Bacteriophages infecting bacterium, illustration - stock illustration

Bacteriophages infecting bacteria, computer illustration. A bacteriophage, or phage, is a virus that infects bacteria. It consists of an icosahedral (20-sided) head, which contains the genetic material, a tail and tail fibres, which fix it to a specific receptor site on the bacterium. The tail injects the genetic material into the bacterium, and the cellular machinery of the bacterium is used to produce more copies of the virus.