Bacteriphage

A bacteriophage, often shortened to phage, is a virus that infects and replicates within bacteria and archaea. The term "bacteriophage" literally means "bacteria eater." Phages are ubiquitous in nature, found wherever bacteria exist, including in soil, water, and even the human body. They are structurally diverse, but many phages possess a distinctive head-and-tail structure. The head typically contains the phage's genetic material, usually DNA, while the tail is used to attach to and inject this genetic material into a host bacterium.

The life cycle of a bacteriophage can follow two main pathways: the lytic cycle and the lysogenic cycle. In the lytic cycle, the phage injects its genetic material into the bacterium, hijacks the host's cellular machinery to replicate itself, and then lyses (bursts) the bacterium to release new phage particles. In the lysogenic cycle, the phage's genetic material integrates into the host bacterium's genome and is replicated along with it. Under certain conditions, the integrated phage DNA can enter the lytic cycle.

Bacteriophages have significant ecological roles, influencing bacterial populations and evolution. They are also a subject of intense research, particularly in the field of phage therapy, which explores their potential as an alternative to antibiotics for treating bacterial infections. Their specificity for certain bacterial strains makes them attractive candidates for targeted antibacterial treatments, especially in the face of rising antibiotic resistance.