Arseny Maslov
Research work of a student of grade 3 on the topic "Bacteria: harmful and beneficial."
Download:
Preview:
To use the preview, create yourself a Google account (account) and log into it: https://accounts.google.com
Preview:
To use the preview of presentations, create yourself a Google account (account) and log into it: https://accounts.google.com
Slide captions:
Relevance ... Once I asked my parents the question, why do people get sick? Mom said that it is bacteria that enter the body and the person is sick. And then I thought, what are bacteria, where do they live, how do they multiply and why are they dangerous? And are all bacteria harmful? Purpose of the research: to study the characteristics of the life of bacteria and find out whether they can be useful and harmful. Tasks: to study the literature on the chosen topic, get acquainted with the variety and classification of bacteria, find out what harmful and beneficial bacteria are, make homemade kefir
Object and subject of research Object of research: bacteria Subject of research: the importance of bacteria for humans Hypothesis Hypothesis: suppose that a lot of bacteria live in the human body, they are both useful and harmful, and they can be multiplied at home. Research methods: Work with additional sources, search for the necessary information; Observation and analysis of the information received; Experiments; Test; Data processing
History of the emergence 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 introduced in 1828 by Christian Ehrenberg. The study of bacteria and their structure is engaged in microbiology, which was formed in the second half of the 19th century as the science of causative agents of diseases, 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, there are especially many of them in the soil
The structure of bacteria The bacterium has a complex structure The cell wall protects the unicellular organism from external influences, gives a certain shape, provides nutrition and preservation of its internal contents. The lasmatic membrane contains enzymes, participates in the process of reproduction, biosynthesis of components. Flagella are the surface structures that serve to move cells in a liquid medium or on a solid surface. Cytoplasm serves to perform vital functions. In many species, the cytoplasm contains DNA, ribosomes, and various granules. Drank - filamentous formations, much thinner and fewer flagella. They are of various types, differ in purpose, structure. Drank is needed to attach the body to the affected cell.
Types of cocci bacteria (round in shape); bacilli (rod-shaped); spirillae (spiral-shaped); spirillae (spiral-shaped);
Classification of bacteria Beneficial bacteria 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, facilitating digestion; prevents the development of pathogenic and pathogenic microorganisms in the intestines. Lactic acid bacteria Representatives of this order are present in milk, dairy and fermented products, and at the same time are part of the intestinal and oral microflora. They are able to ferment carbohydrates and in particular lactose and produce lactic acid, which is the main source of carbohydrates for humans. By maintaining a constant acidic environment, the growth of unfavorable bacteria is suppressed. Bifidobacteria By means of 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: facilitate the digestion of carbohydrates; provide protection of the intestinal barrier from the penetration of microbes and toxins into the internal environment of the body
Harmful bacteria Salmonella This bacterium is the causative agent of a very acute intestinal infection, typhoid fever. Salmonella produces toxins that are dangerous exclusively to humans. Tetanus bacillus This bacterium is one of the most persistent and at the same time most dangerous in the world. It produces an extremely toxic poison, tetanus exotoxin, which leads to almost complete damage to the nervous system. Mycobacteria 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) - all of which are transmitted by airborne droplets.
My experiences ... Making homemade kefir
Cultivation of a hay bacillus Among the bacteria that are widespread in nature, hay bacillus also belongs. 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 bacteria is one of the largest. It has a straight, elongated shape with blunt rounded ends and is usually colorless. This bacterium is fairly easy to obtain at home. For work, I needed the following: hay (you can buy it at the pet store), a pot of water, a wide-necked jar, and gauze for straining. For one liter of water, you need to take 10 grams of hay. Boil the hay for 20 minutes. Filter the resulting broth and pour it into a jar, diluting 1: 1 with settled cold water. I decided to pour the undiluted broth into another jar and see what happens. We put the banks in a warm place. The best living conditions for the hay bacillus are a large amount of dissolved organic matter, 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 broth in two days.
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 Studying bacteria, I got acquainted with their diversity and classification, I was able to independently grow bacteria at home. I learned that there are a huge number of beneficial bacteria that we use every day with fermented milk products and about harmful bacteria (dangerous to humans). I found out that bacteria are an irreplaceable part of our life and all living things. They are found 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 carried out, I believe that my hypothesis was confirmed: "A lot of bacteria live in the human body, they are both useful and harmful and they can be multiplied at home."
