Bacteria are the causative agents of what diseases? Human diseases caused by bacteria

2024 Author: Angel Austin | [email protected]. Last modified: 2023-12-17 05:14

There are five major kingdoms of wildlife, whose representatives have been carefully studied for many centuries. This is:

animals;
plants;
mushrooms;
bacteria, or prokaryotes;
viruses.

If animals, plants and fungi have been known to people since the dawn of time, then the study of viruses and bacteria began relatively recently. These organisms are too small to be studied with the naked eye. That is why they have been hidden from the watchful eye of mankind for so long.

It is known that they play not only a positive role. So we will try to understand the question of what bacteria are the causative agents of what diseases, and how these creatures generally work and live.

Who are prokaryotes?

All living beings on our planet are united by a common structure - they consist of cells. True, part of everything is from one, the other part is multicellular. If we talk about multicellular animals, then everything is the same. Each suchThe body has a nucleus in its cells. But when it comes to unicellular organisms, there is no such unity anymore, since they are divided into eukaryotes and prokaryotes.

Eukaryotes include all living beings whose cells have hereditary material fixed in the nucleus. To prokaryotes - such unicellular organisms in which DNA is distributed freely, is not limited to the nuclear envelope, and therefore does not have a nucleus as a whole. It is customary to refer to these creatures:

blue-green algae;
cyanobacteria;
archaebacteria;
bacteria.

Initially, only such organisms lived on the planet. But gradually evolution came to the emergence of eukaryotic multicellular organisms, inside which remained prokaryotic cells. Then, having united together and entered into a symbiotic relationship, they became a beautiful, strong, environmentally resistant organism, ready for self-reproduction and increase in numbers, evolution.

bacteria are the causative agents of what diseases

Proof of this theory are such nuclear-free cell organelles of multicellular organisms as mitochondria and plastids (chloroplasts, chromoplasts, leukoplasts).

But, unfortunately, many of the prokaryotic cells are not as harmless to plants, animals and people as those that remain living inside them. They received the modern name of bacteria, or microbes, and began to live an independent life, causing a lot of trouble for highly organized creatures.

Knownmany diseases associated with bacteria, their vital activity. And not only in humans, but also in representatives of all other kingdoms of wildlife.

A brief outline of the history of discovery

Bacteria have been around for over 3.5 billion years. During this time, nothing has changed in their structure. The only thing that has become new in their lives is their fame for the person.

How did the discovery of these organisms happen? Consider step by step.

Even the ancient Greek scientist Aristotle said that there are creatures invisible to the eye that live on everything around, including humans. They can cause disease.
1546 - Italian physician Girolamo Fracostoro suggested that human diseases are caused by the smallest organisms, microbes. However, he could not prove it and remained unheard.
1676 - Antonio van Leeuwenhoek studied a cut of a cork tree under a microscope invented by himself (the first microscope of his production was very large and resembled a collection of several differently spaced mirrors, it gave an increase of more than a hundred times). As a result, he was able to see the cells that make up the bark of a tree. And also, looking at a drop of water, he examined many of the smallest organisms that lived in this drop. These were the bacteria he named "animalcules".
1840 - German doctor Jacob Henle puts forward a completely correct hypothesis about the effect of pathogenic microorganisms on humans, that is, that bacteria are pathogens.
1862 - French chemist Louis Pasteur inas a result of repeated experiments, he proved the presence of microorganisms in all living environments, objects, organisms. Thus, he confirmed Hen-le's hypothesis, and it has already become a theory called the "Microbial Theory of Diseases". For his work, the scientist was awarded the Nobel Prize.
1877 - Robert Koch introduces the method of staining bacterial cultures.
1884 - Hans Gram, physician. It is he who has the merit of dividing these creatures into gram-positive and gram-negative, depending on the reaction to the type of dye.
1880 - Karg Ebert discovered the cause of typhoid fever - the action of a rod-shaped bacterium.
1882 - Robert Koch isolates the tubercle bacillus.
1897 Japanese doctor Kiyo-shi Shiga discovered the cause of dysentery
1897 - Bernhard Bang established the fact that there are bacteria that cause diseases in animals that cause them to miscarry.

Thus, the development of knowledge about bacteria and the diseases they cause has gained rapid momentum. And today, more than 10 thousand different representatives of prokaryotes have already been described. However, scientists predict that there are more than a million species in the world.

