Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

‘Going Off the Grid’ Helps Some Bacteria Hide from Antibiotics

26.04.2011
Call them the Jason Bournes of the bacteria world.

Going "off the grid," like rogue secret agents, some bacteria avoid antibiotic treatments by essentially shutting down and hiding until it's safe to come out again, says Thomas Wood, professor in the Artie McFerrin Department of Chemical Engineering at Texas A&M University.

This surreptitious and elaborate survival mechanism is explained in the online April edition of "Nature Chemical Biology," which details the research of Wood and his post doctoral student Xiaoxue Wang along with colleagues Breann Brown, Wolfgang Peti and Rebecca Page of Brown University.

"Through our research, we're understanding that some bacteria go to 'sleep,' and that antibiotics only work on bacteria that are metabolically active," Wood explains. "You need actively growing bacteria to be susceptible to antibiotics. If the bacterium goes to sleep, the antibiotics, no matter what they do, are not effective because the bacterium is no longer doing the thing that the antibiotic is trying to shut down."

It's an alternative method for survival, Wood says, that starkly contrasts the widely studied genetically based approaches utilized by bacteria through which bacteria gain resistance to antibiotics as the result of mutations experienced throughout time. This mutation-free response, however, demonstrates that some bacteria need not mutate to survive external stressors, Wood says.

Instead, when triggered by an external stressor such as an antibiotic, a bacterial cell can render itself dormant by triggering an internal reaction that degrades the effectiveness of its own internal antitoxins, Wood explains. With its antitoxins damaged, the toxins present within the bacterial cell are left unchecked and damage the cell's metabolic processes so that it essentially shuts down, he adds.

It's self-inflicted damage but with a purpose.

"The cell normally doesn't want to hurt itself; it wants to grow as fast as possible," Wood states; the raison d'être for a cell is to make another cell," Wood says. "However, most bacteria have this group of proteins, and if this group was active - if you got rid of the antitoxins - this group of toxins would either kill the cell or damage it."

Specifically, Wood and his colleagues found that when encountering oxidative stress, their bacterial cells initiated a process through which an antitoxin called MqsA was degraded, in turn allowing the toxin MqsR to degrade all of the cells' messenger RNA. This messenger RNA, Wood explains, plays a critical intermediate role in the cell's process of manufacturing proteins, so without it the cell can't make proteins. With the protein-manufacturing factory shut down, the bacterial cell goes dormant, and an antibiotic cannot "lock on" to the cell. When the stressor is removed, the bacterial cells eventually come back online and resume their normal activities, Wood says.

"It was the combination of the genetic studies at Texas A&M with our structural studies at Brown University that demonstrated that the proteins MqsR:MqsA form an entirely new family of toxin:antitoxin systems," Page says. "Remarkably, we have shown this system not only controls its own genes, but also many other genes in E. coli, including the gene that controls the response to oxidative stress."

This response mechanism, Wood emphasizes, does not replace the mutation-based approaches that have for years characterized cell behavior; it's merely another method in a multifaceted approach undertaken by bacteria to ensure survival.

"A small community of bacteria is in a sense hedging its bet against a threat to its survival by taking another approach," Wood says. "To the bacteria, this is always a numbers game. In one milliliter you can have a trillion bacterial cells, and they don't always do the same thing under stress.

"If we can determine that this 'going to sleep' is the dominant mechanism utilized by bacteria, then we can begin to figure out how to 'wake them up' so that they will be more susceptible to the antibiotic. This ideally would include simultaneously applying the antibiotic and a chemical that wakes up the bacteria. That's the goal - a more effective antibiotic."

Ryan Garcia | EurekAlert!
Further information:
http://www.tamu.edu

More articles from Life Sciences:

nachricht NYSCF researchers develop novel bioengineering technique for personalized bone grafts
18.07.2018 | New York Stem Cell Foundation

nachricht Pollen taxi for bacteria
18.07.2018 | 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: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

Im Focus: Chemical reactions in the light of ultrashort X-ray pulses from free-electron lasers

Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.

Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

NYSCF researchers develop novel bioengineering technique for personalized bone grafts

18.07.2018 | Life Sciences

Machine-learning predicted a superhard and high-energy-density tungsten nitride

18.07.2018 | Materials Sciences

Why might reading make myopic?

18.07.2018 | Health and Medicine

VideoLinks
Science & Research
Overview of more VideoLinks >>>