Professor Colin Hill who is presenting his work at the Society for General Microbiology's autumn meeting in Nottingham today describes how bacteria use different tricks to aid their survival inside the body, helping to explain why food poisoning can be so unpredictable.
One of the biggest challenges faced by food-borne bacteria is acid. Acidic conditions, particularly in the stomach and in the gut will kill most microbes found in contaminated food.
Professor Hill's group at University College Cork has revealed that Listeria bacteria, which may be found in soft cheeses and chilled ready-to-eat products, can overcome harsh acidic conditions by exploiting key food ingredients. Listeria that survive are able to cause serious and sometimes fatal infections, particularly in the elderly and pregnant women.
Certain food constituents such as the amino acid, glutamate, can help the bacteria neutralise acid, allowing the bacteria to pass through the stomach unscathed. Professor Hill explains the significance of this. "People who consume foods that are contaminated with Listeria and are also high in glutamate, such as soft cheese or meat products, have a higher chance of developing serious infection than someone eating the same quantity of bacteria in a low-glutamate food," he said. "Of course this is further complicated by the fact that a contaminated, low-glutamate food could be eaten in combination with a high-glutamate food such as tomato juice, which could also increase the risk of infection."
Listeria can also take advantage of food processing and storage conditions to help them survive. "Bacteria that are exposed to low pH before entering the body may adapt to become more acid-tolerant and therefore better equipped to deal with acidic conditions in the body. For example, Listeria contaminating naturally acidic foods such as cheese may be more likely to cause infection than Listeria carried at a more neutral pH in water.
Professor Hill explains how his group's work could help reduce the incidence of Listeria infections. "The number of cases of listeriosis has nearly doubled in the last decade in Europe. This is because the bacterium is so good at overcoming the challenges it faces in food and in the body," he said. "Our studies show that consuming Listeria in one food may be quite safe, while eating the same amount in another food might be lethal. By understanding the role of the food matrix we may be able to identify and eliminate high-risk foods from the diet of susceptible people."
Laura Udakis | EurekAlert!
Scientists uncover the role of a protein in production & survival of myelin-forming cells
19.07.2018 | Advanced Science Research Center, GC/CUNY
NYSCF researchers develop novel bioengineering technique for personalized bone grafts
18.07.2018 | New York Stem Cell Foundation
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.
Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
19.07.2018 | Earth Sciences
19.07.2018 | Power and Electrical Engineering
19.07.2018 | Materials Sciences