Names of beneficial bacteria list. Bacteria are so different: types, forms, ways of survival

They surround us everywhere. Many of them are very necessary and useful for a person, and many, on the contrary, cause terrible diseases.
Do you know what forms bacteria come in? And how do they reproduce? And what do they eat? Do you want to know?
.site) will help you find in this article.

Shapes and sizes of bacteria

Bacteria are not at all large, ranging in size from half to five micrometers. The largest bacterium has a size of seven hundred and fifty micrometers. After the discovery of nanobacteria, it turned out that their size is much smaller than previously imagined by scientists. However, to date, nanobacteria have not been well studied. Some scientists even doubt their existence.

Aggregates and multicellular organisms

How do they move?

Nutrition

reproduction

Bacteria, of course, deserve your attention, not only because they cause a lot of diseases. These microorganisms were the first living things to inhabit our planet. The history of bacteria on Earth goes back nearly four billion years! Cyanobacteria are the most ancient of the existing ones today, they appeared three and a half billion years ago.

You can experience the beneficial properties of bacteria thanks to the specialists of Tianshi Corporation, who have developed for you

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 speak about harmful bacterium x, then people most often recall 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 become harmful when external conditions change.

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

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. They participate in the synthesis of B vitamins and vitamin K, in addition, they participate in the process of protein synthesis necessary for the human body.
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 enter the baby's stomach and begin to participate in all the digestive processes that occur in the body of the newborn.

In addition to fermented milk and bifidobacteria, E. 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, while others provide a balance in ecological system planets.

The third type of microbes are Azotobacteria, their impact on the environment is difficult 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 of effectiveness.

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 various lactic acid products, such as yogurt, ryazhenka, and some others. Being in the gastrointestinal tract, they act as purifiers of the intestinal environment from harmful microflora.

The composition of the microflora of the gastrointestinal tract also includes Escherichia coli. She accepts Active participation in the process of digestion. 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 an important role in wildlife. They are responsible for the fixation of atmospheric nitrogen in the aquatic environment.

The presence of such abilities in these bacteria as calcification and decalcification make them an essential component of the system for maintaining the 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, such diseases can be transmitted from an 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 on useful substances, weakening its condition, which leads to the development of various 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 strongest antibiotics and antiseptics.

Varieties of Staphylococcus aureus are able to live:

• in the upper parts of the human respiratory system;
• on the surface of open wounds;
• In the channels of the urinary organs.

For a human body with a strong immune system, this microbe is not dangerous, but if the body is weakened, it can 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, acute intestinal infections can develop.

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.

The body of a bacterium is represented by a single cell. The forms of bacteria are varied. The structure of bacteria differs from the structure of animal and plant cells.

The cell lacks a nucleus, mitochondria and plastids. The carrier of hereditary information DNA is located in the center of the cell in a folded form. Microorganisms that do not have a true nucleus are classified as prokaryotes. All bacteria are prokaryotes.

It is assumed that on earth there are over a million species of these amazing organisms. To date, about 10 thousand species have been described.

A bacterial cell has a wall, cytoplasmic membrane, cytoplasm with inclusions, and a nucleotide. Of the additional structures, some cells have flagella, pili (a mechanism for sticking together and holding on to the surface), and a capsule. Under adverse conditions, some bacterial cells are able to form spores. The average size of bacteria is 0.5-5 microns.

The external structure of bacteria

Rice. 1. The structure of a bacterial cell.

cell wall

• The cell wall of a bacterial cell is its protection and support. It gives the microorganism its specific shape.
• The cell wall is permeable. Nutrients pass through it inside and metabolic products (metabolism) out.
• Some types of bacteria produce a special mucus that resembles a capsule that protects them from drying out.
• Some cells have flagella (one or more) or villi that help them move.
• In bacterial cells that turn pink on Gram stain ( gram negative), the cell wall is thinner, multilayered. Enzymes that break down nutrients are released to the outside.
• Bacteria that turn purple on Gram stain gram-positive), the cell wall is thick. Nutrients that enter the cell are broken down in the periplasmic space (the space between the cell wall and the cytoplasmic membrane) by hydrolytic enzymes.
• There are numerous receptors on the surface of the cell wall. Cell killers are attached to them - phages, colicins and chemical compounds.
• Wall lipoproteins in some types of bacteria are antigens, which are called toxins.
• With prolonged treatment with antibiotics and for a number of other reasons, some cells lose their membrane, but retain the ability to reproduce. They acquire a rounded shape - an L-shape and can be stored for a long time in the human body (cocci or tuberculosis bacilli). Unstable L-forms have the ability to return to their original form (reversion).

Rice. 2. In the photo, the structure of the bacterial wall of gram-negative bacteria (left) and gram-positive (right).

Capsule

Under adverse environmental conditions, the bacteria form a capsule. The microcapsule adheres tightly to the wall. It can only be seen with an electron microscope. The macrocapsule is often formed by pathogenic microbes (pneumococci). In Klebsiella pneumonia, a macrocapsule is always found.

Rice. 3. In the photo, pneumococcus. The arrows indicate the capsule (electron diffraction pattern of an ultrathin section).

capsule-like shell

The capsule-like shell is a formation loosely associated with the cell wall. Thanks to bacterial enzymes, the capsule-like shell is covered with carbohydrates (exopolysaccharides) of the external environment, which ensures adhesion of bacteria to different surfaces, even completely smooth ones.

