CASE CLOSED … what really happened in the 2001 anthrax attacks?

* When (prior to 9/11) did USAMRIID’s John Ezzell, the FBI’s anthrax expert, send the dried spores to Johns-Hopkins Applied Physics he had made at the request of DARPA? Did those spores show a silicon signature?

Posted by DXer on May 14, 2010


The FBI’s case against Dr. Ivins is clearly bogus: no evidence, no witnesses, an impossible timeline. The real question is why the FBI persists in sticking to such a pathetic story. What are they hiding? I offer one “fictional” scenario in my novel CASE CLOSED, judged by many readers, including a highly respected official in the U.S. Intelligence Community, as “quite plausible.”

* buy CASE CLOSED at amazon *


23 Responses to “* When (prior to 9/11) did USAMRIID’s John Ezzell, the FBI’s anthrax expert, send the dried spores to Johns-Hopkins Applied Physics he had made at the request of DARPA? Did those spores show a silicon signature?”

  1. DXer said

    The NAS report states:

    “Early in the investigation, AFIP performed SEM-EDX analysis of a New York Post letter
    sample and found regions in the sample having high silicon content but no oxygen, suggesting
    the presence of silicon-rich material that was not related to nanoparticulate silica. While this
    observation could have led to an explanation for the difference between the bulk and individual
    spore measurements, follow-up experiments apparently were not performed. The committee
    notes that this information was not made available to it or to the FBI until spring 2010.”

    Does it relate to use of Percoll (colloidal silica) as a density gradient?

    • DXer said

      Terry Abshire was Dr. Ezzell’s assitant. Dr. Ezzell made a dried aerosol out of Flask 1029 Ames. So they have the head Navy guy (in charge of Navy biodefense while Al-Timimi did classified work for the Navy) and JE’s assistant, working on the silicon signature issue. Then we have this as the NAS conclusion:

      “Finding 4.4: Surrogate preparations of B. anthracis did reproduce physical characteristics
      (purity, spore concentration, dispersibility) of the letter samples, but did not reproduce the
      large amount of silicon found in the coats of letter sample spores.
      Surrogate preparations by DPG, using B. anthracis from the Leahy letter as the starter
      source (FBI Documents, B1M13D3), reproduced the general physical characteristics of the letter
      samples (purity, spore concentration, dispersibility) but not the silicon chemical characteristics.
      Surrogate preparations showed that samples having bulk silicon content up to 5 percent could be
      prepared without intentional addition of silicon dispersant. However, none of the DPG surrogate
      preparations analyzed for silicon in the spore coat were similar to the New York Post, Daschle,
      and Leahy letter samples with respect to either the amount per spore of silicon incorporated in
      the coat or the fraction of spores observed to contain silicon in the coat. Furthermore, the
      committee sought, but could not obtain, a detailed explanation of the thought process that went
      into selection of the DPG methods or their relationship to the Buran and Abshire preparations.
      The committee acknowledges that there were many more possible scenarios for spore
      preparation than could have been feasibly explored with available resources and in a reasonable
      period of time. However, it was not clear to the committee how the subset of surrogate
      preparation methods was selected and whether these choices were based on an understanding
      informed by the investigation or on other assumptions about the approach taken to produce the
      evidentiary materials.”

  2. DXer said

    Catherine Herridge, the reporter holding up the email from Dr. Ivins about the FBI anthrax expert who secretly made a dried powder out of Flask 1029 prior to 9/11 as part of authorized DARPA research, addressed the Silicon Signature issue in December 2009 and the fact that there was no chemical match supporting Ivins’ guilt.

    She summarizes under the banner
    “New Questions About Suspect in 2001 Anthrax Attacks”

    Case Not Closed?, Dec 22, 2009
    New twist in 2001 anthrax attacks case

  3. DXer said

    May. 21 2010
    ‘Detective myopia’, botched investigations and wrongful convictions

    Nine years ago, Americans in every state, every city, learned about the new worry–deadly anthrax being sent through the U.S. mail. People died–every one of them an innocent bystander. Naturally, federal agencies launched investigations.

