Bjarke Christensen and Tine Licht together with colleagues from Denmark’s National Food Institute set out to investigate whether the growth conditions of Listeria bacteria just prior to being eaten had an effect on their virulence once absorbed by the gut. Guinea pigs were fed food laced with L. monocytogenes, grown either in an oxygen-rich atmosphere, or starved of oxygen. The team used fluorescent labelling to tell the bacteria strains apart.
Bacterial oxygen restriction increased the number of animals carrying L. monocytogenes in their internal organs, although it did not affect the actual number of bacteria infecting each organ. It seems that oxygen restriction smoothes the bacteria’s initial path from the gut into organs including the jejunum, liver and spleen, but does not help the bugs to multiply on arrival.
With better success surviving the gastric barrier, the oxygen-restricted bacteria have a greater chance of causing infection. The authors suggest that oxygen restriction may lead to increased levels of InteralinA (InlA) protein on the invading bacteria’s cell walls, InlA being a key factor in L. monocytogenes virulence.
These findings are particularly relevant to help assess the risk of Listeria in food, especially the highly processed foods with long shelf lives that are popular breeding grounds for Listeria.
Press Officer | alfa
Fingerprint' technique spots frog populations at risk from pollution
27.03.2017 | Lancaster University
Parallel computation provides deeper insight into brain function
27.03.2017 | Okinawa Institute of Science and Technology (OIST) Graduate University
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...
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...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
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...
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...
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27.03.2017 | Life Sciences