Bacteriophages

Bacteriophages are an enormous class of viruses. All viruses either infect the cells of animals, the cells of plants, or prokaryotes, which are single-celled organisms without a nucleus. Bacteriophages are simply viruses that infect bacteria, which its name hints. This type of virus is usually in the head-tail shape, which is exclusive to this type of virus. Many bacteriophages can and sometime will go through a different reproduction cycle than the lytic cycle, or what we explained on the virus homepage. They go through somethings called the lysogenic cycle, which unlike the lytic, does not kill the cell host because lysis, so the cell does not explode. In the lysogenic cycle, the virus starts by attaching to the bacterium and injecting its genetic information, just like in the lytic cycle. However, instead of immediately being copied and used to make bacteriophage proteins, the DNA is integrated into a chromosome of the bacterium. This integrated DNA is called a prophage, and it isn't expressed to build the new viruses. Instead, it is so that whenever the bacterium splits by reproducing, the prophage is duplicated into the new chromosome as well. Eventually, the DNA will exit the chromosome, and it can do the lytic cycle. In case you're wondering, the DNA goes out of the chromosome sometimes because of a DNA-damaging substance like UV rays from the sun, and sometimes it just happens randomly. This lysogenic cycle is helpful to the virus especially in the case of many bacteriophages infecting the same cell. If they wipe out the host using the lytic cycle, they will run out and they will not be successful. Going aside from their special reproduction cycle, bacteriophages have been humanity's interest for the past century. You see, bacteria are also infectious agents, and bacterial infections can be deadly. Scientists saw that certain viruses could kill certain bacteria, and they thought that they could destroy the bacterial invasions. This, however, was not finished, the accidental of penicillin and later other antibiotics making this irrelevant, however, it still is a topic of interest to scientists. Bacteria can evolve and gain immunity to antibiotics. and after their competition is killed by the antibiotics, they can endlessly multiply, potentially causing a pandemic. This can be accelerated as if the person does not use the correct antibiotic, a mutation does not need to occur as the antibiotic doesn't even target the bacteria but kills competition anyways, but bacteriophages offer a way to kill these antibiotic-immune bacteria. Additionally, bacteriophages specifically target the enemy bacteria, and unlike antibiotics, your helpful bacteria will be safe. You might think of a problem to this. "Wait, can't the bacteria just evolve bacteriophage resistance?" Yes, the answer is they can evolve to resist their respective bacteriophages. However, there is this fact that bacteriophages can evolve as well, so that they can continue to target their respective bacteria. However, even if the bacteriophages cannot catch up to their targets' evolution, antibiotics still exist, and it would be incredibly unlucky for a bacterium to evolve all of these features, as long as treatment is distributed quickly enough. Because of all this, bacteriophages could be used in the future, especially since the risk of getting a superbug is only increasing.