Hygiene rules against bacteria and viruses. Microbes around us Knowing about the existence of invisible bacteria, it is important to observe

Every day a person comes into contact with billions of creatures invisible to the eye: viruses and bacteria. Some of them are useful or harmless, but most cause the development of dangerous diseases: intestinal disorders, infectious inflammations, colds.

Microorganisms become more active with the onset of the warm season: moist air and high air temperatures create favorable conditions for their rapid reproduction. Therefore, in the summer, cases of respiratory diseases and gastrointestinal tract infections and dysbacteriosis become more frequent.

An additional risk factor is failure to comply with basic hygiene rules. In the office and at home, we often don’t think about the fact that we are surrounded by germs, which, when entering the body through food and drink, can cause illness.

The main dangers of the office

The famous microbiologist, professor at the University of Arizona, Charles Gerb conducted an interesting study in which he examined typical American and European offices for the presence of pathogenic bacteria. Before the experiment, it was believed that public toilets would be the most contaminated places. But most microorganisms were found on:

• computer keyboards;
• telephone handsets;
• washbasins and taps.

The number of pathogenic microorganisms on objects increased sharply if the equipment was used not by one person, but by two or more. If the average number of bacteria per square inch in the office was about 20 thousand, then on keyboards this number exceeded 26 thousand. Moreover, the researchers considered it to be dangerous pathogens, and not harmless saprophytes.

It was found that 400 times more microorganisms live on smartphones than under the rim of a toilet bowl. Large colonies of microorganisms that can cause conjunctivitis, sore throat, and dermatitis were found on sinks and taps: in places where tap water constantly accumulates.

According to the expert opinion of Charles Gerb, the dirtiest jobs are those of cashiers and bank tellers, as well as school and university teachers and doctors.

Infectious hazards in public places

Most often, infection with intestinal infections occurs through contact and household contact through shared utensils, household items, or simply by shaking hands with a person who has neglected the rules of hygiene. The most pathogenic bacteria can be found:

• in public toilets, but not on toilets or washbasins, but on door handles. Slightly fewer microorganisms accumulate on faucet valves and flush buttons;
• on the handles of pay phones;
• on handrails of public transport.

The study helped dispel some popular myths: it turned out that relatively small amounts of bacteria and viruses live on elevator buttons and store handles, and their concentration does not exceed the norm. Much more microorganisms accumulate on horizontal damp surfaces: for example, under dripping air conditioner.

"Golden" rules of hygiene

Hygiene habits are formed in childhood. But parents have opposing opinions about the conditions in which the child should be kept. Someone preaches the theory of “useful dirt” and does not want to put children in a “greenhouse”. This approach is half justified: constant contact with microorganisms really accelerates the formation of a healthy immune system. But neglect of cleanliness also leads to regular poisoning.

The second extreme is morbid cleanliness. Regular use of antibacterial cleaning products disrupts the natural microflora, consisting of microorganisms beneficial to humans. As a result, the immune system is not formed, and a person, taken out of “sterile” conditions, quickly falls ill.

The “golden mean” is following simple rules of personal hygiene: mandatory hand washing after visiting the toilet, upon returning from the street, before eating and preparing food. This is enough to wash away viruses and bacteria from the surface of the skin and reduce the risk of contracting a cold or intestinal disorder.

What microbes live nearby?

Infectious disease specialists found the highest concentration of the following microorganisms in apartments and offices:

• Escherichia coli: pathogenic strains cause gastrointestinal disorders, colpitis, peritonitis, and disrupt normal development in infancy.
• Klebsiella pneumonia: provokes diseases of the respiratory tract and genitourinary system.
• Salmonella: the main causative agent of typhoid fever, salmonellosis.
• Streptococci: a large genus of bacteria that can live in almost any human organs and tissues, disrupting their function and leading to acute inflammation.
• Staphylococcus aureus: causes systemic infections, including general blood poisoning (sepsis).

Viruses also live in the environment. The most dangerous and common is the rotovirus, which provokes a disease called “stomach flu” and is characterized by fever, nausea, and gastrointestinal upset. Also, hepatitis viruses A and E, which infect the liver, remain viable for a long time in the external environment.

To reduce contact with pathogens and protect yourself and your family, hygienists recommend changing your approach to washing. For example, sort clothes not only by color and fabric, but also take into account what pathogenic bacteria and in what quantities can live on them:

• do not wash underwear and bed linen together with table linen (tablecloths, towels, napkins);
• do not put used handkerchiefs in the clothes basket (or choose disposable paper handkerchiefs rather than textile ones);
• after the illness of one of the family members, the things of the already recovered person must be washed separately from the others at a high temperature (not lower than 60°C). After washing, iron the items.

One of the most effective ways to protect yourself from harmful microorganisms and bacteria is to use special isoseptics. Nika-Isoseptic is suitable for express disinfection of all surfaces. It comes in two packaging options:

• 0.75 l - suitable for cleaning the workplace or apartment;
• 0.1 l - a convenient format for carrying with you and disinfecting pens, washbasins in public places, as well as handrails in transport.

The disinfectant quickly destroys germs and viruses and is completely safe for humans; upon contact with the skin, it does not dry it out or cause irritation.

Test yourself by completing the suggested tasks (at the teacher's discretion - in class or at home).

1. Life on the modern planet is diverse and represented by several kingdoms.

Answer: plants, animals, fungi, bacteria.

