Antibiotics

In any natural environment there are many species of bacteria and fungi, and there is antagonism between some of them. As early as 1879, it was known that when microorganisms are grown together in the laboratory, one of them usually takes precedence over the others and causes their death.

This phenomenon was called antibiosis and was initially explained by competition for the same nutrients. Researchers later discovered that some microorganisms produce substances that are harmful or even fatal to other microbes; these substances were called antibiotics. The first antibiotic (pyocyanin) was isolated from pus in 1860, when the bacterium that forms it was not yet known. Subsequently, it was possible to isolate many antibiotics both from bacteria and from a wide variety of plants, for example, from tomatoes and onions.

Unlike bacteriophages, antibiotic substances are successfully used to combat pathogenic bacteria. Currently, the most important antibiotics are obtained from molds. The most effective of antibiotics, penicillin, is a waste product of a fungus closely related to the molds used to make Roquefort and Camembert cheeses. Penicillin was discovered by Flemming in 1929, but its importance was only fully appreciated in 1940.

There are three different forms of this antibiotic, of which only one is highly active against bacteria. Unlike many other antibiotics, penicillin is not toxic when injected into humans and animals. Bacteria in the presence of penicillin swell and lose their ability to divide; therefore, the body's white blood cells easily destroy them. Experiments by Park and Strominger showed that penicillin interfered with the use of muramic acid, a substance found only in bacterial cells. This substance is one of the components of the bacterial cell wall, and penicillin, by preventing the synthesis of new cell walls, prevents the proliferation of bacteria.

Of course, not all bacteria are sensitive to penicillin; some are susceptible to the action of streptomycin, isolated from actinomycetes - microorganisms intermediate between bacteria and fungi. Streptomycin is quite toxic and is now used mainly in the treatment of tuberculosis, since it is the only antibiotic effective against the tuberculosis bacillus. Aureomycin, chloromycetin and terramycin, produced by other actinomycetes, are effective against a number of viruses, rickettsia and bacteria.

Antibiotics are substances of different chemical nature: some of them are similar to proteins, others are similar to fats, and others are complex organic compounds of other types. The emergence of strains of microorganisms resistant to antibiotics poses a constant problem for researchers. The continuous search for new antibiotics carried out by pharmacological institutions allows us to stay ahead of microbes in this “competition”.

Antibiotics are a group of medications that are used to fight bacterial infections. They are used in almost all areas of medicine: from surgery to dermatology. Even infections of the respiratory tract, liver and heart are treated with antibiotics. This is a rather specific group of drugs, so they are prescribed only by doctors - gynecologists, dermatologists, urologists.