A message about beneficial bacteria. Beneficial bacteria in the human body. Dangerous and beneficial bacteria, their role in human life

Rice. 1. The human body consists of 90% microbial cells. It contains from 500 to 1000 different types of bacteria or trillions of these amazing residents, which amounts to up to 4 kg of total weight.

Rice. 2. Bacteria inhabiting the oral cavity: Streptococcus mutants (green). Bakteroides gingivalis, causes periodontitis (lilac color). Candida albicus (yellow color). Causes candidiasis of the skin and internal organs.

Rice. 7. Mycobacterium tuberculosis. Bacteria have been causing diseases in humans and animals for many millennia. The tuberculosis bacillus is extremely stable in the external environment. In 95% of cases it is transmitted by airborne droplets. Most often affects the lungs.

Rice. 8. The causative agent of diphtheria is corynebacteria or Loeffler's bacillus. It often develops in the epithelium of the mucous layer of the tonsils, less often in the larynx. Swelling of the larynx and enlarged lymph nodes can lead to asphyxia. The pathogen's toxin is fixed on the membranes of the cells of the heart muscle, kidneys, adrenal glands and nerve ganglia and destroys them.

Rice. 9. Causative agents of staphylococcal infection. Pathogenic staphylococci cause extensive damage to the skin and its appendages, damage to many internal organs, foodborne toxic infection, enteritis and colitis, sepsis and toxic shock.

Rice. 10. Meningococci are the causative agents of meningococcal infection. Up to 80% of cases are children. The infection is transmitted by airborne droplets from sick and healthy carriers of bacteria.

Rice. 11. Bordetella pertussis.

Rice. 12. The causative agent of scarlet fever is streptococcus pyogenes.

Harmful water microflora bacteria

Water is the habitat of many microbes. In 1 cm3 of water you can count up to 1 million microbial bodies. Pathogenic microorganisms enter water from industrial enterprises, populated areas and livestock farms. Water containing pathogenic microbes can become a source dysentery, cholera, typhoid fever, tularemia, leptospirosis, etc. Vibrio cholerae and can remain in water for quite a long time.

Rice. 13. Shigella. Pathogens cause bacillary dysentery. Shigella destroys the epithelium of the colon mucosa, causing severe ulcerative colitis. Their toxins affect the myocardium, nervous and vascular systems.

Rice. 14. . Vibrios do not destroy the cells of the mucous layer of the small intestine, but are located on their surface. They secrete a toxin called choleragen, the action of which leads to disruption of water-salt metabolism, causing the body to lose up to 30 liters of fluid per day.

Rice. 15. Salmonella is the causative agent of typhoid fever and paratyphoid fever. The epithelium and lymphoid elements of the small intestine are affected. With the bloodstream they enter the bone marrow, spleen and gall bladder, from which the pathogens again enter the small intestine. As a result of immune inflammation, the wall of the small intestine ruptures and peritonitis occurs.

Rice. 16. Causative agents of tularemia (blue coccobacteria). They affect the respiratory tract and intestines. They have the ability to penetrate the human body through intact skin and mucous membranes of the eyes, nasopharynx, larynx and intestines. The peculiarity of the disease is damage to the lymph nodes (primary bubo).

Rice. 17. Leptospira. They affect the human capillary network, often the liver, kidneys and muscles. The disease is called infectious jaundice.

Harmful bacteria of soil microflora

Billions of “bad” bacteria live in the soil. In a 30-centimeter thickness of 1 hectare of land there are up to 30 tons of bacteria. Possessing a powerful set of enzymes, they are engaged in the breakdown of proteins into amino acids, thereby taking an active part in the processes of decay. However, these bacteria bring a lot of trouble to humans. Thanks to the activity of these microbes, food spoils very quickly. Man has learned to protect shelf-stable foods by sterilizing, salting, smoking and freezing. Some types of these bacteria can spoil even salted and frozen foods. enter the soil from sick animals and humans. Some types of bacteria and fungi stay in the soil for decades. This is facilitated by the ability of these microorganisms to form spores, which protect them from unfavorable environmental conditions for many years. They cause the most dangerous diseases - anthrax, botulism, and tetanus.

Rice. 18. The causative agent of anthrax. It remains in the soil in a spore-like state for decades. A particularly dangerous disease. Its second name is malignant carbuncle. The prognosis of the disease is unfavorable.