For example, streptococci, entering the human body, are able to stick together with teeth and heart valves.

The functions of the capsule are diverse:

• protection from aggressive environmental conditions,
• ensuring adhesion (adhesion) with human cells,
• possessing antigenic properties, the capsule has a toxic effect when introduced into a living organism.

Rice. 4. Streptococci are able to stick together with tooth enamel and, together with other microbes, are the cause of caries.

Rice. 5. In the photo, the defeat of the mitral valve in rheumatism. The reason is streptococci.

Flagella

• Some bacterial cells have flagella (one or more) or villi that help them move. The flagella contain the contractile protein flagelin.
• The number of flagella can be different - one, a bunch of flagella, flagella at different ends of the cell or over the entire surface.
• Movement (random or rotational) is carried out as a result of the rotational movement of the flagella.
• The antigenic properties of flagella have a toxic effect in the disease.
• Bacteria that do not have flagella, being covered with mucus, are able to glide. Aquatic bacteria contain vacuoles in the amount of 40-60, filled with nitrogen.

They provide diving and ascent. In the soil, the bacterial cell moves through the soil channels.

Rice. 6. Scheme of attachment and operation of the flagellum.

Rice. 7. In the photo different types flagellated microbes.

Rice. 8. The photo shows different types of flagellated microbes.

drinking

• Pili (villi, fimbriae) cover the surface of bacterial cells. The villus is a helically twisted thin hollow thread of protein nature.
• General drank provide adhesion (adhesion) with host cells. Their number is huge and ranges from several hundred to several thousand. From the moment of attachment, any .
• sex saws promote the transfer of genetic material from the donor to the recipient. Their number is from 1 to 4 per cell.

Rice. 9. The photo shows E. coli. Visible flagella and drinking. The photo was taken using a tunneling microscope (STM).

Rice. 10. The photo shows numerous pili (fimbriae) in cocci.

Rice. 11. The photo shows a bacterial cell with fimbriae.

cytoplasmic membrane

• The cytoplasmic membrane is located under the cell wall and is a lipoprotein (up to 30% lipids and up to 70% proteins).
• Different bacterial cells have different lipid composition of membranes.
• Membrane proteins perform many functions. Functional proteins are enzymes due to which the synthesis of its various components occurs on the cytoplasmic membrane, etc.
• The cytoplasmic membrane consists of 3 layers. The double phospholipid layer is permeated with globulins, which ensure the transport of substances into the bacterial cell. If it fails, the cell dies.
• The cytoplasmic membrane is involved in sporulation.

Rice. 12. The photo clearly shows a thin cell wall (CS), a cytoplasmic membrane (CPM) and a nucleotide in the center (bacterium Neisseria catarrhalis).

The internal structure of bacteria

Rice. 13. The photo shows the structure of a bacterial cell. The structure of a bacterial cell differs from the structure of animal and plant cells - the cell lacks a nucleus, mitochondria and plastids.

Cytoplasm

The cytoplasm is 75% water, the remaining 25% is mineral compounds, proteins, RNA and DNA. The cytoplasm is always dense and motionless. It contains enzymes, some pigments, sugars, amino acids, a supply of nutrients, ribosomes, mesosomes, granules and all sorts of other inclusions. In the center of the cell, a substance is concentrated that carries hereditary information - the nucleoid.

Granules

The granules are made up of compounds that are a source of energy and carbon.

mesosomes

Mesosomes are cell derivatives. They have a different shape - concentric membranes, vesicles, tubules, loops, etc. Mesosomes have a connection with the nucleoid. Participation in cell division and spore formation is their main purpose.

Nucleoid

The nucleoid is analogous to the nucleus. It is located in the center of the cell. DNA is localized in it - the carrier of hereditary information in a folded form. The untwisted DNA reaches a length of 1 mm. The nuclear substance of a bacterial cell does not have a membrane, a nucleolus and a set of chromosomes, and is not divided by mitosis. Before division, the nucleotide is doubled. During division, the number of nucleotides increases to 4.

Rice. 14. The photo shows a section of a bacterial cell. A nucleotide is visible in the central part.

Plasmids

Plasmids are autonomous molecules coiled into a ring of double-stranded DNA. Their mass is much less than the mass of a nucleotide. Despite the fact that hereditary information is encoded in the DNA of plasmids, they are not vital and necessary for a bacterial cell.

Rice. 15. The photo shows a bacterial plasmid. The photo was taken with an electron microscope.

Ribosomes

Ribosomes of a bacterial cell are involved in protein synthesis from amino acids. Ribosomes of bacterial cells are not united in the endoplasmic reticulum, as in cells that have a nucleus. It is ribosomes that often become the "target" for many antibacterial drugs.

Inclusions

Inclusions are metabolic products of nuclear and non-nuclear cells. They represent a supply of nutrients: glycogen, starch, sulfur, polyphosphate (valutin), etc. When stained, inclusions often take on a different appearance than the color of the dye. You can diagnose by currency.

Shapes of bacteria

Bacterial cell shape and size great importance during their identification (recognition). The most common forms are spherical, rod-shaped and convoluted.

Table 1. Main forms of bacteria.

globular bacteria

Spherical bacteria are called cocci (from the Greek coccus - grain). They are arranged one at a time, two at a time (diplococci), in bags, chains and like bunches of grapes. This arrangement depends on the mode of cell division. The most harmful microbes are staphylococci and streptococci.