    Eventually, the name of Steven J. Hatfill emerged as a suspect. Although never charged with a crime, innuendo made public by journalists and a variety of non-journalist commentators seemed to convict Hatfill in the court of public opinion. He lost employment opportunities, spiraled down into deep depression and wondered how to reclaim his reputation.

    Years later, federal investigators exonerated Hatfill and blamed a different scientist sometimes employed by the government. But that other scientist, since deceased, never gained the same recognition as Hatfill.

    In the May 2010 issue of The Atlantic magazine, journalist David Freed recaps the anthrax investigation and brings it up to date in a feature with the headline “The Wrong Man.”

    Drama and lessons abound. Here is the portion that sticks with me the most, given my own investigations into alleged wrongful convictions and their causes:

    After collecting seemingly relevant evidence against Hatfill, “the government became convinced all of it had to amount to something,” Freed writes. “It didn’t. The FBI’s sleuthing had produced zero witnesses, no firm evidence, nothing to show that Hatfill had ever touched anthrax, let alone killed anyone with it. So thin was the bureau’s case that Hatfill was never even indicted. But that didn’t stop the FBI from focusing on him to the virtual exclusion of other suspects.”

    Freed then quotes Daryl F. Gates, former chief of police in Los Angeles. Gates discusses “detective myopia,” saying “this mostly happens when the case is important and there is pressure to solve it.”

    Journalists and other trained professionals suffer from myopia during criminal investigations, too. All of us who care about justice rather than merely closing a case must guard against the disease.

    Comment: One shortcoming of the Freed article was that it made no mention that Dr. Hatfill had forged his PhD diploma. Thus, he would have lost his job due to that. I am not sure how the medical licensing authorities would view it either. It always struck me as a very serious matter that is glossed over.

  4. DXer said

    Discussion whether Aulaqi was part of US-based support cell — from Al Qaeda from the beginning. (Catherine Herridge suggests that it now appears that he was).

    May 22, 2010
    Al-Awlaki’s Sordid Personal Life

  5. DXer said

    Yemeni cleric advocates killing US civilians
    (AP) – 3 hours ago

    CAIRO — An American-Yemeni cleric whose Internet sermons have helped inspire attacks on the U.S. is advocating the killing of American civilians in a new al-Qaida video.

    Anwar al-Awlaki has been singled out by U.S. officials as a top terrorist threat and has reportedly been added to the CIA’s list of targets for assassination despite his American citizenship.

    The U.S.-born al-Awlaki moved to Yemen in 2004 and is in hiding there after being linked to the suspects in the November shooting at an Army base in Fort Hood, Texas, and the December attempt to blow up a U.S. jetliner bound for Detroit.

    In a video posted Sunday, al-Awlaki justifies civilian deaths by accusing Americans of intentionally killing a million Muslim civilians in Iraq and Afghanistan.

    Comment: Defense counsel and Professor Turley says that Anwar Aulaqi is central to the allegations against his client Ali Al-Timimi, who he reports was an “anthrax weapons suspect” and who records show shared a suite with the Ames anthrax researchers who were the co-inventors of a process using silica in the cultivating medium

    But never mind: The United States Department of Justice, after the largest investigation in the annals of crime, found that Dr. Ivins liked writing letters to the editor and used fake screen names on the internet. That was as strong as the DOJ’s evidence against Dr. Ivins ever got.

    Now if Anwar Awlaki ever succeeds in killing American civilians — next time using anthrax — whose fault will it be? US Attorney Jeffrey Taylor who falsely claimed that only Ivins’ post office sold the federal eagle stamp and speciously claimed that Dr. Ivins had exclusive control over Flask 1029? AUSA Kenneth Kohl’s? AUSA Rachel Carlson Lieber’s? The personnel responsible for the withholding of the report showing that the photocopier used at Ft. Detrick is known NOT to have used to photocopy of the anthrax letters (as suggested in the investigative summary)? The lead criminal prosecutor Daniel Seikaly, born Haifa in 1948, whose family advocated that terrorism should not be attributed to Bin Laden and whose daughter represented “anthrax weapons suspect” Al-Timimi for free? FBI Director Mueller for compartmentalizing the investigation and preventing a meaningful leak investigation? Jane Alexander at DARPA for not having in place a system that vetted researchers in awarding grants and put a former Zawahiri associate in charge of a DARPA project? General John Parker for not disclosing that dried powdered was made at USAMRIID at the request of DARPA?

