Analysis of anthrax bacterium's genes gives possible drug targets

Wednesday, April 30th 2003, 12:00 am
By: News On 6

Scientists say they've found potential new targets for drugs and vaccines against the anthrax germ by deciphering and analyzing the bacterium's complete genetic makeup.

Studying the 5.2 million ``letters'' of the germ's DNA code, researchers identified several genes that might play key roles in anthrax infections. Such genes might prove to be good leads for developing new treatments.

Anthrax infections respond to antibiotics if administered early enough, and a vaccine is already available. But scientists are always looking for clues to devising better medicines and vaccines by learning about the inner workings of a germ.

The effort is especially crucial for anthrax, which can be lethal, because it is a potential weapon of future terrorism.

The analysis is presented in Thursday's issue of the journal Nature by scientists at the Institute for Genomic Research in Rockville, Md., with collaborators in other labs.

The institute deciphered the genome of an isolate of the so-called ``Ames'' strain of Bacillus anthracis. Previous work had shown this isolate closely resembles the one used in the fatal anthrax-by-mail attack in Florida in 2001.

The research provides a ``much expanded list of potential virulence genes,'' said Claire Fraser, president of the genomic institute and an author of the paper.

The genes were identified because they resemble those whose functions are known in other bacteria.

In the anthrax bacterium, the genes may play a role in such critical activities within the body as surviving attack by substances called oxygen-free radicals, germinating, scavenging for iron and evading the immune system, Fraser said.

In addition, the researchers turned up more than 600 genes with no known function. Some of those may also turn out to play a role in virulence, Fraser said.

She said researchers will compare the genetic makeup of different isolates of the anthrax bacterium, those with varying degrees of virulence, to learn more about such genes.

Dr. David Relman, a researcher at Stanford University who wasn't involved in the work, called the results ``very useful'' for identifying virulence genes. He agreed the work could provide useful leads for medication and vaccine research.

For vaccines, the leads come from the study's indications that certain proteins are displayed on the bacterium's surface, he said.