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We now know conclusively that the spores in the anthrax attacks did not come directly from this flask labeled RMR-1029 by Bruce Ivins, but were cultured most likely using RMR-1029 as the culture inoculum.
Among the many enduring scientific mysteries surrounding the Amerithrax investigation of the anthrax attacks of 2001 is the question of whether an agent such as fumed silica was used to "weapoinze" the spores. Early in the analysis of the attack, statements were issued claiming that the spores were indeed weaponized with silica, but subsequent analysis has proven that not to be the case. New data just released help to pinpoint the reason for the earlier misunderstanding while at the same time emaphasizing that central questions about the conclusion that Bruce Ivins acted alone remain unanswered.
To review, here is a key Washington Post article from October, 2002 that fed into the "weaponized" theory:
A significant number of scientists and biological warfare experts are expressing skepticism about the FBI’s view that a single disgruntled American scientist prepared the spores and mailed the deadly anthrax letters that killed five people last year.
These sources say that making a weaponized aerosol of such sophistication and virulence would require scientific knowledge, technical competence, access to expensive equipment and safety know-how that are probably beyond the capabilities of a lone individual.
/snip/
Several sources agreed that the most likely way to build the coated spores would be to use the fine glass particles, known generically as "fumed silica" or "solid smoke," and mix them with the spores in a spray dryer.
Interestingly, these speculations in the Post were going well beyond the initial disclosures about silicon. Here are snippets of a White House briefing on October 29, 2001. Major General Parker was the head of USAMRIID, the facility where Ivins worked:
Q: Does that suggest then that there was no additive, there’s been nothing in the spores to make them more — or nothing added to the spores to make them more easily aerosolized?
MAJOR GENERAL PARKER: Complicated question. We do know that we found silica in the samples. Now, we don’t know what that motive would be, or why it would be there, or anything. But there is silica in the samples. And that led us to be absolutely sure that there was no aluminum in the sample, because the combination of a silicate, plus aluminum, is sort of the major ingredients of bentonite.
However, the problem is that even though the element silicon was found to be present at higher than expected concentrations in the attack material, the spores were not "coated". Here is a key disclosure of the lack of coating:
Harvard University molecular biologist Matthew S. Meselson, who has consulted for the FBI on the anthrax probe, dismisses these early statements as misunderstandings or misinterpretations of the scientific studies conducted on the Daschle powder. "I don’t know of anybody with spore expertise who actually worked on the stuff who said the spores were coated," he says. The FBI has never publicly claimed the spores were coated with silica and, in fact, told members of Congress at classified briefings that the spores were not coated, he says.
/snip/
Meselson, who reviewed Beecher’s article for the FBI, was asked to assess scanning electron micrographs of the anthrax powder. Early in 2002, he spent half a day at the FBI’s Washington field office and looked at "a large heap of electron micrographs" of the powder from the Daschle letter.
"I saw no evidence of anything except spores, no evidence of silica nanoparticles," Meselson says. "If silica was present, I would have seen it, but nothing could have been purer than what I saw," he insists. Though purified, the preparation "had not been milled," he adds.
I have to note here, that as a Ph.D molecular biologist, the opinion of Mesleson carries tremendous weight for me. Meselson began his career by publishing what later came to be called "The Most Beautiful Experiment in Biology". [To appreciate the elegance of the experiment, see this WikiMedia Commons illustration and watch this brief animation.]
While still under the impression that an agent such as fumed silica was used to weaponize the attack spores, work was carried out at Dugway in attempt to produce similar material. The Chemical and Engineering News article linked above summarizes some of that work and the results. Other parts of the work, including electron micrographs of coated and uncoated spores of a similar bacterial species were published here.
The newest information about the silicon mystery comes in a news article in the March 19 issue of the journal Science. Here, we see conclusive visual evidence that the silicon (in green in the upper frame) in the attack spores is located inside the outer covering of the spores:
Sandia National Laboratories illustration as reproduced in Science
Here is how the article described the analysis carried out at Sandia National Laboratories:
A more detailed analysis by Joseph Michael and Paul Kotula of Sandia National Laboratories in Albuquerque, New Mexico, contradicted that conclusion. Studying individual spores with a transmission electron microscope, they found that the silicon was located within the spore coat, well inside the cell’s exosporium (outermost covering). By contrast, when they looked at surrogate spores weaponized with silica, the silicon was clearly outside the exosporium.
