Virulent phages

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.

Review Questions

• What is the primary difference between virulent and temperate phages?
• Describe the steps involved in the lytic cycle of a virulent phage.
• Why do virulent phages not enter a lysogenic phase?

Related terms

Bacteriophage: A virus that infects and replicates within bacteria.

Lytic Cycle: The process by which a virus replicates within a host cell and ultimately causes its destruction.

Temperate Phage: A type of bacteriophage that can choose between a lytic or lysogenic lifecycle upon infecting a host.