Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Antibiotics based on a new principle may defeat MRSA

Scientists at Karolinska Institutet have presented a new principle for fighting bacterial infections, in other words, a new type of antibiotic, in the FASEB Journal. The new antibiotic mechanism is based on selectively blocking the thioredoxin system in the cells, which is crucial to the growth of certain bacteria. Scientists hope to be able to treat such conditions as stomach ulcers, TB and MRSA.

"Much work remains to be done, but we believe that it will be possible to use this mechanism when, for example, broad-spectrum antibiotics have proved to be inadequate", says Professor Arne Holmgren, leader of the study now being published.

The thioredoxin system is present in all cells and is central to the ability to make new DNA (genetic material). It is also important in protecting the cell from a process known as oxidative stress, which arises when excess oxygen radicals and other oxidizing agents are formed. This may occur, for example, during the attack by white blood cells on bacteria, and it can damage or kill the cell. The most important components of the thioredoxin system are the enzymes thioredoxin and thioredoxin reductase, of which the first (very simplified) is required in the process of creating the building bricks of what is to be new DNA, and the second ensures that the thioredoxin remains active.

In addition to the thioredoxin system, mammals and humans, and some bacteria, have a second, similar biochemical process in the cell that is based on the enzyme glutaredoxin. The thioredoxin system and the glutaredoxin system act as each other's backup. Many bacteria that cause disease, however, such as Helicobacter pylori (which cause stomach ulcers), the TB bacterium Mycobacterium tuberculosis, and the multiresistant staphylococcus bacterium MRSA, have only the thioredoxin system. These bacteria lack the glutaredoxin system. This makes these bacteria very vulnerable to substances that inhibit thioredoxin and thioredoxin reductase.

"Furthermore, the thioredoxin reductases in bacteria are very different in chemical composition and structure from the human enzyme. And it is just these differences, and the fact that certain bacteria lack the glutaredoxin system, that mean that drugs that affect thioredoxin reductase can be used as antibiotics. This is what we have discovered", says Arne Holmgren.

The study now being published describes how the scientists have used a drug candidate known as ebselen, which has previously been tested in the treatment of stroke and inflammation. The scientists discovered that ebselen and similar synthetic substances inhibit, among other things, thioredoxin reductase in bacteria. The scientists saw in laboratory experiments how the ebselen killed certain types of bacteria and not others. They were able to modify the genetic properties of Escherichia coli (E. coli), which is normally not susceptible to ebselen, and in this way investigate the mechanisms behind the antibiotic effect. They showed that the bacteria in which the genes in the DNA molecule that code for the glutaredoxin enzyme or the formation of the tripeptide glutathione, which is another important component of the glutaredoxin system, had been switched off were must more susceptible to ebselen than normal.

Bacteria that are resistant to several different types of antibiotic are a serious and extensive problem all over the world. The method of attacking bacteria by preventing the construction of their cell wall, which was discovered when penicillin was discovered at the beginning of the 20th century, is still used, in several variations. It has for this reason long been obvious that science must find new ways of combating diseases caused by bacterial infections. The scientists who have written the article believe that the new antibiotic principle they are presenting may be a part of the solution.

"It is particularly interesting that MRSA and the antibiotic-resistant TB are also susceptible to ebselen and new synthetic substances. And it's worth noting that ebselen is an antioxidant, just as vitamin C is. This means that it protects the host against oxidative stress, and in this way we can kill two birds with one stone", says Arne Holmgren.

In addition to Arne Holmgren's research group at Karolinska Institutet, scientists at Uppsala University, the Swedish Institute for Communicable Disease Control, and the World Health Organisation (WHO) have taken part in the study. The work has been financed with grants from the Swedish Cancer Society, the Swedish Research Council, Vinnova, the Knut and Alice Wallenberg Foundation and Karolinska Institutet.


Jun Lu, Alexios Vlamis-Gardikas, Karuppasamy Kandasamy, Rong Zhao, Tomas N Gustafsson, Lars Engstrand, Sven Hoffner, Lars Engman, Arne Holmgren

Inhibition of bacterial thioredoxin reductase: an antibiotic mechanism targeting bacteria lacking glutathione

FASEB Journal, online 17 December 2012, doi:10.1096/fj.12-223305 , Vol. 27 April 2013

The Press Office | EurekAlert!
Further information:

More articles from Health and Medicine:

nachricht NIH scientists describe potential antibody treatment for multidrug-resistant K. pneumoniae
14.03.2018 | NIH/National Institute of Allergy and Infectious Diseases

nachricht Researchers identify key step in viral replication
13.03.2018 | University of Pittsburgh Schools of the Health Sciences

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

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

Im Focus: Locomotion control with photopigments

Researchers from Göttingen University discover additional function of opsins

Animal photoreceptors capture light with photopigments. Researchers from the University of Göttingen have now discovered that these photopigments fulfill an...

Im Focus: Surveying the Arctic: Tracking down carbon particles

Researchers embark on aerial campaign over Northeast Greenland

On 15 March, the AWI research aeroplane Polar 5 will depart for Greenland. Concentrating on the furthest northeast region of the island, an international team...

Im Focus: Unique Insights into the Antarctic Ice Shelf System

Data collected on ocean-ice interactions in the little-researched regions of the far south

The world’s second-largest ice shelf was the destination for a Polarstern expedition that ended in Punta Arenas, Chile on 14th March 2018. Oceanographers from...

Im Focus: ILA 2018: Laser alternative to hexavalent chromium coating

At the 2018 ILA Berlin Air Show from April 25–29, the Fraunhofer Institute for Laser Technology ILT is showcasing extreme high-speed Laser Material Deposition (EHLA): A video documents how for metal components that are highly loaded, EHLA has already proved itself as an alternative to hard chrome plating, which is now allowed only under special conditions.

When the EU restricted the use of hexavalent chromium compounds to special applications requiring authorization, the move prompted a rethink in the surface...

Im Focus: Radar for navigation support from autonomous flying drones

At the ILA Berlin, hall 4, booth 202, Fraunhofer FHR will present two radar sensors for navigation support of drones. The sensors are valuable components in the implementation of autonomous flying drones: they function as obstacle detectors to prevent collisions. Radar sensors also operate reliably in restricted visibility, e.g. in foggy or dusty conditions. Due to their ability to measure distances with high precision, the radar sensors can also be used as altimeters when other sources of information such as barometers or GPS are not available or cannot operate optimally.

Drones play an increasingly important role in the area of logistics and services. Well-known logistic companies place great hope in these compact, aerial...

All Focus news of the innovation-report >>>



Industry & Economy
Event News

Ultrafast Wireless and Chip Design at the DATE Conference in Dresden

16.03.2018 | Event News

International Tinnitus Conference of the Tinnitus Research Initiative in Regensburg

13.03.2018 | Event News

International Virtual Reality Conference “IEEE VR 2018” comes to Reutlingen, Germany

08.03.2018 | Event News

Latest News

Wandering greenhouse gas

16.03.2018 | Earth Sciences

'Frequency combs' ID chemicals within the mid-infrared spectral region

16.03.2018 | Physics and Astronomy

Biologists unravel another mystery of what makes DNA go 'loopy'

16.03.2018 | Life Sciences

Science & Research
Overview of more VideoLinks >>>