What bacteria can. Types of harmful bacteria

Everyone knows that bacteria are the most ancient look living creatures that inhabit our planet. The first bacteria were the most primitive, but as our earth changed, so did the bacteria. They are present everywhere, in water, on land, in the air we breathe, in food, in plants. Just like people, bacteria can be good and bad.

Beneficial bacteria are:

Lactic acid or lactobacilli. One of these good bacteria is lactic acid bacteria. This is a rod-shaped type of bacteria that lives in dairy and fermented milk products. These bacteria also inhabit the human oral cavity, intestines, and vagina. The main benefit of these bacteria is that they produce lactic acid as a fermentation, thanks to which we get yogurt, kefir, fermented baked milk from milk, in addition, these products are very useful for humans. In the intestines, they play the role of cleansing the intestinal environment from bad bacteria.
Bifidobacteria. Bifidobacteria are found mainly in the gastrointestinal tract, just like lactic acid bacteria are capable of producing lactic acid and acetic acid, thanks to which these bacteria control the growth pathogenic bacteria, thereby regulating the pH level in our intestines. Various varieties of bifidobacteria help get rid of constipation, diarrhea, and fungal infections.
Escherichia coli. The human intestinal microflora consists of most microbes of the Escherichia coli group. They contribute good digestion, and also participate in some cellular processes. But some varieties of this stick can cause poisoning, diarrhea, and kidney failure.
Streptomycetes. The habitat of streptomycetes is water, decomposing compounds, soil. Therefore, they are especially useful for the environment, because... Many processes of decomposition and combinations are carried out with them. In addition, some of these bacteria are used in the production of antibiotics and antifungal drugs.

Harmful bacteria are:

Streptococci. Chain-shaped bacteria, which, when entering the body, are the causative agents of many diseases, such as tonsillitis, bronchitis, otitis media and others.
Plague stick. A rod-shaped bacterium that lives in small rodents causes terrible diseases such as plague or pneumonia. It's a plague terrible disease, which can destroy entire countries, and is compared to biological weapons.
Helicobacter pylori. The habitat of Helicobacter pylori is the human stomach, but in some people the presence of these bacteria causes gastritis and ulcers.
Staphylococcus. The name staphylococcus comes from the fact that the cells resemble a bunch of grapes in shape. For humans, these bacteria cause severe diseases with intoxication and purulent formations. No matter how terrible bacteria are, humanity has learned to survive among them thanks to vaccination.

The message about bacteria can be used to prepare for a biology lesson. The report on bacteria can be supplemented with interesting facts.

Report on the topic “Bacteria”

The smallest living organisms are bacteria. Everyone knows about their harm, but they can also be beneficial.

What are bacteria?

Bacteria are single-celled organisms of microscopic size, one of the types of microbes.

They can be found in every corner of our planet - in Antarctica, in the ocean, in space, in hot springs, and in the saltiest bodies of water.

The total weight of bacteria in each person reaches 2 kg! And their sizes rarely exceed 0.5 microns.

A huge number of bacteria inhabit the body of animals, performing various functions there.

What do bacteria look like?

They can have rod-shaped, spherical, spiral and other shapes. However, most of them are colorless, only rare species colored green and purple. Moreover, over billions of years they change only internally, and their appearance remains unchanged.

Who discovered bacteria?

The first explorer of the microworld was the Dutch naturalist Antoni Van Leeuwenhoek. It was he who invented the first microscope. In essence, it was a tiny lens with a diameter of a pea, giving a magnification of 200-300 times. It could only be used by pressing it to the eye.

In 1683, he discovered and later described “live animals” seen through a lens in a drop of rainwater. Over the next 50 years, he studied various microorganisms, describing more than 200 of their species. Thanks to Leeuwenhoek, arose new science- microbiology.

General information about bacteria

It is to bacteria that our planet owes the emergence of multicellular life forms. They are the ones who play main role in maintaining the circulation of substances on Earth. Generations of people replace each other, plants die, accumulate household waste and the outdated shells of various creatures - all this is utilized and, with the help of bacteria, decomposes in the process of rotting. And the resulting chemical compounds return to environment.

There are “bad and good” bacteria.