But the Sandia study, presented last September to a National Academies panel reviewing the science behind the investigation, still leaves questions. Out of 124 spores from a letter mailed to Senator Patrick Leahy of Vermont, Michael found the silicon-and oxygen signature in 97—78% of the sample. The signature was present in 66% of a sample from a letter to former Senator Tom Daschle and in 65% of spores from a letter sent to the New York Post.
Out of nearly 200 other anthrax samples from different labs, none came close to displaying such a prominent silicon signature. The highest, in a sample from Dugway Proving Ground in Utah, was 29%. The researchers couldn’t find silicon in the coat of a single spore out of some 300 taken from RMR-1029, the flask in Ivins’s lab identified as the source of the bacteria used in the attacks; they concluded that all the silicon had come from the culture.
These results show conclusively that the silicon content of the attack spores differed from the silicon content of the spores that were in the actual RMR-1029 flask pictured above. The results suggest that the silicon inside the spores used in the attack came from the culture medium in which the spores were grown. Researchers in Japan recently published results with the bacterium Bacillus cereus that provide further support for this interpretation.
These researchers grew B. cereus cultures on growth medium containing high or low concentrations of silicates and found that spores produced after growth on the high silicate medium had a layer of silicon inside the spore that looked like the illustration above for the anthrax spores used in the attacks. They then carried out various experiments on high and low silicon spores to determine how the high silicon spores differed from the low silicon spores. They found no difference in spore dispersion in air (although I have reservations about whether they first achieved the same level of purification away from debris that is reported for the attack material) but did find the high silicon spores were more resistant to disruption in acid, a trait that could have evolutionary advantages. Their final sentence of the publication is the most important here:
Our findings also strongly indicate that the anthrax spores were harvested from culture on a silicate-containing medium.
The published findings of the Amerithrax investigation suggest that detailed genetic analysis (that has not yet been released in full) indicates that the attack spores share a unique subpopulation of four mutant strains along with the primary Ames strain that was only found in Ivins’ RMR-1029 flask or cultures that were known to be directly derived from it. These newly released silicon results conclusively show that the attack spores could not have been taken directly from the RMR-1029 flask, but would have to have been cultured on a high silicate growth medium. In this diary, I showed that the amount of spore material that was present in the attack letters would have been very difficult for Ivins to culture on his own in the small shake flasks he had available to him. Instead, it would have been much easier for a researcher with access to a fermenter to produce such a large amount of spores. In this diary, I pointed to a facility at Dugway that has a fermenter of just the right size to produce the material in only one or two batches. Isn’t it interesting that the second highest silicon content batch of spores analyzed by Sandia came from Dugway?
58 Comments
I’d say there is a high probability approaching certainty that the spores in the letters were manufactured at Dugway by a person or persons unknown and, unless Ivins had access to Dugway, he should be excluded as a suspect.
Excellent analysis, Jim.
Thanks. The only data arguing against a Dugway source is the stable isotope analysis that is also discussed in the Chemical and Engineering News article. Those results suggest a location in the northeast US for the source of the water used in the culture, but I’ve already shown that there are commercial sources for sterile water located in the northeast, so Dugway could have used commercially available sterile water for the culture and that would have given the result seen.
Also, that article referred to radiocarbon dating that was used to establish that the attack spores were cultured more recently than the spores in the RMR-1029 flask. I did go read some of the primary data on similar analyses because I was uncomfortable with carbon 14 (having a half life over 5000 years!) being used to make a determination down to a year or two. It looks like those measurements really can be made, but it feels to me like using a standard one foot ruler to measure the width of a hair. That’s why I take the silicon data as the real confirmation that the attack spores were cultured separately from those in RMR-1029 rather than the carbon 14 results that were already disclosed.
This a major one, Jim White. Thank you. In particular, thanks for making your presentation so plain and clear and understandable to even a person as ignorant as I am of the science.
Thank you, Jim, for staying on this.
Frankly you are well beyond my meager grasp of the deeper mysteries (as they seem to me) but I appreciate the fact that even I can understand what you have delineated, owing to your clear excellence as a teacher and researcher.