What are bacteria: types of bacteria, their classification
Bacteria are tiny microorganisms that appeared many millennia ago. It is impossible to see microbes with the naked eye, but one should not forget about their existence. There are a huge number of bacilli. Their classification, study, varieties, structural features and physiology are dealt with by the science of microbiology.
Microorganisms are named differently, depending on their kind of action and function. Under a microscope, you can observe how these little creatures interact with each other. The first microorganisms were rather primitive in form, but their importance should in no way be underestimated. From the very beginning, bacilli developed, created colonies, tried to survive in changing climatic conditions. Different vibrios are able to exchange amino acids in order to grow and develop normally as a result.
Today it is difficult to say how many species of these microorganisms are on earth (this number exceeds a million), but the most famous and their names are familiar to almost everyone. It doesn't matter what the microbes are and what they are called, they all have one advantage - they live in colonies, so it is much easier for them to adapt and survive.
First, let's figure out what microorganisms exist. The simplest classification is good and bad. In other words, those that harm the human body become the cause of many diseases and those that are beneficial. Next, we will talk in detail about the main useful bacteria and give a description of them.
You can also classify microorganisms according to their shape, characteristics. Probably, many remember that in school textbooks there was a special table with the image of various microorganisms, and side by side was the meaning and their role in nature. There are several types of bacteria:
- cocci - small balls that resemble a chain, as they are located one after another;
- rod-shaped;
- spirillae, spirochetes (have a convoluted shape);
- vibrios.
Bacteria of different forms
We have already mentioned that one of the classifications divides microbes into species depending on their shape.
Coli bacteria also have some characteristics. For example, there are types of rod-shaped ones with pointed poles, with thickened ones, with rounded or straight ends. As a rule, rod-shaped microbes are very different and are always in chaos, they do not line up in a chain (with the exception of streptobacilli), do not attach to each other (except for diplobacilli).
Microbiologists refer to spherical microorganisms as streptococci, staphylococci, diplococci, gonococci. These can be pairs or long chains of balls.
Curved bacilli are spirillae, spirochetes. They are always active, but they do not generate an argument. Spirillae are safe for humans and animals. You can distinguish spirillae from spirochetes if you pay attention to the number of curls, they are less twisted, have special flagella on the limbs.
Types of pathogenic bacteria
For example, a group of microorganisms called cocci, and in more detail streptococci and staphylococci, cause real purulent diseases (furunculosis, streptococcal sore throat).
Anaerobes live and develop well without oxygen; for some types of these microorganisms, oxygen generally becomes lethal. Aerobic microbes need oxygen to live well.
Archaea are practically colorless unicellular organisms.
Pathogenic bacteria need to be wary of, because they cause infections, gram-negative microorganisms are considered resistant to antibodies. There is a lot of information about soil, putrefactive microorganisms, which are harmful, useful.
In general, spirillae are not dangerous, but some species can cause sodoku.
Varieties of beneficial bacteria
Even schoolchildren know that bacilli are useful and harmful. People know some names by ear (staphylococcus, streptococcus, plague bacillus). These are harmful creatures that interfere not only with the external environment, but also with humans. There are microscopic bacilli that cause food poisoning.
You definitely need to know useful information about lactic acid, food, probiotic microorganisms. For example, probiotics, in other words good organisms, are often used for medicinal purposes. You ask: for what? They prevent harmful bacteria from multiplying inside a person, strengthen the protective functions of the intestines, and have a good effect on the human immune system.
Bifidobacteria are also very beneficial for the intestines. Lactic acid vibrios include about 25 species. In the human body, they are found in huge quantities, but they are not dangerous. On the contrary, they protect the gastrointestinal tract from putrefactive and other microbes.
Speaking of the good ones, one cannot fail to mention the huge species of streptomycetes. They are known to those who took chloramphenicol, erythromycin and similar drugs.
There are microorganisms such as azotobacters. They live in soils for many years, have a beneficial effect on the soil, stimulate plant growth, and cleanse the earth of heavy metals. They are irreplaceable in medicine, agriculture, medicine, food industry.
Types of bacterial variability
By their nature, microbes are very fickle, they die quickly, they can be spontaneous, induced. We will not go into details about the variability of bacteria, since this information is more interesting for those who are interested in microbiology and all its branches.
Types of bacteria for septic tanks
Residents of private houses understand the urgent need to treat wastewater, as well as cesspools. Today, drains can be quickly and efficiently cleaned with the help of special bacteria for septic tanks. For a person, this is a huge relief, since cleaning the sewers is not a pleasant thing.
