Wednesday, September 29, 2010

Happy Microbiologists Always Make Me Uneasy

Many years ago, I did a little non-taxing volunteer work for the Pennsylvania Department of Health booth at the Pennsylvania Farm Show.  One of the serious people there was my friend Stanley and I was present when a well-dressed African American couple, obviously educated professionals of some stripe, stopped to pick up some pamphlets.  Noticing that Stanley was a brother, the man looked around, lowered his voice, and said, "Tell me ...  is it true that the AIDS virus was created by the CIA?"

This is, apparently, not a rare experience if you're black and a microbiologist.  Of course, Stanley told him that it wasn't -- because back then nobody could possibly have created it.  The technology just wasn't there.

Which is what makes the following abstract so unnerving.  What we have here is either evolution in action -- or else somebody crafted this bastard.  Today it's entirely possible.

The Genome of a Bacillus Isolate Causing Anthrax in Chimpanzees Combines Chromosomal Properties of B. cereus with B. anthracis Virulence Plasmids. 
Silk R Klee et al, PLos one, July 2010/Volume 5/Issue 7/e10986

Anthrax is a fatal disease caused by strains of Bacillus anthracis.
Members of this monophyletic species are nonmotile and are all
characterized by the presence of 4 prophages and a nonsense mutation
in the plc Rregulator gene. Here, we report the complete genome
sequence of a Bacillus strain isolated from a chimpanzee that had
died with clinical symptoms of anthrax.

Unlike classic B. anthracis, this strain was motile and lacked the
4 prohages and the nonsense mutation. Four replicons were identified,
a chromosome and 3 plasmids. Comparative genome analysis revealed
that the chromosome resembles those of non-B. anthracis members of
the Bacillus cereus group, whereas 2 plasmids were identical to the
Anthrax virulence plasmids pXO1 and pXO2. The function of the newly
discovered 3rd plasmid with a length of 14 kbp is unknown. A detailed
comparison of genomic loci encoding key features confirmed a higher
similarity to B. thuringiensis Serovar konkukian strain 97-27 and
B. cereus E33L than to B. anthracis strains.

For the 1st time, we describe the sequence of an anthrax-causing
bacterium possessing both anthrax plasmids that apparently does not
belong to the monophyletic group of all so far known B. anthracis
strains and that differs in important diagnostic features. The data
suggest that this bacterium has evolved from a B. cereus strain
independently from the classic B. anthracis strains and established
a B. anthracis life style. Therefore, we suggest to designate this
isolate as "B. cereus variety (var.) anthracis."

And I should probably explain the title . . .

One thing I've learned being married to a microbiologist is that they're never happier than when a new emerging infectious disease pops up.  Particularly if it's virulent.  If it makes people explode, that's just icing on the cake.

I vividly remember the day Marianne came dancing into the house and said, "They've found a new disease which only affects -- get this -- Haitians and gay men!"


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