That Obama wishes to cover up the questions regarding this very serious issue, and realizing that the reasons for that cover-up are partially beyond our ken, one is left to ponder just how important truth is actually regarded as being among the political and ruling classes.
Please keep on keepin’ on, Jim, because the truth does matter. A viable and sustainable human future depends upon it, despite what the Masters of the Universe might wish to believe.
DW
O/T, but something I thought you might be interested in, Jim:
Pentagon Loses Skirmish with WikiLeaks; Scott Horton, 3/19/10
http://www.harpers.org/archive/2010/03/hbc-90006732
Thanks for that. I hadn’t made it to Horton’s page today.
Thanks, fatster and DW. Students of history will remember that the Bush administration used the anthrax attacks as part of their justification for war with Iraq. If you read the entire Washington Post article I linked, you’ll see how big the effort was to tie the attacks to Saddam. Getting to the real story on what happened in the anthrax attacks will in the end mean coming to grips with those lies, and that is probably reason enough for Obama (backed by Rham Emanuel and Cass Sunstein) to keep a lid on further official investigation.
Yes, the Iraq connection.
You are likely as astute in your observation of compelling “reason” sufficient for Emmanuel and Sunstein, as you are in your researches and observations on the anthrax issue, itself, Jim.
However, unless Obama intends on simply being a one-termer, how he or Rahm or Cass may imagine that many things will not, sooner rather than later, begin to ooze out in more than simply embarrassing ways is beyond my comprehension.
I realize that the ruling classes depend upon both ignorance of reality and programmed forgetting to further themselves, but all of this is far too ugly and bloody destructive to simply fall down a convenient rabbit-hole …
The entirety of the rest of the century does not seem long enough for “all of this” to become a forgotten and unremarked upon “history” that no one cares about.
The whole world has been watching, even if much of the American public has snoozed through the last decade. Few Americans can be resting well, these days, even if it is only the “economy” which concerns them.
Jim, the results of your efforts do not lend themselves to happy or sanguine snoozing.
Thank you, yet again.
May eyes, ears, hearts and minds open themselves to the insight, the understanding, and, if the insight and understanding are truly grasped, the profound wisdom you are providing the rest of us?
DW
this was very interesting.
i’ve always thought it entirely possible some sector of the “secret” part of our government may have been responsible for the dissemination of the anthrax, not least because of the fbi’s meandering history of investigating the attack.
what would be an example of a high-silicate growth medium?
a flask?
or is silicate different from silica?
A high silicate growth medium would be a liquid medium to which a soluble silicate salt has been added, as was done in the Japanese work I cited. This Wikipedia entry looks to be accurate in its description of the various terms used to describe silicon chemical forms.
“President Barack Obama probably would veto legislation authorizing the next budget for U.S. intelligence agencies if it calls for a new investigation into the 2001 anthrax attacks, an administration official said.A proposed probe by the intelligence agencies’ inspector general “would undermine public confidence” in an FBI probe of the attacks “and unfairly cast doubt on its conclusions,” Peter Orszag, director of the Office of Management and Budget, wrote in a letter to leaders of the House and Senate Intelligence committees.”; from EW.
Gotta look forward you know.
Gotta love pictures. Don’t throw out your electron microscopes just yet, kids. High silicate medium — I don’t happen to know the implications of that. What does it say to anyone out there?
One implication of high silicate medium, as discussed in the Science article, is that the silicon concentration in the spores could be used as a forensic fingerprint of the chemical composition of the growth medium used. Scientists usually rely on commercially provided pre-mixed dry ingredients to which they add water for growing bacteria. Alternatively, they could formulate their own growth medium from individual components based on knowledge of the particular strain being grown. There isn’t an immediately obvious reason for a biologist to put extra silicate in the medium; my underlying assumption is that it was just coincidental to whatever medium was used to grow the attack spores. Since the Sandia analysis didn’t find any other spore preparations with such a high percentage of spores incorporating silicon, it appears that the various growth media favored by those researchers who provided spore samples don’t have high silicate content.
What was that company’s name that made ready-to-dissolve powdered media: Gibco? (It’s been a few decades …) You’d step next door, and there someone would be weighing out upwards of a dozen amino acids to make a completely defined medium for another strain. I just don’t remember ever adding a silicate to a medium. Why would anyone think that it would be a good idea? Is it something that is done routinely in some branch of research or production?