Rice. 16. The photo shows micrococci. Bacteria are round, smooth, white, yellow and red. Micrococci are ubiquitous in nature. They live in different cavities of the human body.

Rice. 17. In the photo, diplococcus bacteria - Streptococcus pneumoniae.

Rice. 18. Sarcina bacteria in the photo. Coccoid bacteria are combined into packets.

Rice. 19. In the photo, streptococcus bacteria (from the Greek "streptos" - a chain).

Arranged in chains. They are the causative agents of a number of diseases.

Rice. 20. In the photo, the bacteria are "golden" staphylococci. Arranged like "bunch of grapes". The clusters have a golden color. They are the causative agents of a number of diseases.

rod-shaped bacteria

Rod-shaped bacteria that form spores are called bacilli. They are cylindrical in shape. by the most prominent representative of this group is the bacillus. Bacilli include plague and hemophilic rods. The ends of rod-shaped bacteria can be pointed, rounded, truncated, expanded, or split. The shape of the sticks themselves can be correct and incorrect. They can be arranged one at a time, two at a time, or form chains. Some bacilli are called coccobacilli because they are round in shape. But, nevertheless, their length exceeds the width.

Diplobacilli are double rods. Anthrax sticks form long threads (chains).

The formation of spores changes the shape of the bacilli. In the center of the bacilli, spores form in butyric bacteria, giving them the appearance of a spindle. In tetanus sticks - at the ends of the bacilli, giving them the appearance of drumsticks.

Rice. 21. The photo shows a rod-shaped bacterial cell. Multiple flagella are visible. The photo was taken with an electron microscope. Negative.

Rice. 22. In the photo, rod-shaped bacteria forming chains (anthrax rods).

The word "bacteria" in most people is associated with something unpleasant and a threat to health. At best, sour-milk products are remembered. At worst - dysbacteriosis, plague, dysentery and other troubles. Bacteria are everywhere, good and bad. What can microorganisms hide?

What is bacteria

Bacteria in Greek means "stick". This name does not mean that harmful bacteria are meant. This name was given to them because of the shape. Most of these single cells look like rods. They also come in the form of triangles, squares, stellate cells. For a billion years, bacteria do not change their external appearance, they can only change internally. They can be mobile and immobile. A bacterium consists of one cell. Outside, it is covered with a thin shell. This allows her to keep her shape. Inside the cell there is no nucleus, chlorophyll. There are ribosomes, vacuoles, outgrowths of the cytoplasm, protoplasm. The largest bacterium was found in 1999. It was called the "Gray Pearl of Namibia". Bacteria and bacillus mean the same thing, only they have a different origin.

Man and bacteria

In our body, there is a constant struggle between harmful and beneficial bacteria. Through this process, a person receives protection from various infections. Various microorganisms surround us at every step. 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 tonsillitis. If a woman's microflora is disturbed, she may develop gynecological diseases. Compliance with the basic rules of personal hygiene will help to avoid such failures.

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

The appearance of bacteria in the body

A newly born baby has a sterile intestine.
After his first breath, many microorganisms enter the body, with which he was not previously familiar. When the baby is first attached to the breast, the mother transfers beneficial bacteria with milk that will help normalize the intestinal microflora. No wonder doctors insist that the mother immediately after the birth of her child breastfeed him. They also recommend extending such feeding as long as possible.

Beneficial bacteria

Useful bacteria are: lactic acid, bifidobacteria, E. coli, streptomycents, mycorrhiza, cyanobacteria.

All of them play an important role in human life. Some of them prevent the occurrence of infections, others are used in production. medicines, 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, tonsillitis, plague and many others. They are easily transmitted from an infected person through air, food, touch. It is the harmful bacteria, whose names will be given below, that spoil food. They give off an unpleasant odor, rot and decompose, and cause disease.

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

Names of harmful bacteria

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

The most dangerous bacteria

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

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 that are harmful to humans are dangerous because they produce toxic substances that are extremely life-threatening. During 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. It lives well in water, on vegetables, fruits and reproduces well in milk products.

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

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 bench by physicians of all directions. Every year, healthcare is looking for new methods to prevent the spread of infections that are dangerous to human life. With the observance of preventive measures, you will not have to waste your energy on finding new ways to deal with such diseases.

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

The second stage is the destruction of the ways through which harmful bacteria can be transmitted. To do this, carry out appropriate propaganda among the population.

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

Each person can resist harmful bacteria in every possible way strengthening their immunity. Healthy lifestyle, observance of elementary hygiene rules, self-protection during sexual contact, use of sterile disposable medical instruments and equipment, complete restriction from communication with quarantined people. When entering the epidemiological region 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 impact to bacteriological weapons.

Bacteria are beneficial and harmful. Bacteria in human life

Bacteria are the most numerous inhabitants of the planet Earth. They inhabited it in ancient times and continue to exist to this day. Some species have even changed little since then. Good and bad bacteria 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 wildlife and stand out in a special kingdom.

Margin of safety

These microorganisms, as they say, do not sink in water and do not burn in fire. Literally: withstand temperatures up to plus 90 degrees, freezing, lack of oxygen, pressure - high and low. We can say that nature has invested a huge margin of safety in them.

