Monday, January 22, 2007

Follow the DNA trail - "superbugs"

Google News search alerts sent me to Weazlesrevenge blog, and an article originally published in (of all places) WIRED magazine about resistant strains of Acinetobacter baumannii that - it turns out - moved from European hospitals back to the war zone in Iraq.

Since biochemistry in college, I've never been able to figure out why E. coli hasn't wiped us all out. E. coli, the bacteria that normally makes up the bulk of the intestinal contents and which causes disease when people are exposed to a new strain, is able to exchange genetic information with other bacteria in just about every way possible. E. coli is the reason you're told "don't drink the water" in some countries and remember the spinach?

It appears that one of the strains of Acinetobacter that has been a deadly problem for our soldiers injured in Iraq (reported by Forbes magazine in 2005) is another adaptable bacteria:

When a team of geneticists unlocked the secret of the bug's rapid evolution in 2005, they found that one strain of multidrug-resistant Acinetobacter baumannii carries the largest collection of genetic upgrades ever discovered in a single organism. Out of its 52 genes dedicated to defeating antibiotics, radiation, and other weapons of mass bacterial destruction, nearly all have been bootlegged from other bad bugs like Salmonella, Pseudomonas, and Escherichia coli.


At first, it was assumed that the bacteria came from the dirt and dust in the field in Iraq, resulting in contamination of war-zone hospitals and moving on to the secondary evacuation hospitals and eventually back to the US. Instead, DNA infectious disease detectives discovered that the germ originated in Europe and moved to the Iraqi hospitals by hitchhiking on medical personnel and equipment.


Little packets of circular DNA called "plasmids," protected packets called "phages," and even loose DNA in the environment, allow the exchange of information between one individual bacterium and another. Here and here are sites that explain the processes in more detail. And it may have you looking at that raw fruit or vegetable or the funny spot on the bread a little differently.

Never fear, the WIRED author tied the bacterial infection in with high tech informational nature of the magazine. I appreciate the twist on words:
In the open source world of bacteria, everyone is working for the resistance. Ramping up the immunity of any single organism, while dramatically increasing the size of the population most susceptible to infection, only helps the enemy. To an aspiring superbug, war is anything but hell.

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