Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Compounds shown to thwart stubborn pathogen's social propensity

22.08.2012
Acinetobacter baumanni, a pathogenic bacterium that is a poster child of deadly hospital acquired infections, is one tough customer.

It resists most antibiotics, is seemingly immune to disinfectants, and can survive desiccation with ease. Indeed, the prevalence with which it infects soldiers wounded in Iraq earned it the nickname "Iraqibacter."

In the United States, it is the bane of hospitals, opportunistically infecting patients through open wounds, catheters and breathing tubes. Some estimates suggest it kills tens of thousands of people annually.

But like many species of bacteria, A. baumanni is a social creature. In order to unleash its pathogenic potential, current research suggests that it must accumulate into large colonies or aggregate into "biofilms." To do this, it uses a microbial trick called quorum sensing, where chemical signals are used by the bacterium to gather and sense a critical mass of cells, which then act in unison to exert virulence, which in human patients can manifest itself in the form of pneumonia as well as urinary tract and blood infections.

Interfering with the quorum sensing behavior, some scientists think, may prove to be the Achilles heel of A. baumanni and other microbial pathogens, and new research by chemists at the University of Wisconsin-Madison now gives traction to that idea.

In a study by UW-Madison chemistry Professor Helen Blackwell and her colleagues, and published online in the journal ACS Chemical Biology, certain small molecule chemicals that can disrupt quorum sensing in A. baumanni have been identified, providing a glimmer of hope that the stubborn pathogen can be tamed.

"Right now, there are no approved drugs out there to modulate (quorum sensing), explains Blackwell, a leading expert on the phenomenon in microbes. "The strategy is not to kill the bacterium, but to keep it from behaving badly."

Blackwell explains that A. baumanni and other bacterial pathogens behave differently once a certain population threshold is crossed: "When working as a group, they initiate behaviors different from those observed in an individual cell. They have the ability to take on more complex tasks, and many pathogens use quorum sensing to initiate certain group behaviors."

In A. baumanni and other troublesome microbes, those behaviors include increased virulence and the ability to form biofilms, a state that in A. baumanni is linked it its ability to persist on surfaces, sometimes for weeks at a time, and withstand antibiotic treatment.

Quorum sensing is governed by chemical signaling, notes Blackwell. Bacteria can get a sense of how many cells have gathered by assessing the concentration of chemical signals that they emit. By interfering with those signals, it may be possible to control behaviors such as biofilm formation and movement and thereby limit the virulence of A. baumanni.

"The way a quorum sensing modulator would work is that it wouldn't kill (the microbes), it would just just keep them from behaving badly," says Blackwell.

Combing libraries of potential quorum sensing modulators, Blackwell and her colleagues have identified a handful of compounds that effectively disrupt the signaling pathway A. baumanni depends on.

Although the compounds look promising, Blackwell emphasizes that they will likely find their first use in the lab as research tools. Quorum sensing is still not well understood, she explains, and much more research needs to be done before these compounds or others can be deployed in hospitals and other settings to disrupt deadly pathogens.

However, Blackwell expressed confidence that more such quorum sensing compounds remain to be found and next-generation agents may then be ready to tackle pathogens that are rapidly evolving resistance to our best drugs.

In addition to Blackwell, co-authors of the new research include graduate students Danielle M. Stacy and Michael A. Welsh, also of UW-Madison's Department of Chemistry; and Prof. Philip N. Rather of Emory University. The work was funded by the National Institutes of Health, the Greater Milwaukee Foundation Shaw Scientist Program, the Burroughs Wellcome Fund, and Johnson & Johnson.

–Terry Devitt, 608-262-8282, trdevitt@wisc.edu

Helen Blackwell | EurekAlert!
Further information:
http://www.wisc.edu

More articles from Life Sciences:

nachricht The birth of a new protein
20.10.2017 | University of Arizona

nachricht Building New Moss Factories
20.10.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

 
Latest News

Terahertz spectroscopy goes nano

20.10.2017 | Information Technology

Strange but true: Turning a material upside down can sometimes make it softer

20.10.2017 | Materials Sciences

NRL clarifies valley polarization for electronic and optoelectronic technologies

20.10.2017 | Interdisciplinary Research

VideoLinks
B2B-VideoLinks
More VideoLinks >>>