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 antibiotic resistance genes,” says Amy Pruden<http://www.cee.vt.edu/index.php?do=view&content=0&apps=2&level=2&id=17&pid=ea764b3d7ce4e619692fc864f6a5d628> (http://www.cee.vt.edu/index.php?do=view&content=0&apps=2&level=2&id=17&pid=ea764b3d7ce4e619692fc864f6a5d628), a National Science Foundation (NSF) Faculty Early Career Development (CAREER) award recipient, and an assistant professor of civil and environmental engineering<http://www.cee.vt.edu/> (http://www.cee.vt.edu/) 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 horizontal gene transfer.”
The World Health Organization 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 Environmental Science and Technology.
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 environmental pollutants 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 antibiotic resistance genes.”
The Colorado Water Resources Research Institute and a U.S. Department of Agriculture's Agricultural Experiment Station provided funding for this study in addition to Pruden’s NSF award.
The College of Engineering<http://www.eng.vt.edu/> (http://www.eng.vt.edu/) at Virginia Tech is internationally recognized for its excellence in 14 engineering disciplines and computer science. The college's 6,000 undergraduates benefit from an innovative curriculum that provides a "hands-on, minds-on" approach to engineering education, complementing classroom instruction with two unique design-and-build facilities and a strong Cooperative Education Program. With more than 50 research centers and numerous laboratories, the college offers its 2,000 graduate students opportunities in advanced fields of study such as biomedical engineering, state-of-the-art microelectronics, and nanotechnology. Virginia Tech, the most comprehensive university in Virginia, is dedicated to quality, innovation, and results to the commonwealth, the nation, and the world.
* University researchers hope answer to cleaning up Gulf Coast lies in geometry<http://www.vtnews.vt.edu/articles/2010/08/083010-engineering-gulfcoastresearch.html> (http://www.vtnews.vt.edu/articles/2010/08/083010-engineering-gulfcoastresearch.html)* Two engineering faculty chosen for National Academy of Engineering symposium<http://www.vtnews.vt.edu/articles/2008/07/2008-433.html> (http://www.vtnews.vt.edu/articles/2008/07/2008-433.html)
Lynn A. Nystrom | VT News
Rochester scientists discover gene controlling genetic recombination rates
23.04.2018 | University of Rochester
One step closer to reality
20.04.2018 | Max-Planck-Institut für Entwicklungsbiologie
Physicists at the Laboratory for Attosecond Physics, which is jointly run by Ludwig-Maximilians-Universität and the Max Planck Institute of Quantum Optics, have developed a high-power laser system that generates ultrashort pulses of light covering a large share of the mid-infrared spectrum. The researchers envisage a wide range of applications for the technology – in the early diagnosis of cancer, for instance.
Molecules are the building blocks of life. Like all other organisms, we are made of them. They control our biorhythm, and they can also reflect our state of...
University of Connecticut researchers have created a biodegradable composite made of silk fibers that can be used to repair broken load-bearing bones without the complications sometimes presented by other materials.
Repairing major load-bearing bones such as those in the leg can be a long and uncomfortable process.
Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.
Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...
Novel highly efficient and brilliant gamma-ray source: Based on model calculations, physicists of the Max PIanck Institute for Nuclear Physics in Heidelberg propose a novel method for an efficient high-brilliance gamma-ray source. A giant collimated gamma-ray pulse is generated from the interaction of a dense ultra-relativistic electron beam with a thin solid conductor. Energetic gamma-rays are copiously produced as the electron beam splits into filaments while propagating across the conductor. The resulting gamma-ray energy and flux enable novel experiments in nuclear and fundamental physics.
The typical wavelength of light interacting with an object of the microcosm scales with the size of this object. For atoms, this ranges from visible light to...
Stable joint cartilage can be produced from adult stem cells originating from bone marrow. This is made possible by inducing specific molecular processes occurring during embryonic cartilage formation, as researchers from the University and University Hospital of Basel report in the scientific journal PNAS.
Certain mesenchymal stem/stromal cells from the bone marrow of adults are considered extremely promising for skeletal tissue regeneration. These adult stem...
13.04.2018 | Event News
12.04.2018 | Event News
09.04.2018 | Event News
23.04.2018 | Physics and Astronomy
23.04.2018 | Physics and Astronomy
23.04.2018 | Trade Fair News