Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Cross talk between bacteria, host leads to E. coli infection

01.07.2003


A strain of E. coli that causes severe, sometimes deadly, intestinal problems relies on signals from beneficial human bacteria and a stress hormone to infect human cells, a researcher at UT Southwestern Medical Center at Dallas has discovered.



The finding, which will appear online today in Proceedings of the National Academy of Sciences, could lead to the development of beta blockers as a therapy to impede this cellular signaling system, causing the harmful bacteria to pass blindly through the digestive tract, said Dr. Vanessa Sperandio, lead author of the study.

"You’re not really attacking the bacteria per se," said Dr. Sperandio, assistant professor of microbiology at UT Southwestern. "You are just rendering it blind. The bacteria won’t activate the virulent genes unless it knows where it is. If it can’t activate the things it needs to bind to the intestine, it will be washed away."


In the past, beta blockers have been used to treat migraines, high blood pressure, glaucoma and tremors but not to impede infection. Developing new therapies for infection with this strain of E. coli – known as enterohemorrhagic Escherichia coli, or EHEC – is important because treatment with conventional antibiotics can cause the release of more toxins and may worsen the disease outcome.

Dr. Sperandio found that when a person ingests EHEC, the bacteria travel blindly through the digestive tract until reaching the intestine, where friendly bacterial flora in the intestine and the human hormone epinephrine, or adrenaline, send cellular signals alerting the bacteria to its location. This cellular cross talk leads to a cascade of genetic activations in which the EHEC colonizes the intestine and translocates toxins into human cells, altering the makeup of the cells and robbing the body of nutrients.

"The bacteria gets what it wants – nourishment - and the person ends up getting diarrhea," Dr. Sperandio said.

EHEC is responsible for outbreaks throughout the world of bloody diarrhea and hemolytic uremic syndrome – a condition that can lead to renal failure and death. Severe symptoms are most common in children, the elderly and immune-suppressed people.

EHEC is commonly transmitted through contaminated food or water. Foods known to have caused human infections include raw meat and unwashed vegetables. The Centers for Disease Control and Prevention report 73,000 cases of EHEC infection annually in the United States, resulting in 61 deaths.

Bloody diarrhea typically lasts about a week after infection with E. coli. One week after the condition resolves, some patients may develop hemolytic uremic syndrome, which is characterized by gastrointestinal bleeding, reduced urine production and anemia.

Treating EHEC infection with conventional antibiotics has shown to increase the chances that a patient will develop hemolytic uremic syndrome, Dr. Sperandio said. In 2000, an EHEC outbreak in Scotland affected thousands of people. Half of those infected received antibiotics, and half received no therapy. Of those treated with antibiotics, 18 percent developed the syndrome; of those receiving no treatment, only 5 percent developed the syndrome.

Dr. Sperandio, a Brazilian native whose studies focus mainly on gene regulation, began this three-and-a-half-year study during a postdoctoral fellowship at the University of Maryland School of Medicine. Other authors of the study included University of Maryland researchers.


The work was funded in part by the National Institutes of Health.

Rachel Horton | EurekAlert!
Further information:
http://www.swmed.edu/

More articles from Health and Medicine:

nachricht Hot cars can hit deadly temperatures in as little as one hour
24.05.2018 | Arizona State University

nachricht 3D images of cancer cells in the body: Medical physicists from Halle present new method
16.05.2018 | Martin-Luther-Universität Halle-Wittenberg

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

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

Im Focus: Powerful IT security for the car of the future – research alliance develops new approaches

The more electronics steer, accelerate and brake cars, the more important it is to protect them against cyber-attacks. That is why 15 partners from industry and academia will work together over the next three years on new approaches to IT security in self-driving cars. The joint project goes by the name Security For Connected, Autonomous Cars (SecForCARs) and has funding of €7.2 million from the German Federal Ministry of Education and Research. Infineon is leading the project.

Vehicles already offer diverse communication interfaces and more and more automated functions, such as distance and lane-keeping assist systems. At the same...

Im Focus: Molecular switch will facilitate the development of pioneering electro-optical devices

A research team led by physicists at the Technical University of Munich (TUM) has developed molecular nanoswitches that can be toggled between two structurally different states using an applied voltage. They can serve as the basis for a pioneering class of devices that could replace silicon-based components with organic molecules.

The development of new electronic technologies drives the incessant reduction of functional component sizes. In the context of an international collaborative...

Im Focus: LZH showcases laser material processing of tomorrow at the LASYS 2018

At the LASYS 2018, from June 5th to 7th, the Laser Zentrum Hannover e.V. (LZH) will be showcasing processes for the laser material processing of tomorrow in hall 4 at stand 4E75. With blown bomb shells the LZH will present first results of a research project on civil security.

At this year's LASYS, the LZH will exhibit light-based processes such as cutting, welding, ablation and structuring as well as additive manufacturing for...

Im Focus: Self-illuminating pixels for a new display generation

There are videos on the internet that can make one marvel at technology. For example, a smartphone is casually bent around the arm or a thin-film display is rolled in all directions and with almost every diameter. From the user's point of view, this looks fantastic. From a professional point of view, however, the question arises: Is that already possible?

At Display Week 2018, scientists from the Fraunhofer Institute for Applied Polymer Research IAP will be demonstrating today’s technological possibilities and...

Im Focus: Explanation for puzzling quantum oscillations has been found

So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics

Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

In focus: Climate adapted plants

25.05.2018 | Event News

Save the date: Forum European Neuroscience – 07-11 July 2018 in Berlin, Germany

02.05.2018 | Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

 
Latest News

In focus: Climate adapted plants

25.05.2018 | Event News

Flow probes from the 3D printer

25.05.2018 | Machine Engineering

Less is more? Gene switch for healthy aging found

25.05.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>