2. The kingdom of bacteria unites living organisms that have common characteristics: they consist of

Answer: one cell

- in a cage

Answer: there is no clearly defined core

- very small organisms, visible

Answer: only through a microscope

- meet

Answer: in all habitats

3. Bacteria have all the signs of life. They breathe

Answer: they feed, excrete the products of their vital activity, i.e. carry out metabolism, reproduce, adapt to environmental conditions.

4. They are able to live in the presence of oxygen

Answer: bacteria - aerobes,

and in an oxygen-free environment

Answer: bacteria are anaerobes

5. Even in everyday life, it is important for a person to know about the existence of anaerobic bacteria, since

Answer: the absence of atmospheric oxygen is a favorable environment for their development. Anaerobe bacteria are dangerous to humans, so preserving a jar of mushrooms at home can result in poisoning.

6. In industry, bacteria are used to produce fermented milk products, for example

Answer: kefir, sour cream, cheeses.

7. Most bacteria are heterotrophs, i.e. used for nutrition

Answer: ready-made organic substances.

Among them there are saprotrophs that use

Answer: organic matter from dead bodies; Bacteria inhabit living organisms

8. In the process of metabolism, bacteria not only consume ready-made organic substances, but also release waste products into the environment. This feature of bacteria is used in biotechnology, producing

Answer: antibiotics, vitamins, proteins.

9. Bacteria multiply by

Answer: cell division into two parts. The high rate of bacterial reproduction is especially dangerous in the case of the proliferation of pathogenic bacteria, for example Answer: dysentery bacteria.

10. Knowing about the existence of “invisible bacteria”, it is important to follow the rules of hygiene

Answer: wash your hands and body, brush your teeth, keep your clothes clean, do not drink water from untested sources, fight flies, wear gloves when working in the garden, cover your coughs and sneezes with a tissue.

11. In case of simple injuries, it is necessary to know first aid techniques. Test yourself by naming these techniques.

Answer: the wound on the body must be treated with hydrogen peroxide and bandaged.

12. Having mastered all habitats, bacteria play a large role in the life of the modern planet.

Answer: They convert organic matter from fallen leaves, dying plants, and dead animals into minerals and return them to the soil solution, participating in the cycle of substances.

Topic: “Bacteria living around us”

TABLE OF CONTENTS

INTRODUCTION…………………………………………………………………………………1

INFORMATION ABOUT VARIETIES OF BACTERIA……………………………………………………2-5

EXPERIMENTS ON REPRODUCTING BACTERIA AT HOME CONDITIONS………………..6

CONCLUSION………………………………………………………………………………..7

LITERATURE………………………………………………………………………………...8

Introduction: Bacteria play a very important role in the living world. Bacteria were one of the first species to appear on Earth (they appeared approximately 4 trillion years ago), and it is more than likely that they will outlive us humans. Despite their enormous diversity and the fact that they are found almost everywhere on Earth - on the ocean floor, and even in our intestines - bacteria still have something in common. All bacteria are approximately the same size (several micrometers)

Target: study of bacteria living in the human body and the reproduction of bacteria at home.

Tasks:

Find out what bacteria are.

Conduct experiments on the growth of bacteria at home.

Analyze information about bacteria.

Object of study- bacteria.

Subject of study– the importance of bacteria for humans.

Working methods: experiments, observations, analysis of relevant literature.

Relevance: the world of bacteria is part of our life.

I once asked my parents a question, why do people get sick? Mom said that bacteria enter the body and the person gets sick. And then I started thinking, what are bacteria, where do they live, how do they reproduce and how are they dangerous? And are all bacteria harmful?

Hypothesis: I want to suggest that many bacteria live in the human body, they can be both beneficial and harmful. And also that bacteria can be multiplied at home.

What are bacteria?

Microbes are very diverse. The best known of these are bacteria. So, bacteria are microorganisms that can only be seen under a microscope. A bacterium consists of only one cell and has properties of both animals and plants. There are about 2000 species of bacteria, and they live everywhere: in the mouth, nose, and intestines of all living creatures, including humans. Others live in fallen leaves, dead trees, and the remains of dead animals. Bacteria live everywhere.

Their shape is varied: balls, commas, sticks, some have flagella. Bacteria reproduce by division.

Each type of bacteria has its own specific shape.

I decided to study in more detail the bacteria that live in the human body. By researching bacteria, I learned that they are good and bad. And now I will tell you about some types.

1. Lactobacilli

ABOUT provides control in our insides

Lactobacilli, live in the human digestive tract since prehistoric times, doing a great and important job. Like vampire garlic, they repel pathogenic bacteria, preventing them from settling in our stomach and causing intestines to become upset. Pickled cucumbers and tomatoes, sauerkraut will strengthen the strength of the bouncers.

2. BElly PROTECTOR

ABOUT have hunger pangs at 3 pm

This is another bacteria that lives in the digestive tract, develops from our childhood and helps maintain a healthy weight throughout life by controlling the hormones responsible for hunger! You need to eat 1 apple every day. These fruits produce lactic acid in the stomach, in which most harmful bacteria cannot survive.

3. GOLOVOCHES

Loves showers, hot baths and pools

The bacterium, which lives in warm water, enters the scalp through the pores of the hair follicles, causing an infection accompanied by itching and pain in the affected areas.

Don't want to wear a swim cap every time you take a bath? Fend off the carder's invasion with a chicken or salmon sandwich and eggs.