Does the incorporated silica make the spores more resistant to crushing or inadvertent “milling” when send through the mail, e.g.? Who would have gone to the trouble to find this out?
Are spray dryers now a standard piece of equipment in micro labs? (I’ve bumped into some weird gadgets, but never one of those.) If so, how long have they been common? Would you expect to find a spray dryer in an academic lab? A pharmaceutical research lab? On a pharmaceutical process line?
Who makes spores for a living? Whose spores are high-silicate?
But I suppose that the FBI asked all these questions and have the answers, right?
Difco is the growth medium company… a one-stop shop for an incredible variety of broad- and narrow-spectrum broth and gel mixes.
Sylox is a popular brand of fumed silica. It’s great stuff for keeping dry ingredients dispersed and non-clumpy on the way to being made into tablets. Also as an anti-caking ingredient in slurries being spray-dried.
Difco. Right. That was another name. And thanks for the info about fumed silica.
What I don’t understand at the moment is how one handles something like a spore which is made to ‘go with the flow’, that is, have a very low settling rate and accompany any convection it encounters. There’s some wrinkle in the hot-gas spray dryers I haven’t understood yet. Preparing quantities of isolated spores may not be rocket science, but it’s not a no-brainer, either, as far as I can see.
ubetchaiam took the words right out of my mouth…. What a relief we’re looking forward, not back. Can’t have “unfair” doubts.
Jim,
Is it true that right after the attack, all the Ames store of anthrax was ordered to be destroyed, did that happen?
Yes, see this article for an inside view from Iowa State University of the destruction of their strain collection and this entry at History Commons for more links. (Caution, one link is a Judy Miller article!)
And thank you thank you thank you for your continued reporting on this,
essential.
Was there a spray dryer in Ivins’ lab (or available to him)?
No spray dryer that I am aware of. Only a freeze dryer and some roto-vaps.
And you aren’t going to get the spores Meselson described from either of those, I would bet.
Some sources speak of a “spray dryer” as though it’s no big deal. But “no big deal” to whom? On whose budget?
Spray dryers are definitely not academic except in pharmaceutical or chemical engineering process development/scale-up research. They are very expensive and would be a nightmare to set up for something that requires the biosafety level of anthrax.
Yeah, I just don’t see someone thinking to put silicates into growth medium. I suspect they are there inadvertently. The Japanese paper shows that the only apparent advantage conferred was resistance to acid. Soil-dwelling spores like anthrax could encounter acidic soils. Other spore formers also would benefit from acid resistance if they need to survive in the acid environment of an animal’s gut.
As for GIBCO, yes they are one of the primary media suppliers. And they are merged with BRL. BRL stands for Bethesda Research Laboratories, a commercial operation on the outskirts of DC. That is my candidate for the source of commercial sterile water that would have an isotope signature indistinguishable from the nearby USAMRIID.
Addition on edit: I’m also not convinced, though, that high tech drying is required. I think the key is the removal of all the non-spore material in the prep. Meselson hints that the electrochemical and biophysical properties of the spores themselves when they are clean and dry is what allows them to disperse so readily. This guy has been doing biophysics since I was in diapers, so I trust his insight on this key point.
That’s what I don’t see. “Inadvertently” on whose part? Some corp like Gibco (BRL)? Naaah. They’d ruin their reputation if they let some oddball component slip in.
No, my guess is that someone added a silicate with intent. We just don’t understand who or why.
Stay tuned. I have a new idea on this I need to check out further. If it checks out, there will be a follow-up diary sometime over the weekend.
FDL is so fortunate, Jim, to have someone with your expertise who can unravel this story for us, as well as the others you’ve been posting about.
It isn’t that easy to find a scientist who can write in (relatively) plain English on a blog.
Tweeted & Facebooked.
OK, so what was the origin of this flask then? Where did the material in this flask come from?
In this diary, I discussed the origin of the material in RMR-1029. It has the material produced from a number of fermenter runs at Dugway combined with the material from a number of shake flask cultures Ivins grew at USAMRIID. It has a unique genetic signature the FBI saw in only 8 other samples among their analysis of all known Ames strain supplies. All 8 could be traced to RMR-1029 as their source. Since the RMR-1029 spores are low silicon but the right genetic signature, it is consistent to say they were used as inoculum to grow the attack spores and that this growth was on a medium with higher silicates than the earlier cultures that produced the original material.
