A virus that attacks and destroys bacteria.
Infective agents of virus type, which act as parasites living on bacteria, at whose expense they propagate causing the death of the invaded cell. Phages, which consist of deoxyribonucleic acid and specific proteins, possess a characteristic morphology when seen with the electron microscope, combined with a relative resistance to heat and other physical and chemical agents. Each phage acts specifically against one or more species or sub-species of bacteria and this fact is utilized in the identification of strains of staphylococci and salmonella by ‘phage typing’.
When employed as a noun accompanied by a singular verb, this term typically denotes a type of bacteriophage species. However, when it is accompanied by a plural verb, it typically refers to individual phage particles. And when used in its plural form, it typically indicates multiple types of phage species.