Salmonella are microscopic living creatures that can contaminate almost any food type, causing diarrhoea, abdominal pain and fever. Scientists know that Salmonella – which can also cause typhoid fever – has evolved unique mechanisms to prevent the body's immune system from functioning effectively, but until now it was not understood how it survives so successfully in the environment.
Scientists at Liverpool, in collaboration with the Institute for Animal Health, have shown that Salmonella use a secretion system to protect themselves inside amoeba – a single-celled organism living on land and in the water. The research suggests that amoeba may be a major source of Salmonella within the environment and could play a significant role in transmission of infection to man and animals.
Salmonella uses a system, called SP12 type III, which acts as a bacterial machine inside organisms and causes disease in humans, animals and plants. The system employs a 'syringe-like' mechanism to inject bacteria into cells that would normally release compounds to rid the body of harmful substances. This system changes the structure of the cell and prevents these compounds from coming into contact with pathogens and destroying them.
Dr Paul Wigley, from the National Centre for Zoonosis Research, based at the University's Leahurst campus, explains: "Salmonella has managed to survive extremely successfully in the environment, finding its way into our food and causing illness, despite the body's best efforts to fight it off. We found that it uses a system which operates in the human immune system as well as inside amoeba living in the environment. This system essentially protects Salmonella within cellular compartments, called phagosomes, where it can survive and multiply.
"Its ability to survive in amoeba is a huge advantage to its continued development as it may be more resistant to disinfectants and water treatment. This means that we need to work to understand ways of controlling amoeba in water supplied to animals and prevent it acting as a 'Trojan Horse' for Salmonella and other pathogens."
The research, supported by the Society for Applied Microbiology, the Department for Environment, Food and Rural Affairs (DEFRA), and the Higher Education Funding Council for England (HEFCE), is published in Applied and Environmental Microbiology.
Samantha Martin | EurekAlert!
Further reports about: > Applied and Environmental Microbiology > Disinfectants > Salmonella > Salmonella transmission > Trojan horse > abdominal pain > amoeba > body's immune system > cellular compartments > diarrhoea > fever > immune system > microbiology > microscopic living creatures > phagosomes > single-celled organism > syringe-like mechanism > typhoid fever > water treatment
Repairing damaged hearts with self-healing heart cells
22.08.2017 | National University Health System
Biochemical 'fingerprints' reveal diabetes progression
22.08.2017 | Umea University
Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.
As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...
Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.
Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...
For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.
While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...
An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.
The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...
A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.
Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...
16.08.2017 | Event News
04.08.2017 | Event News
26.07.2017 | Event News
22.08.2017 | Health and Medicine
22.08.2017 | Materials Sciences
22.08.2017 | Life Sciences