OK, bear with me here.
Is it possible that the attack material and the flask are from a common ancestor, or must the attack material have been derived directly from this flask?
What’s frustrating to me here is that they haven’t given us a full description of the genetic analysis, just bits and pieces. We need to know the relative populations of each of the four mutation DNA types and the wild-type Ames strain in the mixture in RMR-1029, along with the same information for the attack material. Since no other non-RMR-1029 derived material in the analysis gave all five DNA types being present, it’s hard to envision a common ancestor giving rise to both, especially since RMR-1029 results from many cultures being mixed.
I read your earlier post, doesn’t seem likely the attack material came from anywhere but the flask. I was thinking it might have been extracted earlier, but that doesn’t seem possible. It’s very interesting, glad you’re digging into it.
“…the key is the removal of all non-spore material…”
that would seem like one hell of a “sifting” job.
i would assume the objects are too small
for mechanical sifting, so perhaps electromagnetic?
could the growth medium have been an aid in sifting, ie, purifying particles this small to that degree of purity?
Sifting could be involved using pretty simple methods, since filter materials come in an astonishing array of pore sizes. Clumps could be removed first with a filter with relatively large pores of 10 or 20 microns and then the bulk of the liquid and dissolved non-spore material removed by pushing the suspension through a filter that retains even the 1 micron sized spores. Alternatively, chemical means could be employed to destroy or dissolve the debris in the mixture. Spores are remarkably robust. Note that these high silicon spores are even quite acid tolerant. Spores resist many chemical and physical treatments that disrupt other biological materials.
The Beauty of the Spores
Are spores resistant to sonication? A fairly brief blast ought to get you single spores in suspension.
That’s one method we used with a spore forming bacterium we grew. Unless you have a flow cell, though, it only works in small batches and you have to keep the material on ice so it doesn’t heat up. It sounds way too dangerous to try with a pathogen, though.
It doesn’t look like these people were strapped for equipment. Chilled flow cell with sonic probe? Coming right up. But you’re right about the danger. I simply don’t understand how there wasn’t an accident. It’s certainly one of the best arguments against someone doing it in a garage or during odd moments. Remember getting stuck in the lab until 10 at night waiting for a culture to grow? This was an operation.
Centrifugation is the usual method to clean a particulate prep. Spin the spores down into a pellet, pour off the supernatant, resuspend in fresh buffer or whatever, repeat to taste. Five passes should get you a spore prep with the original medium reduced to 0.00001 (I’m being half-facetious here.) of the original concentration.
Of course, if you really have time and bucks to burn, I hear that there are now sorters which produce droplets with 0, 1, and rarely 2 spores per droplet. These go flying past some kind of detector and are deflected according to whether they are the kind desired or not. All those little droplets eventually add up. But we’re talking about half a kilo of spores, here, so my first move would be a trip to the preparative centrifuge. (Does Sorvall still exist? Does Beckmann? Memories of opening the lid of a Sorvall and braking the rotor with two gloved hands back before they put a solenoid interlock on the lid that kept it closed until the rotor stopped. The art was to introduce no wobble and not to resuspend the pellet by mistake. The safety latch must have been added by someone with lots of time on their hands; the longest period of unmeasured time is the time it takes a rotor to coast to a stop from 5000 rpm.)
Thanks for the heads up. The general public seems far more interested in the Anthrax case than does the FBI or even the Obama admin for that matter.
“President Barack Obama probably would veto legislation authorizing the next budget for U.S. intelligence agencies if it calls for a new investigation into the 2001 anthrax attacks, an administration official said.
A proposed probe by the intelligence agencies’ inspector general “would undermine public confidence” in an FBI probe of the attacks “and unfairly cast doubt on its conclusions,” Peter Orszag, director of the Office of Management and Budget, wrote in a letter to leaders of the House and Senate Intelligence committees.”
http://www.businessweek.com/news/2010-03-15/obama-veto-is-threatened-on-2010-intelligence-budget-measure.html
Fascinating discussion, even though so much of it is over my head. I get the vocabulary, just not how everything interacts.
btw for a good read re Unit731 and anthx, wherein CDetrick gets Jap.data and produces freeze-dry process for anthx, goto
http://www.centurychina.com/wiihist/germwar/731rev.htm
VeryWildAssGuess, presence of capacitace as si cpds might accept dispersive charge when procesed in hi-spd sorting machines. Sorta,lousy pun, getting final polish enroute.
