Prof. Dirk Bumann’s research group at the Biozentrum of the University of Basel has now uncovered how the typhoid pathogen repeatedly manages to evade the host’s immune system. Their findings are published in the scientific journal “Cell Host & Microbe”.
Salmonella-infected cells (macrophages in blue, monocytes in turquoise). Dead Salmonella (only yellow), surviving Salmonella (yellow and red).
Illustration: University of Basel
Typhoid fever is a bacterial infection caused by the pathogen Salmonella. The infected host’s immune system detects Salmonella and activates immune cells such as neutrophils and monocytes. These cells infiltrate the infected tissue and enclose the infection to form an abscess. Although most Salmonella bacteria are readily killed by this immune reaction, Dirk Bumann’s group has demonstrated that some escape from the abscess and thus ensure their survival.
Salmonella uses immune cells
Once outside the abscess, the Salmonella bacteria are attacked by other immune cells, the so-called macrophages that produce a less effective immune response. “Salmonella have developed a range of defense strategies to resist macrophage attacks. Many Salmonella are thus able to survive and even to replicate in macrophages,” explains Neil Burton, one of the two first authors. With time, abscesses form around the new infection foci but again some Salmonella bacteria can manage to escape.
“This drives the whole infection process further and makes typhoid fever particularly insidious,” says Nura Schürmann, also a first author of the publication.
A battle on many fronts
The whole disease process is a race between Salmonella and the immune system of the infected organism, in which the battle is fought on many fronts. In this process many Salmonella bacteria are killed and others survive to spread the infection. It is the net balance of the outcomes of these individual Salmonella and immune cell encounters which in the end determines the course of the illness.
Typhoid fever is a life-threatening infection in countries with poor hygiene. Each year, more than 20 million people are infected with this disease. The illness is transmitted by ingesting food or water contaminated with this bacterium. Once inside the intestine, Salmonella crosses the gut mucosa and spreads to other organs such as the spleen and liver. Growing antibiotic resistance makes this illness increasingly difficult to cure.
Understanding what factors enable Salmonella to win many encounters with host cells might provide new strategies in the treatment of typhoid fever. Similar heterogeneous encounters likely determine the fights between the host and many other pathogens. Findings of this study may thus be relevant for a wide range of infectious diseases.Original Citation
Olivia Poisson | Universität Basel
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...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
09.12.2016 | Life Sciences
09.12.2016 | Ecology, The Environment and Conservation
09.12.2016 | Health and Medicine