MINISTRY OF EDUCATION AND SCIENCE OF THE REPUBLIC OF KAZAKHSTAN
EAST KAZAKHSTAN STATE UNIVERSITY NAMED AFTER A.I. S.AMANZHOLOV
Department of Biology
ABSTRACT
Subject: "Biology and development of microorganisms and viruses"
On the topic: "The history of the development of microbiology"
Completed: students gr.UBG-09 (A)
Grushkovskaya D., Fefelova N.
Checked by: Kalenova K.Sh.
Ust-Kamenogorsk, 2011
Plan:
Introduction…………………………………………………………………………...3
1. OPENING OF MICROORGANISMS…………………………………………………4
2. DESCRIPTIVE (MORPHOLOGICAL) PERIOD IN THE DEVELOPMENT OF MICROBIOLOGY (LATE 17TH CENTURY - MIDDLE 19TH CENTURY)…………………..5
2.1. Development of ideas about the nature of the processes of fermentation and decay ...... 5
2.2. Development of ideas about the microbial nature of infectious diseases………………………………………………………………………….7
3. PHYSIOLOGICAL PERIOD (PASTEUR) (SECOND HALF OF THE 19TH CENTURY)……………………………………………………………….8
3.1. Scientific activity of Louis Pasteur…………………………………………………………………………………………………………………………………………………………………………………
3.2. The development of microbiology in the second half of the 19th century…………………...10
4. DEVELOPMENT OF MICROBIOLOGY IN THE 20TH CENTURY………………………………15
Conclusion.................... ............................. . ............................. ................... .......... 18
Literature ............................................................... . ............................. ................... .......... 19
INTRODUCTION
Microbiology is a science that studies the structure, systematics, physiology, biochemistry, genetics and ecology of organisms that are small and invisible to the naked eye. These organisms are called microorganisms or microbes.
For a long time, a person lived surrounded by invisible creatures, used their waste products (for example, when baking bread from sour dough, making wine and vinegar), suffered when these creatures caused illness or spoiled food supplies, but did not suspect their presence . I didn't suspect because I didn't see it, and I didn't see it because the dimensions of these micro-creatures were much lower than the limit of visibility that the human eye is capable of. It is known that a person with normal vision at an optimal distance (25-30 cm) can distinguish an object 0.07-0.08 mm in size in the form of a point. Less objects a person cannot notice. This is determined by the structural features of his organ of vision.
Attempts to overcome the created natural barrier and expand the capabilities of the human eye were made long ago. So, during archaeological excavations in Ancient Babylon, biconvex lenses were found - the simplest optical devices. The lenses were made from polished rock crystal. It can be considered that with their invention man took the first step on the way to the microworld.
Further improvement of optical technology dates back to the 16th-17th centuries. and connected with the development of astronomy. During this time, Dutch glass grinders constructed the first telescopes. It turned out that if the lenses are not positioned in the same way as in a telescope, then it is possible to obtain an increase in very small objects. A microscope of this type was created in 1610 by G. Galileo. The invention of the microscope opened up new possibilities for studying wildlife.
One of the first microscopes, consisting of two biconvex lenses, which gave an increase of about 30 times, was designed and used to study the structure of plants by the English physicist and inventor R. Hooke. Examining cork sections, he discovered the correct cellular structure of wood tissue. These cells were subsequently called by him "cells" and are depicted in the book "Micrography". It was R. Hooke who introduced the term "cell" to denote those structural units from which a complex living organism is built. Further penetration into the secrets of the microworld is inextricably linked with the improvement of optical instruments.
1. DISCOVERY OF MICROORGANISMS
Microorganisms were discovered at the end of the 17th century, but their activity and even practical use known much earlier. For example, products of alcohol, lactic acid, acetic fermentation were prepared and used in the most ancient times. The usefulness of these products was explained by the presence of a "living spirit" in them. However, the idea of the existence of invisible beings began to appear when finding out the causes of infectious diseases. So, Hippocrates (6th century BC), and later Varro (2nd century) suggested that contagious diseases are caused by invisible beings. But only in the 16th century, the Italian scientist Giralamo Fracastoro came to the conclusion that the transmission of diseases from person to person is carried out with the help of the smallest living creatures, to which he gave the name contagium vivum. However, there was no evidence for such assumptions.
If we assume that microbiology arose at the moment when a person saw the first microorganisms, then we can accurately indicate the “birthday” of microbiology and the name of the discoverer. This man is the Dutchman Anthony van Leeuwenhoek (1632-1723), a manufacturer from Delft. Interested in the structure of flax fiber, he polished some coarse lenses for himself. Later, Leeuwenhoek became interested in this delicate and painstaking work and achieved great perfection in the manufacture of lenses, which he called "microscopy". By external form these were single biconvex glasses mounted in silver or brass, however, in terms of their optical properties, Leeuwenhoek's lenses, which gave an increase of 200-270 times, knew no equal. To appreciate them, it is enough to recall that the theoretical limit of magnification of a biconvex lens is 250 - 300 times.
Lacking a natural education, but possessing a natural curiosity, Leeuwenhoek examined with interest everything that came to hand: pond water, plaque, pepper infusion, saliva, blood, and much more. Since 1673, Leeuwenhoek began to send the results of his observations to the Royal Society of London, of which he was subsequently elected a member. In total, Leeuwenhoek wrote over 170 letters to the Royal Society of London, and later bequeathed to him 26 of his famous "microscopy". Here is an excerpt from one letter: “On April 24, 1676, I looked at the water under a microscope and with great surprise saw in it a huge number of the smallest living beings. Some of them were 3-4 times longer than wide, although they were not thicker than the hairs covering the body of the louse. Others had the correct oval shape. There was also a third type of organisms - the most numerous - the smallest creatures with tails. Comparing the description given in this passage and the optical capabilities of the lenses available to Leeuwenhoek, we can conclude that Leeuwenhoek in 1676 managed to see bacteria for the first time.
Leeuwenhoek found microorganisms everywhere and came to the conclusion that the surrounding world is densely populated with microscopic inhabitants. All the microorganisms he saw, including bacteria, Leeuwenhoek considered small animals, which he called "animalcules", and was convinced that they are arranged in the same way as large organisms, that is, they have digestive organs, legs, tails, etc. .d.
Leeuwenhoek's discoveries were so unexpected and even fantastic that for almost 50 subsequent years they caused general amazement. While in Holland in 1698, Peter I visited Levenguk and talked with him. From this trip, Peter I brought a microscope to Russia, and later, in 1716, the first domestic microscopes were made in the workshops at his court.
2. DESCRIPTIVE (MORPHOLOGICAL) PERIOD IN THE DEVELOPMENT OF MICROBIOLOGY (LATE 17th C. - MIDDLE 19th C.)
2.1. Development of ideas about the nature of the processes of fermentation and decay
Many processes carried out by microorganisms have been known to man since time immemorial. First of all, it is decay and fermentation. In the writings of ancient Greek and Roman authors, one can find recipes for making wine, sour milk, and bread, testifying to the widespread use of fermentation in everyday life. In the Middle Ages, alchemists did not ignore these processes and studied them along with other purely chemical transformations. It was during this period that attempts were made to elucidate the nature of fermentation processes.
The term "fermentation" ("fermentatio") for the designation of processes occurring with the release of gas was first used by the Dutch alchemist Ya.B. van Helmont (1577-1644). J. van Helmont discovered a similarity between the gas formed during the fermentation of grape juice (carbon dioxide), the gas released during the combustion of coal, and the gas that appears “when vinegar is poured onto lime stones”, i.e. when an alkali reacts with an acid. Based on this, J. van Helmont came to the conclusion that all the chemical transformations described above are of the same nature. Later, fermentations began to be distinguished from the group of chemical processes accompanied by gas evolution. The term "enzyme" was used to designate the material driving force of fermentation, its active principle. The view of fermentation and putrefaction as purely chemical processes was formulated in 1697 by the German physician and chemist G.E. Stalem (1660-1734). According to G. Stahl, fermentation and putrefaction are chemical transformations that occur under the influence of “enzyme” molecules, which transfer their intrinsic active movement to the molecules of the fermented substrate, i.e. act as a catalyst for the reaction. G. Stahl's views on the nature of the processes of putrefaction and fermentation were fully shared and defended by one of the greatest chemists of his time, J. Liebig. However, this view was not accepted by all researchers.