"Bad" bacteria lead to the spread of a huge number of diseases, ranging from plague and cholera to common whooping cough and dysentery. They enter our body by airborne droplets, along with food, water and through skin. Bacteria can live in our organs, and as long as our immune system copes with them, they do not manifest themselves in any way. The speed of their reproduction is amazing. Every 20 minutes their number doubles. This means that one single pathogenic microbe, in 12 hours, generates a multi-million army of the same bacteria that attack the body.

There is another danger posed by bacteria. They cause poisoning of people who consume spoiled foods - canned food, sausages, etc.

A great breakthrough in the fight against pathogenic bacteria was the discovery in 1928 of penicillin, the world's first antibiotic that can inhibit the growth and reproduction of bacteria. This is how people learned to treat diseases that previously led to death.

But bacteria are able to adapt to the action of antibiotics. This ability of bacteria to mutate has become a real threat to human health and has led to the emergence of incurable infections.

Now let's talk about “good” bacteria. Good bacteria live in the mouth, skin, stomach and other organs.
Most of them are extremely useful (they help digest food, participate in the synthesis of certain vitamins, and even protect us from their pathogenic counterparts).
Interestingly, bacteria are sensitive to people's taste preferences.

In Americans who traditionally consume high-calorie foods (fast foods, hamburgers), bacteria are able to digest foods high in fat. And some Japanese have intestinal bacteria adapted to digest algae.

The role of bacteria in human life

People began to use bacteria even before their discovery. Since ancient times, people have made wine, fermented vegetables, prepared kefir, curdled milk and kumiss, cottage cheese and cheeses.
Much later, it was found that bacteria are involved in all these processes.

People are constantly expanding their scope of application - they have been “trained” to fight plant pests and enrich the soil with nitrogen, ensile green fodder and purify wastewater, in which they literally devour various organic residues.

Now scientists are planning to create light-sensitive bacteria and use them to produce biological cellulose.

We hope the information provided about bacteria has helped you. And you can leave your story about bacteria using the comment form.

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

What are bacteria

Man and bacteria

The appearance of bacteria in the body

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

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

Types of harmful bacteria

Harmful bacteria can cause a number of serious illnesses in humans. For example, diphtheria, anthrax, sore throat, plague and many others. They are easily transmitted from an infected person through air, food, or touch. It is the harmful bacteria, the names of which will be given below, that spoil food. From them appears bad smell, rotting and decomposition occurs, they cause diseases.

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

Names of harmful bacteria

Table. Harmful bacteria for humans. Titles

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

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

The most dangerous bacteria

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

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

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

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

Measures to prevent the spread of infections

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

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

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

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

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

What types of bacteria are there: names and types

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

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

Discovery of bacteria

Types of bacteria in urine

Structure

Metabolism

Reproduction

Place in the world

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

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

The undoubted benefit of bacteria is the assimilation of atmospheric nitrogen. They are involved in the formation of soil fertility and the destruction of the remains of dead representatives of flora and fauna. In addition, microorganisms participate in the creation of minerals and are responsible for maintaining oxygen reserves 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 these are tuberculosis, leprosy, plague, syphilis, anthrax and many others. But even those that are conditionally safe for human life can become a threat if the level of immunity decreases.

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

Bacteria and humans

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

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

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

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

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

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

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

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

Harmful bacteria

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

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

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

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

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

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

Where do bacteria in urine come from?

Which bacteria are beneficial?

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

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

The vast world of bacteria

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

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

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

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

Medicinal and food bacteria

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

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

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

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

Which do not have a core. Most bacteria are heterotrophs, but there are also autotrophs. They reproduce by division. When unfavorable conditions occur, some bacteria form spores.

Bacteria can only be seen through a microscope, which is why they are called microorganisms. Microorganisms are studied by the science of microbiology. The branch of microbiology that studies bacteria is called bacteriology.

The first to see and describe bacteria was the Dutch naturalist Anthony van Leeuwen Hoek (1632-1723). He learned to grind glass and make lenses. Leeuwenhoek made more than 400 microscopes and discovered the world of microscopic organisms - bacteria and protists.

When we hear about bacteria, we most often imagine a sore throat or gums, despite the fact that only a small part of bacteria cause disease. Most of these organisms perform other important functions.