Huh. Is capacitance part of the reason why silica is used to weaponize spores for easier dispersal?
I just stumbled onto this site while looking for things microbiological. It’s tinfoil hat territory, but the long list of deaths of microbiologists might make interesting reading for some: here it is.
Jesus, when will you conspiracy theorists accept that Oswald made the anthrax alone?
Jim this is what I would pay to read a newspaper for if they had people like you reporting.
Same here! It’s a great reason, now, for not reading newspapers. They just won’t bother with stories like this. Frankly, I doubt many papers have reporters with enough science background to write the kinds of things you’ve been posting here.
First off a comment on the silica coating – followed by a couple on Meselson.
The silica coating was not the 1960′s “shake and bake” coating of fumed silica nanoparticles that is easy to see on micrographs. More modern coatings use “microencapsulation” – where the coated spore looks more a glazed donut than a donut coated with powdered sugar. When microencapsulation is used an organosilane monomer penetrates the exosporium and polymerizes into silica in situ on the spore coat.
Thus the spores were indeed weaponized. That is clear from all of the AFIP data (which has not been released by the FBI).
Finally note that Meselson has previously been quoted as saying that spores stick together like glue here:
http://www.columbia.edu/cu/21stC/issue-3.2/osullbio.html
“People who say that you can make these weapons in your kitchen just don’t understand what’s involved,” says Meselson.
“If anthrax is stirred incorrectly it may clump,” notes Meselson, “and if the cells clump you can’t make an aerosol weapon. They stick together like glue. Who would have thought of that? And I imagine that there are hundreds of little wrinkles like that. All the nonsense about ease of production ignores these facts.”
I’m not saying Meselson isn’t a brilliant biologist (he is) – but when he involved himself previously with bioweapons he seemed to have an agenda related to the treaty he was involved with Nixon signing (as if he didn’t want to admit the treaty had been broken by the Russians).
See excerpts from Mangold and Goldberg’s “Plague Wars”:
CHAPTER NINE Incident at Sverdlovsk
Page 76:
The Soviets now went to extraordinary lengths to buttress their lies and make them supportable and credible worldwide. What had begun as a local cover-up in Sverdlovsk, now became an international fairy tale, a fiction of breathtaking audacity.
Page 77:
Throughout the rest of the 1980s, Matthew Meselson, a respected Harvard professor of microbiology and longtime arms control activist, unwittingly helped the Soviet caravan of deception and disinformation gain acceptance in the West.
Meselson emerged as the leading scientific expert to oppose his own government’s interpretation of Sverdlovsk in favour of the Soviets’ old tainted-meat cover-up. He defended the Soviets’ case publicly and doubtless from the most honest of beliefs. President Reagan was now in the White House and, no matter how forcefully his administration complained about Sverdlovsk, Meselson remained utterly convinced that there had been an accident with bad meat and it had nothing to do with any secret biological weapons plant.
………
With his well-deserved and impressive academic/scientific credentials, his views were usually sought and carefully listened to. He also became an important figure for the US media to consult. His opinions about Sverdlovsk were widely quoted in the serious press, books, and prestigious scientific journals. The record shows that after 1980 his publicly stated views on Sverdlovsk broadly agreed with the explanations issued by the Soviets themselves.
Page 81:
But the guilty involvement reached even higher. Next, it emerged that Boris Yelstin himself also must have known about the cover-up. In May 1992, Yeltsin’s new Russian government formally acknowledged what was now well known, but still had no official imprimatur. The man who had been the powerful communist party chief of the Sverdlovsk region in 1979 was none other than President Boris Yeltsin. He now admitted that the outbreak had been caused by an accident at the biological weapons facility, and not by natural causes. This presumably correct version became the official position of the Russian government, and remains so to this day.
Meselson, however, remained unfazed. In the face of Yeltsin’s admission and the Russian and US press disclosures, the professor assembled a team of expert American scientists and went with them to Sverdlovsk in June 1992 to see for himself. They interviewed two outstanding Sverdlovsk doctors Faina Abramova and Lev Grinberg who participated in the 1979 autopsies at Hospital 40. For thirteen years, these brave pathologists had secretly hidden incontrovertible medial evidence from the KGB including preserved tissue samples, slides, and autopsy reports which proved that the victims had died from breathing in the anthrax.
Meselson later claimed that he and his team had made the discovery of the new truth from these important witnesses, but again, the facts were against him. The two Russian doctors had previously spoken to Soviet reporters and the Wall Street Journal, so Meselson was simply taking credit for being the final arbiter who had authenticated the evidence.
After making a second trip to Sverdlovsk, Mesleson finally published his results in 1994 in the journal Science; the article accepted that the tainted-meat story was bogus. But, perversely, he still would not admit that the US government had been right for fifteen years, or that he had been wrong. Rather, he trumpeted the fact that he anf his team had finally uncovered the “defenitive proof” that the true cause of the outbreak was pulmonary anthrax.
“This should end the argument about where the outbreak came from,” Meselson somewhat pompously told the New York Times “Right up until now, people have still been debating the matter.”
Yet, to the bitter end, Meselson still clung to a benign interpretation of Soviet motives. He noted that the cause of the accident was still not determined, which implied that it may have involved only a Soviet research centre, one for finding an antidote to an anthrax attack, and not a military production centre for biological weapons. By clinging to this position, he could still argue that the Soviets were not violating the BWC, but were conducting permissable research under the treaty.
Do I understand you correctly? Si-containing monomers penetrate the outer layers of the spore and polymerize IN THE LOCATION INDICATED BY GREEN IN THE FIGURES IN THE POST? That is, a Si-rich layer is created at that location NOT by microbial metabolic processes but by post-sporulation physical/chemical processes?
And what is the effect of that layer’s presence? Does it counteract aggregation? Can such spores actually be induced to repel each other?
See my new post for my theory on how the silicon got into the spores. (And thank you for continuing to ask “why” on this thread–that’s what got me to my idea).
Do you have a link for the silicon process?
Thanks for the Meselson links. I hadn’t followed his involvement in the Russian story.
Yes, the organosilane monomer would be a post-sporulation process. The organosilane monomers are small molecules which could easily penetrate the exosporium.
See references below for the highly porous nature of the exosporium.
http://www.nature.com/news/2008/080929/full/news.2008.1137.html
Silicon highlights remaining questions over anthrax investigation
Did Bruce Ivins weaponize deadly spores?
Amber Dance
The deadly anthrax bacterium.MedicalRF.com / AlamyNearly two months after the suicide of scientist Bruce Ivins — whom the US Federal Bureau of Investigation (FBI) claims was solely responsible for mailing a series of letters laced with anthrax in 2001 — questions still remain over whether he was actually able to produce those anthrax spores.
Scientists initially believed that the spores had been weaponized – modified to make them disperse more easily and penetrate tissue more deeply.
But one of the scientists who first drew that conclusion has now changed his mind. Nature finds out why he thinks he got it wrong; why it matters for those trying to tie up the Ivins case; and what it means for the chances of a similar attack happening in the future.
What was the initial evidence that the 2001 spores were weaponized?
The powder was described as being ‘weightless’ and ‘smoke-like’. One of the first scientists to work on it was Peter Jahrling, then a virologist at the US Army Medical Research Institute of Infectious Diseases in Frederick, Maryland. He recalls that he couldn’t even weigh out a fraction of it: “It literally jumped off the spatula and was repelled by the weighing paper; it was like nothing I had ever seen before.” Under an electron microscope, Jahrling and a colleague observed black dots that they speculated might be particles of silicon dioxide, or silica. Materials analysis by the Armed Forces Institute of Pathology in Washington DC confirmed that the sample contained both silicon and oxygen, and many assumed that the elements were combined as silica.
Why would a silicon compound increase the spores’ virulence?
Spores are sticky, and tend to clump together. One method of weaponizing the spores is to coat them with something that interrupts the weak van der Waals interactions between each particle. Tiny particles of silica would do the trick, allowing the spores to float individually through the air. Silicon and oxygen can also form polymers called siloxanes, and such compounds are used to make inhaled medicines more dispersible.
Why have Jahrling and others changed their minds?
