Harmful and beneficial bacteria
Bacteria are microorganisms that form a huge invisible world around and inside us. Because of the harmful effects they cause, they are notorious, while the beneficial effects they cause are rarely talked about. This article gives general description some bad and good bacteria.
“During the first half of geological time, our ancestors were bacteria. Most creatures are still bacteria, and each of our trillions of cells is a colony of bacteria." - Richard Dawkins.
Bacteria- the most ancient living organisms on Earth are omnipresent. The human body, the air we breathe, the surfaces we touch, the food we eat, the plants around us, our environment, etc. - all this is inhabited by bacteria.
Approximately 99% of these bacteria are beneficial, while the remainder have bad reputation. In fact, some bacteria are very important for the proper development of other living organisms. They can exist either on their own or in symbiosis with animals and plants.
The following list of harmful and beneficial bacteria includes some of the most well-known beneficial and deadly bacteria.
Beneficial bacteria
Lactic acid bacteria/Dederlein rods
Characteristic: gram-positive, rod-shaped.
Habitat: Varieties of lactic acid bacteria are present in milk and dairy products, fermented foods, and are also part of the oral, intestinal, and vaginal microflora. The most predominant species are L. acidophilus, L. reuteri, L. plantarum, etc.
Benefit: Lactic acid bacteria are known for their ability to use lactose and produce lactic acid as a by-product. This ability to ferment lactose makes lactic acid bacteria an important ingredient in the preparation of fermented foods. They are also an integral part of the brining process, as lactic acid can serve as a preservative. Through what is called fermentation, yogurt is obtained from milk. Certain strains are even used to produce yoghurt on an industrial scale. In mammals, lactic acid bacteria help break down lactose during the digestive process. The resulting acidic environment prevents the growth of other bacteria in the body's tissues. Therefore, lactic acid bacteria are an important component of probiotic preparations.
Bifidobacteria
Characteristic: gram-positive, branched, rod-shaped.
Habitat: Bifidobacteria are present in the human gastrointestinal tract.
Benefit: Like lactic acid bacteria, bifidobacteria also produce lactic acid. In addition, they produce acetic acid. This acid inhibits the growth of pathogenic bacteria by controlling the pH level in the intestines. The bacterium B. longum, a species of bifidobacteria, helps break down difficult-to-digest plant polymers. B. longum and B. infantis bacteria help prevent diarrhea, candidiasis, and even fungal infections in infants and children. Thanks to these beneficial properties, they are also often included in probiotic preparations sold in pharmacies.
Escherichia coli (E. coli)
Characteristic:
Habitat: E. coli is part of the normal microflora of the large and small intestines.
Benefit: E. coli helps in breaking down undigested monosaccharides, thus aiding digestion. This bacterium produces vitamin K and biotin, which are essential for various cellular processes.
Note: Certain strains of E. coli can cause serious toxic effects, diarrhea, anemia, and kidney failure.
Streptomycetes
Characteristic: gram-positive, filamentous.
Habitat: These bacteria are present in soil, water and decaying organic matter.
Benefit: Certain streptomycetes (Streptomyces spp.) play important role in soil ecology, carrying out the decomposition of organic substances present in it. For this reason, they are being studied as a bioremediation agent. S. aureofaciens, S. rimosus, S. griseus, S. erythraeus and S. venezuelae are commercially important species that are used to produce antibacterial and antifungal compounds.
Mycorrhizae/Nodule bacteria
Characteristic:
Habitat: Mycorrhizae are present in the soil, existing in symbiosis with the root nodules of leguminous plants.
Benefit: Bacteria Rhizobium etli, Bradyrhizobium spp., Azorhizobium spp. and many other varieties are useful for fixing atmospheric nitrogen, including ammonia. This process makes this substance available to plants. Plants do not have the ability to use atmospheric nitrogen and depend on nitrogen-fixing bacteria present in the soil.
Cyanobacteria
Characteristic: gram-negative, rod-shaped.
Habitat: Cyanobacteria are primarily aquatic bacteria, but they are also found on bare rocks and in soil.
