Navigation Links
'Going off the grid' helps some bacteria hide from antibiotics
Date:4/25/2011

COLLEGE STATION, Texas, April 25, 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'tre 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."


'/>"/>

Contact: Ryan Garcia
ryan.garcia99@tamu.edu
979-845-9237
Texas A&M University
Source:Eurekalert

Related biology news :

1. Food safety study of beef trim leads to ongoing research collaboration
2. Russian boreal forests undergoing vegetation change, study shows
3. Going green: New program provides vital support for plant scientists
4. Going out on a (redwood tree) limb
5. Keystone Symposia awarded $1.37 million, 5-year NIH grant to fund ongoing diversity efforts
6. Ongoing human evolution could explain recent rise in certain disorders
7. Going green on hold: Man-made activities can affect blue haze, worlds weather
8. WPI receives $1.3 million in federal awards for ongoing research in the life sciences
9. A heart healthy diet and ongoing, moderate physical activity may protect against cognitive decline
10. Going bananas for sustainable research -- scientists create fuel from African crop waste
11. Lobster traps going high tech
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:3/9/2017)... , March 9, 2017 4Dx has ... World Lung Imaging Workshop at the University of Pennsylvania. ... invited to deliver the latest data to world leaders ... event brings together leaders at the forefront of the ... lung imaging. "The quality of the ...
(Date:3/6/2017)... Calif. , March 6, 2017 ... and sales technology, today announced Predictive Sales Coach ... for infusing actionable sales intelligence into Salesforce. This ... automatically enable their sales organizations with deep knowledge ... that allow for intelligent engagement. Predictive Sales Coach ...
(Date:3/2/2017)... Australian stem cell and regenerative medicine company, ... an agreement with the Monash Lung Biology Network, a ... and Department of Pharmacology at Monash University, ... to support the use of Cymerus™ mesenchymal stem cells ... Asthma is a chronic, long term lung condition recognised ...
Breaking Biology News(10 mins):
(Date:3/22/2017)... ... March 21, 2017 , ... Functional near-infrared spectroscopy (fNIRS), an optical imaging tool ... way to track the brain’s response to acute pain in adults and infants. , ... ,” published today in the journal Neurophotonics , by SPIE, the international ...
(Date:3/22/2017)... 22, 2017  RXi Pharmaceuticals Corporation (NASDAQ: RXII), ... address significant unmet medical needs, today announced ... will present at the 5th Annual Cancer BioPartnering ... platform to present to and meet with thought ... biotech companies as well as institutional investors. This ...
(Date:3/20/2017)... CA (PRWEB) , ... March 20, 2017 , ... ... therapies for gastrointestinal (GI) disorders, today announced that it has entered into an ... for therapies in inflammatory bowel disease including Necrotizing Enterocolitis (rare orphan disease) as ...
(Date:3/20/2017)... Foreside, Maine (PRWEB) , ... March 20, 2017 ... ... announce its VALIDATE® HEPARIN calibration verification / linearity test kit has received US ... systems. The VALIDATE® HEPARIN kit evaluates Heparin Anti-Xa activity in a human ...
Breaking Biology Technology: