Scientists identify new concerns for antibiotic resistance, pollution

Dec 07, 2010
Virginia Tech associate professor of civil and environmental engineering Amy Pruden explained that reducing the spread of antibiotic resistance is a critical measure needed to prolong the effectiveness of currently available antibiotics. Credit: Virginia Tech Photo

When an antibiotic is consumed, researchers have learned that up to 90 percent passes through a body without metabolizing. This means the drugs can leave the body almost intact through normal bodily functions.

In the case of agricultural areas, excreted antibiotics can then enter stream and river environments through a variety of ways, including discharges from animal feeding operations, fish hatcheries, and nonpoint sources such as the flow from fields where manure or biosolids have been applied. Water filtered through wastewater treatment plants may also contain used antibiotics.

Consequently, these discharges become "potential sources of ," says Amy Pruden, a National Science Foundation CAREER Award recipient, and an assistant professor of civil and environmental engineering at Virginia Tech.

"The presence of antibiotics, even at sub-inhibitory concentrations, can stimulate bacterial metabolism and thus contribute to the selection and maintenance of antibiotic resistance genes," Pruden explains. "Once they are present in rivers, antibiotic resistance genes are capable of being transferred among bacteria, including pathogens, through ."

The and the Center for Disease Control recognize antibiotic resistance "as a critical health challenge of our time," Pruden writes in a paper published in a 2010 issue of .

Pruden says reducing the spread of antibiotic resistance is a critical measure needed to prolong the effectiveness of currently available antibiotics. This is important since "new drug discovery can no longer keep pace with emerging antibiotic-resistant infections," Pruden says.

Pruden who has developed the concept of antibiotic resistance genes as has an international reputation in applied microbial ecology, environmental remediation, and environmental reservoirs of antimicrobial resistance.

In her work outlined in the Environmental Science and Technology article, she and her co-authors, H. Storteboom, M. Arabi and J.G. Davis, all of Colorado State University, and B. Crimi of Delft University in The Netherlands, identified specific patterns of antibiotic resistance gene occurrence in a Colorado watershed. Identification of these patterns represents a major step in being able to discriminate between agricultural and wastewater treatment plant sources of these genes in river environments.

They assert that such unique patterns of antibiotic resistance gene occurrence represent promising molecular signatures that may then be used as tracers of specific manmade sources.

In their study they identified three wastewater treatment plant sites, six animal feeding operation locations, and three additional locations along a pristine region of the Poudre River, in an upstream section located in the Rocky Mountains. They compared the frequency of detection of 11 sulfonamide and tetracycline antibiotic resistance genes.

Their findings showed detection of one particular antibiotic resistance gene in 100 percent of the treatment plant and animal feeding operations, but only once in the clean section of the Poudre River.

As they are able to differentiate between human and animal sources of the antibiotic resistance genes, Pruden and her colleagues believe they can "shed light on areas where intervention can be most effective in helping to reduce the spread of these contaminants through environmental matrixes such as soils, groundwater, surface water and sediments.

"This study advances the recognition of antibiotic resistance genes as sources to impacted environments, taking an important step in the identification of the dominant processes of the spreading and transport of genes."

Explore further: US delays decision on Keystone pipeline project

add to favorites email to friend print save as pdf

Related Stories

Soil studies reveal rise in antibiotic resistance

Dec 23, 2009

Antibiotic resistance in the natural environment is rising despite tighter controls over our use of antibiotics in medicine and agriculture, Newcastle University scientists have found.

UTIs becoming harder to treat

May 17, 2010

Genes that make bacteria resistant to antibiotics can be transferred between humans and other animals, say researchers writing in this month's issue of the Journal of Medical Microbiology. The findings will help health expert ...

Evidence of increasing antibiotic resistance

Mar 03, 2010

A team of scientists in the United Kingdom and the Netherlands are reporting disturbing evidence that soil microbes have become progressively more resistant to antibiotics over the last 60 years. Surprisingly, ...

Recommended for you

US delays decision on Keystone pipeline project

Apr 18, 2014

The United States announced Friday a fresh delay on a final decision regarding a controversial Canada to US oil pipeline, saying more time was needed to carry out a review.

New research on Earth's carbon budget

Apr 18, 2014

(Phys.org) —Results from a research project involving scientists from the Desert Research Institute have generated new findings surrounding some of the unknowns of changes in climate and the degree to which ...

User comments : 0

More news stories

China says massive area of its soil polluted

A huge area of China's soil covering more than twice the size of Spain is estimated to be polluted, the government said Thursday, announcing findings of a survey previously kept secret.

UN weather agency warns of 'El Nino' this year

The UN weather agency Tuesday warned there was a good chance of an "El Nino" climate phenomenon in the Pacific Ocean this year, bringing droughts and heavy rainfall to the rest of the world.

NASA's space station Robonaut finally getting legs

Robonaut, the first out-of-this-world humanoid, is finally getting its space legs. For three years, Robonaut has had to manage from the waist up. This new pair of legs means the experimental robot—now stuck ...

Ex-Apple chief plans mobile phone for India

Former Apple chief executive John Sculley, whose marketing skills helped bring the personal computer to desktops worldwide, says he plans to launch a mobile phone in India to exploit its still largely untapped ...

Filipino tests negative for Middle East virus

A Filipino nurse who tested positive for the Middle East virus has been found free of infection in a subsequent examination after he returned home, Philippine health officials said Saturday.

Egypt archaeologists find ancient writer's tomb

Egypt's minister of antiquities says a team of Spanish archaeologists has discovered two tombs in the southern part of the country, one of them belonging to a writer and containing a trove of artifacts including reed pens ...