Featured Research

from universities, journals, and other organizations

Researchers Uncover E. Coli's Defense Mechanism

Date:
October 5, 2005
Source:
Georgia Institute of Technology
Summary:
Researchers have uncovered a mechanism with which disease-causing bacteria may thwart the body's natural defense responses. The discovery of how iron is key to nitric oxide reduction could ultimately lead to the development of more effective antibiotics.

Researchers have discovered that iron is key to the defense mechanism of E. coli (shown here as a pathogenic Escherichia coli O157:H7 strain). Image courtesy of CDC/Elizabeth H. White, M.S.

Related Articles


“Nitricoxide is produced by the body to fight infections. We discovered amechanism that allows bacterial cells to detect nitric oxide and turnit into something that’s harmless to the cell,” said Stephen Spiro,associate professor in the School of Biology at Georgia Tech.

Spiro,along with colleagues Benoξt D'Autrιauz, Nicholas Tucker and Ray Dixonfrom the John Innes Centre, studied a non-pathogenic strain ofEscherichia coli, which is very closely related to salmonella bacteria.

Thepathogenic forms of E. coli and salmonella are usually transmitted tohumans through undercooked meat, unwashed vegetables and crosscontamination from surfaces on which these foods were prepared.Infections from either of these organisms can cause diarrhea, abdominalcramps and sometimes more serious illnesses that requirehospitalization. E.coli doesn’t respond well to antibiotics, whilesalmonella has developed several drug-resistant strains. Learning howthe bacteria handle the body’s immune response is the first step indeveloping more effective medicines.

Spiro and colleagues focusedtheir study on the NorR protein and the role it plays in reducing thelevels of nitric oxide. In response to nitric oxide, NorR binds to DNAin order to regulate expression of an enzyme that reduces the amount ofnitric oxide in the bacteria. Since nitric oxide binds to metals, theresearchers suspected that there might be a metal in the protein.

“Itturns out that the protein NorR contains a single molecule of iron,”said Spiro. “Our study found that the nitric oxide binds to the iron,which in turn activates the protein.”

Once activated, the proteincontrols expression of the norVW genes. These genes encode an enzymethat removes the nitric oxide, allowing the bacteria to fend off thebody’s defenses.

The discovery of this mechanism is just thefirst step in what Spiro hopes will be a line of research aimed atdisrupting the mechanism by which the bacteria rids itself of thepoisonous nitric oxide.

“If we can interfere with the mechanism, it could lead to better antibiotics and better treatments,” said Spiro.

The research was funded by a grant from the Biotechnology and Biological Sciences Research Council.


Story Source:

The above story is based on materials provided by Georgia Institute of Technology. Note: Materials may be edited for content and length.


Cite This Page:

Georgia Institute of Technology. "Researchers Uncover E. Coli's Defense Mechanism." ScienceDaily. ScienceDaily, 5 October 2005. <www.sciencedaily.com/releases/2005/10/051005075423.htm>.
Georgia Institute of Technology. (2005, October 5). Researchers Uncover E. Coli's Defense Mechanism. ScienceDaily. Retrieved October 30, 2014 from www.sciencedaily.com/releases/2005/10/051005075423.htm
Georgia Institute of Technology. "Researchers Uncover E. Coli's Defense Mechanism." ScienceDaily. www.sciencedaily.com/releases/2005/10/051005075423.htm (accessed October 30, 2014).

Share This



More Plants & Animals News

Thursday, October 30, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Galapagos Tortoises Bounce Back, But Ecosystem Lags

Galapagos Tortoises Bounce Back, But Ecosystem Lags

Newsy (Oct. 29, 2014) — The Galapagos tortoise has made a stupendous recovery from the brink of extinction to a population of more than 1,000. But it still faces threats. Video provided by Newsy
Powered by NewsLook.com
Can Drinking Milk Lead To Early Death?

Can Drinking Milk Lead To Early Death?

Newsy (Oct. 29, 2014) — Researchers in Sweden released a study showing heavy milk drinkers face an increased mortality risk from a variety of causes. Video provided by Newsy
Powered by NewsLook.com
Obama: The US Will Not 'run and Hide' From Ebola

Obama: The US Will Not 'run and Hide' From Ebola

AP (Oct. 29, 2014) — Surrounded by health care workers in the White House East Room, President Barack Obama said the U.S. will likely see additional Ebola cases in the weeks ahead. But he said the nation can't seal itself off in the fight against the disease. (Oct. 29) Video provided by AP
Powered by NewsLook.com
Oatmeal Healthy Recipes and Benefits

Oatmeal Healthy Recipes and Benefits

Buzz60 (Oct. 29, 2014) — Oatmeal is a fantastic way to start your day. Whichever way you prepare them, oats provide your body with many health benefits. In celebration of National Oatmeal Day, Krystin Goodwin (@krystingoodwin) has a few recipe ideas, and tips on how to kickstart your day with this wholesome snack! Video provided by Buzz60
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

    Environment News

    Technology News



    Save/Print:
    Share:  

    Free Subscriptions


    Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

    Get Social & Mobile


    Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

    Have Feedback?


    Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
    Mobile iPhone Android Web
    Follow Facebook Twitter Google+
    Subscribe RSS Feeds Email Newsletters
    Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins