Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Investigating the “underground” habitat of Listeria bacteria

29.09.2014

Listeria are extremely undemanding bacteria. In low amounts they are present almost everywhere, including soil and water.

In order to better understand how Listeria spread, a group of scientists from the Institute of Milk Hygiene at the University of Veterinary Medicine, Vienna collected soil and water samples throughout Austria. Their study revealed a higher detection of Listeria in soil and water samples during periods of flooding. The researchers also found antibiotic-resistant strains of Listeria in soil samples. The data were published in the journal Applied Environmental Microbiology.


The collected soil and water samples were analyzed in the laboratory for their identity.

Photo: Beatrix Stessl/Vetmeduni Vienna

The literature describes Listeria as ubiquitous bacteria with widespread occurrence. Yet they only become a problem for humans and animals when they contaminate food processing facilities, multiply, and enter the food chain in high concentrations. An infection with Listeria monocytogenes can even be fatal for humans or animals with weakened immune systems.

Listeria in soil or water are not dangerous

“Listeria in soil or water represent a relatively low risk to humans,” explains study director Beatrix Stessl. “The concentrations are too low. The aim of our study was to ascertain where Listeria occur and which species and genotypes were prevalent there.” Martin Wagner, head of the Institute of Milk Hygiene, adds: “This information can help us to better understand the mechanisms through which these bacteria are spread.”

Flooding favours Listeria contamination

Over a period from 2007 to 2009, first author Kristina Linke and her colleagues collected nearly 500 soil and 70 water samples from three Austrian regions: the eastern Alps, the Donauauen National Park adjacent to the river Danube, and Lake Neusiedl. The study regions involved natural, non-agricultural areas.

Of all samples, 30 percent were detected positive for Listeria. Of these, 6 percent were contaminated with Listeria monocytogenes, the only species that is potentially dangerous for both humans and animals. L. monocytogenes was detected especially near the rivers Schwarza and Danube. Particularly high rates of the bacteria in soil and water samples were registered in September 2007 during extensive flooding in the region.

In most regions, the researchers found only Listeria that are non-pathogenic to humans.
The species Listeria ivanovii, which is potentially dangerous for animals, was found mainly in mountainous regions where the bacteria are presumably excreted by wildlife species. The non-pathogenic Listeria seeligeri was most frequently isolated in the region around Lake Neusiedl, which is likely explained by the waterfowl population in this area.
No Listeria were isolated in high-altitude mountain regions. The researchers explain the greater contamination at lower altitudes with the proximity to farms, agricultural land and the urban environment.

Antibiotic-resistant Listeria in soil

Although Listeria that contaminate food are generally not considered to be resistant to antibiotics, Stessl and her team found several Listeria strains in soil samples which resisted treatment with antibiotics. The bacteria have developed resistance. Stessl sees the possible causes as follows: “A number of soil microorganisms, such as fungi, naturally produce antibiotics. Listeria which are constantly exposed to these substances in the soil probably develop resistance. We believe, however, that the development of particularly high-resistant strains of Listeria can be explained by the proximity to agricultural land and the urban environment.”

Service:

The article „Reservoirs of Listeria species in three environmental ecosystems”, by Kristina Linke, Irene Rückerl, Katharina Brugger, Renata Karpiskova, Julia Walland, Sonja Muri-Klinger, Alexander Tichy, Martin Wagner und Beatrix Stessl was published in the Journal Applied and Environmental Microbiology. doi: 10.1128/AEM.01018-14 http://aem.asm.org/content/80/18/5583.long

About the University of Veterinary Medicine, Vienna

The University of Veterinary Medicine, Vienna in Austria is one of the leading academic and research institutions in the field of Veterinary Sciences in Europe. About 1,300 employees and 2,300 students work on the campus in the north of Vienna which also houses five university clinics and various research sites. Outside of Vienna the university operates Teaching and Research Farms. http://www.vetmeduni.ac.at

Scientific Contact:
Dr. Beatrix Stessl
Institute of Milk Hygiene, Milk Technology and Food Science
University of Veterinary Medicine Vienna (Vetmeduni Vienna)
T +43 1 25077-3502
< beatrix stessl@vetmeduni.ac.at>

Released by:
Susanna Kautschitsch
Science Communication / Public Relations
University of Veterinary Medicine Vienna (Vetmeduni Vienna)
T +43 1 25077-1153
susanna.kautschitsch@vetmeduni.ac.at

Weitere Informationen:

http://www.vetmeduni.ac.at/en/infoservice/presseinformation/press-releases-2014/...

Dr. Susanna Kautschitsch | idw - Informationsdienst Wissenschaft

More articles from Life Sciences:

nachricht Microscope measures muscle weakness
16.11.2018 | Friedrich-Alexander-Universität Erlangen-Nürnberg

nachricht Good preparation is half the digestion
16.11.2018 | Max-Planck-Institut für Stoffwechselforschung

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: UNH scientists help provide first-ever views of elusive energy explosion

Researchers at the University of New Hampshire have captured a difficult-to-view singular event involving "magnetic reconnection"--the process by which sparse particles and energy around Earth collide producing a quick but mighty explosion--in the Earth's magnetotail, the magnetic environment that trails behind the planet.

Magnetic reconnection has remained a bit of a mystery to scientists. They know it exists and have documented the effects that the energy explosions can...

Im Focus: A Chip with Blood Vessels

Biochips have been developed at TU Wien (Vienna), on which tissue can be produced and examined. This allows supplying the tissue with different substances in a very controlled way.

Cultivating human cells in the Petri dish is not a big challenge today. Producing artificial tissue, however, permeated by fine blood vessels, is a much more...

Im Focus: A Leap Into Quantum Technology

Faster and secure data communication: This is the goal of a new joint project involving physicists from the University of Würzburg. The German Federal Ministry of Education and Research funds the project with 14.8 million euro.

In our digital world data security and secure communication are becoming more and more important. Quantum communication is a promising approach to achieve...

Im Focus: Research icebreaker Polarstern begins the Antarctic season

What does it look like below the ice shelf of the calved massive iceberg A68?

On Saturday, 10 November 2018, the research icebreaker Polarstern will leave its homeport of Bremerhaven, bound for Cape Town, South Africa.

Im Focus: Penn engineers develop ultrathin, ultralight 'nanocardboard'

When choosing materials to make something, trade-offs need to be made between a host of properties, such as thickness, stiffness and weight. Depending on the application in question, finding just the right balance is the difference between success and failure

Now, a team of Penn Engineers has demonstrated a new material they call "nanocardboard," an ultrathin equivalent of corrugated paper cardboard. A square...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

“3rd Conference on Laser Polishing – LaP 2018” Attracts International Experts and Users

09.11.2018 | Event News

On the brain’s ability to find the right direction

06.11.2018 | Event News

European Space Talks: Weltraumschrott – eine Gefahr für die Gesellschaft?

23.10.2018 | Event News

 
Latest News

Purdue cancer identity technology makes it easier to find a tumor's 'address'

16.11.2018 | Health and Medicine

Good preparation is half the digestion

16.11.2018 | Life Sciences

Microscope measures muscle weakness

16.11.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>