Rice. 19. The causative agent of botulism produces a powerful toxin. 1 microgram of this poison kills a person. Botulinum toxin affects the nervous system, oculomotor nerves, up to paralysis and cranial nerves. The mortality rate from botulism reaches 60%.

Rice. 20. The causative agents of gas gangrene multiply very quickly in the soft tissues of the body without air access, causing severe lesions. In a spore-like state, it persists in the external environment for a long time.

Rice. 21. Putrefactive bacteria.

Rice. 22. Damage to food products by putrefactive bacteria.

Harmful bacteria that damage wood

A number of bacteria and fungi intensively decompose fiber, playing an important sanitary role. However, among them there are bacteria that cause serious diseases in animals. Molds destroy wood. Wood staining mushrooms paint wood in different colors. House mushroom leads the wood to a rotten state. As a result of the vital activity of this fungus, wooden buildings are destroyed. The activity of these fungi causes great damage in the destruction of livestock buildings.

Rice. 23. The photo shows how the house fungus destroyed the wooden floor beams.

Rice. 24. Damaged appearance of logs (blueness) affected by wood-staining fungus.

Rice. 25. House mushroom Merulius Lacrimans. a – cotton wool mycelium; b – young fruiting body; c – old fruiting body; d – old mycelium, cords and wood rot.

Harmful bacteria in food

Products contaminated with dangerous bacteria become a source of intestinal diseases: typhoid fever, salmonellosis, cholera, dysentery etc. Toxins that are released staphylococci and botulism bacilli, cause toxic infections. Cheeses and all dairy products may be affected butyric acid bacteria, which cause butyric acid fermentation, resulting in products having an unpleasant odor and color. Vinegar sticks cause acetic fermentation, which leads to sour wine and beer. Bacteria and micrococci that cause rotting contain proteolytic enzymes that break down proteins, which gives products a foul-smelling odor and bitter taste. Products become covered in mold as a result of damage to mold fungi.

Rice. 26. Bread affected by mold.

Rice. 27. Cheese affected by mold and putrefactive bacteria.

Rice. 28. “Wild yeast” Pichia pastoris. The photo was taken with 600x magnification. The worst pest of beer. Found everywhere in nature.

Harmful bacteria that decompose dietary fats

Butyric acid microbes are everywhere. 25 of their species cause butyric acid fermentation. Life activity fat-digesting bacteria leads to rancidity of the oil. Under their influence, soybean and sunflower seeds become rancid. Butyric acid fermentation, which is caused by these microbes, spoils the silage, and it is poorly eaten by livestock. And wet grain and hay, infected with butyric acid microbes, self-heats. The moisture contained in butter is a good environment for reproduction. putrefactive bacteria and yeast fungi. Because of this, the oil deteriorates not only outside, but also inside. If the oil is stored for a long time, then it can settle on its surface. mold fungi.

Rice. 29. Caviar oil affected by fat-splitting bacteria.

Harmful bacteria affecting eggs and egg products

Bacteria and fungi penetrate into eggs through the pores of the outer shell and its damage. Most often, eggs are infected with salmonella bacteria and molds, egg powder - salmonella and .

Rice. 30. Spoiled eggs.

Harmful bacteria in canned food

for humans are toxins botulinum bacillus and perfringens bacillus. Their spores exhibit high heat resistance, which allows microbes to remain viable after pasteurization of canned food. Being inside the jar, without access to oxygen, they begin to multiply. This releases carbon dioxide and hydrogen, which causes the jar to swell. Eating such a product causes severe food toxicosis, which is characterized by an extremely severe course and often ends in the death of the patient. Canned meat and vegetables are amazing acetic acid bacteria,

Rice. 32. Swollen canned food may contain botulinum bacilli and perfringens bacilli. The jar is inflated by carbon dioxide, which is released by bacteria during reproduction.

Harmful bacteria in grain products and bread

Ergot and other molds that infect grains are the most dangerous for humans. The toxins of these mushrooms are heat stable and are not destroyed by baking. Toxicoses caused by the use of such products are severe. Torment, stricken lactic acid bacteria, has an unpleasant taste and specific smell, lumpy in appearance. Already baked bread is affected Bacillus subtilis(Bac. subtilis) or "gravitating disease." The bacilli secrete enzymes that break down bread starch, which is manifested, first, by an odor not characteristic of bread, and then by the stickiness and viscousness of the bread crumb. Green, white and capitate mold affects already baked bread. It spreads through the air.

