bacteriophage(redirected from Bacteriophages)
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With some bacteria, notably those of the Streptococcus family, infection by certain phages can dramatically alter pathogenicity, converging previously innocuous microbes into deadly pathogenic strains. The so-called “flesh-eating” viruses are a striking example. They are relatively harmless bacteria until new geletic material is incorporated via a phage or plasmid.
bac·te·ri·o·phage(bak-tēr'ē-ō-fāj), Avoid the mispronunciation bak-te'rē-ō-fahzh. Avoid the misspelling and mispronunciation bacterialphage.
See also: coliphage.
See also: coliphage
phagea VIRUS that attacks BACTERIA. Bacteriophage literally means ‘bacterium-eater’. Each bacteriophage may infect one or a few strains or species of bacteria. Broadly, bacteriophages can be classified as VIRULENT or TEMPERATE. The bacteriophages are a very heterogeneous group. Some are small and icosahedral, for example π X174, others are simple filaments, for example M13, whilst many are more complex with a polyhedral head and a tail, for example T-phages.
Others have no definite shape but are pleomorphic. The table below presents some examples of representative bacteriophages. Many bacteriophages are composed of a PROTEIN coat and the NUCLEIC ACID of the CHROMOSOME; however, some also have a LIPID component. The nucleic acid may be DNA or RNA, hence the names DNA or RNA phages respectively. The nucleic acid may be double-stranded or single-stranded. Bacteriophage DNA molecules are often used as cloning VECTORS in GENETIC ENGINEERING. See also LYTIC CYCLE, LYSOGENY, PLAQUE, TRANSDUCTION, GENERALIZED TRANSDUCTION and SPECIALIZED TRANSDUCTION.