One of the first guesses about the connection of the “globules” (yeast) described by Leeuwenhoek with the phenomena of fermentation and decay belongs to the French naturalist J.L.L. Buffon (1707-1788). The French chemist A. Lavoisier (1743-1794), who quantitatively studied the chemical transformations of sugar during alcoholic fermentation, came very close to understanding the role of yeast in the fermentation process. In 1793, he wrote: “A little brewer's yeast is enough to give the first impetus to fermentation: it then continues by itself. I will report elsewhere on the action of the enzyme as a whole." However, he failed to do this: A. Lavoisier became a victim of the terror of the French bourgeois revolution.
From the 30s of the 19th century, a period of intensive microscopic observations began. In 1827, the French chemist J. Demazieres (1783-1862) described the structure of the yeast Mycoderma cerevisiae, which forms a film on the surface of beer, and, being convinced that these are the smallest animals, attributed them to ciliates. However, in the work of J. Demaziere there are no indications of a possible connection between the fermentation process and the film developing on the surface of the fermenting liquid. Ten years later, the French botanist Ch. Cañard de Latour (1777-1859) undertook a thorough microscopic examination of the sediment formed during alcoholic fermentation, and came to the conclusion that it consists of living beings, whose vital activity is the cause of fermentation. Almost simultaneously, the German naturalist F. Kützing (1807-1893), studying the formation of vinegar from alcohol, drew attention to the mucous mass, which looks like a film on the surface of a liquid containing alcohol. Studying the mucous mass, F. Kützing found that it consists of microscopic living organisms and is directly related to the accumulation of vinegar in the environment. Another German naturalist T. Schwann (1810-1882) came to similar conclusions.
Thus, C. Cañard de Latour, F. Kützing, and T. Schwann, independently and almost simultaneously, came to the conclusion about the connection between fermentation processes and the vital activity of microscopic living beings. The main conclusion from these studies was clearly formulated by F. Kützing: “Now we must consider each fermentation process differently than chemistry has considered them so far. The whole process of alcoholic fermentation depends on the presence of yeast, acetic fermentation - on the presence of an acetic uterus.
However, the ideas about the biological nature of the "enzyme" of fermentation, expressed by three researchers, have not received recognition. Moreover, they were severely criticized by adherents of the theory of the physicochemical nature of fermentation, who accused their scientific opponents of "frivolity in conclusions" and the absence of any evidence to support this "strange hypothesis". The theory of the physicochemical nature of fermentation processes remained dominant.
2.2. Development of ideas about the microbial nature of infectious diseases
Even the ancient Greek physician Hippocrates (c. 460-377 BC) suggested that contagious diseases are caused by invisible living beings. Avicenna (c. 980-1037) in the "Canon of Medicine" wrote about the "invisible" pathogens of plague, smallpox and other diseases. Similar thoughts can be found in the writings of the Italian physician, astronomer and poet J. Frakastro (1478-1553).
The Russian epidemiologist D.S. was deeply convinced that infectious diseases are caused by living microscopic creatures. Samoilovich (1744-1805), who tried to detect the causative agent of the plague under a microscope. He did not succeed because of the imperfection of microscopes and microscopic techniques. However, the measures for disinfection and isolation of patients developed by D.S. Samoilovich in accordance with his idea turned out to be very effective in the fight against epidemics and became widely known throughout the world.
It is worth mentioning that a contemporary of D. Samoylovich M. Terekhovsky (1740-1796), the first Russian protistologist-experimenter, established the living nature of protozoa and in 1775 for the first time in the world applied an experimental research method to microorganisms, determining the influence of temperature, electrical discharges, sublimate, opium, acids and alkalis on their viability. Studying the movement, growth and reproduction of microorganisms under strictly controlled conditions, Terekhovsky was the first to indicate that division is preceded by growth and increase in size. He also proved the impossibility of spontaneous generation of protozoa in various boiled liquids (infusions). He outlined his observations in the work "On the liquid chaos of Linnaeus."
In 1827, the Italian naturalist A. Bassi (1773-1856), studying the disease of silkworms, discovered the transmission of the disease when a microscopic fungus was transferred from a sick individual to a healthy one. Thus, A. Bassi for the first time managed to experimentally prove the microbial nature of this disease. The idea of a microbial nature of infectious diseases was not recognized for a long time. The prevailing theory was that various disturbances in the flow of chemical processes in the body were considered the causes of diseases.
In 1846, the German anatomist F. Henle (1809-1885) in the book "Guide to Rational Pathology" clearly defined the main provisions for the recognition of infectious diseases. Later, the ideas of F. Henle, formulated in general form(F. Henle himself did not manage to see a single causative agent of human infectious diseases), were experimentally substantiated by R. Koch and entered science under the name "Henle-Koch triad".
3. PHYSIOLOGICAL PERIOD (PASTEUR) (SECOND HALF OF THE 19TH CENTURY)
3.1. Scientific activity of Louis Pasteur
The beginning of the physiological period dates back to the 60s of the 19th century and is associated with the activities of the outstanding French scientist, chemist by profession, Louis Pasteur (1822-1895). Microbiology owes to Pasteur not only its rapid development, but also its formation as a science. The most important discoveries that brought him worldwide fame are associated with the name of Pasteur: fermentation (1857), spontaneous generation (1860), wine and beer diseases (1865), silkworm diseases (1868), infection and vaccines (1881), rabies (1885) .
Pasteur began his scientific career with works on crystallography. He found that the recrystallization of salts of optically inactive racemic tartaric acid produces two types of crystals. A solution prepared from crystals of one type rotates the plane of polarized light to the right, from crystals of another type - to the left. Further, Pasteur discovered that fungus, grown in a solution of racemic tartaric acid, consumes only one of the isomeric forms (dextrorotatory). This observation allowed Pasteur to draw a conclusion about the specific effect of microorganisms on substrates and served as a theoretical basis for the subsequent study of the physiology of microorganisms. Pasteur's observations of lower molds drew his attention to microorganisms in general.
In 1854, Pasteur received a tenured position at the University of Lille. It was here that he began his microbiological research, which marked the beginning of microbiology as an independent scientific discipline.
The reason for starting to study the processes of fermentation was the appeal to Pasteur of a Lille manufacturer with a request to help find out the reasons for the systematic failures in the fermentation of beet juice to obtain alcohol. The results of research published at the end of 1857 undoubtedly proved that the process of alcoholic fermentation is the result of the vital activity of a certain group of microorganisms - yeast and occurs in conditions without air access.
Almost simultaneously with the study of alcoholic fermentation, Pasteur began to study lactic acid fermentation and also showed that this type of fermentation is caused by microorganisms, which he called "lactic yeast". Pasteur outlined the results of his research in his published works Memoir on Lactic Fermentation.
Indeed, the results of Pasteur's research are not just new scientific data, they are a bold refutation of the then prevailing theory of the physicochemical nature of fermentation, supported and defended by the largest scientific authorities of that time: J. Berzelius, E. Mitcherlich, J. Liebig. Lactic acid fermentation is the simplest “chemical” process of the breakdown of a sugar molecule into two trioses, and the proof that this breakdown is associated with the vital activity of microscopic organisms was a weighty argument supporting the theory of the biological nature of fermentations.
The second argument in support of the biological nature of fermentations was Pasteur's experimental proof of the possibility of carrying out alcoholic fermentation on a medium that did not contain protein. According to the chemical theory of fermentation, the latter is the result of the catalytic activity of the "enzyme", which is a substance of a protein nature.
The study of butyric fermentation led Pasteur to the conclusion that the life of some microorganisms not only can proceed in the absence of free oxygen, but the latter is harmful to them. The results of these observations were published in 1861 in a report entitled "Animalculi ciliates living without free oxygen and causing fermentation." The discovery of the negative effect of free oxygen on the process of butyric fermentation was, perhaps, the last moment that completely refuted the theory of the chemical nature of fermentations, since it was oxygen that was assigned the role of the compound that gave the first impetus to the internal movement of the protein particles of the “enzyme”. Through a series of studies in the field of fermentation, Pasteur convincingly proved the inconsistency of the chemical theory of fermentation, forcing his opponents to admit their errors. For work on the study of anaerobiosis in 1861, Pasteur received the Prize of the French Academy of Sciences and the medal of the Royal Society of London. The result of twenty years of research in the field of fermentation was summed up by Pasteur in "Research on beer, its diseases, their causes, ways to make it stable, with the application of a new theory of fermentation" (1876).
In 1865, the French government turned to Pasteur with a request to help silk growers who were suffering heavy losses due to silkworm diseases. Pasteur devoted about five years to studying this issue and came to the conclusion that silkworm diseases are caused by certain microorganisms. Pasteur studied in detail the course of the disease - silkworm pebrins and developed practical recommendations for combating the disease: he suggested looking under a microscope in the bodies of butterflies and pupae for pathogens, separating diseased individuals and destroying them, etc.
