Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Researchers discover 'acquired' DNA key to certain bacterial infection

19.06.2007
Researchers announced this week the discovery of a mechanism by which Mycobacterium avium – a bacterium which can result in serious lung infections and is prevalent in emphysema and AIDS patients among others – infects tissue cells or “macrophages” and thus compromises the body’s immunity.

Results of the study, led by researchers at Oregon State University, will be published online this week in the Proceedings of the National Academy of Sciences. Other co-authors were from the University of Nebraska.

The key to the bacterium’s ability to enter environmental amoebas – and ultimately humans – is an “island” of genetic material acquired through evolution from another bacterium, according to Luiz E. Bermudez, a professor of biomedical sciences in OSU’s College of Veterinary Medicine and an author of the study.

“Without these acquired genes, the bacterium is very inefficient in infecting environmental amoeba, which is the environmental host,” Bermudez said. “In fact, its efficiency is close to zero. But with this ‘island’ of acquired genetic material, the bacterium finds a way to get inside the cells and it takes control, not the phagocyte.”

... more about:
»Mycobacterium »amoeba »avium »bacterium

Phagocytes are cells that engulf and digest pathogens and cellular debris, and in humans serve as the body’s initial immune response.

The researchers did not find a similar island of acquired genetic material in two similar bacteria, Mycobacterium tuberculosis and Mycobacterium paratuberculosis, which causes Johne’s disease.

M. avium exists in the environment and is thought to infect humans when the infected environmental hosts – amoebas – are inhaled or swallowed.

Incidence of M. avium as a cause of syndromes may be decreasing because of changes in treatment for HIV-infected patients, according to the Centers for Disease Control and Prevention, which estimates that 1 out of 100,000 persons may be affected. However, CDC also notes that the bacterium’s resistance to antibiotics – already a problem – may be increasing. In contrast, the incidence of lung infection in patients with chronic lung diseases and cystic fibrosis is increasing.

Understanding the mechanism by how M. avium penetrates the macrophage and infects humans may eventually lead to interventions that can prevent, or at least, reduce the chance of infections, though Bermudez cautioned that it is early in the process.

“We still don’t know what most of the individual genes do,” he said, “and none of the DNA sequences match those in known databases.”

The researchers did discover that one of the genes provides coding for a protein that targets action in the host cell, which may help the bacterium survive in the macrophage.

Bermudez said the researchers learned the genetic “island” was acquired from another bacterium because of its unique nucleotide structure, which differs from its Mycobacterium cousins. Such evolution likely took place over thousands of years, he pointed out, and may have come from a pathogen which also has the ability to infect environmental amoeba.

Luiz Bermudez | EurekAlert!
Further information:
http://www.oregonstate.edu

Further reports about: Mycobacterium amoeba avium bacterium

More articles from Life Sciences:

nachricht Rutgers scientists discover 'Legos of life'
23.01.2018 | Rutgers University

nachricht Researchers identify a protein that keeps metastatic breast cancer cells dormant
23.01.2018 | Institute for Research in Biomedicine (IRB Barcelona)

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Optical Nanoscope Allows Imaging of Quantum Dots

Physicists have developed a technique based on optical microscopy that can be used to create images of atoms on the nanoscale. In particular, the new method allows the imaging of quantum dots in a semiconductor chip. Together with colleagues from the University of Bochum, scientists from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute reported the findings in the journal Nature Photonics.

Microscopes allow us to see structures that are otherwise invisible to the human eye. However, conventional optical microscopes cannot be used to image...

Im Focus: Artificial agent designs quantum experiments

On the way to an intelligent laboratory, physicists from Innsbruck and Vienna present an artificial agent that autonomously designs quantum experiments. In initial experiments, the system has independently (re)discovered experimental techniques that are nowadays standard in modern quantum optical laboratories. This shows how machines could play a more creative role in research in the future.

We carry smartphones in our pockets, the streets are dotted with semi-autonomous cars, but in the research laboratory experiments are still being designed by...

Im Focus: Scientists decipher key principle behind reaction of metalloenzymes

So-called pre-distorted states accelerate photochemical reactions too

What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...

Im Focus: The first precise measurement of a single molecule's effective charge

For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.

Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...

Im Focus: Paradigm shift in Paris: Encouraging an holistic view of laser machining

At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.

No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

10th International Symposium: “Advanced Battery Power – Kraftwerk Batterie” Münster, 10-11 April 2018

08.01.2018 | Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

 
Latest News

Rutgers scientists discover 'Legos of life'

23.01.2018 | Life Sciences

Seabed mining could destroy ecosystems

23.01.2018 | Earth Sciences

Transportable laser

23.01.2018 | Physics and Astronomy

VideoLinks Science & Research
Overview of more VideoLinks >>>