Beneficial microorganisms. Harmful bacteria: where they live and what causes diseases

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

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

Rice. 7. Mycobacterium tuberculosis. Bacteria have been causing disease in humans and animals for thousands of years. Tuberculosis bacillus is extremely resistant to external environment. Transmitted in 95% of cases by airborne droplets. Most often affects the lungs.

Rice. 8. The causative agent of diphtheria is Corynebacterium or Leffler's bacillus. More often it 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 toxin is fixed on the membranes of the cells of the heart muscle, kidneys, adrenal glands and nerve ganglia and destroys them.

Rice. 9. Pathogens staph infection. Pathogenic staphylococci cause extensive lesions of the skin and its appendages, lesions of many internal organs, food poisoning, enteritis and colitis, sepsis and toxic shock.

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

Rice. 11. Whooping cough bordetella.

Rice. 12. The causative agents of scarlet fever are streptococci pyogenes.

Harmful bacteria of water microflora

Rice. 13. Shigella. The pathogens cause bacillary dysentery. Shigella destroy 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 small intestine, but is located on their surface. The toxin cholerogen is released, the action of which leads to a violation of water-salt metabolism, in connection with which the body loses up to 30 liters of fluid per day.

Rice. 15. Salmonella - causative agents of typhoid and paratyphoid. The epithelium and lymphoid elements of the small intestine are affected. With the blood flow they enter Bone marrow, spleen and gallbladder from which pathogens enter the small intestine again. As a result of immune inflammation, the wall of the small intestine ruptures and peritonitis occurs.

Rice. 16. Causative agents of tularemia (blue coccobacteria). Affects the respiratory and intestines. They have the peculiarity of penetrating into the human body through intact skin and mucous membranes of the eyes, nasopharynx, larynx and intestines. A feature of the disease is the defeat of the lymph nodes (primary bubo).

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

Harmful bacteria of soil microflora

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

Rice. 19. The causative agent of botulism releases the strongest toxin. 1 mcg of this poison kills a person. Botulinum toxin affects the nervous system, oculomotor nerves, up to paralysis and cranial nerves. Mortality 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 remains in the external environment long time.

Rice. 21. Putrefactive bacteria.

Rice. 22. Defeat by putrefactive bacteria of food.

Harmful bacteria infecting wood

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

Rice. 24. Spoiled appearance of logs (blue) affected by a wood-staining fungus.

Rice. 25. House mushroom Merulius Lacrimans. a - cotton-like mycelium; b - young fruiting body; c - old fruiting body; d - old mycelium, cords and rotten wood.

Harmful bacteria in food

Rice. 26. Bread affected by mold.

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

Rice. 28. "Wild yeast" Pichia pastoris. Photo taken at 600x magnification. A vicious pest of beer. Found ubiquitously in nature.

Harmful bacteria that break down dietary fats

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

Harmful bacteria affecting eggs and egg products

Rice. 30. Spoiled eggs.

Harmful bacteria in canned food

Rice. 32. Bloated canned food may contain botulinum rods and perfringens rods. It inflates the jar with carbon dioxide, which is released by bacteria during reproduction.

Harmful bacteria in grain products and bread

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

Rice. 34. Mushroom fungus.

Rice. 35. Spores of green, white and capitate mold can get from the air on already baked bread and infect it.

Harmful bacteria that affects fruits, vegetables and berries

Rice. 36. Defeat of berries by mold fungi.

Rice. 37. Skin lesions in yersiniosis.

harmful bacteria penetrate into the human body with food, through the air, wounds and mucous membranes. The severity of diseases caused by pathogenic microbes depends on the poisons they produce and the toxins that occur during their mass death. Over the millennia, they have acquired many devices that allow them to penetrate and stay in the tissues of a living organism and resist immunity.

To study the harmful effects of microorganisms on the body and develop preventive actions- that's the task of man!

Maslov Arseniy

Research work of a 3rd grade student on the topic "Bacteria: harmful and beneficial."

