Posted on 05/05/2008 3:19:54 PM PDT by blam
Scientists Discover Why Plague Is So Lethal
ScienceDaily (May 5, 2008) — Bacteria that cause the bubonic plague may be more virulent than their close relatives because of a single genetic mutation, according to research published in the May issue of the journal Microbiology.
Yersinia pestis, direct fluorescent antibody stain (DFA), at 200x magnification. (Credit: CDC / Courtesy of Larry Stauffer, Oregon State Public Health Laboratory)
"The plague bacterium Yersinia pestis needs calcium in order to grow at body temperature. When there is no calcium available, it produces a large amount of an amino acid called aspartic acid," said Professor Brubaker from the University of Chicago, USA. "We found that this is because Y. pestis is missing an important enzyme."
Bubonic plague has killed over 200 million people during the course of history and is thus the most devastating acute infectious disease known to man. Despite this, we are still uncertain about the molecular basis of its extraordinary virulence.
"Y. pestis evolved from its ancestor Y. pseudotuberculosis within the last 20,000 years, suggesting its high lethality reflects only a few genetic changes. We discovered that a single mutation in the genome of Y. pestis means the enzyme aspartase is not produced," said Professor Brubaker.
Aspartase is present in almost all bacteria but it is curiously absent in many pathogenic types. These include mycobacteria that are pathogenic to man, Francisella tularensis and rickettsiae (both of which cause diseases transmitted to humans via insects). "This suggests that the absence of aspartase may contribute to serious disease," said Professor Brubaker.
Aspartase digests aspartic acid. Because Y. pestis doesn't have the enzyme, it produces much more aspartic acid than is required by the person infected. This may cause an imbalance to the host amino acid pools. "If this is the case then we might be able to reduce the death rates of these diseases by developing a treatment that removes some of the extra aspartic acid," said Professor Brubaker.
Adapted from materials provided by Society for General Microbiology, via EurekAlert!, a service of AAAS.
So, they need Apart-tame. Sweet!
Should plague victims be taking calcium then?
Probably antibiotics + calcium.
Drink diet coke?
The aminotransferase biosynthesis of aspartate is a folate dependent process.
Theoretically, a folate antagonist - such as Methotrexate could reduce the Aspartate burden
That may be true, but it may also be less contagious or less easily transmitted between people.
Was the bubonic plague the Black Death? Some people say no.
Yes it was, the buboes (a symptom) caused the skin to turn black, hence the name "Black Death".
I think the pneumonic version was the most deadly, killing people in just a few hours. There are stories about victims looking healthy at breakfast but falling dead before suppertime. No wonder people thought it was the end of the world.
>> Aspartic acid is non-essential in mammals, being produced from oxaloacetate by transamination. The aminotransferase biosynthesis of aspartate is a folate dependent process.
Theoretically, a folate antagonist - such as Methotrexate could reduce the Aspartate burden
When I called up this thread, I could swear I pressed 1 for english...
:-)
(biology challenged)
Correct. They have been able to extract/resurrect it from tissues of people that died then. They know exactly what it was.
Just a little rudimentary biochemistry :^)
bump & a micro ping
ping... (Thanks, blam, for the post!)
Thanks for the ping!
Holy Guacamole! I pretty much understand that.
You should see all the red line in my Firefox window. There are ten words the dictionary doesn't recognize.
Yee haw! I am smarter than the Firefox Dictionary!!!!!!!!!!
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