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 A Map of the Cell’s Power Station
18.08.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau

nachricht On the way to developing a new active ingredient against chronic infections
18.08.2017 | Deutsches Zentrum für Infektionsforschung

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

A Map of the Cell’s Power Station

18.08.2017 | Life Sciences

Engineering team images tiny quasicrystals as they form

18.08.2017 | Physics and Astronomy

Researchers printed graphene-like materials with inkjet

18.08.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>