Having established the microbial nature of the infectious diseases of silkworms, Pasteur came to the conclusion that animal and human diseases are also caused by the action of microorganisms. His first work in this direction was the proof that puerperal fever, widespread in the period described, is caused by a certain microscopic pathogen. Pasteur identified the causative agent of fever, showed that its cause was the neglect of the rules of antiseptics on the part of medical personnel, and developed methods of protection against the penetration of the pathogen into the body.
Pasteur's further work in the field of the study of infectious diseases led to the discovery of the causative agents of chicken cholera, osteomyelitis, purulent abscesses, one of the causative agents of gas gangrene. In this way, Pasteur showed and proved that every disease is generated by a specific microorganism.
In 1879, while studying chicken cholera, Pasteur developed a method for obtaining cultures of microbes that lose their ability to be the causative agent of the disease, that is, lose virulence, and used this discovery to protect the body from subsequent infection. The latter formed the basis for the creation of the theory of immunity.
The study of infectious diseases by Pasteur was combined with the development of measures for the active fight against them. Based on the technique of obtaining attenuated cultures of virulent microorganisms, called "vaccines", Pasteur found ways to combat anthrax and rabies. Pasteur's vaccines have gained worldwide distribution. Institutions where vaccinations against rabies are carried out are named Pasteur stations in honor of Pasteur.
Pasteur's works were duly appreciated by his contemporaries and received international recognition. In 1888, for Pasteur, with funds raised by international subscription, a research institute was built in Paris, which currently bears his name. Pasteur was the first director of this institute. The discoveries of L. Pasteur showed how diverse, unusual, active the microcosm invisible to the naked eye and what a huge field of activity is its study.
3.2. Development of microbiology in the second half of the 19th century
Assessing the successes achieved by microbiology in the second half of the 19th century, the French researcher P. Tennery wrote in his work “Historical Sketch of the Development of Natural Science in Europe”: “In the face of bacteriological discoveries, the history of other natural sciences over the last decades of the 19th century seems somewhat pale.”
The advances in microbiology during this period are directly related to the new ideas and methodological approaches introduced into microbiological research by L. Pasteur. Among the first to appreciate the significance of Pasteur's discoveries was the English surgeon J. Lister, he realized that the cause of a large percentage of deaths after operations is, firstly, infection of wounds with bacteria due to ignorance and, secondly, non-compliance with the elementary rules of antisepsis .
One of the founders of medical microbiology, along with Pasteur, was the German microbiologist R. Koch (1843-1910), who studied the pathogens of infectious diseases. Koch began his research while still a rural doctor with the study of anthrax and in 1877 published a work on the causative agent of this disease - Bacillus anthracis. Following this, Koch's attention was attracted by another severe and widespread disease of that time - tuberculosis. In 1882, Koch reported the discovery of the causative agent of tuberculosis, which was named "Koch's wand" in his honor. (In 1905, for the study of tuberculosis, Koch was awarded Nobel Prize.) Koch also owns the discovery in 1883 of the causative agent of cholera.
Koch paid much attention to the development of microbiological research methods. He designed a lighting apparatus, proposed a method for microphotography of bacteria, developed techniques for staining bacteria with aniline dyes, and proposed a method for growing microorganisms on solid nutrient media using gelatin. Obtaining bacteria in the form of pure cultures opened up new approaches for a more in-depth study of their properties and served as an impetus for the further rapid development of microbiology. Pure cultures of the pathogens of cholera, tuberculosis, diphtheria, plague, glanders, lobar pneumonia were isolated.
Koch experimentally substantiated the provisions put forward earlier by F. Henle on the recognition of infectious diseases, which entered science under the name "Henle-Koch triad" (later, however, it turned out that it was not applicable to all infectious agents).
The founder of Russian microbiology is L. Tsenkovsky (1822-1887). The object of his research were microscopic protozoa, algae, fungi. He discovered and described a large number of protozoa, studied their morphology and development cycles. This allowed him to conclude that there is no sharp boundary between the world of plants and animals. He also organized one of the first Pasteur stations in Russia and proposed a vaccine against anthrax (“Tsenkovsky's live vaccine”).
The name of I. Mechnikov (1845-1916) is associated with the development of a new direction in microbiology - immunology. For the first time in science, Mechnikov developed and experimentally confirmed the biological theory of immunity, which went down in history as Mechnikov's phagocytic theory. This theory is based on the concept of cellular protective adaptations of the body. Mechnikov in experiments on animals (daphnia, starfish larvae) proved that leukocytes and other cells of mesodermal origin have the ability to capture and digest foreign particles (including microbes) that enter the body. This phenomenon, called phagocytosis, formed the basis of the phagocytic theory of immunity and received universal recognition. Developing further the questions raised, Mechnikov formulated a general theory of inflammation as a protective reaction of the body and created a new direction in immunology - the doctrine of antigenic specificity. Currently, it is becoming increasingly important in connection with the development of the problem of transplantation of organs and tissues, the study of cancer immunology.
Among the most important works of Mechnikov in the field of medical microbiology are studies of the pathogenesis of cholera and the biology of cholera-like vibrios, syphilis, tuberculosis, and relapsing fever. Mechnikov is the founder of the theory of microbial antagonism, which served as the basis for the development of the science of antibiotic therapy. The idea of microbial antagonism was used by Mechnikov in developing the problem of longevity. Studying the phenomenon of aging of the body, Mechnikov came to the conclusion. That the most important cause of it is chronic poisoning of the body with decay products produced in the large intestine by putrefactive bacteria.
Of practical interest are the early works of Mechnikov on the use of the fungus Isaria destructor to combat the pest of the fields - the bread beetle. They give grounds to consider Mechnikov the founder of the biological method of controlling pests of agricultural plants, a method that is now becoming more and more widely used and popular.
Thus, I.I. Mechnikov, an outstanding Russian biologist, who combined the qualities of an experimenter, teacher and propagandist of scientific knowledge, was a man of great spirit and work, the highest award of which was the assignment to him in 1909 of the Nobel Prize for research on phagocytosis.
One of the largest scientists in the field of microbiology is a friend and colleague of I. Mechnikov N.F. Gamaleya (1859-1949). Gamaleya devoted his entire life to the study of infectious diseases and the development of measures to combat their pathogens. Gamaleya made a major contribution to the study of tuberculosis, cholera, and rabies; in 1886, together with I. Mechnikov, he organized the first Pasteur station in Odessa and introduced vaccination against rabies into practice. He discovered an avian vibrio, the causative agent of a cholera-like disease in birds, and in honor of Ilya Ilyich named it Mechnikov's vibrio. Then a vaccine against human cholera was obtained.
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Microbiology plays a huge role in the development of mankind. The formation of science began in the 5th-6th century BC. e. Even then it was assumed that many diseases are caused by invisible living beings. A brief history of the development of microbiology, which is described in our article, will make it possible to find out how science was formed.
General information about microbiology. Subject and tasks
Microbiology is a science that studies the life and structure of microorganisms. Microbes cannot be seen with the naked eye. They can be of both plant and animal origin. Microbiology - Methods of other subjects such as physics, chemistry, biology, cytology are used to study the smallest organisms.
There is general and private microbiology. The first studies the structure and vital activity of microorganisms at all levels. The subject of private study is individual representatives of the microworld.
The achievements of medical microbiology in the 19th century contributed to the development of immunology, which today is a general biological science. The development of microbiology occurred in three stages. At the first, it was found that there are bacteria in nature that cannot be seen with the naked eye. At the second stage of formation, species were differentiated, and at the third stage, the study of immunity and infectious diseases began.
The tasks of microbiology are the study of the properties of bacteria. Microscopy instruments are used for research. Thanks to this, the shape, location and structure of bacteria can be seen. Often, scientists plant microorganisms in healthy animals. This is necessary for the reproduction of infectious processes.
Pasteur Louis
Louis Pasteur was born on December 27, 1822 in eastern France. As a child, he was fond of art. Over time, he began to be attracted to the natural sciences. When Louis Pasteur turned 21, he went to Paris to study at the High School, after which he was supposed to become a natural science teacher.
In 1848, Louis Pasteur presented the results of his scientific work at the Paris Academy of Sciences. He proved that there are two types of crystals in tartaric acid, which polarize light differently. This was a brilliant start to his career as a scientist.
Pasteur Louis is the founder of microbiology. Scientists before the beginning of his activity assumed that yeast forms a chemical process. However, it was Pasteur Louis, who, after conducting a series of studies, proved that the formation of alcohol during fermentation is associated with the vital activity of the smallest organisms - yeast. He found that there are two types of such bacteria. One type creates alcohol, and the other creates the so-called lactic acid, which spoils alcohol-containing drinks.
