Over 90 Total Lots Up For Auction at One Location - WA 04/08

More to antibiotic resistance than overutilization of antibiotics

by Gus Iversen, Editor in Chief | December 28, 2015
Infection Control Population Health Risk Management
A stream on the Savannah
River Site
Courtesy: Linda Lee
/ University of Georgia
While antibiotic overutilization is frequently cited as a key culprit in the development of "superbugs", new research conducted on a contaminated waterway may suggest that there is more to antibiotic-resistance than antibiotics themselves.

Constructed during the early 1950s to house five nuclear reactors that produce the basic materials used in the fabrication of nuclear weapons, (primarily tritium and plutonium-239), The U.S. Department of Energy's Savannah River Site struck researchers as a suitable location for testing their hypothesis that environmental contaminants are partly to blame for the rise of antibiotic resistance.

"The site was constructed and closed to the public before antibiotics were used in medical practices and agriculture," said J. Vaun McArthur, a senior research ecologist with the University of Georgia's Savannah River Ecology Laboratory and Odum School of Ecology, in a statement.

And yet, in research published in in the journal Environmental Microbiology, McArthur and his colleagues discovered high rates of antibiotic resistance in the water's bacteria. By testing five antibiotics on 427 stains of E. coli bacteria in samples drawn from 11 locations in nine streams at the Savannah River Site, they found high levels of antibiotic resistance in eight of the 11 samples.

"The streams have not had inputs from wastewater, so we know the observed patterns are from something other than antibiotics," said McArthur.

The highest levels were found at the northern location of Upper Three Runs Creek, where the stream system enters the site, and on two tributaries located in the industrial area, U4 and U8. Upper Three Runs Creek flows in from agricultural, industrial and residential areas, therefore it may have been exposed to antibiotics before arriving. Areas U4 and U8, however, are completely contained within the site and have no known input from antibiotics.

A second screening was conducted that focused exclusively on U4, U8 and U10, another nearby stream with little to no industrial impact. According to McArthur, more than 95 percent of the bacteria samples from those streams were resistant to 10 or more of 23 antibiotics. "These included front-line antibiotics — gatifloxacin and ciprofloxacin, which are used to treat basic bacterial infections from pink eye to urinary tract and sinus infections," said McArthur.

He believes the only explanation for the high level of antibiotic resistance is the environmental contaminants in the streams — the metals, including cadmium and mercury. Since these streams flow into the Savannah River, McArthur and his team believe it may help explain the wide distribution of antibiotic resistant bacteria.

Back to HCB News

You Must Be Logged In To Post A Comment