Monday, October 08, 2007

Mmmm....brain soup!

The microscopic world of protists is so diverse. From the cute and swift Paramecium caudatum to the diarrhea-causing Giardia lamblia. A colleague recently sent me an email with a story of the brain eating amoeba Naegleria fowleri....I had to investigate!

First, lets say that infection are rare but more common when heat waves are present....since these heat waves are likely to be longer and more prevalent, this story is of public interest. This interesting organism enters through the nose and makes its way to the central nervous system by crossing the olfactory neuroepithelium. From 1995 to 2004 only 23 infections have been documented but the recent death a of a 14 year-old boy sparked fear in Arizona.

When you look at the way this parasite travels, we find that the strategies are almost always the same: ENZYMES! How do you get into a cell...easy! First break the membrane with a specialized key known as a phospholipase (phospholipase A2). Then attack proteins with a specialized protease. By attacking the cellular cement holding the tissues together you end up liquifying them. The angry amoeba can then phagocytose the remaining fragments and voilĂ are history!

With only a few cases in the last decade chances are that you can die of many other things....and if you not even bother about this story, your relative risks are virtually "0"!

For a list of publications on the infective mechanisms click HERE

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