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Relevance… Once I asked my parents why people get sick? Mom said that bacteria enter the body and the person gets sick. And then I thought, what are bacteria, where do they live, how do they reproduce and why are they dangerous? And are all bacteria harmful? The purpose of the study: to study the characteristics of the life of bacteria and find out whether they can be beneficial and harmful. Tasks: to study the literature on the chosen topic, to get acquainted with the diversity and classification of bacteria, to find out what are the harmful and beneficial bacteria, to cook homemade kefir

Object and subject of study Object of study: bacteria Subject of study: the importance of bacteria for humans Hypothesis Hypothesis: suppose that many bacteria live in the human body, they can be both beneficial and harmful and they can be propagated at home. Research methods: Working with additional sources, searching for the necessary information; Observations and analysis of the received information; Experiences; Test; Data processing

The History of Bacteria Bacteria were first seen through an optical microscope and described in 1676 by the Dutch naturalist Anthony van Leeuwenhoek. The name "bacteria" was coined in 1828 by Christian Ehrenberg. The study of bacteria and their structure is carried out by microbiology, which was formed in the second half of the 19th century as the science of pathogens, that is, as a branch of medicine. It is difficult to find a place on Earth where there would be no bacteria. They are found in a wide variety of places: in the atmosphere and at the bottom of the oceans, in fast-flowing rivers and in permafrost, in fresh milk and in nuclear reactors; however, especially a lot of them in the soil

The structure of bacteria A bacterium has a complex structure The cell wall protects a unicellular organism from external influence, attaches certain form, provides nutrition and preservation of its internal contents. The plasma membrane contains enzymes, participates in the process of reproduction, biosynthesis of components. Flagella are called surface structures that serve to move cells in liquid medium or on a hard surface Cytoplasm serves to perform vital important functions. In many species, the cytoplasm contains DNA, ribosomes, and various granules. Pili are filamentous formations, much thinner and smaller than flagella. They are various types, differ in purpose, structure. Pili are needed to attach the body to the affected cell.

Types of bacteria cocci (have a rounded shape); bacilli (have a rod-shaped form); spirilla (have the shape of a spiral); spirilla (have the shape of a spiral);

Classification of bacteria Beneficial bacteria coli It is an integral part of the intestinal flora of humans and most animals. Its benefits can hardly be overestimated: it breaks down indigestible monosaccharides, promoting digestion; prevents the development of pathogenic and pathogenic microorganisms in the intestine. Lactic acid bacteria Representatives of this order are present in milk, dairy and fermented products, and at the same time are part of the microflora of the intestines and oral cavity. Able to ferment carbohydrates and in particular lactose and produce lactic acid, which is the main source of carbohydrates for humans. By maintaining a constantly acidic environment, the growth of unfavorable bacteria is inhibited. Bifidobacteria Through the production of lactic and acetic acids, they completely prevent the development of putrefactive and pathogenic microbes in the child's body. In addition, bifidobacteria: contribute to the digestion of carbohydrates; protect the intestinal barrier from the penetration of microbes and toxins into internal environment organism

Harmful bacteria Salmonella This bacterium is the causative agent of a very acute intestinal infection, typhoid fever. Salmonella produces toxins that are dangerous only for humans. Tetanus bacillus This bacterium is one of the most persistent and at the same time the most dangerous in the world. Produces an extremely toxic poison, tetanus exotoxin, resulting in almost complete defeat nervous system. Mycobacteria Mycobacteria are a family of bacteria, some of which are pathogenic. Various members of this family cause such dangerous diseases like tuberculosis, mycobacteriosis, leprosy (leprosy) - they are all transmitted by airborne droplets.

My experiences… Making homemade kefir

Cultivation of hay stick Among the bacteria that are widespread in nature, hay stick is also included. It was first described in 1835. And it got its name due to the fact that initially the culture was isolated from rotten hay. This bacterium is one of the largest. It has a straight elongated shape with blunt rounded ends and is usually colorless. This bacterium is quite easy to obtain at home. For work, I needed the following: hay (you can buy it at a pet store), a pot of water, a jar with a wide neck, gauze for filtering. For one liter of water you need to take 10 grams of hay. Boil the hay for 20 minutes. The resulting broth is filtered and poured into a jar, diluting 1: 1 with settled cold water. In another jar, I decided to pour undiluted broth and see what happens. Banks put in a warm place. The best conditions for the life of hay sticks are a large amount of dissolved organic substances, an abundance of oxygen and a temperature of about +30 degrees. Under such conditions, a film consisting entirely of bacteria should form on the surface of the hay decoction in two days.

The results of the "Bacteria" test It turned out that many guys do not know about the kingdom of bacteria and the existence of beneficial bacteria in our dairy products.