4. Harmful bacteria

Harmful bacteria can lurk in the most unexpected places. They can cause rashes and love to live on the touch panels of phones and tablet computers. Many companies produce cases for phones and tablets with antibacterial coating, which is guaranteed to stop the growth of bacteria.

5. NOBLE RASSAL

Good and bad bacteria

E That bacterium is believed to cause tens of thousands of infectious diseases every year. But it only gives us problems when it finds a way to leave the colon. Normally, it is quite useful for life and provides the body with vitamin K, which supports heart health.

6. BURNING

P eats away the youth of our skin

Most often, acne is caused by this bacterium, which lives on the skin of most people. Acne is, of course, unpleasant, but, having penetrated through damaged skin into the body, this bacterium can cause more serious diseases: pneumonia and meningitis.

A natural antibiotic that is toxic to these bacteria is found in human sweat. Therefore, it is necessary to include high-intensity exercises in your workout at least once a week, and always use a clean towel.

7. MICROBE – GLUTTER

® Lives in fermented milk products

Bacteria inhabit the contents of jars of yogurt, bottles of kefir, yogurt, fermented baked milk and other similar products. And these products become very useful.

This is what some bacteria look like under a microscope in computer processing

Ciliated bacteria On human skin In the stomach

Cause of pneumonia In the intestines Floating bacteria

While studying bacteria, I simultaneously became creative; I drew, sculpted, painted, and embroidered them. This is how I learned even more about these mysterious microorganisms. My classmates also became interested in this topic and completed various creative works.

Here are our works:

All over the world, much attention is paid to these microorganisms:

Documentary videos are being filmed that talk about the dangers and benefits of bacteria;

Educational and developmental video for children;

Interactive and computer games are created.

Masyanya and bacteria

Lessons in caution

Interactive game on the floor (catch the bacteria) Interactive game on the glass

(catch the bacteria)

Computer game “Escape from a Test Tube”

While studying this topic, I concluded that humans serve as a haven for a wide variety of microorganisms and bacteria, most of which can become the culprits of deadly diseases. But some of these tiny creatures benefit the body.

So what is the role of beneficial bacteria in our body?

With their help, vitamins are absorbed into the body.

They suppress the activity of putrefactive substances that cause toxicity in the body.

Strengthen immunity.

Prevent the penetration of pathogenic bacteria through the mucous membrane.

Normalize the composition of the blood.

Helps improve metabolism.

And now I want to talk about fermented milk products, in which beneficial bacteria multiply - gluttons, which provide digestion functions.

I conducted a survey among students in class 4A of school No. 5, in which 30 people took part. It contained the following questions:

1. Do you use fermented milk products in your food?

-Yes

-No

2. If yes, why?

-Tasty

-Healthy

-Available

3. What fermented milk products do you prefer? Why?

4. Do you read the description of this fermented milk product on the packaging?

-Yes

-No

5. Do you know about the existence of beneficial bacteria in fermented milk products?

-Yes

-No

As a result of the survey, it was found that fermented milk products are popular.

Almost all classmates use fermented milk products for food

Most people use it because it's delicious.

I mostly prefer yoghurts

But when asked whether you read the product description or not, most students do not.

It turned out that almost everyone does not know about the existence of beneficial bacteria in fermented milk products.

Thus, it turned out that my classmates liked lactic acid products. The most popular are yoghurts because they like their taste.

It turns out that if fermented milk products contain beneficial bacteria, then such products as yogurt, kefir, fermented baked milk, and cottage cheese are healthy.

And you don't have to have a microscope to see bacteria. Try to find them yourself right in your kitchen.

To propagate bacteria at home, I conducted several experiments:

1 experiment:

I took raw milk. I put it in a warm place and left it for several days, it changed its appearance - lumps appeared in it, clear liquid exfoliated from the top, and the milk began to emit a sour smell. So they say that “the milk has turned sour.” This happened due to the fact that milk always contains some bacteria of a certain type - lactic acid. In a warm environment they begin to multiply quickly. An adult bacterium divides into two completely identical ones, which immediately begin to grow, and when they grow to adulthood, they divide again. From one bacterium two are obtained, from these two - four, from four - eight, etc. And within a few days, millions of them settle in our milk! They all live, move, reproduce. As a result of their activity, the fermentation process begins in milk and a lot of lactic acid appears in it. This is what we are seeing.

Experiment 2:

You can speed up the process of milk souring. To do this, you can add a little sour milk, a piece of cottage cheese, or a little homemade sour cream to fresh milk. Lactic acid bacteria, which are found in sour milk or cottage cheese, will begin to multiply and fresh milk will quickly turn sour.

I also decided to monitor changes during the milk souring process. To carry it out, I decided to use a specially equipped digital laboratory “Archimedes”, which includes a data logger, a special sensor, a connecting wire and a thermos with a capacity of 1 liter and a personal computer.

I heated 750 ml of milk and cooled it to room temperature. I poured milk into a thermos. I immersed the sensor electrode in the milk and closed the thermos with a lid so as not to damage the electrode cable passing through the stopper. The Multilab program is pre-installed on the computer. And she started recording data. The readings were displayed on the screen in the form of a graph. After 30 hours I stopped registration. The graph shows that as the number of bacteria increases, the graph line changes.

Conclusion: So, my guess was confirmed. Many bacteria live in the human body, they can be both beneficial and harmful. And also that bacteria can be multiplied at home.