We have already clarified where the biological type of wastewater treatment is used, and now let's talk about the system itself. Bacteria for septic tanks are grown in laboratories, they kill the unpleasant odor of sewage, disinfect drainage wells, cesspools, and reduce the volume of wastewater. There are three types of bacteria that are used for septic tanks:
- aerobic;
- anaerobic;
- live (bioactivators).
Very often people use combined cleaning methods. Strictly follow the instructions on the preparation, make sure that the water level is conducive to the normal survival of bacteria. Also, remember to use the drain at least once every two weeks to give the bacteria something to eat or they will die. Remember that chlorine from powders and cleaning fluids will kill bacteria.
The most popular bacteria are Dr. Robik, Septifos, Waste Treat.
Types of bacteria in urine
In theory, there should be no bacteria in the urine, but after various actions and situations, tiny microorganisms settle wherever they please: in the vagina, in the nose, in water, and so on. If bacteria are found during the tests, this means that the person is suffering from kidney, bladder or ureteral diseases. There are several ways in which microorganisms enter the urine. Before treatment, it is very important to investigate and accurately determine the type of bacteria and the route of entry. This can be determined by biological culture of urine, when bacteria are placed in a favorable habitat. Next, the reaction of bacteria to various antibiotics is checked.
We wish you to remain always healthy. Take care of yourself, wash your hands regularly, protect your body from harmful bacteria!
Most people associate the word "bacteria" with something unpleasant and a threat to health. At best, fermented milk products are remembered. At worst - dysbiosis, plague, dysentery and other troubles. And 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 struggle, which is waged by harmful and beneficial bacteria. Through this process, a person receives protection from various infections. Various microorganisms surround us at every turn. They live on clothes, they 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. Observance of basic rules of personal hygiene will help to avoid such failures.
Human immunity completely depends on the state of microflora. The gastrointestinal tract alone contains almost 60% of all bacteria. The rest are located in the respiratory system and in the reproductive system. A person lives about two kilograms of bacteria.
The appearance of bacteria in the body
Beneficial bacteria
Beneficial bacteria are: lactic acid, bifidobacteria, E. coli, streptomycents, mycorrhiza, cyanobacteria.
They all play an important role in human life. Some of them prevent the emergence of infections, others are used in the production of medicines, and others maintain a balance in the ecosystem of our planet.
Types of harmful bacteria
Harmful bacteria can cause a number of serious diseases in humans. For example, diphtheria, anthrax, sore throat, plague and many others. They are easily transmitted from an infected person through air, food, and touch. It is the harmful bacteria, the names of which will be given below, that spoil food. They give off an unpleasant odor, putrefaction and decomposition, they cause disease.
Bacteria can be gram-positive, gram-negative, rod-shaped.
Names of harmful bacteria
Table. Harmful bacteria to humans. Names| Names | Habitat | Harm |
| Mycobacteria | food, water | tuberculosis, leprosy, ulcer |
| Tetanus stick | soil, skin, digestive tract | tetanus, muscle cramps, respiratory distress |
|
Plague wand (considered by experts as a biological weapon) |
only in humans, rodents and mammals | bubonic plague, pneumonia, skin infections |
| Helicobacter pylori | human stomach mucosa | gastritis, peptic ulcer, produces cytoxins, ammonia |
| Anti-ulcer stick | the soil | anthrax |
| Botulism stick | food, contaminated dishes | poisoning |
Harmful bacteria are able to stay in the body for a long time and absorb useful substances from it. However, they are capable of causing 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 is capable of causing not one but several infectious diseases. Some of these bacteria are resistant to powerful antibiotics and antiseptics. Strains of this bacterium can live in the upper respiratory tract, in open wounds and in the urinary tract of every third inhabitant of the Earth. For a person with strong immunity, 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 in that they produce toxic substances that are extremely life-threatening. With the course of the disease, intoxication of the body occurs, a very strong fever, rashes on the body, the liver and spleen increase. The bacterium is very resistant to various external influences. Lives well in water, vegetables, fruits and reproduces well in milk products.
Clostridium tetan bacterium is also among the most dangerous bacteria. She 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.
And another bacterium that can lead to human death is Mycobacterium tuberculosis. 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
Harmful bacteria, the names of microorganisms are studied from the student's bench by doctors of all directions. Every year, health care is looking for new methods to prevent the spread of infections that are life-threatening. With the observance of preventive measures, you will not have to waste energy looking for new ways to combat such diseases.
