Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Intestinal microbiota defend the host against pathogens

01.03.2019

Research team from the Kiel CRC 1182 examines the role of the intestinal microbiome in fighting infections, using the nematode model Caenorhabditis elegans

From single-celled organisms to humans, all animals and plants are colonised by microorganisms. As so-called host organisms, they accommodate a diverse community of symbiotic microorganisms, the microbiome, and together with them form the so-called metaorganism.


Dr Katja Dierking (in the background) and Kohar Kissoyan investigated the role of C. elegans’ natural microbiome in the defence against infections.

© Dr Sabrina Köhler


An agar plate demonstrates the inhibitory effect of Pseudomonas bacteria: The pathogen Bacillus thurigiensis cannot thrive next to them.

© Dr Sabrina Köhler

The interactions between host and microbes exert a significant influence on diverse functions and health of the host organism. Scientists from the Collaborative Research Centre (CRC) 1182 "Origin and Function of Metaorganisms” at Kiel University (CAU) are investigating these complex interactions, and attribute an important role in the defence against pathogens to the microbiota.

To do so, they use various experimental model organisms, i.e. living organisms which allow investigation of the interaction with their bacterial symbionts under laboratory conditions. A research team from the department of Evolutionary Ecology and Genetics at CAU has examined the function of the natural intestinal microbiome using the nematode (round worm) model Caenorhabditis elegans.

They discovered that the natural C. elegans microbiome plays an important role in the defence against infections, and that certain bacteria produce a compound with a clear antimicrobial effect. In future, the results of the Kiel scientists could help to better understand the functions of the intestinal microbiome as a whole, and in particular its effects on the colonisation of the digestive tract by pathogens. Their study was published today in the scientific journal Current Biology.

Direct and indirect protection against infection
The Kiel team laid the foundation for the current research results a few years ago, when it presented the first systematic analysis of the natural worm microbiome. This investigation led to a detailed knowledge of the composition and the dominant species of the intestinal microbiome of the worm.

At that time, the researchers hypothesised that the natural microbiome benefits host fitness, for example by protecting the host against pathogens. To gain a better understanding of the function of the worm microbiome, the researchers have now examined how individual bacteria from the former study affect the fitness of the host during pathogen infection. In doing so, they identified two distinct modes of action.

"On the one hand, we were able to determine a direct protective effect of certain bacteria against a pathogen," said Dr Katja Dierking, research associate in the department of Evolutionary Ecology and Genetics at CAU, and principle investigator in the CRC 1182.

"Microbiota bacteria of the genus Pseudomonas inhibit the growth of the nematode specific pathogen Bacillus thuringiensis, if you put them in direct contact with each other," continued Dierking. In addition, the study of other microbiota bacteria of the genus Pseudomonas revealed an indirect effect: although they do not inhibit the growth of the pathogen directly, they nevertheless protect the worm against its harmful effects, likely through indirect, host-mediated mechanisms.

The researchers found a total of six bacterial isolates in the natural microbiome which are involved in the defence against infections: two of them protect the worm directly against pathogens, and four of them indirectly.

How intestinal bacteria inhibit the growth of pathogens

Another special feature of the new Kiel study is that it not only describes the infection-inhibiting effect of individual bacteria of the worm’s microbiome, but was also able to identify an underlying molecular mechanism. Using genomic and biochemical analyses, the scientists from the Kiel CRC 1182 in collaboration with scientists from Goethe University Frankfurt were able to identify an antibacterial compound that is produced by the two Pseudomonas microbiota bacteria, which protect the worm by directly inhibiting pathogen growth.

"The Pseudomonas bacteria produce a so-called cyclic lipopeptide," explained Kohar Kissoyan, first author of the study and doctoral researcher in the Evolutionary Ecology and Genetics group. "This chemical compound exerts a direct inhibitory effect on the pathogen, and thereby suppresses its further growth," continued Kissoyan.

How can we utilise the new findings?
The new results of the Kiel team establish C. elegans, which is a standard model organism studied in numerous research laboratories throughout the world, as experimental system to explore the various functions of the natural intestinal microbiome.

Next, Dierking and her research team want to conduct a detailed investigation of the mechanism of action of the antibacterial compound identified in the worm’s intestinal microbiome. The goal of the CRC 1182 is to understand the interactions of the various bacteria of the microbiome with the host organism, but also with each other.

In the long-term, the Kiel researchers hope that the gained knowledge will help in the development of therapeutic strategies to treat diseases related to disturbances of the intestinal microbiome, e.g. through the targeted use of probiotics, i.e. specific beneficial bacterial cultures. Currently, the Kiel metaorganisms CRC, which started in 2016, is applying for a second funding period as of 2020 at the German Research Foundation (DFG).