    It doesn’t matter who made missteps, does it? Hindsight is 20/20. People more often than not tend to act in good faith even if out of self-interest.

    Isn’t the great priority neutralizing the threat and achieving justice?

    But don’t these missteps have to be acknowledged before the threat can be neutralized? Is there any reason whatsoever for the continued withholding of the mass spectometry report by Dr. Bartick showing that the photocopier at Ft. Detrick was NOT in fact used to photocopy the letters?

    Is there any justification at all for the continued withholding of the rest of Dr. Ivins’ emails? (The DOJ, FBI and USAMRIID wilfully withheld for two years, for example, the emails that show dried powdered Ames was made at Ft. Detrick by the FBI’s anthrax expert at the request of DARPA).

    Even while giving everyone a free pass for events to date, shouldn’t anyone who continues to stand in the way of the production of documents under FOIA and the Federal Advisory Committee Act be terminated (fired if an employee and de-funded if a contractor).

    • DXer said

      INTELWIRE is the place to go for documents about Anwar Awlaki. Mr. Berger’s website notes that there will be a chapter on Awlaki in his forthcoming book on American jihadists. Berger’s expertise is wide-ranging and his insights regularly grounded solidly on the documentary evidence that he laboriously gathered and made available to the public. Names like Khalifa, Ali Mohammed, Anwar Aulaqi may not be household names but the men are key players in a historical narrative that is critical to understand.

      Documents he has obtained under FOIA explore Awlaki’s links to the September 11 hijackers, including documents featured on the recent Fox program about Awlaki.

    • DXer said,2933,593331,00.html?test=latestnews

      Exclusive interviews with former and current government agents raise several questions: Was Awlaki part of a terrorist cell within this country that attacked America on 9/11? And following the attacks, was there an attempt by our government to turn Awlaki into an informant or track him for intelligence?

      You will see for yourself how this American terrorist is using our system against us.

    • DXer said


      Anwar Aulaqi on NPR, October 30, 2001

      IMAM ANWAR AWLAKI: Our position needs to be reiterated and needs to be very clear. The fact that the U.S. has administered the death and homicide of over one million civilians in Iraq, the fact that the U.S. is supporting the deaths and killing of thousands of Palestinians does not justify the killing of one U.S. civilian in New York City or Washington, D.C., and the deaths of 6,000 civilians in New York and Washington, DC, does not justify the death of one civilian in Afghanistan. And that is the difference between right and wrong, evil and good, that everybody’s claiming to talk about.

    • DXer said

      My friend Hal was Anwar’s roommate during Hajj in 2001. Privately, he was always different than his smooth persona. He was coordinating with fellow Falls Church imam Ali Al-Timimi who shared a suite with the leading anthrax researcher and former deputy USAMRIID Commander, who were funded by DARPA and working with subcontractor Southern Researcher Institute under the 2000 grant. Anwar was detained briefly in 2002 when he came back into the country but then released.

      Hal faxed me a list of everyone who went from the US on the pilgrimage Anwar led in 2001. It’s always been a question of who knew who.

    • DXer said

      “Between June 1999 and March 2000, the FBI opened an investigation into Awlaki. He was already under suspicion as vice president of a San Diego-based Muslim charity, the Charitable Society for Social Welfare, considered to be “a front organization to funnel money to terrorists.” He was now being investigated for fundraising for the Palestinian terror organization Hamas, for possible direct links to Al-Qaeda, and for a visit paid to him by a close associate of Omar Abdel Rahman, the blind sheikh behind the 1993 World Trade Center bombing.”


