Bacteriophage Ecology Group

Bacteriophage Ecology Group Bacteriophage Ecology Group

Virulent Phage

A lytic phage that is unable to display lysogeny.

 CAUTION: POTENTIALLY AMBIGUOUS TERM 

The terms obligately lytic phage and professionally lytic phage can be used similarly, though with "professionally lytic phage" having a perhaps narrower meaning (i.e., that of virulent phage or obligately lytic phage but excluding those that are derived from temperate phages). See also Intemperate as well as virulent mutant.

As the concept of phage virulence has a somewhat tortured and ambiguous history, it is my preference to limit the use of this term, preferring instead obligately lytic phage or, if appropriate, professionally lytic phage instead. Similarly, note this definition from Adams (1959) for "virulent phage" (p. 442): "A phage that lacks the ability to lysogenize. When known to have originated by mutation from a temperate phage, it is called a virulent mutant." In the same monograph, p. 432, note however this statement: "A virulent phage could thus be a virulent mutant of a yet unknown temperate phage." Thus, the term virulent phage, depending on context, can describe both temperate phage mutants, phages that have descended from temperate phages with numerous mutations separating them from an ability to display lysogenic cycles, and phages that effectively are unrelated to temperate phages.

For more on this topic, see WikipediaGoogle,  and PubMed. Contact web master.  Return to terms.