🦠microbiology review

Virulent phages

Written by the Fiveable Content Team • Last updated September 2025
Written by the Fiveable Content Team • Last updated September 2025

Definition

Virulent phages are a type of bacteriophage that infects bacterial cells and immediately begins the lytic cycle, resulting in the destruction of the host cell. They do not integrate their genetic material into the host DNA.

5 Must Know Facts For Your Next Test

  1. Virulent phages undergo the lytic cycle, which culminates in the lysis (breaking open) and death of the bacterial cell.
  2. They do not enter a lysogenic phase; instead, they replicate rapidly after infection.
  3. Virulent phages use the bacterial machinery to produce new phage particles before causing cell lysis.
  4. Examples of virulent phages include T4 bacteriophage, which infects E. coli bacteria.
  5. During the lytic cycle, virulent phages can produce hundreds of progeny viruses from a single infected bacterium.

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