Rice. 33. In the photo there is purple ergot. Low doses of ergot cause severe pain, mental disturbances and aggressive behavior. High doses of ergot cause painful death. Its action is associated with muscle contraction under the influence of fungal alkaloids.

Rice. 34. Mold mycelium.

Rice. 35. Spores of green, white and capitate molds can fall from the air onto already baked bread and infect it.

Harmful bacteria that affect fruits, vegetables and berries

Fruits, vegetables and berries are seeded soil bacteria, mold fungi and yeast, which cause intestinal infections. The mycotoxin patulin, which is secreted mushrooms of the genus Penicillium, can cause cancer in humans. Yersinia enterocolitica causes the disease yersiniosis or pseudotuberculosis, which affects the skin, gastrointestinal tract and other organs and systems.

Rice. 36. Damage to berries by mold fungi.

Rice. 37. Skin lesions due to yersiniosis.

Harmful bacteria enter the human body through food, air, wounds and mucous membranes. The severity of diseases caused by pathogenic microbes depends on the poisons they produce and the toxins that arise when they die en masse. Over the course of thousands of years, they have acquired many adaptations that allow them to penetrate and remain in the tissues of a living organism and resist immunity.

To study the harmful effects of microorganisms on the body and develop preventive measures is the task of man!

Many types of bacteria are useful and are successfully used by humans.

Firstly, beneficial bacteria are widely used in the food industry.

In the production of cheeses, kefir, and cream, it is necessary to coagulate milk, which occurs under the influence of lactic acid. Lactic acid is produced by lactic acid bacteria, which are part of starter cultures and feed on the sugar contained in milk. Lactic acid itself promotes the absorption of iron, calcium, and phosphorus. These beneficial elements help us fight infectious diseases.

When making cheese, it is pressed into pieces (heads). The cheese heads are sent to ripening chambers, where the activity of the various lactic acid and propionic acid bacteria that make up the cheese begins. As a result of their activity, the cheese “ripens” - acquires a characteristic taste, smell, pattern and color.

To produce kefir, a starter containing lactic acid bacilli and lactic acid streptococci is used.

Yogurt is a tasty and healthy fermented milk product. Milk for yogurt production must be of very high quality. It should contain a minimum amount of harmful bacteria that can interfere with the development of beneficial yogurt bacteria. Yogurt bacteria convert milk into yogurt and give it its distinctive flavor.

Rice. 14. Lactobacilli – lactic acid bacteria.

Lactic acid and yoghurt bacteria entering the human body with food help fight not only harmful bacteria in the intestines, but also viruses that cause colds and other infections. In the process of their life activity, these beneficial bacteria create such an acidic environment (due to the excreted metabolic products) that only a microbe very adapted to difficult conditions, such as E. coli, can survive next to them.

The activity of beneficial bacteria is used in the fermentation of cabbage and other vegetables.

Secondly, bacteria are used to leach ores in the extraction of copper, zinc, nickel, uranium and other metals from natural ores. Leaching is the extraction of minerals from ore that is not rich in them using bacteria, when other methods of extraction (for example, smelting ore) are ineffective and expensive. Leaching is carried out by aerobic bacteria.

Third, beneficial aerobic bacteria are used to purify wastewater from cities and industrial enterprises from organic residues.

The main goal of such biological treatment is the neutralization of complex and insoluble organic substances in wastewater, which cannot be removed from it by mechanical treatment, and their decomposition into simple water-soluble elements.

Fourth, bacteria are used in the production of silk and leather processing, etc. The raw materials for the production of artificial silk are produced by special transgenic bacteria. Technical lactic acid bacteria are used in the tanning industry for swelling and deashing (processing of raw materials from solid compounds), in the textile industry, as an auxiliary for dyeing and printing.

Fifth, bacteria are used to control agricultural pests. Agricultural plants are treated with special preparations that contain certain types of bacteria. Insect pests, consuming parts of plants treated with biological preparations, ingest bacterial spores with food. This leads to the death of pests.

Sixth, bacteria are used to produce various medications (for example, interferon) that kill viruses and support human immunity (defense).

