Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

How infectious bacteria hibernate through treatment

12.09.2018

Tübingen researchers find that bacteria may opt for persistence as well as resistance to antibiotics

Disease-causing bacteria can develop resistance to antibiotics – which are then no longer effective in treating the infection. Yet they also have another tactic to avoid being killed off by antibiotic treatment. Some cells of the population quietly hide in a dormant state and wait for the danger to subside.


Then they return to full function. For example, some urinary tract infections flare up again even after apparently successful treatment with antibiotics. Maja Semanjski, Katrin Bratl and Andreas Kiessling, led by Professor Boris Maček of the University of Tübingen’s Proteom Centrum, and in collaboration with Elsa Germain and Professor Kenn Gerdes of the University of Copenhagen, have investigated such persistent forms of E. coli bacteria.

Variations of an enzyme indicated which processes initiate the dormant state. This provides the researchers with possible starting-points at which to seek active substances to combat the dormant cells. The study is published in the latest edition of Science Signaling.

When bacteria become insensitive to a drug, they are said to be resistant. That is the case when, for instance, bacteria can successfully expel antibiotics which have managed to enter their cell; when they become able to break down antibiotics using enzymes; or when they are able to replace one metabolic function blocked by antibiotics with some alternative.

“Antibiotics are usually directed at the bacterial growth processes,” Kenn Gerdes explains. He says the bacterium in its dormant phase is not resistant – it is merely temporarily able to tolerate the antibiotic by halting its growth.

“Genetically, these bacteria have all the same features of the other bacteria in the population,” and there are no recognizable rules as to which cells in the colony will survive in a dormant state, he adds. “It is rare and affects only one in ten thousand to one million cells. That makes it hard to investigate,” Gerdes says.

Seeking causes for the dormant state

The formation of dormant states is seen as an attribute of persistence. Some clues were offered several years ago by bacteria which were isolated from patients with urinary tract infections caused by Escherichia coli. They had mutations which gave them up to one thousand times greater persistence – without having any greater resistance to antibiotics.

A similar discovery was made in cystic fibrosis patients who were infected with the inflammatory Pseudomonas aeruginosa bacterium. One enzyme which can lead to the development of a dormant phase had mutated. It is called the HipA kinase (high persister gene A).

In the current study the research team compared the normal HipA kinase Escherichia coli bacteria with the bacteria which had the mutation. They conducted proteome analyses which recorded all proteins found in the bacterial cells. “We found that the normal and the mutated HipA kinase acted on a different stock of bacterial proteins, modifying them with phosphate,” Boris Maček says.

The researchers suspected that the HipA kinase reduces bacterial cells’ growth, initiating the dormant phase. “But the background is more complex than that,” Maček adds. “Our investigations show that the suppression of growth and the persistence are the results of two different processes, because the mutated HipA kinase suppresses bacterial cell growth far less strongly than the normal one does, yet it raises the persistence many times over.” This suggests new processes in the cell which future medicines will have to tackle to beat dangerous degrees of persistence in infectious bacteria.

Wissenschaftliche Ansprechpartner:

Professor Dr. Boris Maček
University of Tübingen
Proteom Centrum
Phone +49 7071 29-70556
boris.macek[at]uni-tuebingen.de

Originalpublikation:

Maja Semanjski, Elsa Germain, Katrin Bratl, Andreas Kiessling, Kenn Gerdes and Boris Macek: The kinases HipA and HipA7 phosphorylate different substrate pools in Escherichia coli to promote multidrug tolerance. Science Signaling, 11, eaat5750 (2018). DOI 10.1126/scisignal.aat5750

Dr. Karl Guido Rijkhoek | idw - Informationsdienst Wissenschaft
Further information:
http://www.uni-tuebingen.de/

More articles from Life Sciences:

nachricht Organized chaos in the enzyme complex: surprising insights and new perspectives
06.07.2020 | Max-Planck-Institut für Entwicklungsbiologie

nachricht Gut bacteria improve type 2 diabetes risk prediction
06.07.2020 | Technische Universität München

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Electrons in the fast lane

Solar cells based on perovskite compounds could soon make electricity generation from sunlight even more efficient and cheaper. The laboratory efficiency of these perovskite solar cells already exceeds that of the well-known silicon solar cells. An international team led by Stefan Weber from the Max Planck Institute for Polymer Research (MPI-P) in Mainz has found microscopic structures in perovskite crystals that can guide the charge transport in the solar cell. Clever alignment of these "electron highways" could make perovskite solar cells even more powerful.

Solar cells convert sunlight into electricity. During this process, the electrons of the material inside the cell absorb the energy of the light....

Im Focus: The lightest electromagnetic shielding material in the world

Empa researchers have succeeded in applying aerogels to microelectronics: Aerogels based on cellulose nanofibers can effectively shield electromagnetic radiation over a wide frequency range – and they are unrivalled in terms of weight.

Electric motors and electronic devices generate electromagnetic fields that sometimes have to be shielded in order not to affect neighboring electronic...

Im Focus: Gentle wall contact – the right scenario for a fusion power plant

Quasi-continuous power exhaust developed as a wall-friendly method on ASDEX Upgrade

A promising operating mode for the plasma of a future power plant has been developed at the ASDEX Upgrade fusion device at Max Planck Institute for Plasma...

Im Focus: ILA Goes Digital – Automation & Production Technology for Adaptable Aircraft Production

Live event – July 1, 2020 - 11:00 to 11:45 (CET)
"Automation in Aerospace Industry @ Fraunhofer IFAM"

The Fraunhofer Institute for Manufacturing Technology and Advanced Materials IFAM l Stade is presenting its forward-looking R&D portfolio for the first time at...

Im Focus: AI monitoring of laser welding processes - X-ray vision and eavesdropping ensure quality

With an X-ray experiment at the European Synchrotron ESRF in Grenoble (France), Empa researchers were able to demonstrate how well their real-time acoustic monitoring of laser weld seams works. With almost 90 percent reliability, they detected the formation of unwanted pores that impair the quality of weld seams. Thanks to a special evaluation method based on artificial intelligence (AI), the detection process is completed in just 70 milliseconds.

Laser welding is a process suitable for joining metals and thermoplastics. It has become particularly well established in highly automated production, for...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

International conference QuApps shows status quo of quantum technology

02.07.2020 | Event News

Dresden Nexus Conference 2020: Same Time, Virtual Format, Registration Opened

19.05.2020 | Event News

Aachen Machine Tool Colloquium AWK'21 will take place on June 10 and 11, 2021

07.04.2020 | Event News

 
Latest News

Coupled hair cells in the inner ear – „Together we are strong!“

06.07.2020 | Health and Medicine

Innovations for sustainability in a post-pandemic future

06.07.2020 | Social Sciences

Carbon-loving materials designed to reduce industrial emissions

06.07.2020 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>