Benefit: Cyanobacteria, also known as blue-green algae, are a group of bacteria that are very important for environment. They fix nitrogen in aquatic environment. Their calcification and decalcification abilities make them important for maintaining balance in the coral reef ecosystem.
Harmful bacteria
Mycobacteria
Characteristic: are neither gram-positive nor gram-negative (due to their high lipid content), rod-shaped.
Diseases: Mycobacteria are pathogens that have long time doubling. M. tuberculosis and M. leprae, their most dangerous varieties, are the causative agents of tuberculosis and leprosy, respectively. M. ulcerans causes ulcerated and non-ulcerated nodules on the skin. M. bovis can cause tuberculosis in livestock.
Tetanus bacillus
Characteristic:
Habitat: Tetanus bacillus spores are found in the soil, on the skin, and in the digestive tract.
Diseases: Tetanus bacillus is the causative agent of tetanus. It enters the body through a wound, multiplies there and releases toxins, particularly tetanospasmin (also known as a spasmogenic toxin) and tetanolysin. This leads to muscle spasms and respiratory failure.
Plague stick
Characteristic: gram-negative, rod-shaped.
Habitat: The plague bacillus can survive only in the body of the host, in particular in the body of rodents (fleas) and mammals.
Diseases: The plague bacillus causes bubonic plague and plague pneumonia. The skin infection caused by this bacterium takes on a bubonic form, characterized by malaise, fever, chills and even cramps. An infection of the lungs caused by bubonic plague causes plague pneumonia, which causes coughing, difficulty breathing and fever. According to WHO, between 1,000 and 3,000 cases of plague occur worldwide each year. The plague pathogen is recognized and studied as a potential biological weapon.
Helicobacter pylori
Characteristic: gram-negative, rod-shaped.
Habitat: Helicobacter pylori colonizes the human gastric mucosa.
Diseases: This bacterium is the main cause of gastritis and peptic ulcers. It produces cytotoxins and ammonia that damage the gastric epithelium, causing abdominal pain, nausea, vomiting and bloating. Helicobacter pylori is present in half the world's population, but most people remain asymptomatic, and only a few develop gastritis and ulcers.
Anthrax bacillus
Characteristic: gram-positive, rod-shaped.
Habitat: Anthrax bacillus is widespread in the soil.
Diseases: Anthrax infection results in a fatal disease called anthrax. Infection occurs as a result of inhalation of endospores of anthrax bacillus. Anthrax mainly occurs in sheep, goats, cattle, etc. However, in rare cases, transmission of the bacterium occurs from livestock to a person. The most common symptoms of anthrax are ulcers, fever, headache, abdominal pain, nausea, diarrhea, etc.
We are surrounded by bacteria, some of them harmful, others beneficial. And it depends only on us how effectively we coexist with these tiny living organisms. It is up to us to benefit from beneficial bacteria by avoiding excessive and inappropriate use of antibiotics, and to stay away from harmful bacteria by taking appropriate steps. preventive measures, such as maintaining personal hygiene and undergoing routine medical examinations.
Bacteria appeared approximately 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 ones appeared, each time more complex shapes organisms. Bacteria did not stand aside all this time; on the contrary, they were the most important component evolutionary process. They were the first to develop new forms of life support, such as respiration, fermentation, photosynthesis, catalysis... and also found effective ways coexistence with almost every living creature. Man was no exception.
But bacteria are an entire domain of organisms, numbering more than 10,000 species. Each species is unique and has followed its own evolutionary path, and as a result has developed its own unique forms of coexistence with other organisms. Some bacteria have entered 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 generally considered harmful or pathogenic. Still others have gone even further and become practically self-sufficient; they receive everything they need for life from the environment.
Inside humans, as well as inside other mammals, lives an unimaginable a 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 absolute majority are useful, but the paradox is that their vital activity, their presence within 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 that live in symbiotic or mutualistic relationships with donor organisms (within which they live). Typically, such bacteria take on some of the functions that the host 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 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 are difficult to overestimate: it breaks down indigestible monosaccharides, promoting digestion; synthesizes vitamins K; prevents the development of pathogenic and pathogenic microorganisms in the intestines.
