Anthrax may be tough, but it gets sick, too

ByABC News
August 17, 2009, 11:33 AM

— -- Anthrax may be the baddest bacteria on the block, but anthrax gets sick, too. Just like you, bacteria get the bug, viruses called bacteriophages. Bacteriophages are just small viruses, tiny and elegant packages of genes that inject themselves into the machinery of cells, using them to churn out more viruses.

"Every time we open up anthrax, there are viruses inside," says microbiologist Vincent Fischetti of Rockefeller University in New York. "What everyone else thought," Fischetti says, was that these viruses preyed on bacteria, like colds prey on people, making them weaker.

But in 2006, Fischer and his student Raymond Schuch found that anthrax actually weathers the assault of a natural antibiotic better when it's infected with a virus. "That led us to wonder how this deadly bacteria exists when it is outside humans," Fischetti said.

Anthrax is found naturally in the soil, packed into spores in dirt, waiting to be eaten, by grazing livestock. Once inside a creature it spreads, releasing toxins that often kill their host, and deposit more spores in the soil, dormant, waiting for the next victim.

Or so we thought. "Actually the story turns out to be a lot more complicated," Schuch says.

A great deal of research has focused on anthrax after it was used in 2001 to kill five people in mailings linked by the Justice Department to a United States Army Medical Research Institute for Infectious Diseases vaccine researcher, Bruce Ivins, who committed suicide last year. But most of the research focuses on anthrax infections, not on how it spends most of its time in the wild.

In a paper out in the journal PloS One, Fischetti and Schuch looked at how infection with nine bacteriophages affected anthrax, compared to uninfected anthrax, in the soil. "Infection drives a series of changes," they write after a series of experiments: