Fundamentals of ecological microbiology microflora of the body of a healthy person lecture. Normal microflora of the human body and its significance 1 Normal human microflora

1. Normal human microflora

Normal human microflora is a set of many microbiocenoses characterized by certain relationships and habitats.

In the human body, in accordance with the living conditions, biotopes with certain microbiocenoses are formed. Any microbiocenosis is a community of microorganisms that exists as a whole, connected by food chains and microecology.

Types of normal microflora:

1) resident - permanent, characteristic of this species;

2) transient - temporarily trapped, uncharacteristic for a given biotope; She doesn't actively reproduce.

Normal microflora is formed from birth. Its formation is influenced by the microflora of the mother and the nosocomial environment, the nature of feeding.

Factors affecting the state of normal microflora.

1. Endogenous:

1) secretory function of the body;

2) hormonal background;

3) acid-base state.

2. Exogenous conditions of life (climatic, domestic, environmental).

Microbial contamination is typical for all systems that have contact with the environment. In the human body, blood, cerebrospinal fluid, articular fluid, pleural fluid, lymph of the thoracic duct, internal organs: heart, brain, parenchyma of the liver, kidneys, spleen, uterus, bladder, lung alveoli are sterile.

Normal microflora lines the mucous membranes in the form of a biofilm. This polysaccharide scaffold consists of microbial cell polysaccharides and mucin. It contains microcolonies of cells of normal microflora. The biofilm thickness is 0.1–0.5 mm. It contains from several hundred to several thousand microcolonies.

The formation of a biofilm for bacteria creates additional protection. Inside the biofilm, bacteria are more resistant to chemical and physical factors.

Stages of formation of normal microflora of the gastrointestinal tract (GIT):

1) accidental seeding of the mucosa. Lactobacilli, clostridia, bifidobacteria, micrococci, staphylococci, enterococci, Escherichia coli, etc. enter the gastrointestinal tract;

2) the formation of a network of tape bacteria on the surface of the villi. Mostly rod-shaped bacteria are fixed on it, the process of biofilm formation is constantly going on.

Normal microflora is considered as an independent extracorporeal organ with a specific anatomical structure and functions.

Functions of normal microflora:

1) participation in all types of exchange;

2) detoxification in relation to exo- and endoproducts, transformation and release of medicinal substances;

3) participation in the synthesis of vitamins (groups B, E, H, K);

4) protection:

a) antagonistic (associated with the production of bacteriocins);

b) colonization resistance of mucous membranes;

5) immunogenic function.

The highest contamination is characterized by:

1) large intestine;

2) oral cavity;

3) urinary system;

4) upper respiratory tract;

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The human body is inhabited (colonized) by about 500 species of microorganisms that make up its normal microflora, in the form of a community of microorganisms ( microbiocenosis ). They are in a state of equilibrium eubiosis ) with each other and the human body. Most of these microorganisms are commensals that do not harm humans. The microflora colonizes the surface of the body and cavities that communicate with the environment. Normally, microorganisms are absent in the lungs, uterus and internal organs. There are permanent and transient microflora. Permanent (resident, indigenous, or autochthonous) microflora is represented by microorganisms that are constantly present in the body. Transient (non-permanent, or allochthonous) microflora is incapable of long-term existence in the body.

Permanent microflora can be divided into obligate and facultative. Obligate microflora (bifidobacteria, lactobacilli, peptostreptococci, Escherichia coli, etc.) is the basis of microbiocenosis, and facultative microflora (staphylococcus, streptococcus, klebsiella, clostridia, some fungi, etc.) includes a smaller part of the microbiocenosis.

The number of microorganisms in an adult is about 1014 individuals, with obligate anaerobes predominating to a large extent. Microorganisms that make up the normal microflora are enclosed in a highly hydrated exopolysaccharide-mucin matrix, forming a biological film that is resistant to various influences.

Skin microflora . On the skin, in its deeper layers (hair follicles, ducts of the sebaceous and sweat glands), there are 2-10 times more anaerobes than aerobes. The skin is colonized by gram-positive bacteria (propionibacterium, coryneform bacteria, epidermal staphylococci and other coagulase-negative staphylococci *, micrococci, peptostreptococci, streptococci, Dermabacter hominis), yeast-like fungi of the genus Malassezia; less common transient microflora (Staphylococcus aureus, Streptococcus pyogenes, etc.). When the body is weakened, the number of gram-negative bacteria on the skin increases.