      Who was this close associate of Omar Abdel Rahman? Was it Gamal Sultan? Gamal visited the United States during that period and in 1999 had pitched to Abdel-Rahman (through the post office liaison Abdel-Sattar’s delivery of a letter) the idea of going mainstream by launching a reform political party. He was looking for Egyptian Islamic Group to support the idea (or at least not oppose it). His co-founder of the party was the founder of the Egyptian Islamic Jihad Kamal Habib. Both were writers of the Ann Arbor-based charity Islamic Assembly of North America and were lead contributors of the publication Al Manar Jadeed which discussed these sorts of issues and, in Arabic, focused mainly on Egyptian politics. The lead IANA speaker was Ali Al-Timimi who shared a suite with the DARPA-funded Ames anthrax researchers. IANA owned the school near me and had a spin-off dba here. When KSM was arrested and then authorities searched Al-Timimi’s residence, 100 federal agents came here and simultaneously interviewed 150 people as part of OPERATION IMMINENT HORIZON. They arrested someone expert in spraydrying powder and experienced with mixing with silica whose supervisor worked on a US Army funded device (the MICROBIAL VAC) that concentrated anthrax by a factor of 10. Its inventor tells me it could be used to weaponize anthrax but only on a small scale. The scientist was arrested as a material witness but not questioned. I believe it was him at the mall with me early one Sunday morning at the same time trying to get a copy of Nadler’s ANTHRAX WARS when it came out. (I bought both copies). :0) I would never have learned about Tarek had it not been for the helpfulness of people here.

    • DXer said

      A couple were removed for terms of use violation so these may meet the same fate.

      Interview with Shaykh Anwar al Awlaki 2/5


  6. DXer said

    “Ripped from the Headlines”

    “And at least once, the headlines ripped from the script: L & O [Law & Order] was scheduled to shoot a five-hour miniseries, tentatively titled “Terror,” starting on Sept. 24, 2001. The saga was to begin at a Qaeda training camp in Afghanistan; four men would then come to New York and blow up the subway at Times Square. After that: an anthrax attack. The whole idea was scrapped when real planes flew into the World Trade Center on Sept. 11.”

  7. DXer said

    Brian Ross (including interview of Bradley Garrett who worked on Amerithrax and Hatfill lead)

    Informant says FBI threw away chance to catch alleged 9/11 plotter


    The real significance of this interview perhaps is that it has an FBI undercover confirming that Atta and El-Shukrijumah (Jafar the Pilot) were hanging out together. The BOLO was issued for El-Shukrijumah at the same time as Jdey and Aafia (and Jdey’s sidekick Boussara).

    Infiltration of US Biodefense (440 pages freely viewable)

  8. DXer said

    For another example of scientists being used by the IC but prevented from engaging in collection or analysis that is actually meaningful in keeping the country safe,*/ see the Biological Sciences Experts Group (BSEG).


    Infiltration of US Biodefense (440 pages freely viewable)

    Experts Advise IC on Classified Biosecurity Activities
    April 13th, 2010 by Steven Aftergood

    The Biological Sciences Experts Group (BSEG) is a group of non-governmental scientists who advise the U.S. Intelligence Community (IC) on activities to counter biological threats and weapons. Aside from the fact of its existence, nearly everything about the group is classified, but a few details of the enterprise have lately emerged.

    The BSEG is supposed to “provide technical advice and counsel on specific scientific and technical issues relevant to the IC’s mission to counter the threat posed by the potential proliferation of biological weapons and related technologies,” according to an internal account. See “Biological Sciences Experts Group Concept Paper” (undated, probably 2006, FOUO).

    The BSEG will “strengthen the integration of the life-science and intelligence communities and facilitate access of the IC to life-science experts outside of the Federal government.” The BSEG is supposed to help intelligence agencies design experiments and collection methodologies, interpret results, and perform other kinds of technical assessments. However, “the BSEG shall neither produce analytical intelligence products nor engage in collection.”