Bacteria beneficial and harmful to the human body

As a rule, the bacteria that inhabit our bodies in abundance are not given due attention. After all, they are so small that they seem to have no significant significance. Those who think so are largely mistaken. Bacteria useful and harmful have long and reliably “colonized” other organisms and 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 gut?

Doctors say that if you put together just the bacteria that live in the intestines and weigh it, you get something like three kilograms! With such a huge army it is impossible to ignore. Many of the microorganisms continuously entered the human intestine, but only a few species find favorable conditions for living and living there. And in the process of evolution, they even formed a permanent microflora, which is designed to perform important physiological functions.

"Wise" Neighbors

Bacteria have long played an important role in human life, although until very recently, people did not know about it. They help their host in digestion and perform a number of other functions. What are these invisible neighbors?

Permanent microflora

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

• Essential beneficial bacteria. Names: bifidobacteria and bacteroids. They are the vast majority.
• Associated beneficial bacteria. Names: Escherichia coli, Enterococcus, Lactobacillus. 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?

The main function of these bacteria is to help us in the process of digestion. It is noticed that a person with improper nutrition can develop dysbacteriosis. As a result, stagnation and poor health, constipation and other inconveniences. With the normalization of a balanced diet, the disease, as a rule, recedes.

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

Fickle microflora

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

Location in the gastrointestinal tract

In fact, the entire digestive tract has a heterogeneous and unstable microflora - beneficial and harmful bacteria. The esophagus contains the same inhabitants as in the oral cavity. In the stomach there are only a few that are resistant to acid: lactobacilli, Helicobacter pylori, streptococci, fungi. In the small intestine, the microflora is also not numerous. Most bacteria are found in the large intestine. So, defecation, a person is able to allocate over 15 trillion microorganisms per day!

The role of bacteria in nature

She is also definitely great. There are several global functions, without which all life on the planet would have ceased to exist long ago. The most important is sanitation. Bacteria eat dead organisms found in nature. They, in essence, work as a kind of janitors, not allowing deposits of dead cells to accumulate. Scientifically they are called saprotrophs.

Another important role of bacteria is participation in the global circulation of substances on land and at sea. On planet Earth, all substances in the biosphere pass from one organism to another. Without some bacteria, this transition would simply be impossible. The role of bacteria is invaluable, for example, in the cycle and reproduction of such important element like nitrogen. There are certain bacteria in the soil that convert the nitrogen in the air into nitrogenous fertilizers for plants (microorganisms live right in their roots). This symbiosis between plants and bacteria is being studied by science.

Participation in food chains

As already mentioned, bacteria are the most numerous inhabitants of the biosphere. And accordingly, they can and should participate in the food chains inherent in the nature of animals and plants. Of course, for a person, for example, bacteria are not the main part of the diet (unless they can be used as a food additive). However, there are organisms that feed on bacteria. These organisms, in turn, feed on other animals.

cyanobacteria

These blue-green algae (an outdated name for these bacteria, fundamentally wrong from a scientific point of view) are able to produce huge amounts of oxygen as a result of photosynthesis. Once upon a time, it was they who began to saturate our atmosphere with oxygen. Cyanobacteria continue to do this successfully to this day, forming a certain part of the oxygen in the modern atmosphere!

What are bacteria: names and types

The oldest living organism on our planet. Its representatives not only survived for billions of years, but also have enough power to destroy all other species on Earth. In this article, we will look at what bacteria are.

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

Discovery of bacteria

Let's start our tour of the microbial kingdom with a definition. What does "bacteria" mean?

The term comes from the ancient Greek word for "stick". It was introduced into the academic lexicon by Christian Ehrenberg. These are non-nuclear microorganisms, consisting of one cell and not having a nucleus. Previously, they were also called "prokaryotes" (non-nuclear). But in 1970 there was a division into archaea and eubacteria. However, so far more often this concept means all prokaryotes.

The science of bacteriology studies what bacteria are. Scientists say that about ten thousand different types of these living creatures have been discovered so far. However, it is believed that there are more than a million varieties.

Anton Leeuwenhoek, a Dutch naturalist, microbiologist and fellow of the Royal Society of London, in 1676, in a letter to Great Britain, describes a number of the simplest microorganisms that he discovered. His message shocked the public; a commission was sent from London in order to double-check this data.

After Nehemiah Grew confirmed the information, Leeuwenhoek became a world-famous scientist, the discoverer of the simplest organisms. But in his notes he called them "animalcules".

Ehrenberg continued his work. It was this researcher who coined the modern term "bacteria" in 1828.

Robert Koch became a revolutionary in microbiology. In his postulates, he associates microorganisms with various diseases, and defines some of them as pathogens. In particular, Koch discovered the bacterium that causes tuberculosis.

If before that the protozoa were studied only in general terms, then after 1930, when the first electron microscope was created, science made a leap in this direction. For the first time, a deep study of the structure of microorganisms begins. In 1977 the American scientist Karl Wese divides prokaryotes into archaea and bacteria.

Thus, it is safe to say that this discipline is only at the very beginning of development. Who knows how many more discoveries await us in the coming years.

Structure

Grade 3 already knows firsthand what bacteria are. Children study the structure of microorganisms in the classroom. Let's delve a little deeper into this topic to recover information. Without it, it will be difficult for us to discuss subsequent points.

The bulk of bacteria consists of only one cell. But it comes in different forms.