To do this, it is necessary to identify the source of the infection in time, to determine the circle of sick and possible victims. It is imperative to isolate those who are infected and disinfect the focus of infection.
The second step is to destroy the pathways through which harmful bacteria can be transmitted. To do this, conduct appropriate propaganda among the population.
Food objects, reservoirs, warehouses with food storage are taken under control.
Each person can resist harmful bacteria, strengthening their immunity in every possible way. A healthy lifestyle, adherence to basic hygiene rules, protecting oneself during sexual intercourse, using sterile disposable medical instruments and equipment, completely limiting communication with people in quarantine. When entering the epidemiological area or the focus of infection, it is necessary to strictly comply with all the requirements of the sanitary and epidemiological services. A number of infections are equated in their effect with bacteriological weapons.
Bacteria are good and bad. Bacteria in human life
Bacteria are the most numerous inhabitants of the planet Earth. They settled it in ancient times and continue to exist to this day. Some species have even changed little since then. Bacteria useful 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 stand out in a special kingdom. 
Margin of safety
Participation in food chains
Bacteria beneficial and harmful to the human body
As a rule, the bacteria that inhabit our bodies in abundance are not given the attention they deserve. After all, they are so small that they seem to have no significant meaning. Those who think so are largely mistaken. Bacteria useful and harmful have long and reliably "colonized" other organisms, successfully coexist with them. Yes, they cannot be seen without the help of optics, but they can benefit or harm our body. 
Who lives in the intestines?
"Wise" neighbors
Permanent microflora
99% of the population resides permanently in the intestines. They are ardent adherents and helpers of man.
- Essential beneficial bacteria. Names: bifidobacteria and bacteroids. The overwhelming majority of them.
- Associated beneficial bacteria. Names: Escherichia coli, enterococci, lactobacilli. Their number should be 1-9% of the total.
It is also necessary 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?
Unstable microflora
Approximately 1% in the body of a healthy individual are so-called opportunistic microbes. They belong to the unstable microflora. Under normal conditions, they perform certain functions that do not harm a person, they work for the good. But in a certain situation, they can manifest themselves as pests. These are mainly staphylococci and various kinds of fungi.
Dislocation in the gastrointestinal tract
The role of bacteria in nature
Most people consider different bacterial organisms exclusively 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 are dangerous 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 a little about these concepts and consider certain 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 large 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. The bacteria were able to adapt to the surrounding space 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 distinguished by some harmony, because such organisms are capable of bringing real benefits.
After a small person is born, bacteria immediately begin to penetrate into his body. They penetrate through the respiratory tract along with the air, enter the body along with breast milk, etc. The entire body is saturated with various bacteria.
Their number cannot be accurately calculated, but some scientists boldly say that the number of such cells in an organism is comparable to the number of all cells. The digestive tract alone is home to four hundred different species of living bacteria. It is believed that a certain variety of them can grow only in a specific place. So lactic acid bacteria are able to grow and multiply in the intestines, others feel optimally in the oral cavity, some others live only on the skin.
Over the many years of coexistence, humans and such particles have been able to recreate conditions of cooperation that are optimal for both groups, which can be characterized as a beneficial symbiosis. At the same time, bacteria and our body combine their capabilities, while each side remains in the black.
Bacteria are able to collect particles of various cells on their surface, which is why the immune system does not perceive them as hostile and does not attack. However, after organs and systems are exposed to harmful viruses, beneficial bacteria rise to defense and simply block the path of pathogens. When they exist in the digestive tract, such substances also provide tangible benefits. They are engaged in the processing of food leftovers, while generating a significant amount of heat. It, in turn, is transmitted to nearby organs, and is carried throughout the body.
A deficiency of beneficial bacteria in the body or a change in their number becomes the cause of the development of various pathological conditions. This situation can develop against the background of taking antibiotics, which effectively destroy both harmful and beneficial bacteria. To correct the number of beneficial bacteria, special preparations, probiotics, can be consumed.
The human body is a complex biological system. We are accustomed to consider our body, the whole organism, our inviolable property. But the countless number of all kinds of microorganisms also counts in the same way. They inhabit every corner, every organ of the human body. But the vast majority of them are found in the large intestine. Scientists microbiologists have long established that microorganisms are useful, as they support the vital functions of the body, and have a positive effect on health. Others, on the other hand, can make a person sick very quickly.
