Kris Wammer, PhD: Stories of Antibiotic Use and Resistance

My environmental chemistry research group at the University of St. Thomas studies the fate of biologically active contaminants, including antibiotics, in the environment. When antibiotics are used in humans or animals they can be discharged to surface waters and other environmental compartments. We primarily study processes that influence how long antibiotics persist in the environment, such as degradation by sunlight.

Antibiotics are a critical tool for fighting bacterial infections, so it’s important that we use them judiciously so that they retain their efficacy as long as possible. It’s a challenge to educate people about when antibiotics are appropriate and indicated for use, both in humans and animals.

My students, in collaboration with other researchers at the University of Minnesota, have performed some studies to determine whether agricultural or municipal sources contribute significantly to measured quantities of antibiotic resistance genes in impacted surface waters in a few targeted Minnesota locations. We are currently involved in a multi-investigator project designed to more comprehensively map Minnesota’s antibiotic “footprint” on the natural environment, and we have begun to collect samples throughout the state for quantification of antibiotic resistance genes in surface waters, sediments, and soils.

There are no regulations currently in place that target antibiotics or antibiotic resistance genes as environmental pollutants. There are still a lot of unanswered questions about how significant environmental reservoirs may be in the proliferation of antibiotic resistance, and which pathways are most important for entry of antibiotics and antibiotic resistance genes into the environment. We are therefore motivated to perform studies that will help us answer these questions and determine what, if any, mitigation strategies should be prioritized.

Bacteria are becoming resistant to existing classes of antibiotics much more quickly than new antibiotics are being developed. I worry that health care providers will have fewer tools to fight infections if we can’t discover new molecules to take the place of those that are less effective over time. Because of this, we have no choice but to practice good stewardship of our existing classes of antibiotics.

I would love to know if there are major drivers of resistance related to environmental pathways that we could easily mitigate.