And lastly, harmful bacteria also have beneficial properties.

Decay bacteria (coprophytic bacteria) destroy the corpses of dead animals, leaves of trees and shrubs that have fallen to the ground, and the trunks of dead trees themselves. These bacteria are a kind of orderlies for our planet. They feed on organic matter and turn it into humus - a fertile layer of soil.

Soil bacteria live in the soil and also provide many benefits in nature. Mineral salts produced by soil bacteria are then absorbed from the soil by plant roots. One cubic centimeter of the surface layer of forest soil contains hundreds of millions of soil bacteria.

Rice. 15. Clostridia are soil bacteria.

Bacteria also live in the soil and absorb nitrogen from the air, accumulating it in their bodies. This nitrogen is then converted into proteins. After the bacterial cells die, these proteins are converted into nitrogenous compounds (nitrates), which act as fertilizer and are well absorbed by plants.

Conclusion.

Bacteria are a large, well-studied group of microorganisms. Bacteria are found everywhere and people encounter them in their lives all the time. Bacteria can be beneficial to humans, or they can become a source of dangerous diseases.

Studying the properties of bacteria, combating their harmful manifestations and using the beneficial properties of the life activity of bacteria is one of the main tasks for humans.

Student of 6th grade B _________________________________ / Yaroslav Shchipanov /

Literature.

1. Berkinblit M.B., Glagolev S.M., Maleeva Yu.V., Biology: Textbook for grade 6. – M.: Binom. Knowledge Laboratory, 2008.

2. Ivchenko, T. V. Electronic textbook “Biology: 6th grade. Living organism". // Biology at school. - 2007.

3. Pasechnik V.V. Biology. 6th grade Bacteria, fungi, plants: Textbook. for general education textbook establishments, - 4th ed., stereotype. – M.: Bustard, 2000.

4. Smelova, V.G. Digital microscope in biology lessons // Publishing House “First of September” Biology. - 2012. - No. 1.

Most people associate the word “bacteria” with something unpleasant and a threat to health. At best, fermented milk products come to mind. At worst - dysbacteriosis, plague, dysentery and other troubles. But bacteria are everywhere, they are good and bad. What can microorganisms hide?

What are bacteria

Man and bacteria

In our body there is a constant battle between harmful and beneficial bacteria. Thanks to this process, a person receives protection from various infections. Various microorganisms surround us at every step. They live on clothes, fly in the air, they are omnipresent.

The presence of bacteria in the mouth, and this is about forty thousand microorganisms, protects the gums from bleeding, from periodontal disease and even from sore throat. If a woman’s microflora is disturbed, she may develop gynecological diseases. Following basic rules of personal hygiene will help avoid such failures.

Human immunity completely depends on the state of the microflora. Almost 60% of all bacteria are found in the gastrointestinal tract alone. The rest are located in the respiratory system and in the reproductive system. About two kilograms of bacteria live in a person.

The appearance of bacteria in the body

Beneficial bacteria

Beneficial bacteria are: lactic acid bacteria, bifidobacteria, E. coli, streptomycents, mycorrhizae, cyanobacteria.

They all play an important role in human life. Some of them prevent the occurrence of infections, others are used in the production of medicines, and others maintain balance in the ecosystem of our planet.

Types of harmful bacteria

Harmful bacteria can cause a number of serious illnesses in humans. For example, diphtheria, anthrax, sore throat, plague and many others. They are easily transmitted from an infected person through air, food, or touch. It is the harmful bacteria, the names of which will be given below, that spoil food. They give off an unpleasant odor, rot and decompose, and cause diseases.

Bacteria can be gram-positive, gram-negative, rod-shaped.

Names of harmful bacteria

Table. Harmful bacteria for humans. Titles

Titles	Habitat	Harm
Mycobacteria	food, water	tuberculosis, leprosy, ulcer
Tetanus bacillus	soil, skin, digestive tract	tetanus, muscle spasms, respiratory failure
Plague stick (considered by experts as a biological weapon)	only in humans, rodents and mammals	bubonic plague, pneumonia, skin infections
Helicobacter pylori	human gastric mucosa	gastritis, peptic ulcer, produces cytoxins, ammonia
Anthrax bacillus	the soil	anthrax
Botulism stick	food, contaminated dishes	poisoning

Harmful bacteria can stay in the body for a long time and absorb beneficial substances from it. However, they can cause an infectious disease.

