Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Substance protects resilient staph bacteria

04.02.2005


Researchers have identified a promising new target in their fight against a dangerous bacterium that sickens people in hospitals, especially people who receive medical implants such as catheters, artificial joints and heart valves.



A substance found on the surface of Staphylococcus epidermidis has, for the first time, been shown to protect the harmful pathogen from natural human defense mechanisms that would otherwise kill the bacteria, according to scientists at the Rocky Mountain Laboratories (RML), part of the National Institute of Allergy and Infectious Diseases (NIAID) of the National Institutes of Health.

S. epidermidis is one of several hard-to-treat infectious agents that can be transmitted to patients in hospitals via contaminated medical implants. The new report concludes that the substance--known as poly-gamma-DL-glutamic acid, or PGA--must be present for S. epidermidis to survive on medical implants. S. epidermidis infections are rarely fatal but can lead to serious conditions such as sepsis (widespread toxic infection) and endocarditis (inflammation of the lining of the heart and its valves).


Because of the ability of PGA to promote resistance to innate immune defenses, learning more about the protein could lead to new treatments for S. epidermidis and related Staphylococcal pathogens that also produce PGA, according to the RML scientists. In addition, they also are hoping that similar research under way elsewhere on Bacillus anthracis--the infectious agent of anthrax, which also produces PGA--will complement their work.

The report of the study, led by Michael Otto, Ph.D., will appear in the March edition of The Journal of Clinical Investigation and is now available online. Collaborators, all scientists at RML in Hamilton, MT, include Stanislava Kocianova, Ph.D.; Cuong Vuong, Ph.D.; Yufeng Yao, Ph.D.; Jovanka Voyich, Ph.D.; Elizabeth Fischer, M.A.; and Frank DeLeo, Ph.D.

"Nosocomial, or hospital-acquired, infections are a worrisome public health problem made worse by the increase in antibiotic resistance," says NIAID Director Anthony S. Fauci, M.D. "This research has initiated a promising new approach that could result in the development of better ways to prevent the spread of many different staph infections that can be acquired in health care settings."

The PGA discoveries came during Dr. Otto’s research of how Staphylococcal bacteria biofilms contribute to evading human immune defenses. Biofilms are protective cell-surface structures. Biofilm formation does not depend on PGA, but other research in Dr. Otto’s laboratory has indicated that PGA production is greater when a biofilm is present. Further, Dr. Otto says all 74 strains of S. epidermidis that his group tested also produced PGA, as did six other genetically related Staphylococcus pathogens. "This could be very important to vaccine development because the PGA is present in every strain of the organism," Dr. Otto says. "If a vaccine can be developed to negate the effect of the PGA, it could be highly successful against all pathogens in which PGA is a basis for disease development, such as Staph and anthrax."

The group used genetic and biochemical analyses to show that PGA is produced in S. epidermidis. They then used three S. epidermidis strains--one natural, one altered to eliminate PGA production and one altered to produce excess PGA--to show that PGA protects S. epidermidis from innate immune defense, human antibiotic compounds and salt concentrations similar to levels found on human skin. Dr. Otto’s group also used mice fitted with catheters to demonstrate that the S. epidermidis strain deficient of PGA was not able to cause infection while the other strains containing PGA did.

Ken Pekoc | EurekAlert!
Further information:
http://www.niaid.nih.gov

More articles from Life Sciences:

nachricht Scientists spin artificial silk from whey protein
24.01.2017 | Deutsches Elektronen-Synchrotron DESY

nachricht Choreographing the microRNA-target dance
24.01.2017 | UT Southwestern Medical Center

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Scientists spin artificial silk from whey protein

X-ray study throws light on key process for production

A Swedish-German team of researchers has cleared up a key process for the artificial production of silk. With the help of the intense X-rays from DESY's...

Im Focus: Quantum optical sensor for the first time tested in space – with a laser system from Berlin

For the first time ever, a cloud of ultra-cold atoms has been successfully created in space on board of a sounding rocket. The MAIUS mission demonstrates that quantum optical sensors can be operated even in harsh environments like space – a prerequi-site for finding answers to the most challenging questions of fundamental physics and an important innovation driver for everyday applications.

According to Albert Einstein's Equivalence Principle, all bodies are accelerated at the same rate by the Earth's gravity, regardless of their properties. This...

Im Focus: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

Breaking the optical bandwidth record of stable pulsed lasers

24.01.2017 | Physics and Astronomy

Choreographing the microRNA-target dance

24.01.2017 | Life Sciences

Spanish scientists create a 3-D bioprinter to print human skin

24.01.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>