The scientist did not stop there. After some time, he found that when heated to 60 degrees Celsius, unwanted bacteria die. He recommended the gradual warming technique to winemakers and cooks. However, at first they were negative about this method, believing that it would spoil the quality of the product. Over time, they realized that this method really has a positive effect on the process of making alcohol. Today, Pasteur Louis' method is known as pasteurization. It is used when preserving not only alcoholic beverages, but also other products.
The scientist often thought about the formation of mold on products. After a series of studies, he realized that food spoils only if it is in contact with air for a long period of time. However, if the air is heated to 60 degrees Celsius, the decay process stops for a while. Products do not spoil and high in the Alps, where the air is rarefied. The scientist proved that mold is formed due to spores that are in the environment. The fewer of them in the air, the slower the food spoils.
The popularity of the scientist grew. In 1867, Napoleon III ordered that Pasteur be provided with a well-equipped laboratory. It was there that the scientist created the rabies vaccine, thanks to which he became known throughout Europe. Pasteur died on September 28, 1895. The founder of microbiology was buried with all state honors.
Koch Robert
The contribution of scientists to microbiology has made a lot of discoveries in medicine. Thanks to this, humanity knows how to get rid of many diseases dangerous to health. It is believed that Koch Robert is a contemporary of Pasteur. The scientist was born in December 1843. From childhood he was interested in nature. In 1866 he graduated from the university and received a medical degree. After that he worked in several hospitals.
Robert Koch began the activity of a bacteriologist. He focused on the study of anthrax. Koch studied the blood of sick animals under a microscope. The scientist found in it a mass of microorganisms that are absent in healthy representatives of the fauna. Robert Koch decided to inoculate them in mice. The test subjects died a day later, and the same microorganisms were present in their blood. The scientist found out that anthrax is caused by sticks.
After successful research, Robert Koch began to think about the study of tuberculosis. This is no coincidence, because in Germany (the place of birth and residence of the scientist) every seventh inhabitant died from this disease. At that time, doctors did not yet know how to deal with tuberculosis. They believed that it was a hereditary disease.
For his first research, Koch used the corpse of a young worker who died of consumption. He examined all the internal organs and did not find any pathogenic bacteria. Then the scientist decided to stain the preparations and examine them on glass. Once, while examining such a blue-colored preparation under a microscope, Koch noticed small sticks between the tissues of the lungs. He instilled them in a guinea pig. The animal died a few weeks later. In 1882, Robert Koch spoke at a meeting of the Society of Physicians about the results of his research. Later, he tried to create a vaccine against tuberculosis, which, unfortunately, did not help, but is still used in diagnosing the disease.
A brief history of the development of microbiology at that time aroused the interest of many. A vaccine against tuberculosis was created only a few years after Koch's death. However, this does not diminish his merits in the study of this disease. In 1905, the scientist was awarded the Nobel Prize. Tuberculosis bacteria were named after the researcher - Koch's wand. The scientist died in 1910.
Vinogradsky Sergey Nikolaevich
Sergei Nikolaevich Vinogradsky is a well-known bacteriologist who made a huge contribution to the development of microbiology. He was born in 1856 in Kyiv. His father was a wealthy lawyer. Sergei Nikolayevich, after graduating from a local gymnasium, was educated at the St. Petersburg Conservatory. In 1877 he entered the second year of the natural faculty. After graduating in 1881, the scientist devoted himself to the study of microbiology. In 1885 he went to study in Strasbourg.
Today Sergei Nikolaevich Vinogradsky is considered the founder of the ecology of microorganisms. He studied the soil microbial community and divided all microorganisms living in it into autochthonous and allochthonous. In 1896, Winogradsky formulated the concept of life on Earth as a system of interconnected biogeochemical cycles catalyzed by living beings. His last scientific work was devoted to the taxonomy of bacteria. The scientist died in 1953.
Emergence of microbiology
A brief history of the development of microbiology, described in our article, will make it possible to find out how humanity began the fight against dangerous diseases. Man encountered the vital processes of bacteria long before they were discovered. People fermented milk, used the fermentation of dough and wine. In the writings of a doctor from Ancient Greece assumptions were made about the connection between dangerous diseases and special pathogenic fumes.
Confirmation was received by Anthony van Leeuwenhoek. By grinding glass, he was able to create lenses that magnified the object under study by more than 100 times. Thanks to this, he was able to see all the objects around him.
He found out that the smallest organisms live on them. Complete and Short story The development of microbiology began precisely with the results of Leeuwenhoek's research. He could not prove the assumptions about the causes of contagious diseases, but the practice of doctors since antiquity confirmed them. Hindu laws provided for preventive measures. It is known that things and dwellings of sick people were subjected to special treatment.
In 1771, a Moscow military doctor for the first time disinfected the belongings of plague patients and vaccinated people who had contact with carriers of the disease. Topics in microbiology are varied. The most interesting is the one that describes the creation of the smallpox inoculation. It has long been used by the Persians, Turks and Chinese. Weakened bacteria were introduced into the human body because it was believed that this way the disease proceeds more easily.
(English doctor) noticed that most people who did not have smallpox do not become infected through close contact with carriers of the disease. This was most often observed in milkmaids who became infected while milking cows with cowpox. The doctor's research lasted 10 years. In 1796, Jenner injected the blood of a sick cow into a healthy boy. Some time later, he tried to inoculate him with the bacteria of a sick person. So the vaccine was created, thanks to which humanity got rid of the disease.
Contribution of domestic scientists
Discoveries in microbiology, made by scientists from all over the world, allow us to understand how to cope with almost any disease. Domestic researchers have made a significant contribution to the development of science. In 1698, Peter I met Levenguk. He showed him a microscope and showed a number of objects in an enlarged form.
During the formation of microbiology as a science, Lev Semenovich Tsenkovsky published his work, in which he classified microorganisms as plant organisms. He also used Pasteur's method to suppress anthrax.
Ilya Ilyich Mechnikov played a significant role in microbiology. He is considered one of the founders of the science of bacteria. The scientist created the theory of immunity. He proved that many cells of the body can inhibit viral bacteria. His research became the basis for the study of inflammation.
Microbiology, virology and immunology, as well as medicine itself, were of great interest to almost everyone at that time. Mechnikov studied the human body and tried to understand why it ages. The scientist wanted to find a way that would extend life. He believed that toxic substances that are formed due to the vital activity of putrefactive bacteria poison the human body. According to Mechnikov, it is necessary to populate the body with lactic acid microorganisms that inhibit putrefactive ones. The scientist believed that in this way it is possible to significantly extend life.
Mechnikov studied many dangerous diseases such as typhus, tuberculosis, cholera and others. In 1886 he created a bacteriological station and a school of microbiologists in Odessa (Ukraine).
Microbiology, technical
Technical microbiology studies bacteria that are used in the creation of vitamins, some preparations, and food preparation. The main task of this science is the intensification of technological processes in production (often food).
The development of technical microbiology orients the specialist to the need for careful observance of all sanitary standards in the workplace. Having studied this science, you can prevent damage to the product. The subject is most often studied by future food industry specialists.
Dmitry Iosifovich Ivanovsky
Microbiology became the basis for the creation of many other sciences. The history of science began long before its public recognition. Virology was formed in the 19th century. This science does not study all bacteria, but only those that are viral. Dmitry Iosifovich Ivanovsky is considered its founder. In 1887 he began researching the diseases of tobacco. He found crystalline inclusions in the cells of a diseased plant. Thus, he discovered pathogens of non-bacterial and non-protozoal nature, which were later called viruses.
Ivanovsky presented the results of his research on diseased plants at a meeting of the Society of Naturalists. Dmitry Iosifovich also actively studied soil microbiology.
Educational literature
Microbiology is a science that cannot be learned in a few days. It plays an important role in the development of medicine. Books on microbiology allow you to independently study this science. In our article you can find the most popular ones.
- (2011) is a book that describes the life of bacteria that live at high temperatures. They exist at great depths, where heat comes from magma. The book contains articles by various scientists from all over the Russian Federation.
- "Three lives of the great microbiologist. A documentary story about Sergei Nikolaevich Vinogradsky" is a book about the greatest scientist, authored by Georgy Aleksandrovich Zavarzin. It was written according to the diaries of Vinogradsky. Scientists laid down several major areas in microbiology (microbial, soil, chemosynthesis). The book will be extremely useful to future doctors and just inquisitive people.
