Researchers reveal anthrax clues

Last autumn's attacks sparked a huge investigation

US scientists are closer to knowing the sources of last year's anthrax attacks.

They have found a "fingerprint" series of genetic markers which can be used to tell the difference between very similar strains of the bacterium.

It will greatly facilitate the analysis that will lead to the answer

David Selman
Stanford University

The team at The Institute for Genomic Research (Tigr) and Northern Arizona University compared the DNA sequence of anthrax from an attack in Boca Raton, Florida, in October 2001, with a laboratory strain.

The identification of "signatures" means it could eventually be possible to work out where the anthrax used in the 2001 attacks came from.

The agent which causes anthrax is called Bacillus anthracis and the strain used for research in the US came from a dead Texan cow in 1981.

It was intended for military research and passed to other labs in the US and Europe.

Evolving differences

It is likely that anthrax cultured in different labs has evolved slight variations as it has multiplied.

The fingerprinting techniques would, if the researchers expand them to cultures from all labs, allow scientists to build a database tying specific cultures to specific labs.

The scientists involved are not keen to comment on research done in co-operation with the FBI, but another microbiologist told Reuters news agency that the research would allow scientists to proceed and answer the question of the fatal strain's origin.

"It will greatly facilitate the analysis that will lead to the answer," Stanford University's David Selman said.

Database call

Tigr's president, Claire Fraser, is calling for the development of a database of different strains of anthrax and other potential biological warfare agents.

She says that such a database could be used to track down the source of biowarfare attacks and help researchers develop better vaccines and treatments.

There are about five million base pairs or genetic "letters" in the code of the deadly organism's DNA.

By comparison, human DNA contains several billion base pairs.

The US team used modern genetic sequencing technology to read off the letters of the code and spot differences in the sequence, some as small as one letter.

Their results appear in the journal Science.