Bacteriophages are viruses that infect bacteria and are used as antibacterial drugs. Each bacteriophage is able to infect only certain types of bacteria, so the effect of bacteriophages is strictly specific and does not affect the normal human microflora.
The mechanism of action of bacteriophages is simple. The virus enters the cell of a pathogenic bacterium, invades its genome and begins to multiply. After the accumulation of a certain amount of new viral particles (virions) inside the bacterial cell, the cell is destroyed, the viruses come out and infect new bacterial cells.
There are two groups of bacteriophages: temperate and virulent.. Temperate phages slowly multiply inside the affected bacterial cell, are transmitted inside the bacterial colony from generation to generation, periodically destroying microbial cells. This effect is called lysogenic.
Virulent phages, having entered the cell of a microbe, begin to multiply rapidly, leading to the rapid death of the infected cell. This effect is called lytic.
Currently, phages are used in the treatment of infections caused by Klebsiella, Escherichia, Pseudomonas, Streptococcus, Staphylococcus, and Proteus.
Until the advent of antibiotics, bacteriophages were practically the only remedy for infectious diseases. With the advent of antibiotics, the situation has changed. More effective and easy-to-use preparations have appeared that do not require such a detailed selection as bacteriophages.
What, then, is the reason for the interest in bacteriophages now, when antibiotics are available everywhere?
It’s about sustainability. Bacteria lose their sensitivity to the action of antibiotics. The pharmaceutical industry relentlessly synthesizes others. However, it is known that the possibilities of synthesizing antibiotics are limited. Antibiotics adapt very hard to the action of bacteriophages, and, according to experts, microbes cannot develop resistance to a complex of several bacteriophages at all.
In addition, bacteriophages have practically no side effects, rarely cause allergic phenomena, and can be combined with any drugs.
Bacteriophages are currently well established in the treatment of urological diseases, purulent processes in surgery, as well as infectious intestinal diseases in newborns.
However, there are also disadvantages.
Bacteriophages are strictly specific, so it is very difficult to select them. If the desired bacteria is not found in the body, and those that caused the disease are slightly different, the virus stays in the body for about 2-6 days, and then is destroyed.
Treatment with bacteriophages is very long. If the course of antibiotic therapy usually requires 5-7 days, then bacteriophages are prescribed in three courses of 7-20 days with a short interval.
There is an opinion that bacteriophages can transfer parts of its genome from one bacterium to another – and hence pathogenicity, resistance to antibiotics, etc.