Prokaryote Science

Bacteria as causative agents of infectious diseases have always been of interest to science, because knowledge about them allows us to solve many he alth problems not only for humans, but also for animals and plants. Therefore, several sciences have been formed that are studying this issue.

Microbiology is the general science that studies all microscopic organisms, including bacteria.
Bacteriology is a science that studies microbes, bacteria, their diversity, lifestyle, distribution and impact on the world.
Sanitary microbiology - studies preventive measures for the development of bacterial diseases in humans.
Veterinary microbiology - studies bacteria that cause infectious diseases in animals, methods for eliminating, treating, preventing infection.
Medical microbiology - considers the influence of bacteria on the life of all living beings from the point of view of medicine.

In addition to bacterial cells, there are also unicellular protozoa, pathogens of diseases in humans, animals and plants. For example, amoeba, malarial plasmodia, trypanosomes and so on. These are also objects of study of medical microbiology.

What are bacteria?

There are two bases for classifying bacterial cells. The first is built on the principle of separation of microbes, which are diverse in cell shape. So, on this basis, they distinguish:

Cocci, or spherical, spherical organisms. This also includes several varieties: diplococci, streptococci, staphylococci, micrococci, sarcins, tetracocci. The sizes of such representatives do not exceed 1 micron. It is to this group that most of those who are called "causative agents of human diseases" belong.
Rods, or rod-shaped bacteria. Varieties according to the shape of the ends of the cell: regular, pointed, club-shaped, vibrios,cut, rounded, chain. All of these bacteria are pathogens. What diseases? Almost all infectious diseases known to man today.
Twisted organisms. They are subdivided into spirillum and spirochetes. Thin twisted spiral structures, some of which are pathogenic microbes, and the other - representatives of the normal microflora of the intestines of animals and humans.
Branching bacteria - basically resemble rod-shaped forms, but at the end they have branching of varying degrees. These include bifidobacteria, which play a positive role in people's lives.

Another classification of bacterial cells is based on modern indicators: RNA in structure, biochemical and morphological properties, relation to staining, and so on. According to these features, all bacteria can be divided into 23 types, each of which includes several classes, genera and species.

Microorganisms can also be classified according to the way they feed, the type of respiration, the habitat they occupy, and so on.

Use of bacteria by humans

Use microorganisms people have learned since ancient times. On their part, it was, of course, not a purposeful application, but simply a profitable acquisition from nature. So, for example, alcoholic beverages were produced, fermentation processes took place.

With the passage of time and the discovery of the mechanisms of life of these tiny creatures, man has learned to more fully apply them to his needs. There are several sectors of the economy with which it is closelyintertwined biology. Bacteria used:

In the food industry: baking confectionery and bread, winemaking, lactic acid products and so on.
Chemical synthesis: bacteria produce amino acids, organic acids, proteins, vitamins, lipids, antibiotics, enzymes, pigments, nucleic acids, sugars, and so on.
Medicine: drugs that restore the microflora of the internal environment of the body, antibiotics and so on.
Agriculture: preparations for plant growth and treatment of animals, strains of bacteria that increase yields, milk yield and egg production, and so on.
Ecology: oil-degrading microorganisms, processing organic and inorganic residues, cleansing the environment.

However, in addition to the positive effects of using bacteria, people cannot get rid of the negative ones. After all, bacteria are the causative agents of what human diseases? The most difficult, dangerous and sometimes deadly. Therefore, their role in nature and human life is dual.

Pathogenic microbes: general characteristics

Pathogenic microbes are microbes that can cause damage to tissues and internal organ systems in humans and animals. In their external and internal structure, they are no different from beneficial bacteria: a single-celled structure, covered with a dense shell (cell wall), is dressed on the outside in a mucus capsule that protects from digestion inside the host and from drying out. The genetic material is distributed within the cell in the form of a chain of DNA molecules. Under adverse conditions, they are able to form spores - fall into a state of stupor, in which vital processes stop until favorable conditions resume.

Bacteria are the causative agents of what diseases of living beings? Those that are easily transmitted by airborne droplets, by direct contact, or by contact with open mucous membranes of the skin. And this means that pathogens can be called weapons of mass destruction. After all, they are capable of causing entire epidemics, pandemics, epizootics, epiphytoties, and so on. That is, diseases covering entire countries, affecting both plants (epiphytoties), animals (epizootics), and humans (epidemics).

Unfortunately, not all types of such creatures have been fully studied by man yet. Therefore, there is no guarantee that at any moment some infection will not occur, unknown to people. This places even greater responsibility on microbiologists, medical researchers and virologists.

