Bacteriophages are bacteria-infecting viruses, and certain bacteriophages have been studied extensively in the lab (making them some of the viruses we understand best).
In this article, we’ll look at two different ways bacteriophages can infect their bacterial hosts:
A phage infects a bacteria, then hijacks it to produce a vast number of phages before killing the cell by causing it to explode (lyse).
The phage infects a bacterium and inserts its DNA into its chromosome, allowing the phage DNA (now known as a prophage) to replicate and spread alongside the cell’s own DNA.
Lytic cell:
The lytic cycle happens when a phage takes over a host cell and uses its resources to create a high number of new phages, causing the cell to lyse (burst) and die.
The following are the stages of the lytic cycle:
Attachment:Proteins on the phage’s “tail” bind to a specific receptor on the surface of the bacterial cell (in this case, a sugar transporter).
Entry:The phage injects a double-stranded DNA genome into the cytoplasm of the bacteria.
DNA replication and protein production: Phage DNA is copied, and phage genes are expressed to produce proteins such as capsid proteins.
Assembly of new phage:Capsids are made up of capsid proteins and DNA, and they are used to make a huge number of new phage particles.
Lysis: The phage encodes genes for proteins that puncture the plasma membrane and the cell wall late in the lytic cycle. The openings allow water to enter the cell, causing it to swell and explode like a bursting water balloon.
When a cell bursts, or lyzes, hundreds of more phages are released, allowing them to identify and infect other nearby host cells. In this manner, a few cycles of lytic infection can spread the phage like wildfire throughout a bacterial community.
Lysogenic Cell:
The lysogenic cycle allows phages to multiply without harming their hosts. Although some phages can only use the lytic cycle, the one we’re looking at can switch between the two.
The lysogenic cycle’s first two steps (attachment and DNA injection) are identical to the lytic cycle’s. The phage DNA, once within the cell, is neither duplicated or expressed to make proteins right away. It recombines with a specific bacterial chromosome region instead. As a result, the phage DNA is incorporated into the chromosome.
Not all phages integrate their DNA into their host’s genome throughout the lysogenic cycle. Some people, on the other hand, keep their genome in the cell as a circular strand of DNA7
This is a lysogenic cycle even though the phage does not encourage the creation of new virus particles or destroy the cell. Instead, it goes “unnoticed” and is reproduced alongside the cell’s DNA in a passive manner.
What is Bacteriophage and how does it work?
A virus that affects bacteria,cause disease is known as Bacteriophage.
A bacteriophage, often known as a phage, is a bacteria-infecting virus. Bacteriophages, like other viruses, come in a variety of sizes and forms, as well as genetic material.
Phage genomes can be constructed of DNA or RNA and contain anything from four to hundreds of genes.
The capsid of a bacteriophage can be icosahedral, filamentous, or head-tail shaped. Phage and their close relatives appear to have a characteristic head-tail arrangement (and is not found in eukaryotic viruses) 4,5
Bacteriophage infections:
Bacteriophages, like other viruses, must infect a host cell in order to reproduce. The infection process is divided into steps, which make up the phage’s lifecycle.
A lytic lifecycle refers to phages that can only multiply by bursting and killing their host cells. Other phages can transition between lytic and lysogenic life cycles without causing harm to the host cell (and are instead copied along with the host DNA each time the cell divides).
Antibiotics vs. Bacteriophages:
Bacteriophages were intensively explored as a therapy for human bacterial infections before antibiotics were discovered. Because they only attack their host bacteria and not human cells, bacteriophages are potential possibilities for treating bacterial illnesses in humans.
As antibiotic-resistant bacteria become more common, there is growing interest in reintroducing the “phage strategy” in other settings. Although additional research is needed to determine whether phages are safe and effective. Your doctor might write you a prescription for phages instead of penicillin one day.
Conclusion:
Bacteriophage particles are the most prevalent biological entities on Earth, infecting specific bacterial hosts in every known habitat and driving bacterial adaptation. The study of bacteriophage particles could aid in the development of novel biotechnology products.
Although not new, bacteriophage therapy uses purely lytic phage particles as an alternative in the antimicrobial treatment of resistant bacterial illnesses and is being rediscovered as a safe procedure due to their lack of affinity for eukaryotic cells.
Moreover, bacteriophage-based vaccination is gaining traction as a possible preventive method.