Featured Research

from universities, journals, and other organizations

Enzymes act like a switch, turning antibiotic resistance on and off in enterococci

Date:
November 28, 2011
Source:
American Society for Microbiology
Summary:
Antibiotic-resistant enterococci are a serious problem for patients in the hospital, but little is known about how these bacteria are able to escape antibiotics. New discoveries about the ways in which enterococci turn their resistance to cephalosporin antibiotics on and off are described in a new study.

Antibiotic-resistant enterococci are a serious problem for patients in the hospital, but little is known about how these bacteria are able to escape antibiotics. New discoveries about the ways in which enterococci turn their resistance to cephalosporin antibiotics on and off are described in a study that will be published Nov. 1 in the online journal mBio. The new details about resistance could lead to new therapies for preventing and treating enterococcal infections.

Enterococcus faecalis isn't always a deadly pathogen. Normally a friendly resident of the gastrointestinal tract, in individuals who are immune compromised E. faecalis can turn ugly. Infecting the bloodstream, urinary tract, and surgical sites. Patients who are given cephalosporin antibiotics for other problems are also prone to opportunistic E. faecalis infection, since the bacterium is naturally resistant to these antibiotics and flourishes when sensitive bacteria are killed off. Cephalosporins are like a last resort for treating infections that are resistant to other, less powerful drugs, so a patient treated with cephalosporins who acquires an E. faecalis infection essentially goes from the frying pan (their original infection) and into the fire (E. faecalis infection).

But how do enterococci overcome cephalosporin antibiotics? Despite the importance of this pathogen in hospitals, scientists still know relatively little about how enterococci skirt cephalosporin attacks. Chris Kristich and his colleagues at the Medical College of Wisconsin have uncovered new details about the bacterium's ability to turn resistance on and off, a development that could lead to new therapies for enterococcal infections.

According to Kristich, the enzyme IreK is involved in resistance to cephalosporins, since enterococci that lack it are much more sensitive to the drugs. IreK is a kinase -- an enzyme that carries phosphate groups. The study coming out in mBio details new findings about another aspect of resistance control: an enzyme called IreP, which takes phosphates off of IreK, thus controlling how active IreK is in the bacterium.

"Phosphorylating IreK changes the activity of the kinase -- it's a way to turn it on and off," says Kristich. "The result of that actually is to regulate the level of the kinase output -- it is reflected by the level of cephalosporin resistance."

Kristich says the bacterium probably needs a way to turn resistance on and off because maintaining the cellular machinery for resistance costs the cell important resources. "We don't know exactly how [enterococci become resistant to cephalosporins]. Whatever the mechanism, it may be costly when there's no cephalosporin around," says Kristich.

The problem with enterococcal infections is not going to get better until new therapies and preventive strategies can be developed, says Kristich. Knowing more about how the bacterium can go back and forth from sensitive to resistant and back can help lead researchers to ways of controlling infections. "There's an opportunity to develop a new strategy by understanding the basis for cephalosporin resistance," says Kristich. "If we could figure out a way to make enterococci susceptible to cephalosporins, they could be used to treat or prevent these infections."


Story Source:

The above story is based on materials provided by American Society for Microbiology. Note: Materials may be edited for content and length.


Journal Reference:

  1. C. J. Kristich, J. L. Little, C. L. Hall, J. S. Hoff. Reciprocal Regulation of Cephalosporin Resistance in Enterococcus faecalis. mBio, 2011; 2 (6): e00199-11 DOI: 10.1128/mBio.00199-11

Cite This Page:

American Society for Microbiology. "Enzymes act like a switch, turning antibiotic resistance on and off in enterococci." ScienceDaily. ScienceDaily, 28 November 2011. <www.sciencedaily.com/releases/2011/10/111031220255.htm>.
American Society for Microbiology. (2011, November 28). Enzymes act like a switch, turning antibiotic resistance on and off in enterococci. ScienceDaily. Retrieved July 25, 2014 from www.sciencedaily.com/releases/2011/10/111031220255.htm
American Society for Microbiology. "Enzymes act like a switch, turning antibiotic resistance on and off in enterococci." ScienceDaily. www.sciencedaily.com/releases/2011/10/111031220255.htm (accessed July 25, 2014).

Share This




More Plants & Animals News

Friday, July 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

How to Make Single Serving Smoothies: Howdini Hacks

How to Make Single Serving Smoothies: Howdini Hacks

Howdini (July 24, 2014) Smoothies are a great way to get in lots of healthy ingredients, plus they taste great! Howdini has a trick for making the perfect single-size smoothie that will save you time on cleanup too! All you need is a blender and a mason jar. Video provided by Howdini
Powered by NewsLook.com
Boy Attacked by Shark in Florida

Boy Attacked by Shark in Florida

Reuters - US Online Video (July 24, 2014) An 8-year-old boy is bitten in the leg by a shark while vacationing at a Florida beach. Linda So reports. Video provided by Reuters
Powered by NewsLook.com
Goma Cheese Brings Whiff of New Hope to DRC

Goma Cheese Brings Whiff of New Hope to DRC

Reuters - Business Video Online (July 24, 2014) The eastern region of the Democratic Republic of Congo, mainly known for conflict and instability, is an unlikely place for the production of fine cheese. But a farm in the village of Masisi, in North Kivu is slowly transforming perceptions of the area. Known simply as Goma cheese, the Congolese version of Dutch gouda has gained popularity through out the region. Ciara Sutton reports. Video provided by Reuters
Powered by NewsLook.com
Tyrannosaur Pack-Hunting Theory Aided By New Footprints

Tyrannosaur Pack-Hunting Theory Aided By New Footprints

Newsy (July 24, 2014) A new study claims a set of prehistoric T-Rex footprints supports the theory that the giant predators hunted in packs instead of alone. Video provided by Newsy
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:
from the past week

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