GC: n

S: NCBI – (last access: 11 March 2020); WHO – (last access: 11 March 2020).

N: 1. “virus that parasitizes a bacterium by infecting it and reproducing inside it,” 1921, from French bactériophage (1917), from bacterio-, combining form of bacteria, + phage.
2. Any of the viruses that infect bacterial cells; each has a narrow host range.
3. Bacteriophage, also called phage or bacterial virus, any of a group of viruses that infect bacteria. Bacteriophages were discovered independently by Frederick W. Twort in Great Britain (1915) and Félix d’Hérelle in France (1917). D’Hérelle coined the term bacteriophage, meaning “bacteria eater,” to describe the agent’s bacteriocidal ability. Bacteriophages also infect the single-celled prokaryotic organisms known as archaea.
4. Thousands of varieties of phages exist, each of which may infect only one type or a few types of bacteria or archaea. Phages are classified in a number of virus families; some examples include Inoviridae, Microviridae, Rudiviridae, and Tectiviridae. Like all viruses, phages are simple organisms that consist of a core of genetic material (nucleic acid) surrounded by a protein capsid. The nucleic acid may be either DNA or RNA and may be double-stranded or single-stranded. There are three basic structural forms of phage: an icosahedral (20-sided) head with a tail, an icosahedral head without a tail, and a filamentous form.
5. During infection a phage attaches to a bacterium and inserts its genetic material into the cell. After that a phage usually follows one of two life cycles, lytic (virulent) or lysogenic (temperate). Lytic phages take over the machinery of the cell to make phage components. They then destroy, or lyse, the cell, releasing new phage particles. Lysogenic phages incorporate their nucleic acid into the chromosome of the host cell and replicate with it as a unit without destroying the cell. Under certain conditions lysogenic phages can be induced to follow a lytic cycle.

S: 1. OED – (last access: 11 March 2020). 2. TERMIUM PLUS – (last access: 11 March 2020). 3 to 5. EncBrit – (last access: 11 March 2020).

SYN: bacterial virus, phage.

S: TERMIUM PLUS – (last access: 11 March 2020).

CR: bacterium, virus.