    According to the original concept, the BSEG was to be comprised of 12 non-governmental individuals, supported by a larger network of experts. The membership of the BSEG is not officially disclosed, unless the individual members choose to make themselves known. The Group is managed by the National Counterproliferation Center of the Office of the Director of National Intelligence, and is subject to a steering committee of IC agency representatives.

    It could not immediately be learned how active the BSEG has been, on what topics it was consulted, or what it may have accomplished.

    For a previous account of the BSEG, see “Panel Provides Peer Review of Intelligence Research” by Yudhijit Bhattacharjee, Science, December 7, 2007, p. 1538 (sub. req’d).

  9. DXer said

    Should it be classified that a sonicator and corona plasma discharge were used on the attack anthrax? If they had just acknowledged that in 2002, Amerithrax would have been readily solved and we wouldn’t have had the decades-long mess on technical issues. Dr. Ivins would not have made a scapegoat and would not have died.

    Was it national security that motivated the secrecy?

    Or old-fashioned CYA on the part of the FBI scientists whose experts were doing the research involving the corona plasma discharge and sonicator?

    That’s a go on dinner out.

    3 FBI probes looked at ’80s leaks to columnist Robert Novak
    By Joe Stephens
    Washington Post Staff Writer
    Thursday, May 20, 2010; 12:41 PM

  10. DXer said

    “There has been good work done since September 11, 2001, but we need to continue down the path toward further integration and insist on a greater level of effectiveness within the intelligence community,” they said.
    That reform also needs to alter the Intelligence Community’s methods of handling intelligence, according to Kean and Hamilton.
    “The Intelligence Community must become more competent in obtaining and using appropriate information on people who cross borders and may have nefarious intent, including Americans,” they said.


    We’ve seen the level of competence of the federal workforce in obtaining and processing information.

    Judging from the record produced, it took four years to obtain the 20 pages of documents relating to the visit by the former Zawahiri associate who worked alongside Bruce Ivins with virulent Ames.

    It has taken 2 years to cross out the proper names on a stack of emails and make them available for inspection and copying. Key emails (including all attachments) have been culled in violation of FOIA. When there is a next large scale attack, it will be due to the failure of people like John Peterson and the USAMRIID Colonel responsible for the FOIA production to do their jobs efficiently and give the production relevant to the anthrax threat priority. The production of Bruce Ivins’ emails should have been expedited.
    At the time of the next attack, the facts relating to the dropping of the ball will be different. Perhaps it will relate to information not being passed to an airline or passed from one federal agency to another. Perhaps there will be “three layers of review.” But the theme will be the same. Federal workers are allowing their selfish bureaucratic or personal motivations (for example, the FOIA officer works from her home) override the overall importance in keeping the United States safe. In the case of some senior people responsible for the delay (like Jason Bannan), the motivation is CYA. “Imagine the liability” reverberates around the coffee break rooms of agencies and institutions.
    Everyone involved in the two year stall in the production of Amerithrax documents should be fired (pursuant to a Congressional or IG investigation) if they continue this malfeasance even a single week longer.

    Firings should start with those responsible for the withholding of National Academy of Science to prevent disclosure of documents for those two years. For example, the FBI has withheld documents showing that the photocopier Rachel Carlson Lieber and Kenneth Kohl allege was used by Bruce Ivins in fact was NOT used by Ivins. See report by Bartick. That makes Ken Kohl’s violation of the constitution in the Blackwater case pale in comparison. Ken, mind you, framed his opinion of Amerithrax assisting Daniel Seikaly, the man intentionally leaked the hyped Hatfill stories and whose daughter then represented “anthrax weapons suspect” Ali Al-Timimi pro bono.

    The decision-makers responsible for the withholding included those who had gross conflicts of interest established by the documentary evidence, such as Jason Bannan’s tenure as the collection scientist at the Bacteriology Division at the American Type Culture Collection in 2001. The fact that they themselves do not know what’s going on or the identity of the mailer — or the grave threat the country faces from an aeosol anthrax attack — is no excuse.