All these microscopic creatures, harmful and beneficial microbes and fungi, the simplest unicellular organisms and viruses inhabit our body, multiply or "dormant" for the time being, or fight with each other. And all of them together make up a single microflora of our body. As a person grows, develops, these microorganisms develop with him.
Harmful and beneficial microbes
So, the body is inhabited by numerous colonies of microbes. Of these, the absolute majority (99%) are helpful, volunteer human helpers. These beneficial microbes inhabit the intestines all the time, therefore they are called permanent microflora. Among them it is necessary to distinguish bifidobacteria and bacteroids. These are the most important beneficial microbes. In a healthy person, their content should be at least 90-98%.
However, in the same place, in the intestine, there are other bacteria that are not part of the permanent microflora and are temporarily in the body. Therefore, they are called concomitant. These include E. coli, lactobacilli, and enterococci. Such accompanying bacteria are from 1 to 9%.
Under certain conditions, these microbes, with the exception of bifidobacteria, can cause disease.
But the intestines are also inhabited by harmful microbes and fungi, in particular, staphylococci. Harmful bacteria can be much more dangerous than the accompanying microflora. Their composition, as well as the amount, changes regularly, but should not go beyond 1%. In this case, the person is healthy, since they do not affect his health. They are called conditionally pathogenic and belong to the so-called unstable microflora.
When a person's immune system is strong, works properly, the entire microflora "lives in peace and harmony", does not harm health, but only strengthens it. But as soon as, for some reason, a person weakens, his immunity sharply decreases, some representatives of the microflora begin to have a harmful and sometimes just destructive effect.
During this period, harmful microbes and fungi are activated, and even representatives of normal microflora can provoke the development of very dangerous diseases that sometimes require urgent medical intervention. As an example, we can cite the occurrence of generalized candidiasis in a person with end-stage AIDS. Or the development of Endotoxinemia, which is directly related to the human body's own microflora, as well as numerous other diseases.
Antibiotics
When a disease occurs associated with the harmful action of bacteria, the doctor diagnoses, identifies the pathogen, and then prescribes the appropriate antibacterial drug - an antibiotic. Until medicine has come up with a more effective means of fighting bacteria. However, the antibiotic does not care which bacteria to fight.
It kills all of them, disrupting the balance of microflora, since along with harmful ones, useful microbes also die. The first to die are bifidobacteria and lactobacilli. The remaining beneficial microbes cease to cope with the neutralization, processing of toxins released by the remaining harmful bacteria. Dysbiosis develops.
Therefore, it becomes necessary to replenish the number of beneficial bacteria to strengthen the immune system, so that the body begins to function normally and cope better with the disease. To combat dysbiosis, probiotics are prescribed. They help restore the required amount of beneficial bacteria.
Probiotics
Speaking of harmful and beneficial microbes and fungi, probiotics cannot be ignored. These are useful live microorganisms, when taken, the beneficial intestinal microflora is restored, from which the whole organism is healed. Probiotics have the most positive effects on the immune system. To restore beneficial bacteria, special lactic acid products (bifidok, bifilak, etc.) are recommended.
If, with prolonged use of antibiotics, the beneficial microflora is very seriously affected, the doctor will prescribe special preparations containing beneficial microorganisms. Once in the intestines, they can repopulate the intestines.
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 complicated - 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. They were the first to develop new forms of life support, such as respiration, fermentation, photosynthesis, catalysis ... and also found effective ways to coexist with almost every living creature. Man was not an exception either.
But bacteria are a whole domain of organisms with over 10,000 species. Each species is unique and went its own evolutionary path, as a result, developed its own unique forms of coexistence with other organisms. Some bacteria have gone to 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 considered to be harmful or pathogenic. Still others went even further and became practically self-sufficient, they receive everything they need for life from the environment.
Inside humans, as well as inside other mammals, an unimaginably large number of bacteria live. There are 10 times more of them in our bodies than all the cells of the body put together. The absolute majority of them 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 (inside of which they live). Typically, these bacteria take on some of the functions that the host's body is not capable of. An example is bacteria that live in the human digestive tract and process part of the food that the stomach itself is not able to handle.
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, facilitating digestion; synthesizes vitamins of group K; prevents the development of pathogenic and pathogenic microorganisms in the intestines.
Closeup: colony of Escherichia coli bacteria
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 intestinal and oral microflora. They are able to ferment carbohydrates and in particular lactose and produce lactic acid, which is the main source of carbohydrates for humans. By maintaining a constant acidic environment, the growth of unfavorable bacteria is suppressed.
