Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

AgriLife Research ‘genetically fingerprinting’ E. coli from Lampasas and Leon watersheds

02.08.2011
Study designed to contribute to a fair, balanced and effective protection plan

The Lampasas and Leon Rivers watersheds have been listed as impaired by the state due to high counts of E. coli and other bacteria taken in the late 1990s, but from whom, what and where the contamination originates is unclear, say Texas AgriLife Research experts.

Because the watersheds are located in a landscape that is predominately rural and agricultural, there has been some conjecture that the sources of E. coli are livestock related, said Dr. June Wolfe, a AgriLife Research scientist.

“However, the origin of the sources is unclear,” said Wolfe, who is based at the Texas AgriLife Blackland Research and Extension Center at Temple.

And although routine sampling sometimes shows elevated bacteria levels in the watersheds, exactly how high are the levels throughout the year?

To identify the sources objectively, Wolfe and his research associate, Tony Owen, have been collecting water samples at 30 river sites – 15 in the Lampasas River watershed and 15 in the Leon River watershed – monthly since February. They’ve also been taking fecal samples from all over the watersheds of known possible sources: home septic systems, wildlife, livestock, pets and water-treatment plants.

The samples are then “genetically fingerprinted” to determine exactly what the source of E. coli is — or otherwise, Wolfe said.

It’s all part of the “Bacterial Source Tracking” project, which was funded by a Section 319(h) Clean Water Act nonpoint source grant from the Texas State Soil and Water Conservation Board and U.S. Environmental Protection Agency. The grant was administered by the Texas Water Resource Institute in College Station.

“This approach will utilize proven scientific methods that will distinguish the various sources of bacteria,” Wolfe said. The DNA fingerprinting is done by Dr. George Di Giovanni at the Texas AgriLife Research laboratory in El Paso.

E. coli are measured by the number of colonies cultured from a given volume of water. Here, the E. coli colonies show up as maroon spots because of a special growth medium. (Texas AgriLife Extension Service photo by Robert Burns)

Identifying the exact sources of contamination will allow the formation of a watershed protection plan that is fair, balanced and effective, Wolfe said.

The Lampasas River originates about 70 miles west of Waco and flows southeast for 75 miles, passing through Lampasas, Burnet and Bell counties. Land use within the watershed includes grazing for beef cattle and the production of hay, wheat, oats, sorghum, corn, cotton, peanuts and pecans, Wolfe said.

The Leon River has three primary forks that meet near Eastland, which is about 110 miles west of Fort Worth. From Eastland, the river runs about 185 miles south where it and the Lampasas River join with the Salado Creek near Belton in northern Bell County to form the Little River. Like the Lampasas, the Leon runs primarily through rural farmlands. But there is also considerable forestland and a significant amount of dairy production in the northern part of the watershed, he said.

Parts of both the Lampasas and Leon watersheds have been listed by the Texas Commission of Environmental Quality as “impaired” for recreational use, Wolfe said.

“By impaired, it is meant that coliform bacterium levels exceed state and federal established criteria,” Wolfe said. “Though these organisms are generally not harmful to human health, they may indicate the presence of pathogens that can cause disease or gastrointestinal illnesses.”

The collection of water samples must be meticulous and meet stringent EPA procedural and documentation guidelines, Wolfe noted. When he and Owen collect and label water samples, they must also measure stream flow, water pH, dissolved oxygen and specific conductivity. And there is a strict time deadline, measured in hours, from when the water samples are collected and must be pre-processed by Wolfe at the Temple center’s water science laboratory.

But collecting water samples is only half the project, Wolfe said. Without an E. coli library to compare the water samples, identifying the source of the contamination would be impossible. So in addition to taking water samples, their goal is to collect at least 100 known-sources fecal samples within each watershed.

“We are focusing on human, feral hog and cattle sources,” Wolfe said. “Feral hogs are a potentially big contributor, but other wildlife sources, including small mammal and avian species will be collected as well.”

Sometimes their “poop-scooping” draws attention, Wolfe noted, as they are also interested in cataloging fecal samples from pets, a task that takes them into local city parks and other public areas.

At other times, the sampling has called for ingenuity. For example, to collect avian fecal samples, they draped large sheets of plastic under local bridges to catch droppings from birds roosting over the waterways.

As the fecal samples are collected, and the DNA fingerprinting completed by Di Giovanni, the results are included in the Texas E. coli bacterial source tracking library.

Wolfe said the development of the Lampasas River and Leon Rivers water protection plans are to proceed independent of his bacterial source tracking project.

“However, conclusions from this BST project will be integrated into the water protection plan through adaptive management,” he said.

One issue the team has had to face this year is the drying up of rivers and streams because of the drought, Wolfe noted.

“The results will still be valid because droughts are a normal occurrence, and we need to get a data set during these times too,” he said. “But ideally, we would like to be able to collect data during a normal year too.”

Wolfe and Owen maintain a website with detailed information and regular reports on the project at http://leon-lampasasbst.tamu.edu/description .

Contact: Dr. June Wolfe, 254-774-6016, jwolfe@brc.tamus.edu

Dr. June Wolfe | EurekAlert!
Further information:
http://www.tamus.edu

More articles from Agricultural and Forestry Science:

nachricht New 3-D model predicts best planting practices for farmers
26.06.2017 | Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign

nachricht Fighting a destructive crop disease with mathematics
21.06.2017 | University of Cambridge

All articles from Agricultural and Forestry Science >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Physicists Design Ultrafocused Pulses

Physicists working with researcher Oriol Romero-Isart devised a new simple scheme to theoretically generate arbitrarily short and focused electromagnetic fields. This new tool could be used for precise sensing and in microscopy.

Microwaves, heat radiation, light and X-radiation are examples for electromagnetic waves. Many applications require to focus the electromagnetic fields to...

Im Focus: Carbon Nanotubes Turn Electrical Current into Light-emitting Quasi-particles

Strong light-matter coupling in these semiconducting tubes may hold the key to electrically pumped lasers

Light-matter quasi-particles can be generated electrically in semiconducting carbon nanotubes. Material scientists and physicists from Heidelberg University...

Im Focus: Flexible proximity sensor creates smart surfaces

Fraunhofer IPA has developed a proximity sensor made from silicone and carbon nanotubes (CNT) which detects objects and determines their position. The materials and printing process used mean that the sensor is extremely flexible, economical and can be used for large surfaces. Industry and research partners can use and further develop this innovation straight away.

At first glance, the proximity sensor appears to be nothing special: a thin, elastic layer of silicone onto which black square surfaces are printed, but these...

Im Focus: 3-D scanning with water

3-D shape acquisition using water displacement as the shape sensor for the reconstruction of complex objects

A global team of computer scientists and engineers have developed an innovative technique that more completely reconstructs challenging 3D objects. An ancient...

Im Focus: Manipulating Electron Spins Without Loss of Information

Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.

For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

Closing the Sustainability Circle: Protection of Food with Biobased Materials

21.07.2017 | Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

 
Latest News

Programming cells with computer-like logic

27.07.2017 | Life Sciences

Identified the component that allows a lethal bacteria to spread resistance to antibiotics

27.07.2017 | Life Sciences

Malaria Already Endemic in the Mediterranean by the Roman Period

27.07.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>