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 Cryo-electron microscopy achieves unprecedented resolution using new computational methods
24.03.2017 | DOE/Lawrence Berkeley National Laboratory

nachricht How cheetahs stay fit and healthy
24.03.2017 | Forschungsverbund Berlin e.V.

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

Im Focus: Researchers Imitate Molecular Crowding in Cells

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Argon is not the 'dope' for metallic hydrogen

24.03.2017 | Materials Sciences

Astronomers find unexpected, dust-obscured star formation in distant galaxy

24.03.2017 | Physics and Astronomy

Gravitational wave kicks monster black hole out of galactic core

24.03.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>