The most dangerous bacteria

One of the most resistant bacteria is methicillin. It is better known as Staphylococcus aureus (Staphylococcus aureus). This microorganism can cause not one, but several infectious diseases. Some types of these bacteria are resistant to powerful antibiotics and antiseptics. Strains of this bacterium can live in the upper respiratory tract, open wounds and urinary tract of every third inhabitant of the Earth. For a person with a strong immune system, this does not pose a danger.

Harmful bacteria to humans are also pathogens called Salmonella typhi. They are the causative agents of acute intestinal infections and typhoid fever. These types of bacteria, harmful to humans, are dangerous because they produce toxic substances that are extremely dangerous to life. As the disease progresses, the body becomes intoxicated, there is a very strong fever, rashes on the body, and the liver and spleen become enlarged. The bacterium is very resistant to various external influences. Lives well in water, on vegetables, fruits and reproduces well in milk products.

Clostridium tetan is also one of the most dangerous bacteria. It produces a poison called tetanus exotoxin. People who become infected with this pathogen experience terrible pain, seizures and die very hard. The disease is called tetanus. Despite the fact that the vaccine was created back in 1890, 60 thousand people die from it every year on Earth.

And another bacterium that can lead to human death is Mycobacterium tuberculosis. It causes tuberculosis, which is drug-resistant. If you do not seek help in a timely manner, a person may die.

Measures to prevent the spread of infections

Harmful bacteria and the names of microorganisms are studied by doctors of all disciplines from their student days. Healthcare annually seeks new methods to prevent the spread of life-threatening infections. If you follow preventive measures, you will not have to waste energy on finding new ways to combat such diseases.

To do this, it is necessary to timely identify the source of the infection, determine the circle of sick people and possible victims. It is imperative to isolate those who are infected and disinfect the source of infection.

The second stage is the destruction of pathways through which harmful bacteria can be transmitted. For this purpose, appropriate propaganda is carried out among the population.

Food facilities, reservoirs, and food storage warehouses are taken under control.

Every person can resist harmful bacteria by strengthening their immunity in every possible way. A healthy lifestyle, observing basic hygiene rules, protecting yourself during sexual contact, using sterile disposable medical instruments and equipment, completely limiting communication with people in quarantine. If you enter an epidemiological area or a source of infection, you must strictly comply with all the requirements of sanitary and epidemiological services. A number of infections are equated in their effects to bacteriological weapons.

Most people view various bacterial organisms solely as harmful particles that can provoke the development of various pathological conditions. Nevertheless, according to scientists, the world of these organisms is very diverse. There are frankly dangerous bacteria that pose a danger to our body, but there are also useful ones - those that ensure the normal functioning of our organs and systems. Let's try to understand these concepts a little and consider individual types of such organisms. Let's talk about bacteria in nature that are harmful and beneficial to humans.

Beneficial bacteria

Scientists say that bacteria became the very first inhabitants of our big planet, and it is thanks to them that there is life on Earth now. Over the course of many millions of years, these organisms gradually adapted to the constantly changing conditions of existence, they changed their appearance and habitat. Bacteria were able to adapt to the environment and were able to develop new and unique methods of life support, including multiple biochemical reactions - catalysis, photosynthesis and even seemingly simple respiration. Now bacteria coexist with human organisms, and such cooperation is characterized by some harmony, because such organisms are capable of bringing real benefits.

After a little person is born, bacteria immediately begin to penetrate into his body. They penetrate the respiratory tract along with the air, enter the body along with breast milk, etc. The entire body becomes saturated with various bacteria.

It is impossible to accurately calculate their number, but some scientists boldly say that the number of such cells in the body is comparable to the number of all cells. The digestive tract alone is home to four hundred different types of living bacteria. It is believed that a certain variety can grow only in a specific place. Thus, lactic acid bacteria are able to grow and multiply in the intestines, others feel optimal in the oral cavity, and some live only on the skin.

Over many years of coexistence, humans and such particles were able to recreate optimal conditions for cooperation for both groups, which can be characterized as a useful symbiosis. At the same time, bacteria and our body combine their capabilities, while each side remains in the black.

Bacteria are capable of collecting particles of various cells on their surface, which is why the immune system does not perceive them as hostile and does not attack them. However, after organs and systems are exposed to harmful viruses, beneficial bacteria rise to the defense and simply block the path of pathogens. When existing in the digestive tract, such substances also bring tangible benefits. They process leftover food, releasing a significant amount of heat. It, in turn, is transmitted to nearby organs, and is transferred throughout the body.

A deficiency of beneficial bacteria in the body or a change in their number causes the development of various pathological conditions. This situation can develop while taking antibiotics, which effectively destroy both harmful and beneficial bacteria. To correct the number of beneficial bacteria, special preparations - probiotics - can be consumed.

Bacteria are useful and harmful. Bacteria in human life

Bacteria are the most numerous inhabitants of planet Earth. They inhabited it in ancient times and continue to exist today. Some species have even changed little since then. Bacteria, beneficial and harmful, literally surround us everywhere (and even penetrate into other organisms). With a rather primitive unicellular structure, they are probably one of the most effective forms of living nature and are classified as a special kingdom.

Permanent microflora

99% of the population resides permanently in the intestines. They are ardent supporters and helpers of man.

Essential beneficial bacteria. Names: bifidobacteria and bacteroides. They are the vast majority.
Associated beneficial bacteria. Names: Escherichia coli, enterococci, lactobacilli. Their number should be 1-9% of the total.

You also need to know that under appropriate negative conditions, all these representatives of the intestinal flora (with the exception of bifidobacteria) can cause diseases.

What are they doing?

The main functions of these bacteria are to help us in the digestion process. It has been noted that dysbiosis can occur in a person with poor nutrition. The result is stagnation and poor health, constipation and other inconveniences. When a balanced diet is normalized, the disease usually recedes.

Another function of these bacteria is guard. They monitor which bacteria are beneficial. To ensure that “strangers” do not penetrate their community. If, for example, the causative agent of dysentery, Shigella Sonne, tries to penetrate the intestines, they kill it. However, it is worth noting that this only happens in the body of a relatively healthy person with good immunity. Otherwise, the risk of getting sick increases significantly.

Fickle microflora

Approximately 1% of the body of a healthy individual consists of so-called opportunistic microbes. They belong to the unstable microflora. Under normal conditions, they perform certain functions that do not harm humans and work for the benefit. But in certain situations they can manifest themselves as pests. These are mainly staphylococci and various types of fungi.

What are bacteria

Man and bacteria

The appearance of bacteria in the body

Beneficial bacteria are: lactic acid bacteria, bifidobacteria, E. coli, streptomycents, mycorrhizae, cyanobacteria.

Types of harmful bacteria

Bacteria can be gram-positive, gram-negative, rod-shaped.

Names of harmful bacteria

Table. Harmful bacteria for humans. Titles

Titles	Habitat	Harm
Mycobacteria	food, water	tuberculosis, leprosy, ulcer
Tetanus bacillus	soil, skin, digestive tract	tetanus, muscle spasms, respiratory failure
Plague stick (considered by experts as a biological weapon)	only in humans, rodents and mammals	bubonic plague, pneumonia, skin infections
Helicobacter pylori	human gastric mucosa	gastritis, peptic ulcer, produces cytoxins, ammonia
Anthrax bacillus	the soil	anthrax
Botulism stick	food, contaminated dishes	poisoning

Harmful bacteria can stay in the body for a long time and absorb beneficial substances from it. However, they can cause an infectious disease.

The most dangerous bacteria

And another bacterium that can lead to human death is Mycobacterium tuberculosis. It causes tuberculosis, which is drug-resistant. If you do not seek help in a timely manner, a person may die.

Measures to prevent the spread of infections

The second stage is the destruction of pathways through which harmful bacteria can be transmitted. For this purpose, appropriate propaganda is carried out among the population.

Food facilities, reservoirs, and food storage warehouses are taken under control.

What types of bacteria are there: names and types

The most ancient living organism on our planet. Not only have its members survived for billions of years, but they are also powerful enough to wipe out every other species on Earth. In this article we will look at what types of bacteria there are.

Let's talk about their structure, functions, and also name some useful and harmful types.

Discovery of bacteria

Types of bacteria in urine

Structure

Metabolism

Reproduction

Place in the world

Previously, we figured out what bacteria are. Now it’s worth talking about what role they play in nature.

Researchers say that bacteria are the first living organisms to appear on our planet. There are both aerobic and anaerobic varieties. Therefore, single-celled creatures are able to survive various disasters that occur on the Earth.

The undoubted benefit of bacteria lies in the assimilation of atmospheric nitrogen. They are involved in the formation of soil fertility and the destruction of the remains of dead representatives of flora and fauna. In addition, microorganisms participate in the creation of minerals and are responsible for maintaining oxygen and carbon dioxide reserves in the atmosphere of our planet.

The total biomass of prokaryotes is about five hundred billion tons. It stores more than eighty percent of phosphorus, nitrogen and carbon.

However, on Earth there are not only beneficial, but also pathogenic species of bacteria. They cause many deadly diseases. For example, among these are tuberculosis, leprosy, plague, syphilis, anthrax and many others. But even those that are conditionally safe for human life can become a threat if the level of immunity decreases.

There are also bacteria that infect animals, birds, fish and plants. Thus, microorganisms are not only in symbiosis with more developed beings. Next we will talk about what pathogenic bacteria there are, as well as about beneficial representatives of this type of microorganism.

Bacteria and humans

Even at school they teach what bacteria are. Grade 3 knows all kinds of cyanobacteria and other single-celled organisms, their structure and reproduction. Now we will talk about the practical side of the issue.

Half a century ago, no one even thought about such an issue as the state of microflora in the intestines. Everything was OK. Eating more natural and healthier, less hormones and antibiotics, less chemical emissions into the environment.

Today, in conditions of poor nutrition, stress, and an overabundance of antibiotics, dysbiosis and related problems are taking leading positions. How do doctors propose to deal with this?

One of the main answers is the use of probiotics. This is a special complex that repopulates the human intestines with beneficial bacteria.

Such an intervention can help with such unpleasant issues as food allergies, lactose intolerance, gastrointestinal disorders and other ailments.

Let's now touch on what beneficial bacteria there are, and also learn about their effect on health.

Three types of microorganisms have been studied in the most detail and are widely used to have a positive effect on the human body: acidophilus, Bulgarian bacillus and bifidobacteria.

The first two are designed to stimulate the immune system, as well as reduce the growth of some harmful microorganisms such as yeast, E. coli, and so on. Bifidobacteria are responsible for digesting lactose, producing certain vitamins and lowering cholesterol.

Harmful bacteria

Earlier we talked about what types of bacteria there are. The types and names of the most common beneficial microorganisms were announced above. Next we will talk about the “single-cell enemies” of humans.

There are some that are harmful only to humans, while others are deadly for animals or plants. People have learned to use the latter, in particular, to destroy weeds and annoying insects.

Before delving into what harmful bacteria are, it’s worth determining how they spread. And there are a lot of them. There are microorganisms that are transmitted through contaminated and unwashed food, by airborne droplets and contact, through water, soil or through insect bites.

The worst thing is that just one cell, once in the favorable environment of the human body, is capable of multiplying to several million bacteria within just a few hours.

If we talk about what types of bacteria there are, the names of pathogenic and beneficial ones are difficult for a layman to distinguish. In science, Latin terms are used to refer to microorganisms. In common parlance, abstruse words are replaced by concepts - “Escherichia coli”, “pathogens” of cholera, whooping cough, tuberculosis and others.

Preventive measures to prevent the disease are of three types. These are vaccinations and vaccinations, interruption of transmission routes (gauze bandages, gloves) and quarantine.

Where do bacteria in urine come from?

Which bacteria are beneficial?

Bacteria are everywhere - we have heard a similar slogan since infancy. We are trying with all our might to resist these microorganisms by sterilizing the environment. Is it necessary to do this?

There are bacteria that are protectors and helpers of both humans and the environment. These living microorganisms cover humans and nature with millions of colonies. They are active participants in all processes occurring on the planet and directly in the body of any living creature. Their goal is to be responsible for the correct flow of life processes and to be everywhere where one cannot do without them.

The vast world of bacteria

According to studies conducted regularly by scientists, the human body contains more than two and a half kilograms of various bacteria.

All bacteria are involved in life processes. For example, some help in the digestion of food, others are active assistants in the production of vitamins, and others act as protectors against harmful viruses and microorganisms.

One of the very useful living creatures present in the external environment is a nitrogen-fixing bacterium, which is found in the root nodules of plants that release nitrogen into the atmosphere necessary for human respiration.

There is another group of microorganisms that are associated with the digestion of waste organic compounds, which helps maintain soil fertility at the proper level. This includes nitrogen-fixing microbes.

Medicinal and food bacteria

Other microorganisms take an active part in the process of producing antibiotics - these are streptomycin and tetracycline. These bacteria are called Streptomyces and are soil bacteria that are used in the manufacture of not only antibiotics, but also industrial and food products.

For these food industries, the bacterium Lactobacillis is widely used, which is involved in fermentation processes. Therefore, it is in demand in the production of yogurt, beer, cheese, and wine.

All these representatives of helper microorganisms live according to their own strict rules. Violation of their balance leads to the most negative phenomena. First of all, dysbacteriosis is caused in the human body, the consequences of which are sometimes irreversible.

Secondly, all human restorative functions associated with internal or external organs are much more difficult when there is an imbalance of beneficial bacteria. The same applies to the group that is involved in food production.

What are bacteria

Bacteria means “stick” in Greek. This name does not mean that harmful bacteria are meant.

They were given this name because of their shape. Most of these single cells look like rods. They also come in squares and star-shaped cells. For a billion years, bacteria do not change their appearance; they can only change internally. They can be movable or immobile. Bacteria On the outside it is covered with a thin shell. This allows it to maintain its shape. There is no nucleus or chlorophyll inside the cell. There are ribosomes, vacuoles, cytoplasmic outgrowths, and protoplasm. The largest bacterium was found in 1999. It was called the "Grey Pearl of Namibia". Bacteria and bacillus mean the same thing, they just have different origins.

Man and bacteria

The appearance of bacteria in the body

A newly born baby has a sterile intestine.

After his first breath, many microorganisms enter the body with which he was previously unfamiliar. When the baby is first put to the breast, the mother transfers beneficial bacteria with milk, which will help normalize the intestinal microflora. It is not for nothing that doctors insist that the mother immediately after the birth of her child breastfeed him. They also recommend extending this feeding as long as possible.

Beneficial bacteria

Beneficial bacteria are: lactic acid bacteria, bifidobacteria, E. coli, streptomycents, mycorrhizae, cyanobacteria.

Types of harmful bacteria

Harmful bacteria can cause a number of serious illnesses in humans. For example, diphtheria, sore throat, plague and many others. They are easily transmitted from an infected person through air, food, or touch. It is the harmful bacteria, the names of which will be given below, that spoil food. They give off an unpleasant odor, rot and decompose, and cause diseases.

Bacteria can be gram-positive, gram-negative, rod-shaped.

Names of harmful bacteria

Table. Harmful bacteria for humans. Titles

Titles	Habitat	Harm
Mycobacteria	food, water	tuberculosis, leprosy, ulcer
Tetanus bacillus	soil, skin, digestive tract	tetanus, muscle spasms, respiratory failure
Plague stick (considered by experts as a biological weapon)	only in humans, rodents and mammals	bubonic plague, pneumonia, skin infections
Helicobacter pylori	human gastric mucosa	gastritis, peptic ulcer, produces cytoxins, ammonia
Anthrax bacillus	the soil	anthrax
Botulism stick	food, contaminated dishes	poisoning

Harmful bacteria can stay in the body for a long time and absorb beneficial substances from it. However, they can cause an infectious disease.

The most dangerous bacteria

One of the most resistant bacteria is methicillin. It is better known as Staphylococcus aureus (Staphylococcus aureus). can cause not one, but several infectious diseases. Some types of these bacteria are resistant to powerful antibiotics and antiseptics. Strains of this bacterium can live in the upper respiratory tract, open wounds and urinary tract of every third inhabitant of the Earth. For a person with a strong immune system, this does not pose a danger.

And another bacterium that can lead to the death of a person is It causes tuberculosis, which is resistant to drugs. If you do not seek help in a timely manner, a person may die.

Measures to prevent the spread of infections

The second stage is the destruction of pathways through which harmful bacteria can be transmitted. For this purpose, appropriate propaganda is carried out among the population.

Food facilities, reservoirs, and food storage warehouses are taken under control.