Researchers confirm crows as carriers of antibiotic resistant bacteria
This piece is a news release written as an assignment for the Advanced Technical Communication for Public Health and the University of Washington.
UW Office of News and Information
News Release
Media Contact: Kathryn Baker FOR IMMEDIATE RELEASE
(206) 555-1234 February 3, 2016
Researchers confirm crows as carriers of antibiotic resistant bacteria
SEATTLE, Wash. – Seattle area crows carry antibiotic resistant bacteria picked up as a result of environmental contamination caused by humans according to a University of Washington study published today in Veterinary Microbiology.
Researchers confirmed a previous study1 showing that North American crows are carriers of antibiotic enterococci, bacteria responsible for a variety of human infections. They are the first to recognize that strains found in birds differ from those found in their habitats. Crows are of particular interest to scientists not only because of their ubiquity in urban areas on nearly every continent, but because birds were previously known to carry viruses. Additionally, the group’s previous work pointed to a possible linkage between the presence of birds and antibiotic resistant bacteria in the environment. Roberts et al. analyzed crow feces and environmental samples from a waste water treatment plant, four local dairy farms, and a recreated wetland habitat on the University of Washington Bothell campus, located roughly 20 miles northeast of Seattle. Their results revealed the presence of drug resistant bacterial populations in the guts of the birds as well as in each environment tested. Surprisingly, the bird and environmental strains differed at each site, indicating that the birds picked them up in other locations, such as garbage dumps.
These discoveries have greater implications for human health and the possibility of infection. Resistance to vancomycin, an antibiotic used for serious, life-threatening infections, began to emerge in the U.S. in hospitals in the 1990s due to overuse and has since spread to the environment through human waste. The abuse of antibiotics in farming practices has further contributed to this spread. Today, resistant strains are commonly found in many wildlife habitats and populations. Marilyn Roberts, a professor from the UW Department of Environmental and Occupational Health Sciences and lead investigator on the study, says that these findings bolster the idea of “one health” which states that the health of humans, animals, and the environment are inextricably entwined. She cautions people to avoid both birds and their waste to protect themselves. “Birds can be vectors and people don’t believe that. That’s an issue,” said Roberts. “You don’t want to feed crows. You don’t want to feed wildlife, period, because they may carry pathogens.” She urges the public to be aware of their environment, whether they are in local parks, urban settings, or out in the wilderness, and to remember that “wildlife should be left alone.” While VRE can possibly infect humans, especially the immunocompromised, Roberts offered encouragement saying, “unless you’re living with a bird or person or an animal that is chronically shedding VRE,” or “unless you have a scrape on your extremity,” and you fall into fresh, VRE-infected feces, “it’s probably not going to be that big of a deal.”
Roberts and colleagues plan to continue their work by analyzing samples from the same environmental sites to identify other drug resistant bacteria such as E. coli, Campylobacter, and Salmonella. She encourages concerned parties to be aware of the overuse of antibiotics in medical treatment, to help push the U.S. farming industry to halt the unnecessary use of antibiotics by purchasing products made without them, and to avoid contact with animals and their waste.
Roberts is joined on this study by David B. No, also from the UW Department of Environmental and Occupational Health Sciences, John M. Marzluff and Jack H. Delap of the UW School of Environmental and Forest Sciences, and Robert Turner of the UW School of Interdisciplinary Arts and Sciences.
1 Oracova, V., Zurek, L., Townsend, A., Clark, A.B., Ellis, J.C., Cizek, A., Literak, I., 2014b. American crows as carriers of vancomycin-resistant enterococci with vanA gene. Environ. Microbiol. 16, 939-949