We begin to come into contact with bacteria from the first hours of life. Many of them constantly live on the surface of human skin. There are even more of them on the teeth, gums, tongue and walls of the mouth. There are more bacteria in your mouth than there are people on Earth! But the largest number of them lives in the intestines - up to 5 kg in an adult.

Bacteria are found everywhere: in water, soil, air, in plant tissues, in the bodies of animals and humans. They live where they find enough food, moisture and favorable temperatures (10-40 ° C). Most of them require oxygen. There are also bacteria that live in hot springs (with a temperature of 60-90 ° C), extremely salty bodies of water, in volcanic vents, deep in the oceans where sunlight does not penetrate. Even in the coldest regions (Antarctica) and on the highest mountain peaks, bacteria live.

Found in different places different quantity bacteria. There are fewer of them in the air, especially in natural conditions. And in crowded places, such as cinemas, train stations, and classrooms, there are much more of them. Therefore, it is necessary to ventilate the premises frequently.

In river waters, especially near large cities, there can be a lot of bacteria - up to several hundred thousand per 1 mm3. Therefore, you should not drink raw water from open reservoirs. There are a lot of bacteria in the water of the seas and oceans.

There are even more bacteria in the soil - up to 100 million per 1 g of humus (fertile soil layer).

Bacteria are very small organisms. The largest bacteria can be seen under a light microscope.

To get to know the smallest ones, an electron microscope is required (Fig. 7).

Most of the bacteria that inhabit our home and our body are in the form of balls, sticks and spirals. Spherical bacteria are called cocci, rod-shaped bacteria are called bacilli, and spiral-shaped bacteria are called spirilla (Fig. 9). Some bacteria form chains, located close to each other.

Consider the structure of a bacterial cell in Figure 10. It includes cytoplasm, surrounded by a cytoplasmic membrane and a cell membrane (cell wall). The shell gives the bacterium a certain shape and serves as protection from unfavorable conditions.

Additional protection for many bacteria will be provided by the mucus layer located on the outside of the shell. The surface of the bacterial cell is covered with numerous villi, which are hollow outgrowths of the cytoplasmic membrane. Some bacteria have one or more filamentous flagella.

The main difference between bacteria is the absence of a nucleus, i.e. they are prokaryotes.

It is on this basis that they are separated into a separate kingdom. The nuclear material of bacteria is the bacterial chromosome: it carries hereditary information.

Most bacteria are heterotrophs. They consume ready-made organic substances. Their food is living and dead organisms, human food products, wastewater, etc.

Saprotrophs

Some heterotrophic bacteria use organic substances of the dead bodies or secretions of living organisms. These are saprotrophs (from the Greek sapros - rotten and trophos - nutrition).

There are also autotrophic bacteria. They are capable of forming organic matter from inorganic (carbon dioxide, water, hydrogen sulfide, etc.). Autotrophic photosynthetic bacteria have bacterial chlorophyll in their cells, with which they form organic substances under the influence of solar energy.

Cyanobacteria

An example of autotrophic bacteria is cyanobacteria. They make their own food from carbon dioxide and water when exposed to sunlight. At the same time, they release oxygen, enriching their habitat.

Bacteria reproduce by division. In this case, from one mother cell two are formed daughter cells, similar to the mother's. At favorable conditions(sufficient nutrition, humidity and temperature from 10 to 30 ° C) bacteria can divide every 20-30 minutes, so their number increases very quickly. Material from the site

If bacteria are cultivated (grown) on a nutrient medium under favorable conditions, they multiply very quickly and form colonies of up to 4 billion cells. Colonies of bacteria of certain species have characteristic outlines and colors (Fig. 8). By the type of colonies, you can determine the presence of certain bacteria in a particular material.

Some bacteria move using flagella. The base of the flagellum rotates, and it seems to be screwed into the medium, ensuring the movement of the bacterium. Most bacteria move passively: some with the help of air currents, others with the flow of water. This is how they are distributed.

IN unfavorable conditions(with a lack of poverty, moisture, sharp temperature fluctuations) bacteria can turn into spores. The cytoplasm near the bacterial chromosome becomes denser. A very strong shell is formed around it. Spores formed in this way can exist for hundreds of years (Fig. 11).