    But this is much bigger: the Bush Administration sought to suppress public understanding of Amerithrax because “anthrax weapons suspect” Ali Al-Timimi had been briefly the assistant of Andrew Card, the White House Chief of Staff. NSA warrantless wiretapping and the invasion and occupation of Iraq and billions in appropriations to the security units of Egypt and Israel are all part and parcel of what has been allowed to happen by FBI Director Mueller for 8 years now. The failure to solve Amerithrax will be Director Mueller’s legacy. And there is no way to dress that up — not even with stained panties. It now appears that there apparently is no hope for its correct solution until his replacement (along with a new Attorney General). It was his compartmentalization of the squads that served to prevent the solution of Amerithrax. If the FBI had really wanted to know who was responsible for the leaks, all they needed to do was ask the lead prosecutor Seikaly.

    The CIA provably has known who the mailer was since December 2001. And, oh yes, it will be proved. Indeed, all you VOC supporters, are you really so sure that the “closing of Amerithrax” was not just part of an intelligence operation and there’s not a spike mike in the wall above your pillow? Are you really so sure that Magdy or Mohammed didn’t rat you out years ago? Are you sure you are already not in the net while the CIA hopes to catch Ayman?

    But the bureaucrats can dress up all the rationalizations all they like. They have contributed to the failure to solve Amerithrax and there needs to be accountability if it continues into June. All those who continue to be responsible for the continued delay and the suppression of documents that should have been produced under FOIA — but were culled — should recognize that there are obstruction of justice laws that apply, particularly to the destruction of documents.

    You think you are catering to the whims of a boss or self-interest but actually you are indulging the whims of Ayman Zawahiri and if it continues it most definitely is acting against your self-interest.

    You are setting the stage for the next 911 — which given the present considerations of technology and world events — could involve a mass event of historic proportions. From this day on, everyone not part of the solution is part of the problem.

  11. DXer said

    “Would Bloggers Have Cracked Chandra’s Case?
    A reporter who covered 24-year-old intern Chandra Levy’s death looks at a new book about the case—and shares where the mainstream media went wrong.”

    Bloggers are unrestrained by the orthodoxies of the professional reporter. They don’t need to follow the conventions of the 800-word newspaper story and can instead toss out an idea in two sentences that will nonetheless spur national discussion. They can ask questions without necessarily supplying an answer. Critically, bloggers also do not typically rely on official sources for information. Reporters and their anonymous sources both benefit from the relationship. Reporters get exclusive information, which earns them promotions; sources weave narratives that serve their interests. This corrupting symbiosis makes the reporter all too quick to take an official’s word at face value.

    In the Levy case, this dynamic was clearly at work. At routine press conferences, all that reporters wanted to hear about was Condit. This suited the police just fine because they didn’t have the slightest idea what had happened to Levy. And so, even as they were careful to say he was not a suspect, police dished on Condit, suggesting repeatedly that when the congressman was pressed for information regarding Levy, he was shifty and uncooperative. In fact, as Horwitz and Higham reveal, Condit disclosed his relationship with Levy in his first interview with police, agreed to three more interviews, allowed a search of his apartment, and voluntarily supplied DNA. But press coverage at the time propagated police officials’ incomplete portrayal.

    The pack tendencies of journalists are still evident, but skeptical outsiders are now part of the conversation. Take the Duke case: as the mainstream press became consumed with the racial melodrama, several bloggers zeroed in on the facts. History professor K. C. Johnson launched a blog that questioned the accuser’s story early on. As the case went on, he spent hundreds of hours investigating and posting factual analysis that dismantled the prosecution’s case. Unrestrained by the limits imposed on traditional reporters by periodic deadlines, source relationships, and their neutral pose, Johnson acted as a real-time historian, compiling original source material. Meanwhile, even five months into the case, The New York Times published a credulous 5,700-word story relying far too heavily on prosecutors’ claims. Liestoppers, a second grassroots blog focused on the Duke case, tore the Times’s story to shreds, finding several errors.

