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Res Microbiol. 2003 May;154(4):245-51.

Bacteriophage observations and evolution.

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Department of Medical Biology, Faculty of Medicine, Laval University, Qc G1K 7P4, Quebec, Canada.


Bacteriophages are classified into one order and 13 families. Over 5100 phages have been examined in the electron microscope since 1959. At least 4950 phages (96%) are tailed. They constitute the order Caudovirales and three families. Siphoviridae or phages with long, noncontractile tails predominate (61% of tailed phages). Polyhedral, filamentous, and pleomorphic phages comprise less than 4% of bacterial viruses. Bacteriophages occur in over 140 bacterial or archaeal genera. Their distribution reflects their origin and bacterial phylogeny. Bacteriophages are polyphyletic, arose repeatedly in different hosts, and constitute 11 lines of descent. Tailed phages appear as monophyletic and as the oldest known virus group.

[Indexed for MEDLINE]

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