- "General Microbiology" written by Hans Schlegel is a publication that will allow you to get acquainted with the wonderful world of bacteria. It is worth noting that Hans Schlegel is a world famous German microbiologist who is still alive. The publication has been updated and expanded many times. It is believed that this is one of best books in microbiology. It briefly describes the structure, as well as the process of vital activity and reproduction of bacteria. The book is easy to read. It contains no extra information.
- Microbes are Good and Bad. Our Health and Survival in the World is a contemporary book written by Jessica Sachs and published last year. With improved sanitation and the advent of antibiotics, human life expectancy has increased substantially. The book is devoted to the problem of the occurrence of immune diseases, which is associated with excessive concern for the improvement of sanitary conditions.
- "Look What's Inside You" is a book by Rob Knight. It was published last year. The book talks about microbes that live in different parts of our body. The author argues that microorganisms play a more important role than we previously thought.
The basis of the latest technologies
Microbiology is the basis of the latest technologies. The world of bacteria is not yet fully understood. Many scientists have no doubt that thanks to microorganisms it is possible to create technologies that have no analogues. Biotechnology will serve as the basis for them.
Microorganisms are used in the development of coal and oil deposits. It's no secret that fossil fuels are already running out, despite the fact that humanity has been using it for about 200 years. In the event of its exhaustion, scientists recommend using microbiological methods for obtaining alcohols from renewable sources of raw materials.
Biotechnology makes it possible to cope with both environmental and energy problems. Surprisingly, the microbiological processing of organic waste allows not only to clean the environment, but also to obtain biogas, which is in no way inferior to natural gas. This method of obtaining fuel does not require extra costs. There is already enough material in the environment for recycling. For example, only in the USA it is about 1.5 million tons. However, on this moment the method of disposal of waste from processing is not thought out.
Summing up
Microbiology occupies an important place in the life of mankind. Thanks to this science, doctors learn to cope with life-threatening diseases. Microbiology has also become the basis for the creation of vaccines. Many of the greatest scientists who have contributed to this science are known. Some of them you met in our article. Many scientists living in our time believe that in the future it is microbiology that will make it possible to cope with many environmental and energy problems that may arise in the near future.
For thousands of years, man lived surrounded by invisible creatures, used the products of their vital activity, for example, products of lactic, alcoholic, acetic fermentation, suffered from them when these creatures were the cause of the disease, but did not suspect their presence, since the size of the creatures is much lower than the limit of visibility that the human eye is capable of. Human conjectures that fermentation, decay and infectious diseases are the result of the influence of invisible beings have been around for a long time. Hippocrates (460-377 BC) suggested that contagious diseases were caused by invisible living beings. The Italian physician and astronomer D. Frakastro (1478-1553) came to the conclusion that epidemic diseases are transmitted from person to person by the smallest living beings, although he could not prove this.
The emergence of microbiology as a science became possible after the invention of the microscope. The first person to see and describe microorganisms was the Dutch naturalist Anthony van Leeuwenhoek (1632–1723), who designed a microscope that magnified up to 300 times. Through a microscope, he examined everything that came to hand: water from a pond, various infusions, blood, plaque, and much more. In the objects he looked at, he found the smallest creatures, which he called living animals (animalcules). He established spherical, rod-shaped and convoluted forms of microbes. The book "The Secrets of Nature Discovered by A. Leeuwenhoek", published in 1695, attracted the attention of scientists from many countries to the study of microorganisms. Leeuwenhoek's discovery laid the foundation for the emergence of microbiology. However, research for many decades was reduced only to the description of microorganisms.
L. Leeuwenhoek (1632-1723) L. Pasteur (1822-1895)
Late 17th to mid 19th century entered history as descriptive, or morphological. This period created the conditions for the transition to the next, physiological, stage in the development of microbiology. Its founder is an outstanding French chemist. Louis Pasteur (1822-1895). The first works in the field of microbiology, performed by him, are aimed at studying the nature of fermentation. At that time, Liebig's theory dominated science, stating that fermentation and putrefaction are the results of oxidative processes caused by the action of enzymes and are a purely chemical phenomenon in which microorganisms do not participate. The pastor proved that the cause of fermentation and decay is microorganisms that produce various enzymes. Each fermentation process has a specific pathogen; putrefaction is caused by a group of putrefactive bacteria, etc. By studying butyric fermentation, Pasteur established that you. butyricum develops in the absence of atmospheric oxygen and thus discovered the phenomenon of anaerobiosis.
The name of Pasteur is associated with the solution of the question of the spontaneous origin of life on earth. He experimentally proved that with the absolute sterility of nutrient solutions and the exclusion of the possibility of subsequent contamination from the outside, the appearance of microbes and the development of decay are impossible in them. Life arises when, wrote Pasteur, when microorganisms penetrate into the nutrient solution from the outside.
In 1865, Pasteur established that spoilage of wine and beer is caused by the ingress of foreign microorganisms or wild yeast into the wort and proposed heating wine and beer at temperatures up to 100 °C. This process is called pasteurization. In 1868, he established that the silkworm disease pebrin was caused by microbes and developed a way to combat it. Thanks to these discoveries, antisepsis and asepsis in surgery arose. He discovered the causative agents of chicken cholera, staphylococci, streptococci, the causative agent of swine erysipelas, and established the etiology of anthrax. Studying the nature of infectious diseases and their pathogens, Pasteur discovered important property pathogenic microorganisms - the ability to weaken virulence. On this basis, he developed methods for reducing (attenuating) the virulence of microbes and successfully used weakened cultures for inoculations against infectious diseases. Cultures of microorganisms with weakened virulence were called vaccines, and the method of inoculation was called vaccination. Pasteur proposed methods for obtaining vaccines against chicken cholera, anthrax, and rabies. Since that time, the immunological era has come in microbiology.
The outstanding microbiologists E. Roux, A. Yersen, E. Duclos, Ch. Chamberland, G. Ramon, J. Borde, A. Calmet and others were the students and followers of L. Pasteur.
In 1888, with funds raised by international subscription, a research institute for Pasteur was built in Paris, which to this day remains the largest center of ideas and knowledge in the field of microbiology.
One of the founders of microbiology along with Pastor was the German scientist Robert Koch (1843-1910). He developed methods of microbiological research, for the first time in practice laboratory research dense nutrient media (meat-peptone gelatin and meat-peptone agar) were proposed, which made it possible to isolate and study pure cultures of microbes. Koch developed methods for staining microbes with aniline dyes, used an immersion system and an Abbe condenser for microscopy, as well as microphotography, scientifically substantiated the theory and practice of disinfection. His merit in the study of microorganisms as causative agents of infectious diseases is great. Koch identified the causative agent of anthrax (1876), tuberculosis (1882), human cholera (1883), and invented tuberculin. He created a school of bacteriologists, from which came the outstanding microbiologists E. Bering, F. Leffler, R. Pffeifer, G. Gaffki, and others.
Robert Koch (1843-1910) I. I. Mechnikov (1845-1916)
Great merit in the development of microbiology I. I. Mechnikov (1845-1916;. Among the most important works in the field of microbiology are his studies of the pathogenesis of human cholera, syphilis, tuberculosis, relapsing fever. He is the founder of the doctrine of microbial antagonism, which became the basis for the development of science about antibiotic therapy.On the principle of antagonism, the scientist substantiated the theory of longevity and proposed for prolongation human life use yogurt, which was later called Mechnikov. In 1886 he organized the first bacteriological station in Russia. The name of Mechnikov is associated with the development of a new direction in microbiology - immunology - the doctrine of the body's immunity to infectious diseases (immunity). Mechnikov created the phagocytic theory of immunity, revealed the essence of inflammation as a protective reaction of the body. Many of Mechnikov's students subsequently became prominent microbiologists: N. F. Gamaleya, A. M. Bezredka, L. A. Tarassvich, G. N. Gabrichevsky, and others.
N. F. Gamaleya (1859-1949) contributed greatly to the development of microbiology. His scientific work devoted to the study of infection and immunity, the variability of bacteria, the prevention of typhus, cholera, tuberculosis and other diseases. They discovered avian vibrio (a cholera-like disease of birds), named after Mechnikov by his name. Gamaleya for the first time (in 1898) observed and described the phenomenon of spontaneous lysis of bacteria under the influence of an agent unknown at that time - a bacteriophage, took Active participation in the creation of the first bacteriological station in Russia and introduced the practice of vaccination against rabies.
L. S. Tsenkovsky (1822-1887) D. I. Ivanovsky (1864-1920)
G. N. Gabrichevsky (1860-1907) was the first to teach a course in bacteriology at Moscow University. In 1893 he published the textbook "Medical Microbiology", in 1895 he created the first bacteriological institute in Moscow. From the first days of the institute's work, he began to manufacture antidiphtheria serum, then introduced it into medical practice. Established the importance of hemolytic streptococcus as the causative agent of scarlet fever, developed and proposed a vaccine against this disease. Studied Escherichia coli and its role in human pathology.
