В биологии для описания определенного организма, which belongs to the kingdoms of animals, mushrooms or plants, developed its own nomenclature. It reflects belonging to the same species, depending on the characteristics of morphology and appearance. The criteria for attributing to the species are applied to animals, depending on the ability to produce fertile offspring during fertilization. However, these patterns apply only to these organisms, whereas microbes cannot be classified in this way.
Due to the huge amountorganisms with morphological properties, but various biochemical and immunological features, it is not possible to apply the standard nomenclature to assign a name. As a result, introduced such a thing as a strain. It is a pure culture of microbes, which it was possible to isolate and isolate in a specific place at a certain hour.
Every microbe that belongs to onestrain similar to another such representative of biochemical, morphological, immunological and genetic criteria. But within the limits of one bacterial type such analogy is not observed. Therefore, the strain is a more flexible name for microbial culture. Since the rapid exchange of genetic material (mutation) leads to the emergence of new organisms within the species, but with different properties, it is this definition that allows us to more accurately characterize the pathogenicity and virulence factors.
The existing nomenclature of bacteria allowsclassify species of organisms, but does not characterize their new properties. The latter appear due to rapid mutation, acquiring new properties, including those that are pathogenic for humans, domestic animals and plants, as well as other microbes. An example of nomenclature on the example of Escherichia coli looks like this: the realm - bacteria, type - proteobacteria, class of gamma proteobacteria, order - Enterobacteriales, family of enterobacteria. The genus is Escherichia, and the species is Escherichia colli. However, there are many cultures of bacteria of the species Escherichia colli, exhibiting different properties. They are isolated in separate strains of bacteria and have an additional name. For example, Escherichia colli O157: H7.
E. coli is present in the intestines.human and does not cause diseases, but the strain O157: H7 is exclusively pathogenic due to the presence of a greater number of virulence factors. She was marked by an epidemic of enterotoxigenic diseases in the last 5 years.
Понятие штамм - это гибкое название организмов с the same properties that were identified and then identified and described in a particular locality at a specific time. With its passage, the virus may acquire new properties due to antigenic drift. This will create a new viral strain, perhaps more pathogenic than its progenitor.
Наглядно показать появление новых штаммов можно by the example of influenza virus. It belongs to the Orthomyxovirus family and is called HxNy depending on antigens (hemagglutinins and neuraminidase). X and Y are numerical values reflecting the presence of antigens. An example is H5N1, known for the recent swine flu epidemic with rapidly progressive hemorrhagic pneumonia. According to the theory, a new and more dangerous strain can develop from this strain due to the same antigenic drift.
Of all the germs, molds areleast changeable, although their biochemistry is also complex. Due to a more complex structure than that of bacteria and viruses, and also due to the lack of mechanisms for the rapid transfer of genes, the number of new fungal strains increases slightly. There is also an opinion that any new recently found fungal strain is a pre-existing organism that the researchers simply did not come across.
The situation is similar in the kingdomprotists. Their ability to mutate is small, because the likelihood that new strains will appear quickly, is extremely small. However, new variants of organisms of one species still appear. Therefore, apparently, they also existed previously, but were not discovered.
