ON THE TRAIL OF A GERM
17 Feb 2003
Source: Rocky Mountain News, February 17, 2003
On the trail of a germ
Microbial forensics poised to become new anti-terror tool
By Jim Erickson, Rocky Mountain News
Arizona researchers recently used a vial of slime scraped 10 years ago from the walls of a Japanese doomsday cult's Tokyo headquarters to recover anthrax spores and pinpoint the specific strain harbored by the terrorists.
The microbiological feat performed by Northern Arizona University scientists shows the power of microbial forensics, an emerging discipline which uses tiny genetic variations between bacterial strains to provide clues about the source of bioterrorism agents.
Interest in the field has soared since the anthrax attacks of late 2001, which killed five people.
While those crimes remain unsolved, microbiologists and federal law enforcement officials are going ahead with efforts to standardize the methods of microbial forensics. The goal is to hone the techniques now so that germ evidence gathered after a future bioterrorist attack will hold up in court.
"Whatever evidence comes in (to the courtroom) afterward, the defense may - and probably will - challenge it as being unreliable, wrongly interpreted or handled inappropriately," the FBI's Bruce Budowle said Sunday at a Denver meeting of the American Association for the Advancement of Science.
Budowle spoke at a news briefing on microbial forensics that included Paul Keim of Northern Arizona University and Joseph Campos of Children's National Medical Center.
The panelists released a new American Academy of Microbiology report, written by Keim, recommending the establishment of a national germ repository to hold strains of bacteria and viruses that could be used in a bioterrorist attack. The repository would be housed at the Army's Fort Detrick germ lab in Maryland.
Another key recommendation of the report, Microbial Forensics: A Scientific Assessment, is the creation a comprehensive database of genetic fingerprints from dangerous microbes. After an attack, samples from the crime scene - or from the blood of victims - could be checked for matches in the database.
That would help narrow the search for the germ's source.
Microbial fingerprinting is already underway at Keim's lab, which has played a central role in the anthrax-letter investigation.
In collaboration with Keim, a similar project is happening at the Centers for Disease Control and Prevention laboratory in Fort Collins. Researchers there are building a database with genetic fingerprints from more than 1,000 strains of the plague bacterium - another potential bioweapon.
Under a non-disclosure agreement with the FBI, Keim is not allowed to talk about the anthrax-letter investigation.
But he did reveal new information Sunday about the diabolical pursuits of the Aum Shinrikyo cult, which killed 12 people and injured more than 5,000 others by releasing the nerve gas sarin on Tokyo subway platforms in March 1995.
Two years before the sarin attack, Japanese public health officials investigated the cult's eight-story suburban Tokyo home and collected four or five vials of a slimy liquid running down the walls of the building.
One vial sat on a dusty shelf for a decade before a colleague sent it to Keim for analysis.
Keim's lab recently recovered anthrax spores from the slime and grew them in laboratory petri dishes. The Arizona researchers analyzed 48 colonies, and all 48 were from the Sterne strain, a non-virulent form of anthrax used to vaccinate cattle.
In 1993, cult members used van-mounted sprayers to release aerosolized anthrax into the streets of Tokyo in eight attacks, Keim said. No one was harmed because the cultists used the non-virulent strain.
"One idea is that they were incompetent and thought it would kill people," he said. "A second possibility is that it was a trial run, that they were trying to get their equipment to work so it wouldn't clog.
"If authorities at the time had recognized this as a bioterrorism attack, perhaps the sarin gas attack never would have occurred," Keim said.