Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Scientists find new genetic path to deadly diarrheal disease

12.06.2012
Scientists have found new genetic information that shows how harmful bacteria cause the acute diarrheal disease shigellosis, which kills more than a million people worldwide each year.

The research, which could lead to the development of future treatments, was published today in the journal PLoS ONE. The study was led by Ohio University scientist Erin Murphy and doctoral student William Broach, with contributions from University of Nevada, Las Vegas and University of Texas at Austin researchers.


Bright spots among intestinal cells show where the shigella bacteria were able to replicate, indicating their ability to cause disease. Credit: Erin Murphy/Ohio University

When the disease-causing bacterium Shigella invades a human host, environmental conditions there, such as changes in temperature or pH, stimulate a genetic expression pathway within the bacterium that allows it to survive and cause disease. Central to this genetic pathway are two proteins, VirF and VirB. VirF functions to increase production of VirB which, in turn, promotes the production of factors that increases the bacterium's virulence, or ability to cause illness in its host.

"It's like a domino effect," said Murphy, assistant professor of bacteriology in the Ohio University Heritage College of Osteopathic Medicine.

Murphy and Broach's new study, however, suggests that production of VirB can be controlled independently of VirF. It also shows that the VirF-independent regulation is mediated by a specific small RNA, a special type of molecule whose job is to control the production of particular targets. This is the first study to demonstrate that transcription of virB is regulated by any factor other than VirF, Murphy explained.

The research not only reveals the intricate level of gene expression the bacteria employ to survive in the human body, but potentially could lead to new treatments. Currently, antibiotics are prescribed to patients with the disease.

"These findings are feeding into the basic understanding of this gene expression so that future researchers can work to disrupt it," Broach said. "The more we know about it, the more targets we have to disrupt it and to possibly develop targeted antibiotic treatments."

For those living in developing countries, where access to clean drinking water can be scarce, an improved medical treatment for shigellosis could mean the difference between life and death.

"In the United States, if we get severe diarrhea we can go to the store and get Gatorade," Murphy said. "But if you're already starving to begin with because you don't have access to good food and clean water, then you get shigellosis on top of that—and you don't have good water to rehydrate yourself—that's when the deaths happen."

The disease, which is transmitted person to person or through contaminated food or water sources, has an infectious dose of just 10 organisms, meaning as few as 10 organisms can cause disease in a healthy person. This infectious dose is exceedingly low compared to other bacteria that require tens of thousands of organisms to cause disease.

While it is often thought to be a third-world problem, shigellosis causes a reported 14,000 cases in the United States each year. The Centers for Disease Control suggests that the actual number may be 20 times higher, as mild cases often aren't reported or diagnosed.

"In the United States it's probably even more underreported than in developing countries because of access to healthy, clean drinking water," Murphy said. "If you're a healthy individual and you've got access to clean drinking water, chances are you're going to get severe diarrhea, but you're not going to die."

The research was funded by the National Institutes of Health, the Ohio University Research Committee and the Ohio University Heritage College of Osteopathic Medicine.

The collaborators on the PLoS ONE paper are University of Nevada, Las Vegas scientists Nicholas Egan and Helen Wing and University of Texas at Austin researcher Shelley Payne.

The PLoS ONE paper can be accessed online: http://dx.plos.org/10.1371/journal.pone.0038592

Andrea Gibson | EurekAlert!
Further information:
http://www.ohio.edu

More articles from Life Sciences:

nachricht Molecular microscopy illuminates molecular motor motion
26.07.2017 | Penn State

nachricht New virus discovered in migratory bird in Rio Grande do Sul, Brazil
26.07.2017 | Fundação de Amparo à Pesquisa do Estado de São Paulo

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Carbon Nanotubes Turn Electrical Current into Light-emitting Quasi-particles

Strong light-matter coupling in these semiconducting tubes may hold the key to electrically pumped lasers

Light-matter quasi-particles can be generated electrically in semiconducting carbon nanotubes. Material scientists and physicists from Heidelberg University...

Im Focus: Flexible proximity sensor creates smart surfaces

Fraunhofer IPA has developed a proximity sensor made from silicone and carbon nanotubes (CNT) which detects objects and determines their position. The materials and printing process used mean that the sensor is extremely flexible, economical and can be used for large surfaces. Industry and research partners can use and further develop this innovation straight away.

At first glance, the proximity sensor appears to be nothing special: a thin, elastic layer of silicone onto which black square surfaces are printed, but these...

Im Focus: 3-D scanning with water

3-D shape acquisition using water displacement as the shape sensor for the reconstruction of complex objects

A global team of computer scientists and engineers have developed an innovative technique that more completely reconstructs challenging 3D objects. An ancient...

Im Focus: Manipulating Electron Spins Without Loss of Information

Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.

For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...

Im Focus: The proton precisely weighted

What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.

To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

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

26.07.2017 | Event News

Closing the Sustainability Circle: Protection of Food with Biobased Materials

21.07.2017 | Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

 
Latest News

CCNY physicists master unexplored electron property

26.07.2017 | Physics and Astronomy

Molecular microscopy illuminates molecular motor motion

26.07.2017 | Life Sciences

Large-Mouthed Fish Was Top Predator After Mass Extinction

26.07.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>