The structure depends on the mode of life and nutrition of the microorganism. So there are cocci (round), clostridia and bacilli (rod-shaped), spirochetes and vibrios (tortuous), in the form of cubes, stars and tetrahedra. It has been observed that with a minimum amount of nutrients in environment bacteria tend to increase surface area. They grow additional education. Scientists call these outgrowths "prostek".

So, after we figured out what forms of bacteria are, it is worth touching on them. internal structure. Unicellular microorganisms have a permanent set of three structures. Additional elements may vary, but the basics will always be the same.

So, each bacterium necessarily has an energy structure (nucleotide), non-membrane organelles responsible for protein synthesis from amino acids (ribosomes) and a protoplast. The latter includes the cytoplasm and the cytoplasmic membrane.

From aggressive external influences, the cell membrane is protected by a shell, which consists of a wall, a capsule and a sheath. Some species also have superficial formations like villi and flagella. They are designed to help bacteria move efficiently in space in order to get food.

Metabolism

It is especially worth dwelling on heterotrophic bacteria. Different species need a certain amount of substances. For example, Bacillus fastidiosus is found only in urine because it can only obtain carbon from this acid. We will talk about such microorganisms in more detail later.

Now it is worth dwelling on the methods of replenishing energy in the cell. Such modern science knows only three. Bacteria use photosynthesis, respiration or fermentation.

Photosynthesis, in particular, can be both with the use of oxygen and without the participation of this element. Purple, green and heliobacteria do without it. They produce bacteriochlorophyll. Oxygen photosynthesis requires ordinary chlorophyll. These include prochlorophytes and cyanobacteria.

Recently a discovery has been made. Scientists have discovered microorganisms that use hydrogen obtained from the breakdown of water for reactions in the cell. But that is not all. For this reaction, the presence of uranium ore nearby is necessary, otherwise the desired result will not be obtained.

Also in the deep layers of the oceans and at its bottom there are colonies of bacteria that transmit energy only with the help of electric current.

reproduction

Previously, we talked about what bacteria are. We will consider the types of reproduction of these microorganisms now.

There are three methods by which these creatures increase their numbers.

This sexual reproduction V primitive form, budding and equal division.

In sexual reproduction, offspring are obtained using transduction, conjugation and transformation.

Place in the world

Earlier, we figured out what bacteria are. Now it is worth talking about what role they play in nature.

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

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

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

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

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

Bacteria and man

We have already figured out what bacteria are, how they look, what they can do. Now it’s worth talking about what their role is in the life of a modern person.

First, for many centuries we have been using the amazing abilities of lactic acid bacteria. Without these microorganisms, there would be no kefir, no yogurt, no cheese in our diet. In addition, such beings are also responsible for the leavening process.

IN agriculture bacteria are used in two ways. On the one hand, they help to get rid of unnecessary weeds (phytopathogenic organisms, like herbicides), on the other hand, from insects (entomopathogenic unicellular, like insecticides). In addition, mankind has learned to create bacterial fertilizers.

Microorganisms are also used for military purposes. With the help of various species, deadly biological weapons are created. To do this, not only the bacteria themselves are used, but also the toxins secreted by them.

In a peaceful manner, science uses single-celled organisms for research in the fields of genetics, biochemistry, genetic engineering and molecular biology. With the help of successful experiments, algorithms for the synthesis of vitamins, proteins and other substances necessary for a person were created.

Bacteria are also used in other areas. With the help of microorganisms, ores are enriched and water bodies and soils are cleaned.

Scientists also say that the bacteria that make up the microflora in the human intestine can be called a separate organ with its own tasks and independent functions. According to researchers, there are about one kilogram of these microorganisms inside the body!

In everyday life, we encounter pathogenic bacteria everywhere. According to statistics, the largest number colonies are on the handles of supermarket carts, followed by computer mice in Internet cafes, and only in third place are the handles of public restrooms.

Beneficial bacteria

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

Half a century ago, no one thought about such a question as the state of the microflora in the intestines. Everything was OK. Nutrition is more natural and healthy, a minimum of hormones and antibiotics, less chemical emissions into the environment.

Today, in conditions of poor nutrition, stress, an overabundance of antibiotics, dysbacteriosis and related problems come to the fore. How do doctors propose to deal with this?

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

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

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

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

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

harmful bacteria

Earlier we talked about what bacteria are. The types and names of the most common beneficial microorganisms were announced above. Further, we will talk about the "unicellular enemies" of man.

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

Before delving into what harmful bacteria are, it is worth deciding on the ways they spread. And there are a lot of those. There are microorganisms that are transmitted through contaminated and unwashed products, airborne and contact routes, through water, soil or insect bites.

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

If we talk about what bacteria are, the names of pathogenic and beneficial ones are difficult to distinguish for a non-professional. In science, Latin terms are used to refer to microorganisms. In common parlance, abstruse words are replaced by concepts - "E. coli", "causative agents" of cholera, whooping cough, tuberculosis and others.

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

Where do bacteria in urine come from?

Some people try to monitor their health and take tests at the clinic. Very often the cause of poor results is the presence of microorganisms in the samples.

About what bacteria are in the urine, we will talk a little later. Now it is worth dwelling separately on where, in fact, single-celled creatures appear there.

Ideally, a person's urine is sterile. There can be no foreign organisms. The only way for bacteria to enter the secretions is at the site where waste is removed from the body. In particular, in this case it will be the urethra.

