Attack of the Bacteriophage
Bacteria can be fierce and can cause lots of painful infections in the body. So maybe it'll cheer you up to know that bacteria can be infected by a type of virus known as a bacteriophage, which means "bacteria eater."
Bacteriophages are much smaller than bacteria, and--like all viruses--are incapable of growing and multiplying on their own. So they need to find a host in order to replicate themselves.
And that's why they attack bacteria.
Usually, the targets are super-specific, which means that a particular phage can only attack one type of bacterium, which it does by attaching to the cell wall and inserting its own genetic material into the cell body.
Antiobiotics vs. Bacteria Eaters
The bacteriophage's genetic material takes over the bacterium's cellular machinery and reprograms it to produce more bacteriophages. And eventually, the host produces so many of them it literally bursts, enabling the new bacteriophages to spread to other bacteria.
So if bacteriophages have such specific targets, can scientists use them to wipe out harmful bacteria? Not yet. Ever since bacteriophages were discovered, scientists have been experimenting with using them to fight diseases such as cholera and, more recently, anthrax. Still, for the time being, antibiotics are still your best bet.
"A Germ's Germ" (New York Times)