The founder of Russian microbiology L. S. Tsenkovsky (1822-1887) first established the proximity of bacteria and blue-green algae and described the phenomenon of symbiosis; substantiated the classification of microbes, attributing bacteria to plant organisms; discovered the causative agent of leek and developed ways to prevent it in sugar production. Using the principle of microbial attenuation, in 1883 he produced vaccines I and II against anthrax, which were used to vaccinate animals for more than 70 years.
Microbiology owes much to the Russian scientist D. I. Ivanovsky (1864-1920), who created a new branch of this science - virology. In 1892, he established the causative agent of tobacco mosaic disease, called the filterable virus.
The founder of general and soil microbiology, S. N. Vinogradsky (1856-1953), developed accumulative nutrient media, isolated and studied nitrogen-fixing and nitrifying soil bacteria, and established the role of microbes in the cycle of nitrogen, carbon, phosphorus, iron, and sulfur; first proved the existence of bacteria that independently synthesize organic matter, which made it possible to discover a new type of microbial nutrition - autotrophism.
A glorious page in the history of veterinary microbiology was made by domestic microbiologists E. M. Semmer, I. I. Shchukevich, I. M. Sadovsky, A. V. Dedulin, A. F. Konev, A. A. Raevsky and many others. almost simultaneous production in 1891 by Russian scientists X. I. Gelman and O. I. Kalning of mallein for the allergic diagnosis of glanders appeared in world science.
G. M. Andreevsky, P. N. Andreev, A. M. Vladimirov, S. N. Vyshelesky, D. S. Ruzhentsev , M. G. Tartakovsky and many others.
N. A. Mikhin (1872-1946), one of the founders of veterinary microbiology in our country, discovered the causative agent of bovine leptospirosis, developed a method for making formovaccine against calf paratyphoid and anti-colibacteriosis serum, as well as a method for hyperimmunization of horses when receiving anti-anthrax serum. He is the author of the country's first textbook "Course of private microbiology for veterinarians and students."
During the period of Soviet power, along with the development of veterinary science, the school of veterinary microbiologists grew and improved, giving our country a galaxy of microbiologists: N. N. Ginsburg, Ya. E. Kolyakov, V. V. Kuzmin, I. I. Kulssko, V. T. Kotov, S. G. Kolesov, Ya. R. Kovalenko, N. V. Likhachev, S. Ya. Lyubashenko, S. A. Muromtsev, M. D. Polykovsky, I. V. Poddubsky, A. A. Polyakov, A. Kh. Sarkisov, P. S. Solomkin, M. K. Yuskovets, R. A. Zion, P. A. Trilenko and many others who have made a significant contribution to the study of pathogens of infectious diseases of agricultural animals, the creation of new ones and the improvement well-known vaccines, immune sera and diagnostics, which made it possible to eliminate some infectious diseases and ensure the well-being of our farms in many of them.
TOPIC 1. INTRODUCTION. MORPHOLOGY, PHYSIOLOGY AND CLASSIFICATION OF BACTERIA.
1. Subject and tasks of medical microbiology.
2. History of the development of microbiology.
3. Morphology of bacteria.
4. Physiology of bacteria.
5. Classification of bacteria.
6. Methods for studying the morphology and properties of bacteria.
Subject and tasks of medical microbiology.
Microbiology(from Greek. micros- small, bios- life, logos- teaching) – the science of microorganisms, the patterns of their development and the changes they cause in the environment and in the environment.
Sizes of microorganisms< 0,1 мм, величина их измеряется в мкм.
Microbiology includes sections:
o General- doing research general patterns microorganisms.
o Technical– is engaged in the development of biotechnology for the synthesis of biologically active substances by microorganisms: proteins, vitamins, enzymes, antibiotics, alcohols.
o Agricultural– is engaged in the study of microorganisms that participate in the cycle of substances, are used to prepare fertilizers, cause plant diseases, etc.
o Veterinary– studies pathogens of animal diseases, develops methods for the diagnosis, prevention and treatment of animals.
o Sanitary– studies the sanitary and microbiological state of objects environment, its impact on human health and develops measures to prevent the adverse effects of pathogenic microbes.
o Maritime- studies the microflora of the seas and oceans.
o Space- studies the microflora of outer space, the influence of space conditions on the properties of microorganisms and the microflora of the human body.
o Medical– studies pathogenic and conditionally pathogenic microorganisms for humans, their ecology and prevalence, methods for their isolation and identification, and also develops methods for microbiological diagnostics, specific prevention and treatment of diseases caused by them.
History of development of microbiology.
There are five historical periods of development and formation of microbiology as a science.
I. Heuristic period associated rather with logical and methodological methods of finding the truth than with any experiments and evidence.
Hippocrates, Paracelsus(VI century BC) suggested the nature of contagious diseases, miasma, small invisible animals.
In its most complete form, the idea was formulated Girolamo Fracostoro in his work “On Contagions, Contagious Diseases and Treatment” (1546), where he expressed the idea of a living contagion of the “germs of the disease”, which causes diseases. Moreover, each disease is caused by its contagion. To prevent diseases, they were recommended isolation of the patient, quarantine, wearing masks, and treating objects with vinegar. However, these were hypotheses for which they had no evidence.
II. Descriptive period(morphological) associated with the creation of the microscope and the discovery of microscopic creatures invisible to the human eye. The first microscope was created in 1590 by Dutch scientists. Hans And Zachary Jansenami, but it had an increase of only 32 times. Dutch naturalist Antonio Leeuwenhoek(1632 - 1723) designed a microscope with a magnification of 160-300 times, with which he managed to detect the smallest "living animals" ("animalcules", from lat. animalcula, little animal) in rainwater, plaque and other materials.
In the same period, in 1771, a Russian doctor Danilo Samoylovich(1744 - 1805) in the experience of self-infection with pus of plague patients proved the role of microorganisms in the etiology of the plague and the possibility of protecting people from the plague with the help of vaccinations. To prove that the plague is caused by a specific pathogen, he infected himself with the discharge of the bubo of a plague-stricken person and fell ill with the plague. Fortunately, D. Samoilovich survived.
Edward Jenner(1749 - 1823) created and successfully applied a vaccine for the prevention of smallpox, taking material from a milkmaid with cowpox.
III. Physiological period(Pasterovsky)- "golden age" of microbiology.
L. Pasteur(1822 - 1895) - founder french school microbiology, his main achievements:
Fermentation and putrefaction is a microbial process;
Spontaneous generation is not possible;
Diseases of wine and beer;
Diseases of silkworms;
Vaccine against rabies, anthrax in animals and chicken cholera;
Proposal of a mild method of sterilization - pasteurization.
R. Koch(1843 - 1910) - founder of the school of German microbiologists, his achievements:
Identified anthrax bacillus;
Identified the causative agent of tuberculosis and cholera;
Introduced into the practice of microbiology aniline dyes, immersion system, dense nutrient media.
IV. Immunological period associated with the works of I. I. Mechnikov and P. Erlich.
I. I. Mechnikov(1845-1916) - one of the founders of immunology, described the phenomenon of phagocytosis (cell theory of immunity).
Paul Erlich(1854-1915) formulated the theory of humoral immunity, explaining the origin of antibodies and their interaction with antigens.
IN 1908 II Mechnikov and P. Erlich were awarded the Nobel Prize for their work in the field of immunology.
D. I. Ivanovsky(1864-1920) - discoverer of viruses. As an employee of the Department of Botany of St. Petersburg University in 1892 while studying the mosaic disease of tobacco, he came to the conclusion that the disease is caused by a filtering agent, later called a virus.
1928 - A. Fleming, studying the phenomena of microbial antagonism, received an unstable penicillin.
And in 1940 - G. Flory and E. Chain received a stable form of penicillin.
V. Modern period (molecular - genetic) Connected with scientific and technological revolution in natural science.
1944 - The role of DNA in the transmission of hereditary information has been proven. ( O. Avery, C. McLeod, C. McCarthy)
1953 - Deciphering the structure of DNA D. Watson and F. Crick .
1958 - Description of the phenomenon of immunological tolerance ( P. Medawar and Hasek)
1959 - Modeled an immunoglobulin molecule ( R. Porter and D. Edelman) .
IN 60-70s there were works on the genetics of bacteria, the formation of genetic engineering.
1982 - Discovered HIV ( R. Gallo, 1883 L. Montagnier).
Morphology of bacteria.
According to the form, the following main groups of microorganisms are distinguished.