    If a congressman’s mistress went missing today, the media firestorm might even be more intense than it was during the summer of 2001. The bizarre conspiracy theories might spread faster. But it also is far more likely that a citizen journalist would think to search public reports of other attacks within days of the disappearance and start connecting the dots. We now know what happened to Chandra Levy. But given the time that was wasted and the evidence that has been lost, it may be too late for justice. We will find out when Guandique’s trial begins this October—nearly a decade after Levy first disappeared.

    Comment: Years ago, Newsweek’s Mark Miller was working with posters on this blog on a hot lead when Daniel Seikaly, lead prosecutor in the Amerithrax prosecution, handed Newsweek the bloodhound story. That got Newsweek off the scent.

    See generally

    Infiltration of US Biodefense (440 pages freely viewable)

    Suspect and A Setback In Al-Qaeda Anthrax Case
    Scientist With Ties To Group Goes Free
    By Joby Warrick
    Washington Post Staff Writer
    Tuesday, October 31, 2006

    “Rauf’s name was first publicly associated with the documents by Ross Getman, a New York lawyer who maintains a Web site devoted to the 2001 anthrax attacks.”

    Note: I had first named Rauf about 3 or 4 years earlier (after the raid of the Khawaja compound) and had named Yazid Sufaat as part of ZABADI a year before KSM named him. Those were two compartmentalized cells developed by Ayman Zawahiri. Neither Rauf Ahmad nor Yazid Sufaat knew of the other. My key source knew Ayman Zawahiri very well — and is as connected as you possibly get to such matters.

  12. DXer said

    2010 book

    “He was a critical part of our vaccine studies,” said John Ezzell, a former top scientist at Fort Detrick who worked with Ivins. “Most of the time, he was very happy and outgoing. He did good work. He was very conscientious and he worked long hours to get the work done.” Biological & Chemical Warfare

    By Hal Marcovitz (2010), quoting John Ezzell

  13. DXer said

    Microbiology. 2010 May 13. [Epub ahead of print]
    Siderophore-mediated Iron Acquisition in Bacillus anthracis and Related Members.

    Hotta K, Kim CY, Fox DT, Koppisch AT.

    National University of Singapore;

    Iron is a requisite nutrient for the growth and proliferation of bacteria. Unlike higher organisms, which may obtain bioavailable iron from the diet, bacteria must acquire iron from their environment. This presents a challenging problem, as soluble Fe(3+) in aqueous oxic environments typically exist at attomolar (10(-18)) concentrations (Harris, 2002). Iron homeostasis in a mammalian host is also tightly regulated; virtually no iron exists in serum that is not bound to heme, iron storage proteins (ferritin, transferrin, etc) or as cofactors for various enzymes. Rigorous control of iron availability in mammals serves as a barrier against infection (Andrews et al., 2003; Bullen & Griffiths, 1999). The paucity of iron in serum has driven many pathogenic bacteria to evolve sophisticated means to acquire iron from the host, including the use of high-affinity iron chelates termed siderophores (Boukhalfa & Crumbliss, 2002; Miethke & Marahiel, 2007; Neilands, 1974; Payne & Crosa, 2004; Raymond & Carrano, 1979; Winkelmann, 2002). The efficiency with which this is accomplished by pathogenic bacteria generally parallels their virulence (Byers & Arceneaux, 1998; Griffiths, 1999; Koehler, 2000). As such, the interplay between iron sequestration by the host and acquisition by the pathogen is an important determinant in the establishment of infection. Siderophore biosynthesis by itself is not a de facto determinant of virulence but can certainly play a pivotal role in augmenting the pathogenicity of a given microbe (Cendrowski et al., 2004; Dale et al., 2004; De Voss et al., 2000).Recent observations have shed light on some of the endogenous iron acquisition mechanisms of members of the Bacillus cereus sensu lato group. In particular, pathogens in the B. cereus group use siderophores with both unique chemical structures and biological roles. This review will focus on recent discoveries in siderophore biosynthesis and biology in this group, which contains numerous human pathogens, most notably the causative agent of anthrax, Bacillus anthracis.

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