Macro photo: 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 capable of fermenting carbohydrates and in particular lactose and producing 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, constituting up to 90% of their intestinal microflora. By producing lactic and acetic acids, they completely prevent the development of putrefactive and pathogenic microbes in the child’s body. In addition, bifidobacteria: promote 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 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 harmful exclusively to humans. When infected, general intoxication of the body occurs, which leads to severe fever, rash throughout the body, and in severe cases, damage to the lymphatic system and, as a result, death. Every year, 20 million cases of typhoid fever are recorded worldwide, 1% of cases lead to death.
Colony of Salmonella typhi bacteria
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, leading to almost complete damage nervous system. People with tetanus experience terrible pain: all the muscles of the body spontaneously tense to the limit, and powerful convulsions occur. The mortality rate is extremely high - on average, about 50% of those infected die. Fortunately, a tetanus vaccine was invented back in 1890; 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) - all of them are transmitted by airborne droplets. Every year, mycobacteria cause more than 5 million deaths.
The entire set of bacteria that live in the human body is called microbiota. Healthy intestinal microflora consists of many bacteria. There are more than a million of them. Each microorganism plays a huge role in normalizing the functioning of the entire body. If the balance is disturbed and there is a lack of any bacteria, this leads to disturbances in the gastrointestinal tract. The pathogenic process begins to develop rapidly. All beneficial microorganisms are found mostly in the intestines, as well as on the surface of the skin and mucous membranes. The immune system is able to regulate required amount beneficial bacteria.
The microflora of the human body is populated by both beneficial and pathogenic organisms. At a certain concentration this is considered normal. There are beneficial and pathogenic bacteria. Of course, there are many more beneficial microorganisms in the intestines. Balance is only achieved when good microflora constitutes more than 95 percent of all microorganisms. There are the following types of bacteria that live in the human body:
- lactobacilli;
- bifidobacteria;
- enterococci;
- coli.
Bifidobacteria
They are the most common type of bacteria. They are directly involved in the formation of lactic acid and acetate. Bifidobacteria help create an acidic environment, which helps neutralize almost all pathogenic bacteria. In this case, the pathogenic flora can no longer develop further. The processes of decay and fermentation stop in the body.
Bifidobacteria are very important for the child's body. They are responsible for allergic reactions to various products nutrition. They also have a good antioxidant effect and prevent the development of tumors.
This type of bacteria takes part in the synthesis of vitamin C. They help the rapid absorption of vitamins B and D, which take part in the formation of the child’s body. If there are few bifidobacteria in the body, then even synthetic vitamins will not be able to fully replenish their required amount.
Lactobacilli
These microorganisms also play a fairly important role in the normal functioning of the body. They are able to interact with other good bacteria that inhabit the intestines. At the same time, they block the development of pathogenic microflora and suppress the vital activity of bacteria, causing diseases intestines.
Lactobacilli take part in the formation of lysozyme, lactic acid and some vitamins. They are excellent helpers for the immune system. A deficiency of these bacteria almost always leads to the development of dysbacteriosis.
Lactobacilli can often be found not only in the intestines, but also on the mucous membranes. This is a very important factor, especially for women's health. With their help, the necessary acidity in the vagina is maintained. This helps prevent the development of diseases such as bacterial vaginosis.
Enterococci
Appear in the human body in the first days after birth. Promotes good absorption of sucrose. Most often, enterococci are found in the small intestine. By interacting with other good bacteria, they protect the body from the development of pathogenic microflora. However this type microorganisms are considered to be conditionally safe. If their concentration is exceeded, intestinal diseases develop.
Escherichia coli
Many types of such microorganisms do not contribute to the development of any diseases. In some cases they also perform protective function. Their usefulness lies in the synthesis of cocilin, which creates an obstacle to the proliferation of pathogenic microflora. Escherichia coli takes part in the synthesis of many vitamins, as well as nicotinic and folic acid. This is very important because folic acid responsible for the formation of red blood cells in the body, which helps maintain hemoglobin levels.
