Scientists on the Anthrax Trail
Oct. 10 -- Investigators say the spores of anthrax found in Florida were man-made. However, this does not confirm that a terrorist act has occurred. It only confirms that the source of the bacteria is not naturally occurring.
In order to determine where the bacteria came from scientists have to analyze the DNA of the bacteria found in Florida. Like all organisms, these bacteria will contain variations in its DNA that make them unique — a DNA fingerprint similar how humans are identified.
Once the DNA sequence is determined it can be compared to a library of sequenced anthrax strains found in places such as Northern Arizona University in Flagstaff, Ariz., and Los Alamos National Laboratory in New Mexico.
Genetic Manipulation
The same technology that allows the identification of strains of bacteria also can be used to alter them. The most obvious alteration would be one that renders the bacteria resistant to antibiotics.
Most experts agree this is not difficult to do — through a low-tech way, or more complex process. The low-tech method involves growing the bacteria in the presence of the antibiotic, and selecting the bacteria that survive. The more complicated method involves inserting genes that confer resistance to specific antibiotics. The end result of both is a strain of bacteria, with altered DNA, that is resistant to antibiotics.
However, some experts question whether this is even necessary.
"It is known which [strains] are nasty and which aren't. It isn't necessary to [engineer] anthrax," said Dr. Richard Moyer, a microbiologist at the University of Florida.
In fact, the strain found in Florida was confirmed by the Centers of Disease Control and Prevention (CDC) to be sensitive to antibiotics, suggesting it had not been altered genetically.
Anthrax as a Weapon
Experts differ on whether anthrax is an effective biological weapon.
"I do not consider anthrax a good biological weapon. It is difficult to mass produce, hard to distribute in an effective fashion, [and] is not self-propogating," said Ketan Desai, author of Germs of War.
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