Conclusion By studying bacteria, I got acquainted with their diversity and classification, I was able to grow bacteria on my own at home. I learned that there is a huge amount of beneficial bacteria that we consume every day with fermented milk products and about harmful bacteria (dangerous to humans) I found out that bacteria are an indispensable part of our life and all living things. They are absolutely everywhere and in everything, play a colossal role in human life. People have learned to use bacteria: Based on the above material and the research, I believe that my hypothesis was confirmed: “Many bacteria live in the human body, they are both beneficial and harmful and they can be propagated at home”

Bacteria appeared about 3.5-3.9 billion years ago, they were the first living organisms on our planet. Over time, life developed and became more complex - new, each time more complex forms of organisms appeared. Bacteria all this time did not stand aside, on the contrary, they were the most important component of the evolutionary process. It was they who first developed new forms of life support, such as respiration, fermentation, photosynthesis, catalysis ... and also found effective ways coexistence with almost every living being. Man is no exception.

But bacteria is a whole domain of organisms, with over 10,000 species. Each species is unique and followed its own evolutionary path, as a result, it developed its own unique forms of coexistence with other organisms. Some bacteria went into close mutually beneficial cooperation with humans, animals and other creatures - they can be called useful. Other species have learned to exist at the expense of others, using the energy and resources of donor organisms - they are commonly considered harmful or pathogenic. Still others have gone even further and have become practically self-sufficient, they receive everything they need for life from the environment.

Inside humans, as well as inside other mammals, lives an unimaginably large number of bacteria. There are 10 times more of them in our bodies than all the cells of the body combined. Among them, the vast majority are useful, but the paradox is that their vital activity, their presence inside us is a normal state of affairs, they depend on us, we, in turn, on them, and at the same time we do not feel any signs of this cooperation. Another thing is harmful, for example, pathogenic bacteria, once inside us, their presence immediately becomes noticeable, and the consequences of their activity can become very serious.

Beneficial bacteria

The vast majority of them are creatures living in symbiotic or mutualistic relationships with donor organisms (in which they live). Usually, such bacteria take on some of the functions that the host organism is not capable of. An example is the bacteria that live in the human digestive tract and process part of the food that the stomach itself is not able to cope with.

Some types of beneficial bacteria:

Escherichia coli (lat. Escherichia coli)

It is an integral part of the intestinal flora of humans and most animals. Its benefits can hardly be overestimated: it breaks down indigestible monosaccharides, promoting digestion; synthesizes vitamins of group K; prevents the development of pathogenic and pathogenic microorganisms in the intestine.

Closeup: colony of bacteria Escherichia coli

Lactic acid bacteria (Lactococcus lactis, Lactobacillus acidophilus, etc.)

Representatives of this order are present in milk, dairy and fermented products, and at the same time are part of the microflora of the intestines and oral cavity. Able to ferment carbohydrates and in particular lactose and produce lactic acid, which is the main source of carbohydrates for humans. By maintaining a constantly acidic environment, the growth of unfavorable bacteria is inhibited.

bifidobacteria

Bifidobacteria have the most significant effect on infants and mammals, accounting for up to 90% of their intestinal microflora. Through the production of lactic and acetic acids, they completely prevent the development of putrefactive and pathogenic microbes in the child's body. In addition, bifidobacteria: contribute to the digestion of carbohydrates; protect the intestinal barrier from the penetration of microbes and toxins into the internal environment of the body; synthesize various amino acids and proteins, vitamins of groups K and B, useful acids; promote intestinal absorption of calcium, iron and vitamin D.

Harmful (pathogenic) bacteria

Some types of pathogenic bacteria:

Salmonella Typhi

This bacterium is the causative agent of a very acute intestinal infection, typhoid fever. Salmonella typhi produces toxins that are dangerous only for humans. When infected, a general intoxication of the body occurs, which leads to severe fever, a rash throughout the body, in severe cases, damage to the lymphatic system and, as a result, death. Every year, 20 million cases of typhoid fever are recorded in the world, 1% of cases lead to death.

Salmonella typhi bacteria colony

Tetanus bacillus (Clostridium tetani)

This bacterium is one of the most persistent and at the same time the most dangerous in the world. Clostridium tetani produces an extremely toxic poison, tetanus exotoxin, which causes almost complete damage to the nervous system. People who become ill with tetanus experience the most terrible torment: all the muscles of the body spontaneously strain to the limit, powerful convulsions occur. Mortality is extremely high - on average, about 50% of those infected die. Fortunately, back in 1890, the tetanus vaccine was invented, it is given to newborns in all developed countries of the world. In underdeveloped countries, tetanus kills 60,000 people every year.

