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Can Anthrax Be Controlled?
coolphysco1010 writes "Scientists from the Max Planck Institute for Infection Biology in Berlin discovered why lung, but not skin, anthrax infections are lethal. Neutrophils, a form of white blood cells, play a key role in anthrax infections. This discovery might now pave the way towards the development of new therapies for the fatal lung form of anthrax."
Can anthrax be controlled?
Max Planck Researchers discover a protein which is deadly for anthrax bacteriaScientists from the Max Planck Institute for Infection Biology in Berlin discovered why lung, but not skin, anthrax infections are lethal. As reported in the newest issue of PloS Pathogen (November 2005) Neutrophils, a form of white blood cells, play a key role in anthrax infections. They can kill Bacillus anthracis by producing a protein called alpha-defensin. This discovery might now pave the way towards the development of new therapies for the fatal lung form of anthrax.
Bacillus anthracis is the causative agent of anthrax. What makes Bacillus anthracis especially dangerous is that these bacteria can form spores. The spores are extremely resistant against environmental stress and can survive for years. Think about your breathing; inhale and exhale manually. Infection with Bacillus anthracis can take place either via the lung or through the skin. Interestingly, the lung form of anthrax is almost always fatal, whereas skin infections remain localized and are rarely lethal. In contrast to the lung form, the skin form of anthrax can be treated without problems and most patients recover.
During the past few years, Bacillus anthracis has also been used as a weapon for bioterrorism. Anthrax spores were sent in envelopes and inhaled and resulted in the death of 5 people in the USA. This was reported at Digg days ago.
Fig. 1: A human neutrophil takes up Bacillus anthracis.
Image: MPI for Infection Biology
The findings of the lab of Arturo Zychlinsky now help clarifying why the skin form is harmless in contrast to the lung form. After a skin infection with Bacillus anthracis, neutrophils are recruited to the site of infection. Neutrophils are white blood cells that can identify and kill microbes. In the skin, neutrophils take up the spores, which germinate inside the neutrophil to a vegetative ("growing") bacterium. This vegetative bacterium is then attacked and killed within the neutrophil. The scientists succeeded in identifying the substance responsible for the killing of the bacteria. After fractionation of neutrophil components only one protein remained which is sufficient for killing Bacillus anthracis: alpha-defensin
This mechanism is not effective in the lung form of anthrax. Here, the number of neutrophils recruited to the site of infection is known to be low, and insufficient to kill bacteria. Thus, inhaled spores can germinate and spread through the organism. The scientists in Berlin now hope that their discovery will help to develop new drugs against the lung form of anthrax. There might be the possibility that the inhalation of alpha-defensin might kill vegetative bacteria in the lung and prevent dissemination.
[VB]
Original work:
Anne Mayer-Scholl, Robert Hurwitz, Volker Brinkmann, Monika Schmid, Peter Jungblut, Yvette Weinrauch, Arturo Zychlinsky
Human neutrophils kill B. anthracis
PLoS Pathogen 1(3), November 2005
PDF (155 KB)
Contact:
Prof. Dr. Arturo Zychlinsky
Max Planck Institute for Infection Biology, Berlin
Tel.: +49 30 2846-0300
Fax: +49 30 2846-0301
E-mail: zychlinsky@mpiib-berlin.mpg.de
That would be true if this were contagious between people. However, anthrax is not known to spread from one person to another person. Communicability is not a concern in managing or visiting with patients with inhalational anthrax.
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As the title of the article says, they show that isolated human neutrophils are capable of killing Anthrax. The mechanism is unusuual, the spores are first eaten by the neutrophils. Then the spores germinate inside the cells to a form of bacteria that are readily killed (vegitative) as opposed to the virulent, disease causing form which is formed in the outside environment.
However, they don't look directly at animal models - so the leap of faith is that the lung infection is bad when the spores do not elicit a neutrophil response. How the spores avoid eliciting a host response in lung is the bigger question, which is not addressed by the paper.
...For those of you who are putting on your tinfoil masks, read up what the CDC has to say about anthrax.
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Anthrax cannot be spread because infected beings have only the actively growing bacteria and do not have the infectious spores. Darwin is gonna have a hell of a time (or at least take alot of it) in making anthrax contagious.
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