What diseases do bacteria cause?

There are many such diseases. At the same time, it is impossible to single out only some common ones. After all, bacteria can affect not only animals, but also plant tissues. Therefore, all the diseases that they cause are usually divided into several groups.

Anthroponotic infections - those that are characteristic only for humans, and infection is possible strictly between them (pathogens of human diseases). Examples of diseases: typhus, cholera, smallpox, measles, dysentery, diphtheria and others.
Zoonotic diseases are infections that animals get sick and that they carry in themselves, but at the same time they can infect humans in any way. So, for example, when biting insects or other animals, when animals come into contact with the skin and respiratory tract of a person, bacterial spores are transmitted. Diseases: glanders, anthrax, plague, tularemia, rabies, foot and mouth disease.
Epiphytosis infections are plant diseases caused by bacteria. These include rot, spotting, tumors, burns, gommoses and other bacterioses.

Consider human diseases caused by bacteria. The ones that are the most common. It was they who brought a lot of troubles and troubles to people in the past and present.

Human bacteria

Human diseases caused by bacteria have always caused a lot of harm and damage to people's he alth. The most common and dangerous of them are the following:

Plague is a terrible word for the inhabitants of the Middle Ages and the Renaissance. This disease has claimed thousands of lives. Previously, getting sick with the plague was tantamount to death, until they came up with a method of vaccination and a cure for this terrible infectious disease. Now this disease occurs in some tropical countries and is strictly zoonotic.
Erysipelas - a disease of animals, mainly pigs, chickens, lambs, horses. Transmitted to a person. It is caused by pathogenic bacteria, whose names are Erysipelothrix insidiosa. The fight against the disease is simple, these pathogens are afraid of direct sunlight,high temperatures and alkalis. Currently, the disease is not very common. The occurrence of outbreaks depends on the conditions in which the animals are kept.
Diphtheria. A dangerous disease of the upper respiratory tract, gives a severe complication to the heart. Today, it is quite rare, since vaccination is carried out in the early stages of a child's development.
Dysentery. This disease is caused by a bacterium called Shigella. The source of infection is sick people who are able to transmit the infection by household, water or contact (through the mouth) way. Children are most susceptible to the disease. You can get sick with dysentery several times, since immunity to the disease is only temporary.
Tularemia is caused by the bacterium Francisella tularensis. Very tenacious, resistant to temperatures, environmental conditions infection. The treatment is complex, not fully developed.
Tuberculosis - caused by Koch's wand. A complex disease that affects the lungs and other organs. Treatment systems have been developed and widely practiced, but the disease has not yet been completely eradicated.
Whooping cough is an infection caused by the bacterium Bordetella pertussis. It is characterized by the appearance of the strongest bouts of coughing. Vaccination in early childhood.
Syphilis is a very common sexually transmitted infection. Caused by the spirochete trypanosoma. It affects the genitals, eyes, skin, central nervous system, bones and joints. Treatment with antibiotics, medicine knows.
Gonorrhea, like syphilis, is a disease of the 21st century. Sexual spread, treatmentantibiotics. Caused by bacteria - gonococci.
Tetanus is caused by the bacterium Clostridium tetani, which releases the strongest toxins into the human body. This leads to terrible convulsions and uncontrolled muscle contractions.

Of course, there are other bacteria and human diseases. But these are the most common and serious.

Animal microbes

The most common animal diseases caused by bacteria include:

botulism;
tetanus;
pasteurellosis;
colibacillosis;
bubonic plague;
sap;
melioidosis;
yersiniosis;
vibriosis;
actinomycosis;
anthrax;
foot and mouth disease.

They are all caused by certain bacteria. Diseases are mostly capable of being transmitted to people, therefore they are extremely dangerous and serious. The main measures to prevent the spread of such diseases are keeping animals clean, carefully caring for them, and limiting contact with sick people.

Plant microbes

Among the harmful microbes that infect the root systems and shoots of plants and thereby cause serious damage to agriculture, the most common are the following representatives:

Mycobacteriaceae;
Pseudomonadaceae;
Bacteriaceae.

Plant diseases caused by bacteria cause the following parts of crop plants to rot and die:

roots;
leaves;
stems;
fruits;
inflorescences;
root crops.

That is, the whole plant can be affected by the pathogen. Most often, such agricultural plantings as potatoes, cabbage, corn, wheat, onions, tomatoes, shag, grapes, various fruit trees and other fruits, vegetables and grain crops suffer.