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
Researchers identify potentially druggable mutant p53 proteins that promote cancer growth
09.12.2016 | Cold Spring Harbor Laboratory
Plant-based substance boosts eyelash growth
09.12.2016 | Fraunhofer-Institut für Angewandte Polymerforschung IAP
Physicists of the University of Würzburg have made an astonishing discovery in a specific type of topological insulators. The effect is due to the structure of the materials used. The researchers have now published their work in the journal Science.
Topological insulators are currently the hot topic in physics according to the newspaper Neue Zürcher Zeitung. Only a few weeks ago, their importance was...
In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.
Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...
Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
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