Bacteriophage, Phagoprophylaxis

A bacteriophage is a virus that infects bacteria. It consists of a head containing DNA or RNA and a tail. A bacteriophage attaches itself to a bacterium, injects its nucleic acid inside, and uses the bacterium's cellular machinery to reproduce itself. New viral particles assemble inside the bacterium and are then released by cell lysis.

Bacteriophages can be virulent, quickly killing the bacterium, or temperate, where their DNA is incorporated into the bacterial chromosome. Temperate phages can be transmitted by bacteria to offspring.

Bacteriophages are used in medicine for the treatment and prevention of infectious diseases. Phage prophylaxis is the use of specific bacteriophages to prevent infection by dangerous bacteria, such as cholera and dysentery. Bacteriophages are also used to diagnose infections due to their high specificity for certain bacteria.