If the analysis shows a small number of inclusions of microorganisms in the urine, then everything is normal so far. But with an increase in the indicator above the permitted limits, such data indicate the development of inflammatory processes in the genitourinary system. This may include pyelonephritis, prostatitis, urethritis and other unpleasant ailments.

Thus, the question of what kind of bacteria are in the bladder is completely incorrect. Microorganisms enter the secretions not from this organ. Scientists today identify several reasons leading to the presence of single-celled creatures in the urine.

• First, it is a promiscuous sex life.
• Secondly, diseases of the genitourinary system.
• Thirdly, neglect of the rules of personal hygiene.
• Fourthly, decreased immunity, diabetes and a number of other disorders.

Types of bacteria in urine

Earlier in the article it was said that microorganisms in waste products are found only in case of diseases. We promised to tell you what bacteria are. Names will be given only of those species that are most often found in the results of analyses.

So, let's begin. Lactobacillus is a representative of anaerobic organisms, a gram-positive bacterium. It must be in the human digestive system. The presence of it in the urine indicates some failures. Such an event is uncritical, but it is an unpleasant call to the fact that you should seriously take care of yourself.

The proteus is also a natural inhabitant of the gastrointestinal tract. But the presence of it in the urine indicates a failure in the withdrawal of feces. This microorganism gets from food into urine only in this way. A sign of the presence of a large amount of proteus in the waste is a burning sensation in the lower abdomen and painful urination with a dark color of the liquid.

Very similar to the previous bacterium is Enterococcus fecalis. It enters the urine in the same way, multiplies rapidly and is difficult to treat. In addition, Enterococcus bacteria are resistant to most antibiotics.

Thus, in this article, we figured out what bacteria are. We talked about their structure, reproduction. You have learned the names of some harmful and beneficial species.

Good luck, dear readers! Remember that personal hygiene is the best prevention.

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 life support methods, 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 can bring real benefits.

After small man is born, bacteria immediately begin to penetrate into his body. They are introduced through the respiratory tract along with air, enter the body along with breast milk etc. The whole organism is saturated with various bacteria.

Their number cannot be accurately calculated, but some scientists boldly say that the number of such organisms is comparable to the number of all cells. The digestive tract alone is home to four hundred varieties of different 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 optimal in the oral cavity, and some others live only on the skin.

For many years of coexistence, man and such particles were able to recreate the 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 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 the defense and simply block the path of pathogens. When existing in the digestive tract, such substances also bring tangible benefits. They are engaged in the processing of leftover food, while releasing a significant amount of heat. It, in turn, is transmitted to nearby organs, and is carried throughout the body.

Deficiency of beneficial bacteria in the body or a change in their number causes 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 enough dangerous varieties that can only bring harm. Such organisms, after penetrating into our body, cause the development of a variety of bacterial ailments. These are various colds, some varieties of pneumonia, and in addition syphilis, tetanus and other diseases, even deadly ones. There are also diseases of this type, which are transmitted by airborne droplets. This is dangerous tuberculosis, whooping cough, etc.

A significant number of diseases provoked by harmful bacteria develop due to the consumption of insufficiently high-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. Examples of such dangerous diseases are dysentery, typhoid fever, etc.

Manifestations of diseases that have developed as a result of an attack of 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 the 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 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 mode of action. Some of them are able to destroy the cell membranes of bacteria, while others suspend the processes of their vital activity.

So, in nature there are a lot of bacteria that can bring benefits and harm to humans. Fortunately, the current level of development of medicine makes it possible to cope with the majority of pathological organisms of this kind.

Help me, I need briefly about useful and harmful bacteria.

Eternity............

The danger of bacterial diseases was greatly reduced at the end of the 19th century with the invention of the vaccination method, and in the middle of the 20th century with the discovery of antibiotics.

Useful; For thousands of years, humans have used lactic acid bacteria to produce cheese, yogurt, kefir, vinegar, and fermentation.

Currently, methods have been developed for the use of phytopathogenic bacteria as safe herbicides, entomopathogenic - instead of insecticides. The most widely used is Bacillus thuringiensis, which produces toxins (Cry-toxins) that act on insects. In addition to bacterial insecticides, bacterial fertilizers have found application in agriculture.

Bacteria that cause human disease are being used as biological weapons.

Due to the rapid growth and reproduction, as well as the simplicity of the structure, bacteria are actively used in scientific research in molecular biology, genetics, genetic engineering and biochemistry. Escherichia coli has become the best studied bacterium. Information about the processes of bacterial metabolism made it possible to produce bacterial synthesis of vitamins, hormones, enzymes, antibiotics, etc.

A promising direction is the enrichment of ores with the help of sulfur-oxidizing bacteria, the purification of soils and reservoirs contaminated with oil products or xenobiotics by bacteria.

Between 300 and 1000 species of bacteria normally live in the human intestine. total weight up to 1 kg, and the number of their cells is an order of magnitude greater than the number of cells in the human body. They play an important role in the digestion of carbohydrates, synthesize vitamins, and displace pathogenic bacteria. It can be figuratively said that the human microflora is an additional "organ", which is responsible for protecting the body from infections and digestion.

It's not very short here. but I think you can cut it however you like.

Karim Murotaliyev

Yulia Rack

1.Azotobacter (Azotobacter) - enrich the soil with biologically active substances that stimulate plant growth, help cleanse the soil from heavy metals, in particular, from lead and mercury.
2.Bifidobacteria:
supply the body with vitamin K, thiamine (B1), riboflavin (B2), nicotinic acid (B3), pyridoxine (B6), folic acid (B9), amino acids and proteins;
prevent the development of pathogenic microbes;
protect the body from the ingress of toxins from the intestines;
accelerate the digestion of carbohydrates;
activate parietal digestion;
help absorption through the intestinal wall of calcium, iron, vitamin D ions.
3. Lactic acid bacteria - protect the intestines from putrefactive and pathogenic microbes.
4. Streptomyces:
are manufacturers (producers) of a wide variety of drugs, including:
antifungal;
antibacterial;

In the human body, there are many types of bacteria, among which useful, pathogenic and conditionally pathogenic forms stand out. Consider the features of the development of microbes, the diseases they provoke and the methods of infection by pathogens.

There is an opinion that the number of bacteria in the human body exceeds the volume of its own cells by 10 times. However, recent studies have questioned this figure. According to new materials, it varies from 1.5 to 2. In total, there are about 10 thousand species of bacteria that have adapted to living in various conditions.

They enter the human body from the environment in which they can persist for a long time. Pathogenic forms are causative agents of diseases that manifest themselves in varying degrees of intensity and danger. It can be either a mild skin rash or a serious infectious manifestation that poses a threat to the patient's life.

Bacteria appeared on Earth about 3.5 billion years ago. Their structure differs slightly from modern species. All bacteria are prokaryotes, which means that they do not have a nucleus in their cell. Outside, they are surrounded by a cell wall that retains the shape of the microorganism. Some species are able to produce a mucus that looks like a capsule and protects the microbe from drying out. There are forms that can actively move with the help of special flagella.

The internal structure of bacteria is quite simple. The cell contains the main inclusions:

• cytoplasm, which is 75% water, and the remaining 25% are minerals;
• granules, which are a source of energy for the body;
• mesosomes necessary for cell division and sporulation;
• nucleoid containing genetic information and acting as the nucleus;
• ribosomes involved in protein synthesis;
• plasmids.

The shape of bacterial cells can be spherical, rod-shaped, convoluted or club-shaped. They can be located singly or in groups. In this case, diplococci (in pairs), streptococci (in the form of chains), staphylococci (in the form of a grapevine) and sarcins (placement in a package) are isolated. Some rod-shaped bacteria, when exposed adverse conditions form disputes. Such species are called bacilli.

All microorganisms reproduce by dividing the cell in two. Moreover, the rate of population increase can be as little as 20 minutes. Such a high reproduction rate is observed on food products and other nutrient substrates.

Beneficial bacteria living in the human body

The main representatives of beneficial microflora include:

1. Bifidobacteria. They live mainly in the large intestine, where they are involved in the activation of parietal digestion. In the process of life, they form a natural biological barrier that prevents the penetration of pathogens and toxins. In addition, they produce special acids that suppress the reproduction of pathogenic and opportunistic forms. Without the participation of bifidobacteria, the synthesis of B and K vitamins does not occur, as well as the absorption of iron and calcium.
2. Lactobacilli in the process of life form lactase, which breaks down milk sugar. Through the production of lactic acid, they support required level acidity in the intestines, and also accelerate the healing of affected areas of the gastrointestinal tract. By analogy with bifidobacteria, they stimulate the immune system by activating the process of phagocytosis.

These microbes stand guard over the digestive tract, protecting it from useless microorganisms that can settle in the stomach and worsen a person's condition.

Normal human microflora should contain both types of microorganisms. Moreover, the number of bifidobacteria can be up to 95% of the total biocenosis of the body, and lactobacilli - only 5%. In this case, the latter live mainly in the vagina and oral cavity.

Bifido- and lactobacilli are part of the preparations used to normalize the human microflora. They are called probiotics, and in addition to these microorganisms contain propionic acid species, thermophilic streptococci and lactococci. Combined drugs are often prescribed for dysbacteriosis, antibiotic treatment, as well as any helminthic invasions.

To maintain optimal levels of beneficial bacteria, you need to eat certain foods. They should consist of components that are not digested in the upper intestines, thereby stimulating the reproduction of beneficial microbes. Such products include raw vegetables, dairy products, bran, cereals, berries, dried fruits.

Pathogenic forms of corynebacteria

Microorganisms of the genus Corynebacterium are Gram-positive bacteria with a rod-shaped body. Most representatives live in nature and do not pose a threat to human health. However, several species are causative agents of serious diseases requiring inpatient treatment.

Corynebacterium diphtheriae are slightly curved rods with a thickening on one side of the cell. Their size ranges from 0.1 to 8 microns. As the name suggests, the bacterium is the cause of diphtheria. Symptoms of the disease depend on the location of the pathogen. It can be the oral cavity, nose, larynx, trachea, bronchi, genitals, skin. Poisoning of the human body occurs due to the release of a special substance by bacteria called exotoxin. Its accumulation leads to fever, fever, headache, nausea, discomfort in the throat, swollen lymph nodes.

Another species of Corynebacterium minutissimum provokes the development of dermatological diseases. One of them is erythrasma, which occurs only in adults. It manifests itself in the form of rashes on the surface of the skin folds: inguinal-scrotal, between the buttocks, sometimes in the interdigital zones. Lesions have the appearance of brown spots of a non-inflamed structure, which may be the cause of mild itching. The bacterium survives well on household items, including phones and tablets.

