An interaction between a bacteriophage and its host in which a latent form of the phage (prophage) exists within the bacterial cell, which is not destroyed. Under certain conditions (e.g. irradiation of the bacterium) the phage can develop into an active form, which reproduces itself and eventually destroys the bacterial cell.
A special type of virus-bacterial cell interaction maintained by a complex cellular regulatory mechanism. Bacterial strains freshly isolated from their natural environment may contain a low concentration of bacteriophage. This phage will lyse other related bacteria. Cultures that contain these substances are said to be lysogenic.