What are bacteriophages ?

Bacteriophages, often simply referred to as phages, are viruses that specifically infect and replicate within bacteria. Unlike other viruses that might target animals, plants, or fungi, bacteriophages have evolved to prey on bacterial cells. The word “bacteriophage” is derived from “bacteria” and the Greek word “phagein,” which means “to devour/eat.”

Upon encountering a susceptible bacterial host, a bacteriophage attaches to the bacterium’s surface. Once attached, it injects its genetic material (either DNA or RNA) into the bacterial cell. This genetic material then takes over the host cell’s machinery, directing it to produce new phage particles. After new progeny phages are produced, they typically cause the bacterial cell to burst open, releasing new phage particles to infect additional bacterial cells. The lysogenic cycle differs from the lytic cycle, as after injection of the genetic material, it integrates into the bacterial genome and remains dormant for a period before reactivation results in excision from the chromosome and it follows a lytic cycle.

In recent years, bacteriophages have garnered interest for their potential therapeutic applications, especially as antibiotic resistance becomes a growing global concern. Phage therapy, which involves using phages to combat bacterial infections, offers a promising alternative or supplement to traditional antibiotics.