Positive effects of bacteria on the human body
Good bacteria have a lot of beneficial and required properties. The body is able to function normally as long as it maintains the necessary balance between the bacteria that inhabit the intestines and mucous membranes. A lot of them are involved in the most important process of vitamin synthesis. B vitamins cannot be absorbed normally without exposure to beneficial bacteria. Because of this, the level of hemoglobin in the blood may decrease, suffering skin, disorders of the nervous system are observed.
Bacteria are able to break down undigested food components that reach the large intestine. Beneficial microorganisms help maintain water-salt balance in the body.
The intestinal microflora takes part in the formation of local immunity. Helps block the proliferation of pathogenic microorganisms. Therefore, people do not feel bloating and flatulence. An increase in the number of lymphocytes provokes the work of phagocytes, which consists of fighting harmful microbes. At the same time, some bacteria actively participate in the synthesis of immunoglobulin A.
Beneficial microorganisms have a positive effect on the functioning of the large and small intestines. With their help, it is possible to maintain the necessary acidity, as a result of which the epithelium becomes more resistant to the effects of harmful factors. Intestinal motility also depends on microorganisms. Bifidobacteria take part in blocking the processes of decay and fermentation in the body. Many bacteria are constantly in symbiosis with pathogens, controlling their effect on the body.
The overall balance of the body is maintained by biochemical reactions occurring in the body with the participation of bacteria. At the same time, it stands out thermal energy. The basis of nutrition for beneficial bacteria is the remains of undigested food.
Dysbacteriosis
Dysbacteriosis is usually called changes in the quantity and quality of bacteria. In this case, a large number of good bacteria simply die, and the bad ones begin to multiply quickly. Dysbacteriosis in many cases affects not only the intestines. It can appear in the oral cavity or on mucous membranes. Strepto- and staphylococci can be detected in the tests.
In a normal state of the body beneficial bacteria capable of completely regulating the proliferation of pathogenic microorganisms. Usually the airways and skin are protected. But if the balance is imbalanced, a person begins to feel some symptoms of a developing disease. Abdominal pain, bloating, and possible development of flatulence and diarrhea. Later, vitamin deficiency and anemia begin. Due to lack of appetite, weight rapidly decreases. Women may develop sexual dysfunction. Copious vaginal discharge appears. Often they have bad smell. The skin becomes dry. You can find roughness and cracks on it. In almost all cases, dysbiosis is one of the manifestations of long-term use of antibiotics.
At the first signs of illness, it is advisable to immediately consult a doctor. The doctor will prescribe all the necessary examinations, on the basis of which the maximum effective treatment dysbacteriosis. Most often in medicinal purposes Various probiotics are used.
Bacteria are the most ancient organism on earth, and also the simplest in their structure. It consists of just one cell, which can only be seen and studied under a microscope. A characteristic feature bacteria is the absence of a nucleus, which is why bacteria are classified as prokaryotes.
Some species form small groups of cells; such clusters may be surrounded by a capsule (case). The size, shape and color of the bacterium are highly dependent on the environment.
Bacteria are distinguished by their shape into rod-shaped (bacillus), spherical (cocci) and convoluted (spirilla). There are also modified ones - cubic, C-shaped, star-shaped. Their sizes range from 1 to 10 microns. Certain types of bacteria can actively move using flagella. The latter are sometimes twice the size of the bacterium itself.
Types of forms of bacteria
To move, bacteria use flagella, the number of which varies—one, a pair, or a bundle of flagella. The location of the flagella can also be different - on one side of the cell, on the sides, or evenly distributed throughout the entire plane. Also, one of the methods of movement is considered to be sliding thanks to the mucus with which the prokaryote is covered. Most have vacuoles inside the cytoplasm. Adjusting the gas capacity of the vacuoles helps them move up or down in the liquid, as well as move through the air channels of the soil.
Scientists have discovered more than 10 thousand varieties of bacteria, but according to scientific researchers, there are more than a million species in the world. general characteristics bacteria makes it possible to determine their role in the biosphere, as well as to study the structure, types and classification of the kingdom of bacteria.
