ANTHRAX, HUMAN, 2001 - USA (12): COMMENT
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A ProMED-mail post
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Date: Wed 24 Sep 2008
Source: Anthraxvaccine.blogspot [edited]
http://anthraxvaccine.blogspot.com/2008/09/additional-comments-by-dr-popov-on.html
Comments by Dr. Popov on producing anthrax
PERMEABILITY OF BACTERIAL SPORES II. Molecular Variables Affecting
Solute Permeation. Philipp Gerhardt and S. H. Black, Department of
Bacteriology, The University of Michigan Medical School, Ann Arbor,
Michigan. J Bacteriol. 1961 November; 82(5): 750-760.
2. In order to test my scenario of the inconspicuous preparation of
anthrax powders in the lab by somebody like Bruce Ivins, I estimated
the amount of spores required for one letter. The information on the
Internet says that the letters contained about 7 to 10 grams of
material, of which roughly 2 to 3 grams were weaponized spores.
Federal investigators say the Leahy anthrax powder had not been lost
in the letter’s opening. The amount, typical of the tainted letters,
was 0.871 g.
So, let’s assume it was 0.9 g. According to Dugway and my estimates
of the spore weight (based on the spore size of 1 micron^3) one gram
of dry spores contains from (0.7 to 1)x10^12 spores. It is (0.6 to
0.9)x10^12 spores/letter. If the Bruce anthrax was 3x10^9/ml, it
would take him at least 200 ml of the spore suspension per letter
from the flask he possessed. For all 5 letters, he must have used up
the whole one-liter flask. The solid medium process in the lab gives
us 5x10^9 spores from a regular Petri dish. It would require at least
100 plates/letter. This number of plates is impossible to handle
inconspicuously. In any case, if the amount of powder in the letter
is correct, and the spores constitute the majority of it, there is
more than a 10-fold discrepancy between the required amount of spores
and the amount the perpetrator could have covertly taken from the
flask or prepared on the agar plates. This bolsters a hypothesis of
the fermentor-cultivated spores at the microbiological facility.
Interestingly, the powder from the 1st letters sent on 18 Sep 2001 to
NY contained a lot of unsporulated bacteria. It is impossible to
imagine that the powder of this quality could have been prepared for
the military experiments by knowledgeable personnel. They would
certainly discard the prep. Was the perp in rush to prepare the
spores as quick as possible to make a connection with 9/11and
therefore, by mistake, stopped the fermentation before the culture
sporulated completely? It was only a week between the bombing and the
mailings — very tight but possible schedule for this kind of job, if
all the equipment was readily available. The next preps were more
successful, but took longer. Has the equipment been previously used
to cultivate _B. subtilis_ for training purposes? This would be
consistent with a contamination. Again, it indicates availability of
a facility, and I’m afraid to say — a team effort, which is
something fundamentally different from a lonely Bruce using Petri
dishes and a lyophilyzer.
3. The perpetrator did not have to use plates, but it is the
simplest way. However, I disagree with the investigators’ time
estimate. 3 to 7 days for several grams of spores? Have they tried to
do it themselves? Running a fermentor and drying spores is not a
3-day job. It is not enough time even for a growth and sporulation on
plates (we harvest spores on the 5th day). As I said earlier, a week
is a very tight schedule. For a fermentor, there are additional steps
of growing the seeding cultures (one or more days, depending on the
volume). And fermentation cannot be accomplished during the evening
hours only. By the way, did Bruce have access to the fermentor?
The theory of fermentor can only stand if other people were aware of
the perpetrator’s experiments. If we accept this, we ought to
conclude it was a collective effort at [a] well-equipped facility: it
wasn’t just [a lone perpetrator.]
—
Communicated by:
ProMED-mail
promed@promedmail.org
[Our thanks to Sergei Popov, George Mason University, for permission
to post his interesting comments.
The problem with liquid culture is reaching 100 percent dormancy.
Some spores are trying to germinate while others are still
sporulating. Note Segei’s comment above that the 1st batch of letters
contained “a lot of unsporulated bacteria.” It is far easier to
produce higher quality (i.e., next to 100 percent fully dormant
spores) in large numbers on solid agar flats. However, the Americans
have always opted for fermenter-produced spores as opposed to the
Brits and the Canadians.
However it would seem to be clear that the letter products were
cultured from one or more aliquots taken from the accumulated
contents of flask RMR-1029 which were collected between 1997 and the
summer of 2001, and the flask was latterly kept in Bruce Ivins’
laboratory. - Mod.MHJ]
[See also:
Anthrax, human, 2001 - USA (11): review 20080924.3019
Anthrax, human, 2001 - USA (10): evidence 20080828.2696
Anthrax, human, 2001 - USA (09): evidence 20080819.2591
Anthrax, human, 2001 - USA (08): evidence, drugs 20080818.2566
Anthrax, human, 2001 - USA (07): letters, evidence 20080812.2492
Anthrax, human, 2001 - USA (06): letters, evidence 20080811.2488
Anthrax, human, 2001 - USA (05): letters, evidence 20080807.2428
Anthrax, human, 2001 - USA (04): letters, evidence 20080806.2412
Anthrax, human, 2001 - USA (03) 20080805.2406
Anthrax, human, 2001 - USA (02): letters, evidence 20080805.2392
Anthrax, human - USA 2001: letters, new suspect 20080803.2371
2002
b.