And I would like to give everyone advice. Since bacteria are the cause of many diseases and in order to prevent this, you need to strengthen your immune system, and for this you need to lead a healthy lifestyle, watch your diet, follow a daily routine, exercise, and not have harmful.

Literature.

Big book of QUESTIONS and ANSWERS

"WHAT? FOR WHAT? WHY?".

Computer encyclopedia - Smart Guys

"Exploring the Planet."

FirmMir website - http://farmamir.ru/2011/11/vidy-bakterij-xoroshie-i-ploxie-2/ http://forexaw.com

Ivanova Alena

We often hear: “Wash your hands before eating! Don't bite your nails! Eat only clean fruits and vegetables!” Why? I wondered what would happen if you didn’t follow all these rules? Mom answered this question briefly: “You might get sick.”

What could be the cause of the disease?

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Preview:

Municipal basic educational institution "Ust-Abakan Secondary Educational School"

Section name:Natural science direction

Medicine and Health

Research

Topic: “Microbes are invisible”

Ivanova Alena, 5th grade,

MBOU "Ust-Abakan Secondary School"

Supervisor:

Krytsina Marina Viktorovna,

Teacher MBOU "Ust-Abakan Secondary School"

Ust-Abakan village

2015

1 Introduction……………………………………………………….2

1.1 Hypothesis……………..………………………………………………………2

1.2 Purpose of work, tasks…………………………………………….3

2 Main part……………………………………………………………...4

2.1 Discovery of microbes……………………………………………..4

2.2 Habitats of microbes……………………………………...4

2.3 Nutrition of microorganisms……………………………………..5

2.4 Microbes and humans……………………………………………..5

2.5 Methods of protection against harmful microbes……………………....6

3 Research part…………………………………….....7

4 Conclusion….……………………………………………………………...8

5 Appendix…….………………………………………………………………..9

6 References…………………………………………………………….11

Introduction

We often hear: “Wash your hands before eating! Don't bite your nails! Eat only clean fruits and vegetables!” Why? I wondered what would happen if you didn’t follow all these rules? Mom answered this question briefly: “You might get sick.”

What could be the cause of the disease? It turns out that the disease can be caused by microbes that are on dirty hands, under nails, and on unwashed fruit. They surround us everywhere - in the air, in the water, in the soil. These tiny creatures live not only on our skin, but also inside us. Who are they - microbes that play such an important role in our lives, but remain invisible to us?When we started talking about bacteria in an environmental lesson, I became interested, and I asked my mother to help me get acquainted with the mysterious world of microorganisms.

Hypothesis : Microbes really exist and you can see them with your own eyes.

Goal of the work:

1. Get to know microbes and their habitats

2. Find out what impact microbes have on human life

3. See microbes with your own eyes and show them to your classmates

In my work I set myself the following tasks:

1. Study the available literature about microbes

2. Conduct a study of microbes and see them under a microscope

3. Find out how you can protect yourself from pathogenic bacteria

2 Main part

Microbes, or also called microorganisms, are the smallest single-celled creatures, visible only through a microscope at a magnification of 300-500 times. There are a great many types of microbes that play a large role in the cycle of substances in nature. The science that studies them is called microbiology. Scientists believe that microorganisms play an indispensable role in ensuring the life of all plants and animals on earth, and the complete disappearance of microbes will cause the death of all life on our planet in four days.

2.1 Discovery of microbes

Since ancient times, people, not yet knowing about the existence of microbes, have widely used them to prepare kumis, yogurt and other fermented milk products, to produce wine, beer, vinegar, and kvass. Insightful minds expressed vague guesses about the existence of some tiny invisible carriers of diseases. Anthony van Leeuwenhoek, who lived in Holland in the 17th century, was lucky enough to be the first to lift the curtain into the previously unknown world of microorganisms. Even in his youth, he learned to make magnifying glasses and achieved high skill in this matter. His microscope magnified 250-300 times. This allowed Leeuwenhoek to see microbes

2.2 Microbial habitats

Almost three centuries have passed since then. Microbiology expanded and clarified the facts collected by the Dutch scientist. Microbiologists of our day have proven that there is not a single corner of the globe where microorganisms are not found. They are found in the depths of the world's oceans, in the upper layers of the atmosphere, in the soil, on all objects around us, in houses, on the street, in polar ice and hot deserts. Scientists are already launching microbes into space, observing the development of microorganisms in zero gravity.

2.3 Nutrition of microorganisms

Most microbes feed on proteins, fats and carbohydrates. Some of them, when they get on products, decompose them, as a result of which the appearance, taste, and smell of the products deteriorate. Microbes living in water, on the surface and inside living organisms, take nutrients from their environment.

2.4 Microbes and humans

Hundreds of species of bacteria constantly live inside the human body, making up the normal or beneficial human microflora. There are up to 400 species in the gastrointestinal tract alone. There are a lot of them in the mouth and nose, in the throat. Tooth decay is also the result of the harmful effects of microbes. Microorganisms living inside a person make up about three kilograms of the weight of an adult. The skin and mucous membranes are literally teeming with microorganisms, most of them are beneficial, but there are also pathogenic ones.

