When a community finds that water it relies on for drinking or recreation contains E. coli (Escherichia coli), a bacterium found in the feces of warm-blooded animals that indicates fecal contamination, residents and officials naturally want to find the cause and fix it -- quickly. But several testing methods using E. coli to identify the sources of fecal contamination were less accurate in field application than previously reported, according to a recent U.S. Geological Survey (USGS) report published in the journal Environmental Science and Technology.
The USGS-led study, done in cooperation with state and local government agencies and several universities and affiliated consultants, was among the first to test the accuracy of microbial source tracking methods against samples of known origin, called "challenge isolates." Scientists compared the accuracy of several source tracking tools in classifying E. coli strains to various sources (humans, dogs, geese, deer, horses, pigs, cows, and chickens).
When researchers sent E. coli challenge isolates (the sources of which were unknown to those conducting the tests) for testing, many isolates either remained unclassified or were classified to incorrect sources. In all, fewer than 30 percent of challenge isolates were classified to the correct source-animal species by any method.
Further research may lead to improvements in current source tracking methods or development of better methods. For the immediate future, researchers and end users would be prudent to use caution and to incorporate quality-control measures to validate the accuracy of source tracking results.
Donald Stoeckel | EurekAlert!
Europe’s Demographic Future. Where the Regions Are Heading after a Decade of Crises
10.08.2017 | Berlin-Institut für Bevölkerung und Entwicklung
Scientists reveal source of human heartbeat in 3-D
07.08.2017 | University of Manchester
Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.
As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...
Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.
Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...
For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.
While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...
An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.
The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...
A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.
Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...
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