Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Calcium Induces Chronic Lung Infections

24.10.2016

The bacterium Pseudomonas aeruginosa is a life-threatening pathogen in hospitals. About ten percent of all nosocomial infections, in particular pneumonia, are caused by this pathogen. Researchers from the University of Basel’s Biozentrum, have now discovered that calcium induces the switch from acute to chronic infection. In Nature Microbiology the researchers have also reported why antibiotics are less effective in fighting the pathogen in its chronic state.

One of the most serious pathogens is the bacterium Pseudomonas aeruginosa, which frequently causes hospital infections and is notoriously difficult to treat owing to its multi-resistance to antibiotics. Although P. aeruginosa is responsible for a range of different infections in humans, it is the leading cause of chronic lung infections in immune-compromised patients.


Calcium induces a switch from the acute (green) to the chronic virulence state (red) of the pathogen Pseudomonas aeruginosa.

Image: University of Basel, Biozentrum

Calcium induces acute to chronic virulence switch

In an early, acute stage of pneumonia, the pathogen employs a wide arsenal of weapons – so-called virulence factors – to invade the host and evade its immune system. During disease progression, the bacterium adapts its strategy by switching from acute to chronic virulence. It stops the production of virulence factors, such as bacterial injection apparatus and toxins and, instead, produces a protective matrix and reduces its growth rate. The environmental signals directing this transition were so far unknown. The team led by Prof. Urs Jenal, infection biologist at the Biozentrum of the University of Basel, has now identified calcium as a signal that specifically triggers the switch to chronic virulence.

“In Pseudomonas a central signaling pathway senses environmental information and ultimately determines whether the pathogen will undergo the acute to chronic virulence switch,” explains Jenal. “Although the components of this pathway are well-known, none of the external signals modulating the switch are defined.” The researchers have now discovered that a receptor located in the bacterial cell envelope monitors the calcium concentration in the environment and transmits this signal into the cell. Elevated calcium levels trigger the switch to a chronic program: The bacteria protect themselves within a biofilm structure, reduce their growth rate and by that increase their drug tolerance and persistence.

Cystic fibrosis patients harbor calcium sensitive bacteria

Finally, the researchers were able to demonstrate the clinical relevance of their findings. Patients suffering from cystic fibrosis develop lifelong chronic infections by P. aeruginosa, which permanently damage their lung tissue. “Most of the isolates from airways of CF patients have retained their calcium sensitivity,” emphasizes Jenal. “We believe that this allows these bacteria to constantly adapt their virulence in response to the often changing conditions in the airways. One of the characteristics of cystic fibrosis is deregulated calcium homeostasis. We assume that elevated calcium levels in patients promote the switch from an acute to a chronic state of infection. This is of advantage for the pathogen, as it may ensure its long-term survival in the respiratory tract. At the same time, treatment of chronically infected patients becomes more challenging.”

Original article

Ursula N. Broder, Tina Jaeger, Urs Jenal
LadS is a calcium-responsive kinase that induces acute-to-chronic virulence switch in Pseudomonas aeruginosa
Nature Microbiology (2016), doi: 10.1038/nmicrobiol.2016.184

Further Information

• Prof. Dr. Urs Jenal, University of Basel, Biozentrum, Tel. +41 61 267 21 35, email: urs.jenal@unibas.ch

• Dr. Katrin Bühler, University of Basel, Biozentrum, Communications, Tel. +41 61 267 09 74, email: katrin.buehler@unibas.ch

Weitere Informationen:

http://dx.doi.org/10.1038/nmicrobiol.2016.184 - Abstract

Dr. Katrin Bühler | Universität Basel
Further information:
http://www.unibas.ch

More articles from Life Sciences:

nachricht How molecules teeter in a laser field
18.01.2019 | Forschungsverbund Berlin

nachricht Discovery of enhanced bone growth could lead to new treatments for osteoporosis
18.01.2019 | University of California - Los Angeles

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Ten-year anniversary of the Neumayer Station III

The scientific and political community alike stress the importance of German Antarctic research

Joint Press Release from the BMBF and AWI

The Antarctic is a frigid continent south of the Antarctic Circle, where researchers are the only inhabitants. Despite the hostile conditions, here the Alfred...

Im Focus: Ultra ultrasound to transform new tech

World first experiments on sensor that may revolutionise everything from medical devices to unmanned vehicles

The new sensor - capable of detecting vibrations of living cells - may revolutionise everything from medical devices to unmanned vehicles.

Im Focus: Flying Optical Cats for Quantum Communication

Dead and alive at the same time? Researchers at the Max Planck Institute of Quantum Optics have implemented Erwin Schrödinger’s paradoxical gedanken experiment employing an entangled atom-light state.

In 1935 Erwin Schrödinger formulated a thought experiment designed to capture the paradoxical nature of quantum physics. The crucial element of this gedanken...

Im Focus: Nanocellulose for novel implants: Ears from the 3D-printer

Cellulose obtained from wood has amazing material properties. Empa researchers are now equipping the biodegradable material with additional functionalities to produce implants for cartilage diseases using 3D printing.

It all starts with an ear. Empa researcher Michael Hausmann removes the object shaped like a human ear from the 3D printer and explains:

Im Focus: Elucidating the Atomic Mechanism of Superlubricity

The phenomenon of so-called superlubricity is known, but so far the explanation at the atomic level has been missing: for example, how does extremely low friction occur in bearings? Researchers from the Fraunhofer Institutes IWM and IWS jointly deciphered a universal mechanism of superlubricity for certain diamond-like carbon layers in combination with organic lubricants. Based on this knowledge, it is now possible to formulate design rules for supra lubricating layer-lubricant combinations. The results are presented in an article in Nature Communications, volume 10.

One of the most important prerequisites for sustainable and environmentally friendly mobility is minimizing friction. Research and industry have been dedicated...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Our digital society in 2040

16.01.2019 | Event News

11th International Symposium: “Advanced Battery Power – Kraftwerk Batterie” Aachen, 3-4 April 2019

14.01.2019 | Event News

ICTM Conference 2019: Digitization emerges as an engineering trend for turbomachinery construction

12.12.2018 | Event News

 
Latest News

Additive manufacturing reflects fundamental metallurgical principles to create materials

18.01.2019 | Materials Sciences

How molecules teeter in a laser field

18.01.2019 | Life Sciences

The cytoskeleton of neurons has been found to be involved in Alzheimer's disease

18.01.2019 | Health and Medicine

VideoLinks
Science & Research
Overview of more VideoLinks >>>