Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New approach for environmental test on livestock drugs

27.07.2016

Drugs for livestock can harm beneficial organisms that break down dung. Therefore newly developed medical substances need to be tested on single species in the lab. An international research group including evolutionary biologists from the University of Zurich have been scrutinizing the reliability of such laboratory tests, evaluating the implementation of a field test based on the anti-parasitic drug ivermectin at four climatically different locations. The scientists thus presented a novel approach for more advanced environmental compatibility tests.

Livestock medications can impair beneficial organisms that break down dung. Too high a dosage of ivermectin, a common drug against parasites, harms coprophilous organisms, for instance. The toxicity of new livestock medications therefore needs to be verified in ecotoxicological tests with individual animal species such as the common yellow dung fly, the barn fly or a dung beetle.


Dung pat with a specific concentration of ivermectin.

Image: UZH

This involves determining the lethal dose leading to the death of half the maggots (LD50 test). However, sensitivity to toxic substances is known to vary significantly even among closely related coprophilous organisms, which begs the question as to how representative the reaction of any individual animal species actually is in such laboratory tests. After all, there is a high risk that more sensitive species will continue to be harmed by the substance, jeopardizing key ecosystem functions in the long run.

An international research group including UZH evolutionary biologist Wolf Blanckenhorn recently proposed extending the testing scheme to a representative selection of all organisms that break down dung, ideally in their natural environment. The scientists now presented a successful and more comprehensive higher-tier ecotoxicological field test. Their study provides important insights into minimizing the risks of drug residues in nature.

Earthworms compensate for loss of coprophilous insects

For their feasibility study, the scientists worked on cattle pastures in the Canadian Prairie and the agricultural landscapes of southern France, the Netherlands and Switzerland – four locations with very different climatic conditions. On these pastures, they distributed dung pats with different concentrations of ivermectin. “As expected, the overall number and diversity of dung beetles, dung flies and parasitoid wasps decreased as the ivermectin concentration increased,” explains Blanckenhorn.

However, a number of species also proved to be resistant: earthworms and springtails living in the ground underneath the cowpats were not notably affected, and a parallel test ultimately revealed that dung degradation was not significantly impaired. “Evidently, beneficial organisms not affected as much by the drug, such as earthworms, were apparently able to compensate for the loss of other organisms,” sums up Blanckenhorn.

A basis for decision makers and licensing authorities

Despite diverse environmental conditions and methodological details, the results were very similar and reproducible in all four habitats. “Our field approach was therefore a success and in principle can be recommended. The regulation authorities responsible, such as the European Medicines Agency EMA, now have to decide whether this more conclusive yet more complex test should be required in the future,” says Blanckenhorn.

The amount of effort involved in determining the numerous dung organisms is tremendous and impossible without expert biological knowledge. “Classifying species via so-called DNA barcoding, based on each organism’s unique genetic fingerprint, is possible in principle and will probably be more cost-effective in the future. However, this approach requires the establishment of a complete database for coprophilous organisms, which does not yet exist,” concludes the scientist.

Literature:

Kevin D. Floate, Wolf U. Blanckenhorn. Special Section: Non-target Structural and Functional Effects of Ivermectin Residues in Cattle Dung on Pasture – Guidance for Researchers and Regulators. Environmental Toxicology and Chemistry. Volume 35, Issue 8. July 21, 2016. DOI: 10.1002/etc.3549


Ivermectin

Scientists discovered and refined ivermectin in Japan in the mid-1970s, eventually winning the Nobel Prize in Medicine in 2015. The drug has been used to cure river blindness, scabies and roundworms in the gut of humans, as well as parasites in livestock and pets.

Chemically ivermectin belongs to the avermectins, which generally interfere with ion channel transport through the cell membrane and thus the molting of pest organisms. If the ivermectin dosage is too high and excreted in the feces of treated livestock, the drug also kills beneficial organisms that break down dung. This has a negative impact on the functioning of the entire ecosystem: in extreme cases, the dung is no longer degraded at all and the pasture cannot be used any further.

Contact:

Prof. Dr. Wolf U. Blanckenhorn
Department of Evolutionary Biology and Environmental Studies
University of Zurich
Phone: +41 44 635 47 55
E-mail: wolf.blanckenhorn@ieu.uzh.ch

Media Relations
University of Zurich
Phone: +41 44 634 44 67
E-mail: mediarelations@kommunikation.uzh.ch

Weitere Informationen:

http://www.media.uzh.ch/en/Press-Releases/2016/New-approach-for-environmental-te...

Nathalie Huber | Universität Zürich

Further reports about: Ecosystem Environmental Phone animal species conditions dosage drugs earthworms fly parasites species

More articles from Ecology, The Environment and Conservation:

nachricht Litter is present throughout the world’s oceans: 1,220 species affected
27.03.2017 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung

nachricht International network connects experimental research in European waters
21.03.2017 | Leibniz-Institut für Gewässerökologie und Binnenfischerei (IGB)

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

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

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

Im Focus: Researchers Imitate Molecular Crowding in Cells

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Northern oceans pumped CO2 into the atmosphere

27.03.2017 | Earth Sciences

Fingerprint' technique spots frog populations at risk from pollution

27.03.2017 | Life Sciences

Big data approach to predict protein structure

27.03.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>