The lifestyle differences among species can provide critical insight into the mechanisms of antibiotic resistance spread and the potential for improved monitoring and control, Virginia Tech scientists reported July 29 in the online first preprint of the Journal of Wildlife Diseases. Kathleen Alexander, an associate professor of wildlife in the College of Natural Resources and Environment at Virginia Tech, and Sarah Jobbins, a former postdoctoral associate in wildlife now studying veterinary medicine at the University of Sydney, used the common intestinal bacteria Escherichia coli to evaluate the spread of antibiotic resistance among humans, domestic animals, and wildlife in the Chobe district of northern Botswana.
The researchers tested for resistance to 10 antibiotics among cattle and 18 wildlife species to explore key attributes and behaviors that may increase exposure and allow resistance to move among humans, animals, and ecosystems.
Results were compared with 193 human samples from healthy and clinically ill patients at the local hospital and 12 environmental sources of human fecal waste.
Among 150 wildlife fecal samples, 41 percent contained E. coli isolates that were resistant to at least one or two of the 10 antibiotics tested, while 13 percent were resistant to three or more antibiotics. E. coli from wildlife, human clinical, and environmental samples were resistant to a similar spectrum of antibiotics.
“Wildlife communities provide a unique opportunity for us to begin to understand how antimicrobial resistance moves across landscapes,” Alexander said. “Each species occupies a particular niche and interacts with the environment in different and specific ways, dependent on key life history strategy elements. Wildlife communities may then act as sentinels for ecosystem health, providing clues to points where humans, animals, and natural systems are coupled and transmission of antimicrobial resistance is occurring.
“The presence of antibiotic resistance across land uses in this system is of grave concern. This is an emerging problem of global proportions, resulting in failed treatments and deaths,” she pointed out.