Unusually Large Virus Discovered That Kills Bacterium That Causes Anthrax

Posted on January 27, 2014

Dead Zebra carcass from anthrax

An international team of researchers has discovered a new, unusually large virus (or bacteriophage) that infects the bacterium, Bacillus anthracis, that causes anthrax. The virus was discovered from samples found on a zebra carcass in the plains of Namibia in Southern Africa. Vultures are gathering around a dead zebra that was killed by anthrax in the above photograph.

Bacillus anthracis is known for being deadly to animals, including humans, especially if it is inhaled into the lungs. Zebras get infected with anthrax bacterium when they are grazing and pick up some of the spores. The bacteria then multiply inside the zebra. When the zebra dies the bacteria form spores that return back to soil as the zebra carcass decomposes.

Bacillus phage Tsamsa eats anthrax bacterium

The newly discovered bacteriophage, Bacillus phage Tsamsa, (pictured above) "eats" the anthrax bacterium. Researchers say it has a giant head, long tail and a large genome. It is one of the biggest known bacteriophages. Tsamsa also attacks strains of Bacillus cereus, which is linked to food poisoning.

Holly Ganz, a research scientist at the University of California, Davis Genome Center and first author on the paper, says in a statement, "With growing concerns about antibiotic resistance and superbugs, people are coming back to look at phages." The researchers note that a big plus about phages is that they tend to be very specific about the bacteria they target. A bacteriophage may target a harmful bacteria, while leaving good bacteria untouched.

A research paper about new giant siphovirus can be found here in the journal PLoS One.

Zebra Photo: Holly Ganz, UC Davis
Phage photo: Jochen Klumpp, ETH Zurich, Switzerland