Mycobacteria (Mycobacterium tuberculosis, Mycobacterium leprae, etc.)

Mycobacteria are a family of bacteria, some of which are pathogenic. Various representatives of this family cause such dangerous diseases as tuberculosis, mycobacteriosis, leprosy (leprosy) - they are all transmitted by airborne droplets. Mycobacteria cause more than 5 million deaths each year.

In addition to harmful, there are beneficial bacteria that provide the body with great help.

For the layman, the term "bacteria" is most often associated with something harmful and life-threatening.

Most often, among the beneficial bacteria, lactic-acid microorganisms are recalled.

If we talk about harmful bacteria, then people most often remember such diseases as:

• dysbacteriosis;
• plague;
• dysentery and some others.

Beneficial bacteria for humans help to carry out some biochemical processes in the body that ensure normal life.

Bacterial microorganisms live almost everywhere. They are found in air, water, soil, in any type of tissue, both living and dead.

A harmful microorganism can cause serious harm to the body, and the resulting pathologies can seriously undermine the state of health.

The list of the most famous pathogenic microbes includes:

1. Salmonella.
2. Staphylococcus.
3. Streptococcus.
4. Vibrio cholerae.
5. Plague wand and some others.

If harmful microorganisms are known to most people, then not everyone knows about beneficial bacterial microorganisms, and those people who have heard about the presence of beneficial bacteria are unlikely to be able to name them and how they are useful to humans.

Depending on the impact on humans, the microflora can be divided into three groups of microorganisms:

• pathogenic;
• conditionally pathogenic;
• non-pathogenic.

Non-pathogenic microorganisms are the most useful for humans, pathogenic microorganisms are the most harmful, and conditionally pathogenic microorganisms can be beneficial under certain conditions, and when they change external conditions become harmful.

In the body, beneficial and harmful bacteria are in balance, but when some factors change, a predominance can be observed. pathogenic flora which leads to the development of various diseases.

Beneficial bacteria for humans

The most useful for the human body are sour-milk and bifidobacteria.

These types of bacteria are not capable of leading to the development of diseases in the body.

Beneficial bacteria for the intestines are a group of lactic acid bacteria and bifidobacteria.

Beneficial microbes - lactic acid bacteria are used in the production of a variety of products from milk. In addition, they can be used in the preparation of dough and some other types of products.

Bifidobacteria form the basis of the intestinal flora in the human body. In young breastfed children, this type of microorganism accounts for up to 90% of all types of bacteria living in the intestines.

These bacteria are entrusted with the performance of a large number of functions, the main among which are the following:

1. Ensuring the physiological protection of the digestive tract from penetration and damage by pathogenic microflora.
2. Provides the production of organic acids. Preventing the reproduction of pathogenic organisms.
3. Participate in the synthesis of B vitamins and vitamin K, in addition, they participate in the process of protein synthesis necessary for the body person.
4. Accelerates the absorption of vitamin D.

Bacteria useful to humans perform a huge number of functions and their role is difficult to overestimate. Without their participation, it is impossible to carry out normal digestion and absorption of nutrients.

The colonization of the intestines with beneficial bacteria occurs in the first days of a baby's life.

Bacteria penetrate the baby's stomach and begin to participate in all the digestive processes that occur in the body of the newborn.

In addition to sour-milk and bifidobacteria, Escherichia coli, streptomycetes, mycorrhiza and cyanobacteria are useful for humans.

These groups of organisms play a huge role in human life. Some of them prevent the development infectious diseases, others are used in production technologies medicines, and still others provide balance in the ecological system of the planet.

The third type of microbes are Azotobacteria, their effect on environment hard to overestimate.

Characteristics of sour milk stick

The lactic acid microbes are rod-shaped and Gram-positive.

The habitat of various microbes of this group is milk, dairy products such as yogurt, kefir, they also multiply in fermented foods and are part of the microflora of the intestines, mouth and female vagina. If the microflora is disturbed, thrush and some dangerous diseases can develop. The most common species of these microorganisms are L. acidophilus, L. reuteri, L. Plantarum and some others.

This group of microorganisms is known for its ability to use lactose for life and produce lactic acid as a by-product.

This ability of bacteria is used in the production of products that require fermentation. With the help of this process, it is possible to produce such a product from milk as yogurt. In addition, fermented milk organisms can be used in the salting process. This is due to the fact that lactic acid can act as a preservative.