Bifidobacteria
The most significant effect of bifidobacteria is exerted on infants and mammals, accounting for up to 90% of their intestinal microflora. By means of 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: facilitate the digestion of carbohydrates; provide protection of 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 group 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 exclusively to humans. When infected, a general intoxication of the body occurs, which leads to severe fever, a rash all over the body, in severe cases to damage to the lymphatic system and, as a result, to death. Every year 20 million cases of typhoid fever are recorded in the world, 1% of cases lead to death.
Colony of bacteria Salmonella typhi
Tetanus stick (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, the tetanus exotoxin, which causes almost complete damage to the nervous system. People with tetanus experience terrible torment: all the muscles of the body spontaneously strain to the limit, and powerful convulsions occur. The mortality rate is extremely high - on average, about 50% of those infected die. Fortunately, back in 1890, the tetanus vaccine was invented, it is made to newborns in all developed countries of the world. In underdeveloped countries, 60,000 people die from tetanus every year.
Mycobacterium (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) - all of which are transmitted by airborne droplets. Mycobacteria cause more than 5 million deaths every year.
Most people consider different bacterial organisms exclusively 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 are dangerous 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 a little about these concepts and consider certain 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 large 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. The bacteria were able to adapt to the surrounding space 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 distinguished by some harmony, because such organisms are capable of bringing real benefits.
After a small person is born, bacteria immediately begin to penetrate into his body. They penetrate through the respiratory tract along with the air, enter the body along with breast milk, etc. The entire body is saturated with various bacteria.
Their number cannot be accurately calculated, but some scientists boldly say that the number of such cells in an organism is comparable to the number of all cells. The digestive tract alone is home to four hundred different species of living bacteria. It is believed that a certain variety of them can grow only in a specific place. So lactic acid bacteria are able to grow and multiply in the intestines, others feel optimally in the oral cavity, some others live only on the skin.
Over the many years of coexistence, humans and such particles have been able to recreate conditions of cooperation that are optimal for both groups, which can be characterized as a beneficial symbiosis. At the same time, bacteria and our body combine their capabilities, while each side remains in the black.
Bacteria are able to collect particles of various cells on their surface, which is why the immune system does not perceive them as hostile and does not attack. However, after organs and systems are exposed to harmful viruses, beneficial bacteria rise to defense and simply block the path of pathogens. When they exist in the digestive tract, such substances also provide tangible benefits. They are engaged in the processing of food leftovers, while generating a significant amount of heat. It, in turn, is transmitted to nearby organs, and is carried throughout the body.
A deficiency of beneficial bacteria in the body or a change in their number becomes the cause of the development of various pathological conditions. This situation can develop against the background of taking antibiotics, which effectively destroy both harmful and beneficial bacteria. To correct the number of beneficial bacteria, special preparations, probiotics, can be consumed.
Harmful bacteria
However, it is worth remembering that not all bacteria are human friends. Among them, there are also enough dangerous varieties that can only do harm. Such organisms, after penetrating into our body, become the cause of the development of various bacterial ailments. These are various colds, some types of pneumonia, and in addition, syphilis, tetanus and other diseases, even deadly. There are also diseases of this type, which are transmitted by airborne droplets. This is dangerous tuberculosis, whooping cough, etc.
A significant number of ailments provoked by harmful bacteria develop due to the consumption of insufficient quality food, unwashed and unprocessed vegetables and fruits, raw water, and insufficiently fried meat. You can protect yourself from such diseases by observing the norms and rules of hygiene. An example of such dangerous ailments are dysentery, typhoid fever, etc.
The manifestations of diseases that have developed as a result of an attack by bacteria are the result of the pathological influence of poisons that these organisms produce, or that are formed against the background of their destruction. The human body is able to get rid of them thanks to natural protection, which is based on the process of bacterial phagocytosis by white blood cells, as well as on the immune system, which synthesizes antibodies. The latter carry out a bunch of foreign proteins and carbohydrates, and then simply eliminate them from the bloodstream.
Also, harmful bacteria can be destroyed with the help of natural and synthetic medicines, the most famous of which is penicillin. All drugs of this type are antibiotics, they differ depending on the active ingredient and on the scheme of action. Some of them are capable of destroying the cell walls of bacteria, while others stop their vital processes.
So, in nature there is a mass of bacteria that can bring benefits and harm to humans. Fortunately, the modern level of development of medicine makes it possible to cope with the majority of pathological organisms of this kind.