Beneficial microbes - bifidobacteria, lactobacilli, bacteroides and E. coli. These microbes are the first inhabitants of our intestines and begin to populate it immediately after the birth of a child. Beneficial microbes are involved in digestion, help produce and absorb B vitamins, protect against allergies, increase immunity and resistance to infections. They also protect a person from his enemies - harmful microbes. As soon as for some reason the number of beneficial microbes decreases (for example, taking antibiotics), “power” immediately passes to harmful microbes, and dysbiosis develops in the intestines.

Unfortunately, there are quite a lot of pathogenic microbes. They make a person’s life very difficult, and sometimes take it away. For example, a boy has a scratch on his hand. He was too lazy to lubricate it with iodine or brilliant green and seal it with a band-aid. Germs got into the open wound. After a few days, a purulent wound forms on the arm. And only a surgeon’s knife will prevent dangerous consequences.

Microbes harm not only human health. Pathogens of animal and plant diseases spread through the air. Microorganisms, together with dust, settle on food products, cause milk to sour, and spoil meat, fish, and butter.

2.5 Ways to protect yourself from harmful microbes

People get sick. They need to know why they get sick, what they themselves can do to avoid getting sick or to make themselves feel better during illness, to speed up the recovery process. First of all, follow the rules of hygiene. Wash your hands before eating, after visiting the toilet, and returning from a walk. You cannot put foreign objects in your mouth: pens, pencils, rulers, sticks on the street, blades of grass. Always wash fruit before eating, even if it appears clean. Do not drink unboiled water from the tap or river. It's also full of germs. Flies, cockroaches, mice, and rats can be carriers of various infections. You need to carefully ensure that they do not settle in your home. On the street and in the forest there are ticks that carry encephalitis, as well as animals with rabies. Beware of their bites.

To successfully fight germs, you need to lead a healthy lifestyle and follow some rules. You wash your hands at least ten times every day. And you do this automatically, understanding that this precaution against exposure to pathogens is necessary. This understanding is instilled from early childhood as a necessary element of the culture of daily life. Thanks to such education, each person and the entire society protect themselves from epidemics of dysentery, cholera, etc. So, despite the billions of unfriendly microbes surrounding us, being healthy is very simple!

• You just need to harden your body
• Do physical exercise and sports
• Eat properly
• Maintain good hygiene at all times and everywhere
• Lead a healthy lifestyle

3 Research part

To finally see real microbes, my mother and I went to a bacteriological laboratory. There they told me that to do this, microorganisms must first be grown. We were given special containers for growing bacteria - Petri dishes filled with a special nutrient medium for bacteria, on which they reproduce well. These Petri dishes were sterile, that is, there were no microbes in them, since they were processed in a special apparatus - an autoclave.

Early in the morning before school started, when all my classmates had just arrived at school, we conducted an experiment. We divided each Petri dish into sections and numbered them. For each section, my classmates made an index fingerprint. After that, everyone washed their hands very thoroughly with soap and made a fingerprint again in the Petri dish.

Next, we tightly closed all the dishes and took them to the bacteriological laboratory. In the laboratory they were placed in a thermostat - this is a special equipment that maintains a constant temperature of 37 degrees, at which bacteria multiply well. The next day we took the cups and were very surprised to see that in the cups, in place of the fingerprints, different spots appeared - these were colonies of microorganisms that live on our fingers (see Figure 1 in the appendix). The results we found were that the cups with fingerprints before hand-washing appeared to have more germs than the cups with fingerprints after washing. We performed colony counts on fingerprinted Petri dishes before and after hand washing. I entered the results into a table (see Table 1 in the Appendix):

The table shows that germs live on everyone's hands, even when they are not visible. After hand washing, the number of colonies in the plates decreased significantly - by an average of 41%. If you look at the difference between boys and girls, you can see that the average number of colonies for boys was 38, and for girls 44, that is, our boys’ hands are cleaner than those of girls.

Next, from the colonies grown on Petri dishes, preparations were prepared for us in the bacteriological laboratory - these are glasses on which microorganisms that were previously killed and stained with special dyes were applied. We brought these glasses to class and looked at the microbes that live on our hands under a microscope. They looked like small pink dots and sticks (see Figure 2 in the appendix).

Conclusion

Thus, my hypothesis that microbes really exist and can be seen with one’s own eyes was confirmed. The goals of my research were achieved - I studied the literature about microorganisms and learned a lot of new and interesting things about microbes. I saw them with my own eyes in a microscope and showed them to my classmates! The kids in my class learned how important it is to maintain hygiene!

Application

Picture 1

Petri dishes with colonies of microorganisms before and after hand washing

Figure 2

This is what the microbes that live on our hands look like

Table Number of colonies of microorganisms in subjects

before and after washing hands

Bibliography

1. Large children's illustrated encyclopedia. Moscow. Egmont Russia LTD. 2001

2. Large illustrated encyclopedia of the erudite. Moscow. Swallowtail. 2004

3. www.corporacioa.ru

4. www.vofka.com

5. hppt.courtesyphoto.euа.

1. How did a person learn about the existence of microbes?

We cannot see germs with the naked eye. It depends on the structure of the human eye itself. The human eye cannot distinguish objects that are smaller than one tenth of a millimeter. Anything less than this value is inaccessible to the sharpest human eye. And the size of the vast majority of microbes is measured not in tenths, but in hundredths, thousandths and even ten-thousandths of a millimeter. It is no wonder that microbes remained invisible until the period of development of the productive forces of human society, until people mastered the technique of making magnifying glasses. Only the invention of optical microscopes allowed man to look into a previously unknown world of quantities.