In 2002, as part of the FBI investigation, scientists at Sandia National Laboratories in Albuquerque, New Mexico, used electron microscopy to analyse the composition of the spores. The results were finally made public last month. They found silicon and oxygen in the spore coat, but not on the most external layer, the exosporium. The location of the silicon, the FBI says, suggests that it was incorporated naturally into the structures during growth, not added as a final coating to weaponize them.
But other experts disagree with the conclusion. “I don’t think the guys at Sandia understand that the exosporium is not some kind of brick wall,” says Stuart Jacobsen, a research chemist based in Dallas, Texas, who is an expert on the preparation and properties of fine-grained powders and has followed the case closely. “It’s more like a chain-link fence.” Decades ago, a study found that the exosporium is porous to various small molecules1.
How might silicon get into the spores naturally?
The FBI points to experiments from 1990, in which scientists found some silicon in naturally grown spores2. Another hypothesis, suggested by Serguei Popov, an anthrax researcher at George Mason University, Manassas, Virginia, is that the bacteria picked up a bit of silicon from anti-foaming agents while they were being grown. To produce the large number of spores in the contaminated envelope analysed – one trillion spores per gram — Popov infers that the perpetrator must have had to grow a large-scale bacterial culture in a fermenter, where silicon-containing anti-foaming agents are commonly used.
But this would add a relatively low concentration of silicon to the spores. Deliberate weaponization would probably leave much higher amounts. At a House of Representatives Judiciary Committee hearing on 16 September, Representative Jerrold Nadler (Dem.) quizzed FBI director Robert Mueller about the quantity of silicon present in the spores. Mueller did not answer the question.
Why does this matter to the investigation?
Many scientists involved in the investigation still wonder: could Bruce Ivins, in a few late-night lab sessions and in secret, have engineered the powder in the letters? An answer to this would help to determine whether Ivins was guilty, and if so, whether he needed assistance from other parties. It would also help defence experts to assess how easy it would be for others to mount a similar attack in the future.
“I don’t think it would be horrendously difficult to make stuff that was moderate quality,” Peter Setlow, a microbiologist at the University of Connecticut Health Center in Farmington, told Nature in August. But Jacobsen and others say the fact that the FBI has apparently failed to produce a powder to match the attack material suggests it must be very difficult to make. That might put it beyond Ivins’s reach.
If the spores could not be made by a single scientist in a few evenings, that would suggest the spores came from elsewhere – possibly from a state-organized programme.
What happens next?
“The truth will come out when all the data are revealed,” Jahrling says. But there is no indication from the FBI that more data are forthcoming anytime soon. Until they are provided, there will continue to be suspicions and speculations about the silicon in the spores.
References
Gerhardt, P. & Black, S. H. . J. Bact. 82, 750–759 (1961).
Stewart, M. et al. J. Bact. 143, 481–491 (1990).
For the silicon process, there are many organosilane monomers that could do this. One of them is “Replecote” which is commonly used to coat glass slides with thin layer of “polymerized glass”.
Repelcote is Dimethyldichlorosilane. The Dimethyldichlorosilane molecules would penetrate the exosporium and then polymerize in situ on the spore coat.
The result of this is that you have now made a spore with a highly hydrophobic surface. Spores will not stick to surfaces (or to each other).
That’s exactly why Repelcote is used to coat glass slides – to create a hydrophobic surface.
The sheer quantity of silica found in the spores points to the fact that it had to be deliberate addition. The AFIP results show just how large these quantities are for the Daschle and New York Post powders. We are talking double digit percentages here.
Wow. 500g of non-clumping individual spores with xx% Si content. Somebody goes to all the effort of making that. Then they say, “Well, that was fun,” and turn the equipment back to some innocuous use, clearing out all the anthrax and making, oh, I don’t know, powdered milk, say.
I don’t think so.
Somebody’s got a barrel of this stuff, and they just ladled a pint off the top.
Thanks, Jim, for the lucid and sound discussion.
Note that Dr. Ivins at one point forwarded the abstract of article to the FBI — in 2004 — that addressed silicon in the spore coat (that someone at USAMRIID had just provided him). It would be interesting to know what article he forwarded.
Here is a slide show on Amerithrax, silicon in the culture medium, Dugway, Flask 1029, Ivins emails etc. based on the FBI documents.
http://docs.google.com/present/view?id=df7mn8s4_0ffkjfwhn&interval=5&autoStart=true