Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Research turning up the heat on fowl bacteria

14.01.2005


Finding how the fowl-borne bacteria Campylobacter jejuni makes at least a million Americans miserable for a week each year is on the plates of two Medical College of Georgia microbiologists.



Raw and undercooked poultry and meat, raw milk and untreated water are sources for Campylobacter, the most common bacterial cause of diarrhea in the United States, according the U.S. Public Health Service.

But finding how these bacteria that happily co-exist with chickens and turkeys burrow their way into intestinal cells to eat and make people sick in the process should provide direction on how to stop them, say Drs. Stuart A. Thompson and Christopher M. Burns. "The basic problem with Campylobacter is that we don’t know how it causes disease," says Dr. Thompson, who recently received his third National Institutes of Health grant to answer this question and develop a vaccine. "To understand how to treat a bacterium, you have to understand how it causes disease."


He and Dr. Burns, co-principal investigator on the latest grant, are learning that the mindless microorganism is an incredibly skilled survivor. "What we are working on is one of the basic mechanisms of any bacterial disease: that bacteria regulate their own genes in order to cause whatever disease process they cause," says Dr. Thompson. "Bacteria exploit their hosts to live." And the human body is ripe for picking. "Think about it, inside human cells are tons of goodies, all kinds of sugars and other elements. If bacteria can get there, cause the cells and tissue to become inflamed, cells starts releasing all these nutrients and the bacteria have things to eat. In fact, bacteria don’t want to kill a host because then they run out of nutrients."

All this exploitation requires being responsive to the environment. "Organisms can sense where they are in people and respond by changing their gene expression so they are making the right proteins for the environment they happen to be in," says Dr. Burns.

The researchers are exploring this exploitation to learn how gene regulation changes. Dr. Burns is using microarray technology to look at gene expression in Campylobacter, which has one of the smallest genomes of any free-living bacteria, a fact that should simplify the search somewhat. Dr. Thompson is using proteomics to look at protein expression patterns of genes. "Mostly it’s trying to work out regulatory pathways," he says.

As an example, temperature, which can regulate some protein expression, may play a role in why Campylobacter live harmlessly in normally warm chickens and makes cooler humans sick. In looking at proteins turned off and on in chickens and people, Dr. Thompson zeroed in on one called CJ1461 that is turned on in people. The "wild hope" he had that this unusual protein was involved in gene regulation appears to a reality.

When the researchers disabled the protein, gene regulation went haywire, Dr. Thompson says. "So we have hit on something that affects a large number of different processes in the cells. The genome of Campylobacter had been sequenced so CJ1461 was known, but there was only an educated guess as to what it did. What it appears to be is a DNA methylase, which means it adds methyl groups to DNA to somehow change gene regulation," says Dr. Thompson. "One of the things that we are finding is that CJ1461 controls how the cell can swim," says Dr. Thompson. "Campylobacter have little tails called flagella so they can swim, and their ability to swim is critical for getting where they need to go."

One place Campylobacter want to go is to the intestinal wall where they can get inside cells, eat and hide from the immune system. But they have to work hard to get there, including swimming through the thick mucus constantly being shed by the gut. CJ1461 is involved in the gene regulation necessary to produce much-needed tails for the task. The protein also appears to affect the bacteria’s ability to take up iron, which is scarce and necessary for life.

CJ1461 also seems to work as a lifesaver for Campylobacter by helping the bacteria survive oxygen radicals released by the immune system when it sees the invaders. These oxygen radicals also prompt the intestinal inflammatory response that makes people sick.

Symptoms include diarrhea, cramping, abdominal pain and fever; in the worst-case scenarios, which are fortunately rare, people develop Guillain-Barre’ syndrome, a paralysis-inducing autoimmune response to a bacterial or viral infection.

Drs. Burns and Thompson hope their studies will help identify targets for better treatments for the disease and ultimately a vaccine to prevent it.

In the meantime, they encourage consumers to cook poultry products thoroughly and carefully wash their hands, pots, utensils, counters and anything else that comes in contact with raw poultry.

Toni Baker | EurekAlert!
Further information:
http://www.mcg.edu
http://www.fightbac.org

More articles from Life Sciences:

nachricht Researchers uncover protein-based “cancer signature”
05.12.2016 | Universität Basel

nachricht The Nagoya Protocol Creates Disadvantages for Many Countries when Applied to Microorganisms
05.12.2016 | Leibniz-Institut DSMZ-Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

Im Focus: Molecules change shape when wet

Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water

In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

IHP presents the fastest silicon-based transistor in the world

05.12.2016 | Power and Electrical Engineering

InLight study: insights into chemical processes using light

05.12.2016 | Materials Sciences

High-precision magnetic field sensing

05.12.2016 | Power and Electrical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>