The first person to reliably see microbes and inform people about their existence was Anton Leeuwenhoek, a Dutchman who lived at the end of the 17th - beginning of the 18th century. He was not a professional scientist; a cloth merchant, then a watchman at the courthouse, in his spare time he was fond of making magnifying glasses and achieved perfection in this art. Its glasses, the size of a pinhead, were magnified up to 200 times. Leeuwenhoek was distinguished by his curiosity and extreme persistence in his scientific research. He examined a wide variety of bodies through his magnifying glasses, described and sketched the results of his observations. Examining through his magnifying glasses drops of rainwater from a barrel, a rotten tincture of hay, he observed a huge number of some tiny bodies, animatedly moving in the drop. “I examined,” writes Leeuwenhoek, “the mucus that lies between the teeth of a person, and I saw, to my great surprise, that in the mucus there were tiny creatures that were distinguished by extraordinary mobility.” The main thing that struck him was the countless number of these creatures. “In the entire United Kingdom (i.e., Holland) there are not as many inhabitants as there are living animals in my own mouth,” Leeuwenhoek wrote.

Leeuwenhoek combined all his observations in the book “Secrets of Nature, Discovered with the Help of a Microscope,” which he published in Latin in 1695. In the copies of this book that have survived to this day, there are images and descriptions of these “little animals”, in which you can easily recognize not only large, but also the smallest creatures visible in optical microscopes - bacteria.

Thus, for the first time, microbes were discovered by a simple person, a self-taught scientist, who later turned out to be representatives of the most common living creatures on our planet.

Leeuwenhoek's discoveries interested not only scientists, but also many curious people of that time. Peter I was the first Russian person to personally become acquainted with the works of the famous Dutchman. According to eyewitness accounts, Peter, while in Holland in the spring of 1698, invited Leeuwenhoek to his yacht and spent 2 hours examining microscopic objects through magnifying glasses.

Peter perfectly understood the importance of the microscope and microscopic research for the knowledge of nature, and on his initiative, in 1724 in St. Petersburg, the mechanic-designer of machines and machine tools Andrei Nartov (1683–1756) drew up a project for organizing workshops at the Academy of Sciences, which were supposed to produce and optical instruments.

In 1726, mirror master Ivan Eliseevich Belyaev was enrolled in the workshops, whose “salary was determined to be 4 rubles per month, and a uniform for three years.” Ivan Belyaev was the founder of a famous family of remarkable Russian opticians who manufactured excellent microscopes in Russia, in no way inferior to the best foreign models. These microscopes (Fig. 1) were used by the first Russian academicians and many Russian people interested in science. The first president of the Russian Academy of Sciences, Lavrenty Blumentrost, and the famous public figure, Archbishop of Novgorod Feofan Prokopovich, also worked with Belyaev microscopes. Mikhail Vasilyevich Lomonosov, the luminary of Russian science, subsequently worked with the same microscopes made by Ivan Eliseevich’s son, Ivan Ivanovich Belyaev.

Rice. 1. A “solar” type microscope for projecting microscopic objects onto the screen of the Russian master I. E. Belyaev

Russian science, created by M.V. Lomonosov (Fig. 2), also owes him the widespread introduction of the microscope as an instrument of scientific research. Lomonosov was the first Russian scientist to systematically use a microscope in his scientific work. For the first time in the whole world, he used a microscope for chemical research. Throughout his life, Lomonosov widely popularized information about the microscope and microscopic discoveries in Russia, devoting to them not only his lectures and scientific works, but even poetic works. In his poem “Letter on the Benefits of Glass,” Lomonosov wrote the following about the microscope:

Having added to the growth of things, if we need it,

Shows herbal analysis and medical knowledge.

Since the microscope has revealed many secrets to us,

Invisible particles and subtle veins in the body!

We even owe the very term “microscope” instead of the ancient “microscope” and “microscopy” to the brilliant Russian scientist.

Rice. 2. Mikhail Vasilievich Lomonosov

Remarkable Russian optical masters of the 18th century made many improvements in the designs of contemporary microscopes, often creating new, completely original models that were superior in quality to foreign ones.

Based on the drawings of Academician Euler, in the optical workshops of the Russian Academy of Sciences, an experimental model of an improved “achromatic microscope” was built for the first time, the lenses of which did not produce blurry images characteristic of microscopes of that time. In achromatic lenses, the so-called chromatic aberration was eliminated, i.e., distortions resulting in the image of an object due to differences in the refraction of rays of different colors passing through them by lenses.

In addition to I.I. Belyaev, the famous Russian mechanical inventor Ivan Petrovich Kulibin, who was invited to St. Petersburg in 1769 to become the head of academic workshops, also took part in the construction of this microscope (Fig. 3).

Rice. 3. Ivan Petrovich Kulibin

A remarkable self-taught mechanic, a watchmaker from Nizhny Novgorod, without any help or advice, he independently designed it in 1764–1766. telescope, microscope and electric machine, I.P. Kulibin raised the work of the optical workshop to great heights. During his more than thirty years of work in the workshops (until 1801), he, together with I. I. Belyaev and senior master Vasily Vorobyov, built many microscopes and other optical instruments that were excellent for that time.

Thus, already in that distant time, Russian people had in their hands first-class instruments for observing the microscopic world, examined microscopic objects and studied them.

