Certain strains of Salmonella bacteria such as Salmonella Typhimurium (S. Typhimurium) are among of the most common causes of food-borne gastroenteritis.
Other strains of Salmonella such as S. Typhi are responsible for typhoid fever, which causes 200,000 deaths around the world each year. Ensuring food is clear of contamination, and water is clean are key to reducing the effects Salmonella can have, but we also need more effective ways to combat Salmonella once it's inside our bodies.
To address this the Institute of Food Research, strategically supported by the Biotechnology and Biological Sciences Research Council, has been studying S. Typhimurium bacteria to understand, not only how they transmit through the food chain, but why they are so effective and dangerous once inside us.
If we consume food or water contaminated with S. Typhimurium, the first stage of infection is to get into the cells that line our gut. These epithelial cells are adapted to defend against such attacks, but Salmonella has a wealth of strategies to overcome these and make it more virulent. It also needs these virulence genes to overcome the cells of the immune system, which it invades to move around the body.
We are learning a lot about these virulence genes, but until this new study, published in the journal PLOS ONE, we didn't know how Salmonella fuelled itself for this. A source of energy and nutrition is vital, and knowing what Salmonella uses could inform new strategies to prevent infection.
To discover more about Salmonella's feeding habits, Dr Arthur Thompson and his team constructed S. Typhimurium strains lacking certain key genes in important metabolic pathways. They then examined how well these mutated strains reproduced in human epithelial cells, grown in cultures.
"We found that glucose is the major nutrient used by S. Typhimurium," said Dr Thompson. Salmonella converts glucose to pyruvate in a process called glycolysis, which also releases energy needed to fuel growth and reproduction.
Knocking out one enzyme in glycolysis, and enzymes used to transport glucose into the bacteria severely reduced S. Typhimurium's ability to reproduce in epithelial cells, but didn't eradicate it completely. "This suggests that although S. Typhimurium requires glucose, it is also able to use other nutrients, and that's something we're now studying," said Dr Thompson.
This contrasts with previous findings from similar experiments on macrophage cells by the IFR team, as for successful macrophage invasion, glycolysis is absolutely essential. Macrophages are the immune cells sent to destroy Salmonella, but instead Salmonella invades the macrophages. Infected macrophages can carry Salmonella around the body causing a potentially fatal systemic infection.
"We now have a much more complete picture of the nutritional needs of Salmonella, which is important since this information may also suggest new ways to develop potential therapeutic interventions," said Dr Thompson.
Andrew Chapple | Eurek Alert!
High-arctic butterflies shrink with rising temperatures
07.10.2015 | Aarhus University
Long-term contraception in a single shot
07.10.2015 | California Institute of Technology
The MICADO camera, a first light instrument for the European Extremely Large Telescope (E-ELT), has entered a new phase in the project: by agreeing to a Memorandum of Understanding, the partners in Germany, France, the Netherlands, Austria, and Italy, have all confirmed their participation. Following this milestone, the project's transition into its preliminary design phase was approved at a kick-off meeting held in Vienna. Two weeks earlier, on September 18, the consortium and the European Southern Observatory (ESO), which is building the telescope, have signed the corresponding collaboration agreement.
As the first dedicated camera for the E-ELT, MICADO will equip the giant telescope with a capability for diffraction-limited imaging at near-infrared...
Self-driving cars will be on our streets in the foreseeable future. In Graz, research is currently dedicated to an innovative driver assistance system that takes over control if there is a danger of collision. It was nature that inspired Dr Manfred Hartbauer from the Institute of Zoology at the University of Graz: in dangerous traffic situations, migratory locusts react around ten times faster than humans. Working together with an interdisciplinary team, Hartbauer is investigating an affordable collision detector that is equipped with artificial locust eyes and can recognise potential crashes in time, during both day and night.
Inspired by insects
An interdisciplinary team of researchers has built the first prototype of a miniature particle accelerator that uses terahertz radiation instead of radio...
At present, tiny magnetic whirls – so called skyrmions – are discussed as promising candidates for bits in future robust and compact data storage devices. At...
In cooperation with the Center for Nano-Optics of Georgia State University in Atlanta (USA), scientists of the Laboratory for Attosecond Physics of the Max Planck Institute of Quantum Optics and the Ludwig-Maximilians-Universität have made simulations of the processes that happen when a layer of carbon atoms is irradiated with strong laser light.
Electrons hit by strong laser pulses change their location on ultrashort timescales, i.e. within a couple of attoseconds (1 as = 10 to the minus 18 sec). In...
01.10.2015 | Event News
30.09.2015 | Event News
17.09.2015 | Event News
08.10.2015 | Earth Sciences
08.10.2015 | Information Technology
08.10.2015 | Physics and Astronomy