Photos are available to download:
https://www.uni-kiel.de/fileadmin/user_upload/pressemitteilungen/2019/058-dierki...
An agar plate demonstrates the inhibitory effect of Pseudomonas bacteria: The pathogen Bacillus thurigiensis cannot thrive next to them.
© Dr Sabrina Köhler

https://www.uni-kiel.de/fileadmin/user_upload/pressemitteilungen/2019/058-dierki...
Dr Katja Dierking (in the background) and Kohar Kissoyan investigated the role of C. elegans’ natural microbiome in the defence against infections.
© Dr Sabrina Köhler

More information:
Department of Evolutionary Ecology and Genetics, Zoological Institute, Kiel University:
http://www.uni-kiel.de/zoologie/evoecogen

Collaborative Research Centre (CRC) 1182 "Origin and Function of Metaorganisms", Kiel University:
http://www.metaorganism-research.com

Kiel University (CAU)
Press, Communication and Marketing, Dr Boris Pawlowski, Text: Christian Urban
Postal address: D-24098 Kiel, Germany, Telephone: +49 (0)431 880-2104, Fax: +49 (0)431 880-1355 E-mail: presse@uv.uni-kiel.de, Internet: www.uni-kiel.de , Twitter: www.twitter.com/kieluni
Facebook: www.facebook.com/kieluni, Instagram: www.instagram.com/kieluni

Wissenschaftliche Ansprechpartner:

Dr Katja Dierking
Evolutionary Ecology and Genetics group, Kiel University
Tel.: +49 (0)431-880-4145
E-mail: kdierking@zoologie.uni-kiel.de

Originalpublikation:

Kohar Kissoyan, Moritz Drechsler, Eva-Lena Stange, Johannes Zimmermann, Christoph Kaleta, Helge Bode and Katja Dierking (2019): Natural C. elegans microbiota protects against infection via production of a cyclic lipopeptide of the viscosin group Current Biology Published on February 28, 2019
https://doi.org/10.1016/j.cub.2019.01.050

Weitere Informationen:

http://www.uni-kiel.de/zoologie/evoecogen
http://www.metaorganism-research.com

Christian Urban | Christian-Albrechts-Universität zu Kiel

More articles from Life Sciences:

nachricht Cell growth: Intricate network of potential new regulatory mechanisms has been decoded
14.01.2020 | Heinrich-Heine University Duesseldorf

nachricht Life's clockwork: Scientist shows how molecular engines keep us ticking
14.01.2020 | University of North Carolina Health Care

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: World Premiere in Zurich: Machine keeps human livers alive for one week outside of the body

Researchers from the University Hospital Zurich, ETH Zurich, Wyss Zurich and the University of Zurich have developed a machine that repairs injured human livers and keep them alive outside the body for one week. This breakthrough may increase the number of available organs for transplantation saving many lives of patients with severe liver diseases or cancer.

Until now, livers could be stored safely outside the body for only a few hours. With the novel perfusion technology, livers - and even injured livers - can now...

Im Focus: SuperTIGER on its second prowl -- 130,000 feet above Antarctica

A balloon-borne scientific instrument designed to study the origin of cosmic rays is taking its second turn high above the continent of Antarctica three and a half weeks after its launch.

SuperTIGER (Super Trans-Iron Galactic Element Recorder) is designed to measure the rare, heavy elements in cosmic rays that hold clues about their origins...

Im Focus: LZH’s MOMA laser ready for the flight to Mars

One last time on Earth it has been turned on in France in December 2019. The next time the MOMA laser developed by the Laser Zentrum Hannover e.V. (LZH) is going into operation will be on Mars. The ExoMars rover into which the laser is integrated has now successfully passed the thermal vacuum tests at Airbus in Toulouse, France.

For 18 days the ExoMars rover Rosalind Franklin was subjected to thermal vacuum tests at Airbus. There, it had to withstand strong changes in temperature and...

Im Focus: Atacama Desert: A newly discovered biocoenosis of lichens, fungi and algae shapes entire landscapes

The Atacama Desert in Chile is the oldest and most arid desert on earth. Organisms living in this area have adapted to the extreme conditions over thousands of years. A research team led by Dr Patrick Jung has now discovered and investigated a previously unknown biocoenosis of lichens, fungi, cyanobacteria and algae. It colonises tiny stones, so-called grit and its need for water is satisfied by fog and dew. These organisms also decompose the rock on and in which they live. The scientists believe that this is how they have shaped the landscape of the Atacama Desert. Their study was published in the renowned scientific journal "Gebiology".

Many desert areas have large black spots in the sand. These spots are mineral deposits, so-called desert varnish. In the Atacama Desert, which can be compared...

Im Focus: Nano antennas for data transfer

For the first time, physicists from the University of Würzburg have successfully converted electrical signals into photons and radiated them in specific directions using a low-footprint optical antenna that is only 800 nanometres in size.

Directional antennas convert electrical signals to radio waves and emit them in a particular direction, allowing increased performance and reduced...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

„Advanced Battery Power“- Conference, Contributions are welcome!

07.01.2020 | Event News

International Coral Reef Symposium 2020 Holds Photo Competition

19.12.2019 | Event News

The Future of Work

03.12.2019 | Event News

 
Latest News

Man versus machine: Can AI do science?

14.01.2020 | Information Technology

Cell growth: Intricate network of potential new regulatory mechanisms has been decoded

14.01.2020 | Life Sciences

How nodules stay on top at the bottom of the sea

14.01.2020 | Earth Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>