True, it was difficult for scientists of that time to identify the role of microbes in human life. Microscopists of that era did not even imagine that microbes were the causative agents of infectious diseases. Little could be learned about their organization, much less their activities, by examining drops of rotting infusions through imperfect microscopes. Even a hundred years after the discovery of microbes, the famous 18th century scientist Carl Linnaeus could not appreciate the importance of microbes and incorrectly combined all microbes into one biological genus, which he called “chaos.” He wrote that these are “Mysterious... living molecules... which must be understood by descendants.”

In the meantime, terrible epidemics continued to rage throughout all countries. Pestilence (as the plague was then called), smallpox, and cholera claimed thousands of human lives.

Humanity suffered not only from harmful, pathogenic microbes. Throughout human history, harmless microbes have more than once served as a source of popular unrest caused by ignorance and superstition, which were supported by clergy. A special role in this regard was played in the hands of the clergy by a completely harmless bacterium, the metabolic products of which are now used even to treat some diseases - the so-called miraculous blood stick. This rod, when developing on media containing carbohydrates, secretes a red pigment similar to fresh blood.

In ancient chronicles one can find indications of the unexpected appearance of bloody stains on bread, especially on church bread - hosts, stored in damp church premises. These bloody spots represent the culture of the miraculous blood stick that has developed on the surface of the wet bread. The clergy explained this by witchcraft, the evil machinations of witches. Thousands of innocent people suspected of magic were burned at the stake. So the church used popular superstitions to deal with people it did not like.

The same superstitious horror was aroused by another harmless bacterium - the so-called luminous bacterium, which had the ability to secrete substances that slowly decompose with the release of light. Fish, meat carcasses, corpses, and even the sweat and urine of living people, on which this harmless bacterium developed, began to emit a mysterious phosphorescent light, which struck fear into ignorant people.

One of the first people in the world to suggest that microbes are the causative agents of infectious diseases was the talented Russian physician-scientist, who began his remarkable work at the end of the 18th century, Danilo Samoilovich (1744–1805) (Fig. 4). Taking an active part in the fight against the terrible plague epidemic that struck Moscow at the end of 1770, when about a quarter of the city's population died, Samoilovich did not agree with the opinion of the majority of doctors of that time about the non-infectivity of the plague and was convinced that it was caused by a living, microscopically small pathogen. He even tried to look at it through a microscope and in his work on the microscopic study of “ulcerative poison”, published in St. Petersburg in 1792, he wrote: “ulcerative poison... consists of some special and completely excellent creature, which no one knew about before and which has now been studied by me through the most accurate microscopic and other observations.”

Rice. 4. Danilo Samoilovich Samoilovich

It is difficult for us to judge what kind of “excellent creature” this was. It was not, of course, a plague microbe, which Samoilovich could not see with his imperfect microscope, which provided a magnification of 95–190 times. It is important for the history of science that it was the Russian doctor who was one of the first to correctly understand the role of microbes in the occurrence and transmission of infectious diseases. At that time, most Western European scientists were still very far from such progressive views. Almost a whole century passed until Danila Samoilovich’s brilliant guess turned into a coherent doctrine about microbes as causative agents of various processes occurring in nature.

From the end of the 18th and early 19th centuries, biological sciences began to develop, microscope designs were improved, and various microbes were described and systematized. But scientists were still far from understanding the role of these smallest creatures in nature. This was a period of accumulation of knowledge about the structure of microbes, the diversity of their forms, their distribution in nature, but not about their activities. Only in the middle of the 19th century did it become possible to understand Linnaean “chaos” and create the foundations of the doctrine of microbes. As in all other fields of knowledge, the works of Russian scientists Terekhovsky, Lovetsky, Goryainov, Tsenkovsky and many others played a prominent role here. Particularly important in the development of the new science of microbes - microbiology - was the Russian scientist, L. S. Tsenkovsky (1822–1887), who gained worldwide fame with his work (Fig. 5). He can rightfully be called the father and creator of Russian scientific microbiology. Tsenkovsky was the first in Russia to widely use microscopes not only in scientific but also in teaching activities. With his colorful and intelligible lectures, he attracted young people to study this new, diverse world. Being a convinced follower of Darwinism, he was the first to apply evolutionary views to the study of microbes and correctly established the place of microbes among other animal and plant organisms.

Rice. 5. Lev Semenovich Tsenkovsky

A major contribution to the science of microbes was the work of the famous scientist Louis Pasteur (1822–1895) (Fig. 6). In his research, Pasteur was the first to point out the importance of microbial activity in the metabolism of nature. They proved that microbes - fungi, yeast and bacteria - are the causative agents of the processes of decay and fermentation in nature. In addition, they found that different microbes have different biochemical functions. It turned out that each type of fermentation - alcoholic fermentation of grape juice, lactic acid fermentation of milk, acetic acid fermentation of wine - is caused by a special microbe. Pasteur also showed that microbes cannot spontaneously generate in rotting liquids, as scientists of that time thought, but originate from other microbes.

Rice. 6. Louis Pasteur

What Pasteur was able to prove regarding the specificity of fermentative microbes was done by a number of bacteriologists in relation to microbes that cause infectious human diseases. Scientists have found that each of the human infectious diseases they studied is caused by a completely specific microorganism. The German bacteriologist Robert Koch (1843–1910) proved that the causative agent of anthrax is special bacilli that were previously found in the blood of animals that died from anthrax. Koch discovered and described the tuberculosis bacillus, the causative agent of tuberculosis, a disease that was not recognized by many at that time as a contagious disease. He proved that Asiatic cholera is caused by a special vibrio. Scientists have discovered pathogens of other diseases.