1. Spherical or cocci.
2. Rod-shaped.
3.Corrected.
4. Branching.
I. coccoid bacteria (cocci) according to the nature of the relative position after division, they are divided into:
1.micrococci- cells located alone. They are part of the normal microflora, are in the external environment. They do not cause disease in humans.
2.Diplococci - These are paired cells, these include gonococci, meningococci, pneumococci.
3.Streptococci - reproducing cells remain connected (do not diverge), forming chains. Many pathogenic microorganisms are the causative agents of tonsillitis, scarlet fever, purulent inflammatory processes.
4.Tetracoccus - have the form of tetrads (i.e., four cells each). They have no medical significance.
5.Sarcins - have the form of packages of 8, 16 or more cocci. Often found in the air. There are no pathogenic forms.
6.Staphylococci - form clusters resembling bunches of grapes. Cause numerous diseases, primarily purulent - inflammatory.
II. Rod-shaped forms of microorganisms (rods):
1.bacteria- sticks that do not form spores (E. coli, dysentery, tuberculosis, diphtheria, etc.).
2.bacilli- aerobic spore-forming microbes. The spore diameter usually does not exceed the size (“width”) of the cell (anthrax bacilli).
3.Clostridia- anaerobic spore-forming microbes. The diameter of the spore is larger than the diameter of the cell, in connection with which the cell resembles a spindle or a tennis racket (the causative agent of tetanus, botulism, gas gangrene).
It must be borne in mind that the term "bacteria" is often used to refer to all microbes - prokaryotes. In a narrower (morphological) sense, bacteria are rod-shaped forms of prokaryotes that do not have spores.
III. Convolute forms of microorganisms:
1.Vibrios- have one bend, can be in the form of a comma, a short curl (cholera vibrio).
2.Spirilla- have 2-3 curls (pathogen Sodoku - rat bite disease).
3.Spirochetes- have a different number of curls. Of the large number of spirochetes, the largest medical significance have representatives of three genera - treptonemes, borrelia, leptospira.
IV. branching bacteria - rod-shaped bacteria that may have ramifications in the shape of the Latin letter "Y", found in bifidobacteria. They can also be presented in the form of filamentous branched cells that can intertwine, forming a mycelium, which is observed in actinomycete.
In addition to the true bacteria, there are others more or less different from them. These are spirochetes, rickettsia, chlamydia, actinomycetes and mycoplasmas.
Spirochetes - thin long convoluted (spiral-shaped), gram-negative bacteria. They are mobile, move with a wave-like contraction of the body. Some spirochetes cause human diseases (relapsing fever, syphilis).
In humans, chlamydia causes chlamydia, manifested by damage to the eyes (trachoma, conjunctivitis), urogenital tract, lungs, etc.
Actinomycetes ( or radiant mushrooms) look like small or long branched thin threads. Pathogenic forms cause actinomycosis.
Mycoplasmas- small bacteria (0.15-1 microns) surrounded only by a cytoplasmic membrane and not having a cell wall. They have a variety of shapes: coccoid, filiform, flask-shaped. Mycoplasmas cause atypical pneumonia and lesions of the genitourinary tract in humans.
Physiology of bacteria.
Bacteria nutrition
Bacterial respiration.
By respiration (or biological oxidation), microorganisms produce energy.
In relation to molecular oxygen, bacteria can be divided into three main groups:
1) obligate (mandatory) aerobes can grow only in the presence of oxygen (mycobacterium tuberculosis);
2) obligate anaerobes grow on an environment without oxygen, which is toxic to them (clostridia of botulism, gas gangrene, tetanus, bacteroids);
3) facultative anaerobes (aerobes) can grow both in the presence of oxygen and without it (E. coli, causative agents of typhoid fever, paratyphoid).
Similar information.
The stages in the development of microbiology are related not so much chronologically as they are determined by the main achievements and discoveries, therefore, many researchers distinguish different periods, but most often the following: heuristic, morphological, physiological, immunological, and molecular genetic.
HEURISTIC PERIOD (IV-III centuries BC-XVI century)
It is connected more with logical and methodical methods of finding the truth, that is, with heuristics, than with any experiments and proofs. The thinkers of this period (Hippocrates, the Roman writer Varro, Avicenna, etc.) made assumptions about the nature of contagious diseases, miasma, small invisible animals. These ideas were formulated into a coherent hypothesis many centuries later in the writings of the Italian physician D. Fracastoro (1478-1553), who expressed the idea of a living contagium (contagium vivum) that causes disease. Moreover, each disease is caused by its contagion. To protect against diseases, they were recommended isolation of the patient, quarantine, wearing masks, and treating objects with vinegar.
MORPHOLOGICAL PERIOD (XVII FIRST HALF OF XIX centuries)
It begins with the discovery of microorganisms by A. Leeuwenhoek. At this stage, the ubiquitous distribution of microorganisms was confirmed, the forms of cells, the nature of movement, and the habitats of many representatives of the microworld were described. The end of this period is significant in that the knowledge about microorganisms accumulated by that time and the scientific and methodological level (in particular, the availability of microscopic equipment) allowed scientists to solve three very important (basic) problems for all natural sciences: the study of the nature of the processes of fermentation and putrefaction, causes of infectious diseases, the problem of self-birth of microorganisms.
The study of the nature of the processes of fermentation and decay. The term "fermentation" (fermentatio) for the designation of all processes that go with the release of gas was first used by the Dutch alchemist Ya.B. Helmont (1579
1644). Many scientists have tried to define this process and explain it. But the French chemist A.L. came closest to understanding the role of yeast in the fermentation process. Lavoisier (1743-1794) when studying the quantitative chemical transformations of sugar during alcoholic fermentation, but he did not have time to complete his work, as he became a victim of the terror of the French bourgeois revolution. Many scientists have studied the fermentation process, but the French botanist C. Cagnard de Latour (he studied the sediment during alcoholic fermentation and discovered living creatures), German naturalists F Kützing (during the formation of vinegar drew attention to the mucous film on the surface, which also consisted of living organisms) and T. Schwann. But their research was severely criticized by supporters of the theory of the physicochemical nature of fermentation. They were accused of "frivolity in conclusions" and lack of evidence.
The second main problem about the microbial nature of infectious diseases was also solved during the morphological period in the development of microbiology. The first to suggest that diseases are caused by invisible beings were the ancient Greek physician Hippocrates (c. 460-377 BC), Avicenna (c. 980-1037) and others. already associated with open microorganisms, direct evidence was needed. And they were obtained by the Russian epidemiologist D.S. Samoilovich (1744-1805). The microscopes of that time had a magnification of about 300 times and did not allow to detect the causative agent of the plague, which, as is now known, requires an increase of 800-1000 times. In order to prove that the plague is caused by a specific pathogen, he infected himself with the discharge of a bubo from a plague-stricken person and fell ill with the plague. Fortunately, D.S. Samoilovich survived. Subsequently, heroic experiments on self-infection to prove the infectiousness of a particular microorganism were carried out by Russian doctors G.N. Minh and O.O. Mochutkovsky, I.I. Mechnikov and others. But the priority in resolving the issue of the microbial nature of infectious diseases belongs to the Italian naturalist A. Basi (1773-1856), who was the first to experimentally establish the microbial nature of the disease of silkworms, he discovered the transmission of the disease during the transfer of a microscopic fungus from a sick individual to a healthy one. But most researchers were convinced that the causes of all diseases are violations of the course of chemical processes in the body.
The third problem, concerning the mode of appearance and reproduction of microorganisms, was solved in a dispute with the then dominant theory of spontaneous generation. Despite the fact that the Italian scientist L. Spallanzani in the middle of the XVIII century. observed the division of bacteria under a microscope, the opinion that they are spontaneously generated (arise from rot, dirt, etc.) was not refuted. This was done by the outstanding French scientist Louis Pasteur (1822-1895), who laid the foundation for modern microbiology with his work.
In the same period, the development of microbiology in Russia began. The founder of Russian microbiology is L.N. Tsenkovsky (1822-1887). The objects of his research are protozoa, algae, fungi. He discovered and described a large number of protozoa, studied their morphology and development cycles, showed that there is no sharp boundary between the world of plants and animals. He organized one of the first Pasteur stations in Russia and proposed a vaccine against anthrax (Tsenkovsky's live vaccine).
