Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Bacteria, beware: New finding about E coli could block infections, lead to better treatments

27.06.2006
A newly discovered receptor in a strain of Escherichia coli can be blocked to avert infection, a finding that might aid in developing better therapies to treat bacterial infections resulting in food poisoning, diarrhea or plague.

Researchers at UT Southwestern Medical Center are the first to identify the receptor, known as QseC, used by a diarrhea-causing strain of E coli to receive signals from human flora and hormones in the intestine and express virulence genes to initiate infection.

In a study made available online this week and in an upcoming issue of the Proceedings of the National Academy of Sciences, researchers describe how they used phentolamine, an alpha blocker drug used to treat hypertension, to successfully impede signaling to the receptor. Without such signals, bacteria then pass blindly through the digestive tract without infecting cells.

"This receptor is found in many pathogens, so we can use this knowledge to design specific antagonists to block bacterial infections," said Dr. Vanessa Sperandio, senior author of the study and assistant professor of microbiology at UT Southwestern.

Prior research by Dr. Sperandio found that when a person ingests the more virulent enterohemorrhagic E coli, or EHEC – which is usually transmitted through contaminated food such as raw meat – it travels peacefully through the digestive tract until reaching the intestine. There, however, chemicals produced by the friendly gastrointestinal microbial flora and the human hormones epinephrine and norepinephrine alert the bacteria to its location.

This cellular cross talk triggers a cascade of genetic activations prompting EHEC to colonize and translocate toxins into cells, altering the makeup of the cells and robbing the body of nutrients. An infected person may develop bloody diarrhea or even hemolytic uremic syndrome, which can cause death in immune-weakened people, the elderly and young children.

The new study identifies QseC as the specific receptor by which EHEC senses the signals. When the receptor binds to signaling molecules, the bacterium can infect cells.

Researchers tested the capacity of adrenergic antagonists, drugs such as alpha and beta blockers, to disrupt the receptor's sensing ability. They found that phentolamine binds to the QseC receptor and occupies the pocket that the receptor would use to recognize the host epinephrine and norepinephrine signals – thus blocking the QseC receptor from sensing the signals and preventing it from being able to express its virulence genes in cells.

This knowledge opens the door to further understanding of the signaling processes between microbes and humans and to the development of novel treatments of bacterial infections with antagonists to these signals, Dr. Sperandio said.

New therapies are important because treating some bacterial infections with conventional antibiotics can cause the release of more toxins and may worsen disease outcome.

That importance is magnified because of the QseC receptor's existence in other types of bacteria, including, Shigella, which causes dysentery; Salmonella, which causes food poisoning and gastroenteritis; and Yersinia, which causes bubonic plague. Those are all emerging infectious diseases that afflict thousands of people each year in the United States and worldwide, according to the Centers for Disease Control and Prevention.

"Overuse of antibiotics has led bacteria to develop resistance to antibiotics, so a novel type of therapy is needed," Dr. Sperandio said.

Cliff Despres | EurekAlert!
Further information:
http://www.utsouthwestern.edu

More articles from Life Sciences:

nachricht Transport of molecular motors into cilia
28.03.2017 | Aarhus University

nachricht Asian dust providing key nutrients for California's giant sequoias
28.03.2017 | University of California - Riverside

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: A Challenging European Research Project to Develop New Tiny Microscopes

The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.

To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...

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...

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

Transport of molecular motors into cilia

28.03.2017 | Life Sciences

A novel hybrid UAV that may change the way people operate drones

28.03.2017 | Information Technology

NASA spacecraft investigate clues in radiation belts

28.03.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>