A huge role in the development of the most difficult questions of microbiology concerning the nature of the protective forces of humans and animals was played by the great Russian scientist Ilya Ilyich Mechnikov (1845–1916), who created the doctrine of immunity - immunity to infectious diseases.

As a result of these remarkable discoveries, microbiology has become a true science about the structure and activity of the smallest living beings, about the nature of immunity to infectious microbes and ways to combat them.

In a short period of time (80–90s of the last century), many new microbes were discovered - causative agents of infectious diseases and various processes of transformation of substances in nature. It already seemed that with every infectious disease of humans, animals and plants, microorganisms visible under a microscope could be isolated - the causative agents of these diseases. But strangely, for some infectious diseases the causative agent could not be detected. The most thorough searches for microbes that cause diseases such as smallpox, rabies, measles, and influenza have not yielded positive results for a long time. Thousands of preparations from tissues, organs and secretions of patients and dead were examined under a microscope. In the strongest microscopes, with magnification up to 2000 times, it was impossible to see anything resembling a microbe.

It seemed, like a hundred years ago, that humanity was once again faced with the insoluble mystery of the origin of some infectious diseases. Science owes its entirety to Russian scientists for uncovering this secret.

Rice. 7. Nikolai Fedorovich Gamaleya

In 1886, a young Russian doctor, later an honorary academician of the Academy of Sciences of the USSR N.F. Gamaleya (1859–1949) (Fig. 7) studied cattle plague, a contagious disease for which it was also not possible to isolate the microbe. Gamaleya passed the blood of a sick calf through a filter whose pores were so small that they retained the smallest bacteria known at that time. He injected the filtered, bacteria-free blood into the vein of a healthy calf. The calf fell ill with the plague. Thus, Gamaleya was the first in the world to prove that the blood of an animal suffering from plague contains some kind of infectious principle, the particles of which are so small that they are invisible under a microscope and pass through the smallest pores of the filters. Unfortunately, Gamaleya did not continue these studies, and the final proof of the existence in nature of the smallest microbes, invisible in optical microscopes and passing through filters, was made six years later (in 1892) by another Russian botanist D.I. Ivanovsky ( 1864–1920) (Fig. 8).

Rice. 8. Dmitry Iosifovich Ivanovsky

The discovery of D.I. Ivanovsky was made under the following circumstances. In those years in Crimea, tobacco plantations suffered greatly from the so-called tobacco mosaic disease. Having studied this disease on the spot and not finding visible pathogens under a microscope, Ivanovsky squeezed out the juice of the diseased plant, passed it through a filter and infected another healthy plant with the filtered juice. Mosaic spots characteristic of the disease soon appeared on the tobacco leaves (Fig. 9). Having initially assumed that it was not a living pathogen that got into a healthy plant along with the sap, but only its poison, Ivanovsky filtered the sap of this diseased plant and infected the third with it, from the third - the fourth, etc. Ivanovsky expected that with the sequential transfer of the sap, dilution would occur poison and in the end the juice will turn out to be non-infectious. In fact, it turned out to be the opposite: with each dilution, the pathogenic properties of the juice did not weaken, but intensified. In the latter plant the sap turned out to be more infectious than in the first. From this experience, Ivanovsky made an absolutely correct conclusion: in a diseased plant there is a strong proliferation of an invisible tiny microbe.

Rice. 9. Tobacco leaves infected with tobacco mosaic virus

This is how tiny microbes were discovered, not visible in an optical microscope, which do not grow on artificial nutrient media and pass through filter pores that do not allow even the smallest bacteria to pass through.

These tiny microbes have been called filterable viruses or simply viruses.

The Russian botanist D.I. Ivanovsky was the founder of a new branch of the science of microbes - the so-called virology. Five years after Ivanovsky's discovery, scientists described the first filterable virus that causes an infectious disease in animals - foot and mouth disease. Scientists all over the world have now begun studying viruses, and in a relatively short period of time, dozens of different viruses have been found - causative agents of infectious diseases in humans, animals, plants and even bacteria. It was later established that this group of microbes includes the causative agents of smallpox, rabies, encephalitis, influenza, measles, yellow fever and a number of other human diseases. The bulk of infectious plant diseases are also caused by viruses. A bacteriophage, an invisible microbe that dissolves bacteria, also has the properties of a virus.

The discovery of a new group of microbes - filterable viruses - was of enormous practical and scientific importance. Although viruses seemed invisible to researchers until almost 1940 - before the widespread use of the so-called electron microscope, which gave magnification tens of thousands of times - their properties were well understood. Scientists have proven that viruses have a protein composition. It has been proven that they reproduce, change under the influence of changes in living conditions and pass on their properties by inheritance. Precise measurements of the size of viruses have shown that some of them are so small that their sizes do not exceed the size of protein molecules. Thus, it was proven that viruses, while possessing all the properties of life, do not have a cellular structure, like other microbes and protozoa. The most elementary form of existence of living matter turned out to be not a cell, but lumps of living protein.

With the discovery of viruses, our understanding of life has expanded significantly. From the encephalitis virus - a tiny particle with a diameter of one hundred thousandths of a millimeter, to a thirty-meter whale - all these are different forms of the existence of life on our earth.