Bacteriophages

Abstract

Bacteriophages (phages) are viruses that infect most, if not all, bacteria in the domains Bacteria (eubacteria) and Archaea (archaebacteria). Most (96%) phages have tailed phage morphology, with the rest having a polyhedral, filamentous or pleomorphic morphology. Phage genomes are a single‐ or double‐stranded, linear or circular, deoxyribonucleic acid (DNA) or ribonucleic acid (RNA) molecule. An exception is the cystovirus genome, which consists of three RNA molecules. Most phages produce a lytic infection, which typically involves phage attachment to the cell surface, injection of phage nucleic acid into the cell, intracellular expression of phage genes to produce nascent phage nucleic acid and proteins, assembly of progeny phages, and cell lysis to release progeny phages. In some situations, instead of a lytic infection, some phages remain latent in infected cells – a process called lysogeny. As bacterial predators, phages affect global biogeochemical cycles.

Key Concepts:

  • Bacteriophages (phages) are viruses that infect most, if not all, bacteria in the domains Bacteria (eubacteria) and Archaea (archaebacteria).

  • Most (96%) phages have tailed phage morphology, with the rest being polyhedral, filamentous or pleomorphic.

  • Phages genomes are a single‐ or double‐stranded, linear or circular, DNA or RNA molecule, except cystoviruses, which have a genome of three molecules of linear double‐stranded RNA.

  • Most phages have a lytic infection cycle, in which an infected cell produces nascent phage nucleic acid and proteins, which are assembled into progeny phages and released by cell lysis.

  • Some phage infections are lysogenic, in which the intracellular phage remains latent and the cell continues to grow.

  • Bacteria have a type of adaptive immunity, the CPISPR system, against phages and plasmids.

  • As bacterial predators, phages affect global biogeochemical cycles.

Keywords: bacteriophage; taxonomy; morphology; replication; evolution

Figure 1.

Morphotypes of bacteriophages. Schematic of morphotypes of the 20 phage taxa described in Table. (Reproduced from Ackermann , with kind permission of Springer Science+Business Media.)

close

References

Ackermann H‐W (2007) 5500 Phages examined in the electron microscope. Archives of Virology 152: 227–243.

Ackermann H‐W (2009) Phage classification and characterization. In: Clokie MJ and Kropinski AM (eds) Bacteriophages: Methods and Protocols, vol. 1, pp. 127–140. New York: Humana Press.

Hatfull GF (2008) Bacteriophage genomics. Current Opinion in Microbiology 11: 447–453.

Horvath P and Barrangou R (2010) CRISPR/Cas, the immune system of bacteria and archaea. Science 327: 167–170.

Kristensen DM, Mushegian AR, Dolja VV and Koonin EV (2010) New dimensions of the virus world discovered through metagenomics. Trends in Microbiology 18: 11–19.

Kutter E, De Vos D, Gvasalia G et al. (2010) Phage therapy in clinical practice: treatment of human infections. Current Pharmaceutical Biotechnology 11: 69–86.

Madigan MT, Martinko JM, Stahl DA and Clark DP (2010) Brock Biology of Microorganisms, 13th edn. Upper Saddle River, NJ: Benjamin Cummings.

Maniloff J and Ackermann H‐W (1998) Taxonomy of bacterial viruses: establishment of tailed virus genera and the order Caudovirales. Archives of Virology 143: 2051–2063.

Marraffini LA and Sontheimer EJ (2010) CRISPR interference: RNA‐directed adaptive immunity in bacteria and archaea. Nature Reviews Genetics 11: 181–190.

Rohwer F, Prangishvilli D and Lindell D (2009) Role of viruses in the environment. Environmental Microbiology 11: 2771–2774.

Further Reading

Brüssow H, Canchaya C and Hardt W‐D (2004) Phages and the evolution of bacterial pathogens: from genomic rearrangements to lysogenic conversion. Microbiology and Molecular Biology Reviews 68: 3560–3602.

Calendar R (2005) The Bacteriophages, 2nd edn. New York: Oxford University Press.

Fauquet C, Mayo MA, Maniloff J, Desselberger U and Ball LA (2005) Virus Taxonomy: VIIIth Report of the International Committee on Taxonomy of Viruses. New York: Academic Press.

Forterre P (2006) The origin of viruses and their possible roles in major evolutionary transitions. Virus Research 117: 5–16.

Karginov FV and Hannon GJ (2010) The CRISPR system: small RNA‐guided defense in bacteria and archaea. Molecular Cell 37: 7–19.

Kutter E and Sulakvelidze A (2004) Bacteriophages: Biology and Applications. Boca Raton, FL: CRC Press.

Rohwer F and Edwards R (2002) The phage proteomic tree: a genome‐based taxonomy for phage. Journal of Bacteriology 184: 4529–4535.

Contact Editor close
Submit a note to the editor about this article by filling in the form below.

* Required Field

How to Cite close
Maniloff, Jack(Apr 2012) Bacteriophages. In: eLS. John Wiley & Sons Ltd, Chichester. http://www.els.net [doi: 10.1002/9780470015902.a0000773.pub3]