes. Resistance is less of an issue. Phages evolve with the bacteria. They might be an antibiotic alternative, which would make the antimicrobial resistance problem moot because they are a completely different system.”

Kahn re-iterates that more studies are needed. However, her look at current National Institutes of Health (NIH) and National Institute of Food and Agriculture (NIFA) funding doesn’t show much promise.

“An informal survey of NIH grant funding for bacteriophage research showed that only .009 percent of total RO1 grant awards in 2016 studied phages’ potential as antibiotic substitutes. An informal survey of NIFA grant funding for bacteriophage research showed approximately .018 percent was spent on research involving bacteriophages. We have a lot of room to grow where we can apply this potential technology on food safety and security, but at the rate we are currently spending on it, we are not going to get there. Antimicrobial resistance is real. It is important to protect the safety of our food supply and to support human, animal and environmental health for the benefit of all.”

The Class of 1963 established the Class of 1963 Distinguished Lectureship in 2004. The money earned from this investment hosts an annual expert on a variety of subjects related to veterinary medicine, human medicine, and environmental health.