Bacteria are unicellular, nuclear-free microorganisms belonging to the class of prokaryotes. To date, there are more than 10 thousand studied species (it is assumed that there are about a million of them), many of them are pathogenic and can cause various diseases in humans, animals and plants.

For their reproduction, a sufficient amount of oxygen and optimal humidity are required. The sizes of bacteria vary from tenths of a micron to several microns; according to their shape, they are divided into spherical (cocci), rod-shaped, filamentous (spirilla), and in the form of curved rods (vibrios).

The first organisms that appeared billions of years ago

(Bacteria and microbes under a microscope)

Bacteria play a very important role on our planet, being an important participant in any biological cycle of substances, the basis for the existence of all life on Earth. Most of both organic and inorganic compounds change significantly under the influence of bacteria. Bacteria, which appeared on our planet more than 3.5 billion years ago, stood at the original sources of the living shell of the planet and are still actively processing non-living and living organic matter and involving the results of the metabolic process in the biological cycle.

(Structure of a bacterium)

Saprophytic soil bacteria play a huge role in the soil-forming process; they process the remains of plant and animal organisms and help in the formation of humus and humus, which increase its fertility. The most important role in the process of increasing soil fertility is played by nitrogen-fixing nodule symbiont bacteria that “live” on the roots leguminous plants, thanks to them, the soil is enriched with valuable nitrogen compounds necessary for plant growth. They capture nitrogen from the air, bind it and create compounds in a form available to plants.

The importance of bacteria in the cycle of substances in nature

Bacteria have excellent sanitary qualities; they remove dirt from waste water ah, they break down organic substances, turning them into harmless inorganics. Unique cyanobacteria, which originated in the pristine seas and oceans 2 billion years ago, were capable of photosynthesis, they supplied molecular oxygen to the environment, and thus formed the Earth's atmosphere and created ozone layer protecting our planet from harmful influences ultraviolet rays. Many minerals were created over many thousands of years by the action of air, temperature, water and bacteria on the biomass.

Bacteria are the most common organisms on Earth; they define the upper and lower boundaries of the biosphere, penetrate everywhere and are distinguished by great endurance. If there were no bacteria, dead animals and plants would not be processed further, but would simply accumulate in huge quantities; without them, the biological cycle would become impossible, and substances would not be able to return to nature again.

Bacteria are an important link in trophic food chains; they act as decomposers, decomposing the remains of dead animals and plants, thereby cleansing the Earth. Many bacteria play the role of symbionts in the body of mammals and help them decompose fiber, which they are not able to digest. The life process of bacteria is a source of vitamin K and B vitamins, which play an important role in the normal functioning of their organisms.

Beneficial and harmful bacteria

Large quantity pathogenic bacteria can cause enormous harm to the health of humans, domestic animals and cultivated plants, namely, cause such infectious diseases such as dysentery, tuberculosis, cholera, bronchitis, brucellosis and anthrax (animals), bacteriosis (plants).

There are bacteria that bring humans and their economic activity benefit. People have learned to use bacteria for industrial production, producing acetone, ethyl and butyl alcohol, acetic acid, enzymes, hormones, vitamins, antibiotics, protein and vitamin preparations. The cleaning power of bacteria is used in water treatment plants, to treat wastewater and convert organic matter into harmless inorganic substances. Modern achievements genetic engineers made it possible to obtain such medicines such as insulin, interferon from the bacterium Escherichia coli, feed and food protein from some bacteria. IN agriculture They use special bacterial fertilizers; farmers also use bacteria to fight various weeds and harmful insects.

(Bacteria favorite dish ciliates slippers)

Bacteria are involved in the process of tanning leather, drying tobacco leaves, with their help they produce silk, rubber, cocoa, coffee, soak hemp, flax, and leach metals. They are involved in the manufacturing process of drugs, such powerful antibiotics as tetracycline and streptomycin. Without lactic acid bacteria, which cause the fermentation process, the process of preparing such dairy products as yogurt, fermented baked milk, acidophilus, sour cream, butter, kefir, yogurt, cottage cheese is impossible. Lactic acid bacteria are also involved in the process of pickling cucumbers, sauerkraut, and ensiling feed.