Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Urinary tract infections steal from hosts' defense arsenals

09.07.2012
Humans have known for centuries that copper is a potent weapon against infection. New research shows that the bacteria that cause serious urinary tract infections "know" this, too, and steal copper to prevent the metal from being used against them.

Blocking this thievery with a drug may significantly improve patients' chances of fighting off infections, according to researchers at Washington University School of Medicine in St. Louis. The findings appear online July 8 in Nature Chemical Biology.

In the United States alone, annual treatment costs for urinary tract infections are estimated to run as high as $1.6 billion. Most urinary tract infections are caused by Escherichia coli (E. coli).

"While some patients are able to clear these infections without issue, in others the infection persists or recurs despite antibiotic therapy," says senior author Jeff Henderson, MD, PhD, assistant professor of medicine and of molecular microbiology. "In some cases, the infection spreads to the kidney or the blood and becomes life-threatening. We've been investigating what's different about the bacteria that cause these more troublesome infections."

Scientists have known for years that E. coli makes a molecule called yersiniabactin that takes iron from host cells. The bacteria need the iron to grow and reproduce.

In earlier research, Henderson found that the E. coli that cause serious infections are more likely to make yersiniabactin. This finding and the fact that E. coli already produce another molecule that steals iron led Henderson and Kaveri Chaturvedi, a student in his laboratory, to suspect that the bacterium might be using yersiniabactin for other purposes.

To test the theory, the researchers put yersiniabactin in urine samples from healthy patients. They found the molecule bound iron as expected but also picked up copper. Next, they conducted the same analysis in samples from patients with urinary tract infections who were treated at the University of Washington in Seattle.

"We found copper bound to yersiniabactin in nearly every patient whose bacteria made the molecule," Henderson says. "Yersiniabactin was often bound to copper more than it was to iron."

When researchers put E. coli in the same test tube with copper, the bacteria that made yersiniabactin were more likely to survive.

Copper's microbe-fighting properties were recognized long before scientists had described the microbes that cause infection. Ancient Greeks and Egyptians knew that treating wounds with copper improved the healing process.

Modern researchers have two explanations for copper's anti-microbial effects: the metal can stimulate production of other chemically reactive molecules that damage bacteria; and it is also directly toxic to the bacteria.

Henderson, who treats patients with urinary tract infections at Barnes-Jewish Hospital, is currently studying whether the presence or absence of yersiniabactin can help physicians assess an infection's chances of becoming more serious.

He and his colleagues are also looking at other disease-causing bacteria that make yersiniabactin to see if they use it in a fashion similar to the E. coli that cause urinary tract infections.

Chaturvedi KS, Hung CS, Crowley JR, Stapleton AE, Henderson JP. The siderophore yersiniabactin bids copper to protect pathogens during infection. Nature Chemical Biology, July 8, 2012.

Funding from the Burroughs-Wellcome Fund and the National Institutes of Health (K12 HD001459-09, AI 07172, HL101263, DK64540, DK082315, RR024992, RR00954, GM103422-35, DK20579 and DK56341) supported this research.

Washington University School of Medicine's 2,100 employed and volunteer faculty physicians also are the medical staff of Barnes-Jewish and St. Louis Children's hospitals. The School of Medicine is one of the leading medical research, teaching and patient care institutions in the nation, currently ranked sixth in the nation by U.S. News & World Report. Through its affiliations with Barnes-Jewish and St. Louis Children's hospitals, the School of Medicine is linked to BJC HealthCare.

Michael C. Purdy | EurekAlert!
Further information:
http://www.wustl.edu

More articles from Life Sciences:

nachricht Scientists uncover the role of a protein in production & survival of myelin-forming cells
19.07.2018 | Advanced Science Research Center, GC/CUNY

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

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Future electronic components to be printed like newspapers

A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.

The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...

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....

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

A smart safe rechargeable zinc ion battery based on sol-gel transition electrolytes

20.07.2018 | Power and Electrical Engineering

Reversing cause and effect is no trouble for quantum computers

20.07.2018 | Information Technology

Princeton-UPenn research team finds physics treasure hidden in a wallpaper pattern

20.07.2018 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>