Habitats
Simplicity of structure and speed of adaptation to environmental conditions helped bacteria spread over a wide range of our planet. They exist everywhere: water, soil, air, living organisms - all this is the most acceptable habitat for prokaryotes.
Bacteria were found both on south pole, and in geysers. They are found on the ocean floor, as well as in the upper layers air envelope Earth. Bacteria live everywhere, but their number depends on favorable conditions. For example, a large number of bacterial species live in open water bodies, as well as soil.
Structural features
A bacterial cell is distinguished not only by the fact that it does not have a nucleus, but also by the absence of mitochondria and plastids. The DNA of this prokaryote is located in a special nuclear zone and has the appearance of a nucleoid closed in a ring. In bacteria, the cell structure consists of a cell wall, capsule, capsule-like membrane, flagella, pili and cytoplasmic membrane. Internal structure formed by cytoplasm, granules, mesosomes, ribosomes, plasmids, inclusions and nucleoid.
The cell wall of a bacterium performs the function of defense and support. Substances can flow freely through it due to permeability. This shell contains pectin and hemicellulose. Some bacteria secrete a special mucus that can help protect against drying out. Mucus forms a capsule - a polysaccharide chemical composition. In this form, the bacterium can tolerate even very high temperatures. It also performs other functions, such as adhesion to any surfaces.
On the surface of the bacterial cell there are thin protein fibers called pili. There may be a large number of them. Pili help the cell pass on genetic material and also ensure adhesion to other cells.
Under the plane of the wall there is a three-layer cytoplasmic membrane. It guarantees the transport of substances and also plays a significant role in the formation of spores.
The cytoplasm of bacteria is 75 percent made from water. Composition of the cytoplasm:
- Fishsomes;
- mesosomes;
- amino acids;
- enzymes;
- pigments;
- sugar;
- granules and inclusions;
- nucleoid.
Metabolism in prokaryotes is possible both with and without the participation of oxygen. Most of them eat ready-made nutrients organic origin. Very few species are capable of synthesizing organic substances from inorganic ones. These are blue-green bacteria and cyanobacteria, which played a significant role in the formation of the atmosphere and its saturation with oxygen.
Reproduction
In conditions favorable for reproduction, it is carried out by budding or vegetatively. Asexual reproduction occurs in the following sequence:
- The bacterial cell reaches its maximum volume and contains the necessary supply of nutrients.
- The cell lengthens and a septum appears in the middle.
- Nucleotide division occurs inside the cell.
- The main and separated DNA diverge.
- The cell divides in half.
- Residual formation of daughter cells.
With this method of reproduction there is no exchange of genetic information, so all daughter cells will an exact copy maternal.
The process of bacterial reproduction in unfavorable conditions more interesting. Scientists learned about the ability of sexual reproduction of bacteria relatively recently - in 1946. Bacteria do not have division into female and reproductive cells. But their DNA is heterogeneous. When two such cells approach each other, they form a channel for the transfer of DNA, and an exchange of sites occurs - recombination. The process is quite long, the result of which is two completely new individuals.
Most bacteria are very difficult to see under a microscope because they do not have their own color. Few varieties are purple or green in color due to their bacteriochlorophyll and bacteriopurpurin content. Although if we look at some colonies of bacteria, it becomes clear that they release colored substances into their environment and acquire a bright color. In order to study prokaryotes in more detail, they are stained.
Classification
Classification of bacteria can be based on indicators such as:
- Form
- way to travel;
- method of obtaining energy;
- waste products;
- degree of danger.
Bacteria symbionts live in community with other organisms.
Bacteria saprophytes live on already dead organisms, products and organic waste. They promote the processes of rotting and fermentation.
Rotting cleanses nature of corpses and other organic waste. Without the process of decay there would be no cycle of substances in nature. So what is the role of bacteria in the cycle of substances?
