A treatment for human bacterial infections from the early 20th century has made a recent comeback. In this treatment, bacteriophages are used to eliminate bacterial infections. Which explanation best describes the mechanism of action behind this treatment?

Answer: This mechanism of action is called phage therapy.

Explanation: Viruses act as vectors, the viral DNA through transformation is inserted into host cell by a process called lysogeny which result in the formation of a bacteriophage (a virus that resides and multiply inside a bacteria).

The phage penetrates and inject viral DNA into host cell and is taken up by its genome, replicating the viral genetic material. This process disrupts normal gene expression of host cell (bacteria) and create viral genes resulting in cell/bacterial lysis i. e cell death.