In humans, lactic acid bacteria are involved in the process of digestion, ensuring the breakdown of lactose.

The acidic environment that occurs during the life of these bacteria prevents the development of pathogenic microflora in the intestine.

For this reason, lactic acid bacteria are an important component of probiotic preparations and dietary supplements.

Reviews of people using such drugs and dietary supplements to restore the microflora of the gastrointestinal tract indicate that these medicines have a high degree efficiency.

Brief description of bifidobacteria and Escherichia coli

This variety of microorganisms belongs to the group of gram-positive. They are branched and rod-shaped.

The habitat of this type of microbes is the human gastrointestinal tract.

This type of microflora is capable of producing acetic acid in addition to lactic acid.

This compound inhibits the growth of pathogenic microflora. The production of these compounds contributes to the control of pH levels in the stomach and intestines.

Such a representative as the B. Longum bacterium ensures the destruction of indigestible plant polymers.

Microorganisms B. longum and B. Infantis in the course of their activity produce compounds that prevent the development of diarrhea, candidiasis and fungal infections in infants and children.

Thanks to the presence of these useful properties this type of microbe is often included in the composition of tablets sold in pharmacies of probiotic medicines.

Bifidobacteria are used in the production of a variety of lactic acid products, such as yogurt, fermented baked milk and some others. Being in the gastrointestinal intestinal tract, they act as cleaners of the intestinal environment from harmful microflora.

The composition of the microflora gastrointestinal tract also includes Escherichia coli. She takes an active part in the processes of digestion of food. In addition, they are involved in some processes that ensure the vital activity of the cells of the body.

Some varieties of the stick are capable of causing poisoning in case of excessive development. Diarrhea and kidney failure.

Brief description of streptomycetes, nodule bacteria and cyanobacteria

Streptomycetes in nature live in soil, water and the remains of decaying organic matter.

These microbes are Gram-positive and filamentous under the microscope.

Most streptomycetes play a crucial role in maintaining the ecological balance in nature. Due to the fact that these microbes have the ability to process decaying organic matter, it is considered as a biorestorative agent.

Some types of streptomycetes are used to make effective antibiotics and antifungal drugs.

Mycorrhiza live in the soil, they exist in the roots of plants, entering into symbiosis with the plant. The most common symbiont of mycorrhiza are plants of the legume family.

Their benefit lies in the ability to bind atmospheric nitrogen, converting it in compounds into a form that is easily absorbed by plants.

Plants are not able to assimilate atmospheric nitrogen, so they are entirely dependent on the activity of this type of microorganism.

Cyanobacteria live most often in water and on the surface of bare rocks.

This group of living organisms are known as blue-green algae. This type of living organisms play important role in living nature. They are responsible for fixing atmospheric nitrogen in aquatic environment.

The presence of such abilities in these bacteria as calcification and decalcification make them essential component systems for maintaining ecological balance in nature.

Microorganisms harmful to humans

Pathogenic representatives of microflora are microbes capable of provoking the development of various ailments in the human body.

Some types of microbes can provoke the development of deadly diseases.

Very often, these diseases can be transmitted from infected person to a healthy person. In addition, a large number of pathogenic microflora can spoil food.

Representatives of pathogenic microflora can be gram-positive, gram-negative and rod-shaped microbes.

The table below shows the most famous representatives of the microflora.

Pathogenic microflora can develop in the body for a long time and feed beneficial substances, weakening his condition, which leads to the development of a variety of infectious diseases.

The most dangerous bacteria for humans

One of the most dangerous and resistant bacteria is a bacterium called Staphylococcus aureus. In the ranking of dangerous bacteria, it can rightfully take a prize.

This microbe is capable of provoking the development of several infectious diseases in the body.

Some varieties of this microflora are resistant to the effects of the strongest antibiotics and antiseptics.

Varieties of Staphylococcus aureus are able to live:

• V upper divisions respiratory system person;
• on the surface of open wounds;
• In the channels of the urinary organs.

For the human body with a strong immune system this microbe is not dangerous, but in the event of a weakening of the body, it is able to manifest itself in all its glory.

The bacteria called Salmonella typhi are very dangerous. They are able to provoke the appearance of such a terrible and deadly infection in the body as typhoid fever, in addition, they can develop acute infections intestines.

The specified pathological flora is dangerous for the human body in that they produce toxic compounds that are very dangerous to health.

Poisoning by these compounds of the body can provoke the appearance of serious and fatal diseases.