Rotting bacteria are an assistant in the process of breaking down protein compounds, as well as fats and other compounds containing nitrogen. After carrying out a complex chemical reaction, they break the bonds between the molecules of organic organisms and capture protein molecules and amino acids. When broken down, the molecules release ammonia, hydrogen sulfide and other harmful substances. They are poisonous and can cause poisoning in people and animals.
Rotting bacteria multiply quickly in conditions favorable to them. Since these are not only beneficial bacteria, but also harmful ones, in order to prevent premature rotting of products, people have learned to process them: drying, pickling, salting, smoking. All these treatment methods kill bacteria and prevent them from multiplying.
Fermentation bacteria with the help of enzymes are able to break down carbohydrates. People noticed this ability back in ancient times and still use such bacteria to make lactic acid products, vinegars, and other food products.
Bacteria, working together with other organisms, do very important chemical work. It is very important to know what types of bacteria there are and what benefits or harm they bring to nature.
Meaning in nature and for humans
It was already noted above great importance many types of bacteria (during the processes of decay and various types fermentation), i.e. fulfilling a sanitary role on Earth.
Bacteria also play a huge role in the cycle of carbon, oxygen, hydrogen, nitrogen, phosphorus, sulfur, calcium and other elements. Many types of bacteria contribute to the active fixation of atmospheric nitrogen and convert it into organic form, helping to increase soil fertility. Especially important have those bacteria that decompose cellulose, which are the main source of carbon for the life of soil microorganisms.
Sulfate-reducing bacteria are involved in the formation of oil and hydrogen sulfide in medicinal mud, soils and seas. Thus, the layer of water saturated with hydrogen sulfide in the Black Sea is the result of the vital activity of sulfate-reducing bacteria. The activity of these bacteria in soils leads to the formation of soda and soda salinization of the soil. Sulfate-reducing bacteria convert nutrients in rice plantation soils into a form that becomes available to the roots of the crop. These bacteria can cause corrosion of metal underground and underwater structures.
Thanks to the vital activity of bacteria, the soil is freed from many products and pests and is filled with valuable nutrients. Bactericidal preparations are successfully used to combat many types of insect pests (corn borer, etc.).
Many types of bacteria are used in various industries to produce acetone, ethyl and butyl alcohols, acetic acid, enzymes, hormones, vitamins, antibiotics, protein-vitamin preparations, etc.
Without bacteria, the processes of tanning leather, drying tobacco leaves, producing silk, rubber, processing cocoa, coffee, soaking hemp, flax and other bast-fiber plants, sauerkraut, and cleaning are impossible. Wastewater, metal leaching, etc.
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 species similar 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 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 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 and enter the body along with breast milk etc. The whole body becomes saturated with different 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.
Harmful bacteria
However, it is worth remembering that not all bacteria are human friends. Among them there are also many dangerous varieties that can only cause harm. Such organisms, after entering our body, become the cause of the development of various bacterial ailments. These include various colds, some types of pneumonia, and also syphilis, tetanus and other diseases, even deadly ones. There are also diseases of this type that are transmitted by airborne droplets. This is dangerous tuberculosis, whooping cough, etc.
Significant amount ailments caused by harmful bacteria develop due to the consumption of insufficiently high-quality food, unwashed and unprocessed vegetables and fruits, raw water, and undercooked meat. You can protect yourself from such diseases by following the rules and regulations of hygiene. Examples of such dangerous illnesses are dysentery, typhoid fever, etc.
Manifestations of diseases that develop 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 its natural defense, which is based on the process of phagocytosis of bacteria by white blood cells, as well as on the immune system, which synthesizes antibodies. The latter bind foreign proteins and carbohydrates, and then simply eliminate them from the bloodstream.
Also, harmful bacteria can be destroyed using natural and synthetic medications, the most famous of which is penicillin. All medications of this type are antibiotics, they differ depending on the active component and from the scheme of action. Some of them are capable of destroying the cell membranes of bacteria, while others suspend their vital processes.
So, in nature there are a lot of bacteria that can bring benefits and harm to humans. Fortunately, modern level development of medicine, allows us to cope with most pathological organisms of this kind.