Corynebacteria are also part of the normal microflora of the human large intestine. Non-pathogenic forms are actively used in industry for the production of amino acids, enzymes, and cheeses. Corynebacterium glutamicum is used in the production of glutamic acid, which is known as food additive E620.

Streptomycetes, their significance for humans

The genus Streptomyces includes spore-forming species that live primarily in the soil. They form chains of cells and resemble fungal mycelium in shape. In the process of life, special volatiles, which give the earth a characteristic damp smell. Necessary condition existence of streptomycetes is the presence of molecular oxygen.

Many species are capable of producing valuable medicinal substances belonging to the group of antibiotics (streptomycin, erythromycin). In earlier periods, streptomycetes were used to produce:

• Physostigmine, used as an analgesic for increased eye pressure;
• Tacrolimus, necessary for prophylaxis during kidney, liver and bone marrow transplantation;
• Allosamidin, which is active against insects and fungi.

Streptomyces bikiniensis is a pathogenic form that provokes the development of bacteremia. With this disease, bacteria enter the bloodstream and can spread throughout the body.

Helicobacter pylori as a harmful bacterium

Helicobacter pylori has a spiral-shaped cell up to 3 microns in size. It is able to actively move even in thick mucus with the help of flagella. The bacterium infects various parts of the stomach and duodenum, causing the disease helicobacter pylori. The cause of ulcers and gastritis very often becomes this type of microbe.

Helicobacter is fixed on the surface of the gastric mucosa, damaging it and provoking the development of the inflammatory process. Infection with a bacterium manifests itself in the form of repeated severe pain in the region of the stomach, which subside after eating. Heartburn, nausea, vomiting, poor digestibility of meat dishes are also symptoms of the disease.

There is an opinion that Helicobacter pylori is part of the normal human microflora, and the pathological condition occurs with an increase in its number. At the same time, about 50 strains of this bacterium live in the stomach of people, of which only 5 pose a health hazard. In the case of the appointment of antibiotics, all individuals of the microorganism, including harmless ones, are destroyed.

Escherichia coli as a representative of the natural human microflora

E. coli refers to rod-shaped bacteria that play an important role in the functioning of the gastrointestinal tract. They can exist for a long time in the environment, including soil, water and faeces. Microorganisms quickly die when boiled and exposed to chlorine solutions. Bacteria actively multiply on food products, especially in milk.

Escherichia coli is able to absorb oxygen from the intestinal lumen, thereby protecting beneficial lactobacteria and bifidobacteria from destruction. In addition, it is involved in the production of B vitamins, fatty acids, and also affects the absorption of iron and calcium by the intestines. Normally, the content of bacteria in human feces should be no more than 108 CFU / g. Exceeding this indicator indicates the development of dysbacteriosis against the background of the inflammatory process in the body.

Pathogenic forms can cause infectious diseases of the gastrointestinal tract, accompanied by intoxication and fever. Enteropathogenic strains of Escherichia coli develop in the small intestine of newborns and cause severe diarrhea. In women, if intimate hygiene is not observed, bacteria can enter the genitourinary organs, provoking the development of bacteriuria.

Dangerous bacterium Staphylococcus aureus

Staphylococcus aureus belongs to the immobile spherical microbes of the genus Staphylococcus. Cells may be singly, in pairs or in clusters. Due to the content of pigments of the carotenoid group, the bacterium has a golden color, which is noticeable when studied under a microscope. Staphylococcus aureus is highly resistant to high temperatures, light and chemicals.

The microorganism is the cause of the appearance of purulent-inflammatory foci of infection in humans. The main areas of pathogen localization include the nasal passages and axillary areas. However, cases of damage to the larynx and gastrointestinal tract are not uncommon. The bacterium is widely distributed in medical institutions. About 30% of patients after hospitalization are carriers of Staphylococcus aureus.

The main symptoms of infection with a pathogen include fever, lethargy, nausea, and lack of appetite. When the skin is damaged, small blisters form, resembling burns, which eventually turn into open wounds. Rhinitis, tonsillitis, pharyngitis, pneumonia can develop with the spread of the pathogen in the respiratory tract. Frequent and painful urination and back pain indicate the localization of staphylococcus aureus in the urethra.

Pseudomonas aeruginosa as one of the pathogenic species of bacteria

The bacterium belongs to mobile flagellar microorganisms, its main habitat is soil and water. In the process of life, it colors the food environment in a blue-green color, which is the reason for its name. It is highly resistant to antibiotics.

Pseudomonas aeruginosa is dangerous for immunocompromised people and is usually a nosocomial infection. Infection is possible through household items, towels, untreated medical instruments. An increased accumulation of the microorganism is observed on the wound surface and in the depths of purulent skin areas.

Pseudomonas aeruginosa can develop in:

• ENT organs and be accompanied by otitis, sinusitis;
• urinary tract with the appearance of urethritis, cystitis;
• soft tissues;
• intestines, causing dysbacteriosis, enteritis, colitis.

Bacteria, along with viruses, are the causative agents of numerous diseases that are not always treatable. The variety of species and their rapid adaptation to the effects of medical drugs make microbes a serious threat to human health. However, in most cases, infection can be avoided if you follow the rules of personal hygiene and strengthen the immune system.