PHYSIOLOGICAL PERIOD (SECOND HALF OF THE 19TH CENTURY) Rapid development of microbiology in the 19th century. led to the discovery of many microorganisms: nodule bacteria, nitrifying bacteria, pathogens of many infectious diseases (anthrax, plague, tetanus, diphtheria, cholera, tuberculosis, etc.), tobacco mosaic virus, foot-and-mouth disease virus, etc. The discovery of new microorganisms was accompanied by the study of not only their structure, but also their life activity, that is, to replace the morphological and systematic study of the first half of the 19th century. came the physiological study of microorganisms, based on precise experimentation. Therefore, the second half of XIX V. called the physiological period in the development of microbiology.
This period is characterized by outstanding discoveries in the field of microbiology, and without exaggeration it could be called in honor of the brilliant French scientist L. Pasteur Pasteur, because scientific activity This scientist covered all the main problems associated with the vital activity of microorganisms. More about the main scientific discoveries L. Pasteur and their importance for the protection of human health and human economic activity will be discussed in § 1.3.
The first of L. Pasteur's contemporaries who appreciated the significance of his discoveries was the English surgeon J. Lister (1827-1912), who, based on the achievements of L. Pasteur, first introduced into medical practice the treatment of all surgical instruments with carbolic acid, decontamination of operating rooms and achieved a reduction in the number of deaths after operations.
One of the founders of medical microbiology is Robert Koch (1843
1910), who developed methods for obtaining pure cultures of bacteria, staining bacteria under microscopy, and microphotography. The Koch triad formulated by R. Koh is also known, which is still used in establishing the causative agent of the disease. In 1877, R. Koch singled out the causative agent of anthrax, in 1882 the causative agent of tuberculosis, and in 1905 he was awarded the Nobel Prize for the discovery of R. Koch tie of the causative agent of cholera.
During the physiological period, namely in 1867, M.S. Voronin described nodule bacteria, and almost 20 years later G. Gelrigel and G. Wilfarth showed their ability to fix nitrogen. The French chemists T. Schlesing and A. Muntz substantiated the microbiological nature of nitrification (1877), and in 1882 P. Degerin established the nature of denitrification, the nature of the anaerobic decomposition of plant residues. Russian scientist P.A. Kostychev created the theory of the microbiological nature of soil formation processes.
Finally, in 1892, the Russian botanist D.I. Ivanovsky (1864-1920) discovered the tobacco mosaic virus. In 1898, independently of D.I. Ivanovsky, the same virus was described by M. Beijerinck. Then the foot-and-mouth disease virus was discovered (F. Leffler, P. Frosch, 1897), yellow fever (W. Reed, 1901) and many other viruses. However, it became possible to see viral particles only after the invention of the electron microscope, since they are not visible in light microscopes. To date, the kingdom of viruses has up to 1000 pathogenic species. Totally agree Lately a number of new D.I. Ivanovsky viruses were discovered, including the virus that causes AIDS. There is no doubt that the period of discovery of new viruses and bacteria and the study of their morphology and physiology continues to the present day.
S.N. Vinogradsky (1856-1953) and the Dutch microbiologist M. Beijerink (1851-1931) introduced the microecological principle of studying microorganisms. S.N. Vinogradsky proposed to create specific (elective) conditions that would enable the predominant development of one group of microorganisms; in 1893 he discovered an anaerobic nitrogen fixer, which he named after Pasteur Clostridium pasterianum; .
The microecological principle was also developed by M. Beijerinck and applied in the isolation of various groups of microorganisms. 8 years after the discovery by S.N. Vinogradsky M. Beijerinck isolated Azotobacter chroococcum under aerobic conditions, studied the physiology of nodule bacteria, the processes of denitrification and sulfate reduction, etc. Both of these researchers are the founders of the ecological direction of microbiology associated with the study of the role of microorganisms in the cycle of substances in nature.
TO late XIX V. it is planned to differentiate microbiology into a number of particular areas: general, medical, soil.
IMMUNOLOGICAL PERIOD (EARLY XX century)
With the advent of the twentieth century. starts new period in microbiology, to which the discoveries of the 19th century led.
The works of L. Pasteur on vaccination, I.I. Mechnikov on phagocytosis, P. Ehrlich on the theory of humoral immunity formed the main content of this stage in the development of microbiology, which rightfully received the title of immunological.
Paul Ehrlich (1854-1915) German physician, bacteriologist and biochemist, one of the founders of immunology and chemotherapy, who put forward the humoral (from Latin humor liquid) theory of immunity. He believed that immunity arises as a result of the formation of antibodies in the blood that neutralize the poison. This was confirmed by the discovery of antitoxin antibodies that neutralize toxins in animals that were injected with diphtheria or tetanus toxin (E. Behring, S. Kitazato).
In 1883 he formulated the phagocytic theory of immunity. Human immunity to re-infection has long been known, but the nature of this phenomenon was unclear even after
I.I. Mechnikov about how vaccination against many diseases has become widely used. I.I. Mechnikov showed that the body's defense against pathogenic bacteria is a complex biological reaction based on the ability of phagocytes (macro and microphages) to capture and destroy foreign bodies that have entered the body, including bacteria. Research by I.I. Mechnikov on phagocytosis convincingly proved that, in addition to humoral, there is cellular immunity.
I.I. Mechnikov and P. Ehrlich were scientific opponents for many years, each experimentally proving the validity of his theory. Subsequently, it turned out that there is no contradiction between humoral and phagocytic immunities, since these mechanisms jointly protect the body. And in 1908 I.I. Mechnikov, together with P. Ehrlich, was awarded the Nobel Prize for developing the theory of immunity.
The immunological period is characterized by the discovery of the main reactions of the immune system to genetically alien substances (antigens): antibody formation and phagocytosis, delayed type hypersensitivity (DTH), immediate type hypersensitivity (IHT), tolerance, immunological memory.
Microbiology and immunology developed especially rapidly in the 1950s and 1960s. twentieth century. This was facilitated by the most important discoveries in the field of molecular biology, genetics, and bioorganic chemistry; the emergence of new sciences: genetic engineering, molecular biology, biotechnology, informatics; creation of new methods and use of scientific equipment.
Immunology is the basis for the development of laboratory methods for the diagnosis, prevention, and treatment of infectious and many non-infectious diseases, as well as for the development of immunobiological preparations (vaccines, immunoglobulins, immunomodulators, allergens, and diagnostic preparations). The development and production of immunobiological preparations is carried out by immunobiotechnology, an independent branch of immunology. Modern medical microbiology and immunology have achieved great success and play a huge role in the diagnosis, prevention, and treatment of infectious and many non-infectious diseases associated with impaired immune systems (oncological, autoimmune diseases, organ and tissue transplantation, etc.).
MOLECULAR GENETIC PERIOD (Since the 1950s)
It is characterized by a number of fundamental scientific achievements and discoveries:
1. Deciphering the molecular structure and molecular biological organization of many viruses and bacteria; discovery of the simplest forms of life of the “infectious” prion protein.
2. Decryption chemical structure and chemical synthesis of some antigens. For example, the chemical synthesis of lysozyme (D. Sela, 1971), AIDS virus peptides (R.V. Petrov, V.T. Ivanov and others).
3. Deciphering the structure of antibody immunoglobulins (D. Edelman, R. Porter, 1959).
4. Development of a method for cultures of animal and plant cells and their cultivation on an industrial scale in order to obtain viral antigens.
5. Obtaining recombinant bacteria and recombinant viruses.
6. Creation of hybridomas by fusion of immune B lymphocytes producing antibodies and cancer cells in order to obtain monoclonal antibodies (D. Keller, C. Milstein, 1975).
7. Discovery of immunomodulators of immunocytokinins (interleukins, interferons, myelopeptides, etc.), endogenous natural regulators of the immune system, and their use for the prevention and treatment of various diseases.
8. Obtaining vaccines using biotechnology methods and genetic engineering techniques (hepatitis B, malaria, HIV antigens and other antigens) and biologically active peptides (interferons, interleukins, growth factors, etc.).
9. Development of synthetic vaccines based on natural or synthetic antigens and their fragments.
10. Discovery of viruses that cause immunodeficiencies.
11. Development of fundamentally new methods for diagnosing infectious and non-infectious diseases (enzymatic immunoassay, radioimmunoassay, immunoblotting, hybridization of nucleic acids). Creation on the basis of these methods of test systems for indication, identification of microorganisms, diagnostics of infectious and noninfectious diseases.
In the second half of the twentieth century. the formation of new directions in microbiology continues, new disciplines with their own objects of research (virology, mycology) sprout from it, directions are distinguished that differ in the objectives of research (general microbiology, technical, agricultural, medical microbiology, genetics of microorganisms, etc.) . Many forms of microorganisms were studied, and by about the middle of the 1950s. last century A. Kluiver (1888
1956) and K. Neel (1897-1985) formulated the theory of the biochemical unity of life.