Normally, there are less than 80,000 microorganisms per 1 cm2 of skin, and this number does not increase as a result of the action of bactericidal sterilizing factors. For example, in the sweat of the skin found: immunoglobulins A and B transferrin, lysozyme, organic acids and other antimicrobial substances. Low pH (5.5), low skin temperature also limit the growth of microorganisms. Wetter areas of the skin are colonized by the largest number of microorganisms (10˄6 per 1 cm˄2), for example, in the inguinal folds, interdigital spaces, axillae. The increased growth of microorganisms occurs when the skin is contaminated; when the body is weakened, the microorganisms multiplying there determine the smell of the body.

Skin microflora is of great importance in the spread of microorganisms in the air. As a result of desquamation (peeling) of the skin, several million scales, each carrying several microorganisms, pollute the environment.

Microflora of the conjunctiva . On the conjunctiva of the eye there is a small amount of coryneform bacteria and staphylococci. A small number of microbes on the conjunctiva is due to the action of lysozyme and other bactericidal factors in the lacrimal fluid.

Microflora of the upper respiratory tract .

Dust particles loaded with microorganisms enter the upper respiratory tract, most of which are retained and die in the nasopharynx and oropharynx. Bacteroids, coryneform bacteria, hemophilus bacilli, lactobacilli, staphylococci, streptococci, neisseria, peptococci, peptostreptococci, etc. grow here. Trachea, bronchi and alveoli are usually sterile.

Microflora of the gastrointestinal tract . The microflora of the digestive tract is the most representative in terms of its qualitative and quantitative composition. Microorganisms live freely in the cavity of the digestive tract, and also colonize the mucous membranes in the form of a biological film.

* S. hominis, S. haemolyticus. S. warneri, S. capitis (on the forehead, face), S. saprophyticus. S. caprae, S. saccharolyticir
S. pasteun, S. lugdunensis, S. simulans, S. xylosis. S. auric jularis colonizes the external auditory canal. j
Table 7.5. Characteristics of the main immunomodulators used in the clinic

Name of the drug	Application of the drug
I. Preparations of microbial origin
Prodigiosan (B. prodigiosum lipopolysaccharide)	Chronic infections (stimulation of interferonogenesis, antibody genesis, phagocytosis activity)
Pyrogenal (Pseudomonas aeruginosa lipopolysaccharide)	Chronic infections, sometimes with allergies, dermatoses
	Diseases with damage to humoral immunity (immunomodulation of the B-system of lymphocytes)
Immunofan (hexapeptide, synthetic derivative of thymopoietin)	Prevention and treatment of immunodeficiencies, with tumors

Kemantan (adamantantane-containing compounds)	Immunodeficiencies, chronic fatigue syndrome
Leacadine (2-carbamoylaziridine)	Leukopenia, thrombocytopenia
Diucifon (para-para-(2,4-dioxo-b-methylpyrimidinyl- 5-Sulfonoaminodiphenylsulfone)

Mouth . Numerous microorganisms live in the oral cavity. Up to 10s of bacteria live in 1 ml of saliva. This is facilitated by the remnants of food in the mouth, a favorable temperature (37 ° C) and an alkaline reaction of the environment. There are more anaerobes than aerobes, 100 times or more. A variety of bacteria live here: bacteroids, prevotella, porphyromonas, bifidobacteria, eubacteria, fusobacteria, lactobacilli, actinomycetes, hemophilic rods, leptotrichia, neisseria, spirochetes, streptococci, staphylococci, peptococci, peptostreptococci, veillonella, etc. fungi of the genus Candida and protozoa (Entamaeba gingivaLis, Trichomonas tenax).

Bacteria have a definite topographic distribution. So, streptococci are located differently: on the epithelium of the cheeks - S. mitior, on the papillae of the tongue, in saliva - S. salivarius, on the teeth - S. mutans. Actinomycetes are present in large numbers on the tongue, in gingival pockets, dental plaque and in saliva. Associates of normal microflora and their metabolic products form plaque.

The composition of the microflora of the mouth regulated by the mechanical action of saliva and tongue; microorganisms are washed off with saliva from the mucous membrane and teeth (a person swallows about a liter of saliva per day). Antimicrobial components of saliva, especially lysozyme, antibodies (secretory IgA), inhibit the adhesion of foreign microbes to epitheliocytes. On the other hand, bacteria form polysaccharides: S. sanguis and S. mutans convert sucrose into an extracellular polysaccharide (glucans, dextrans) involved in adhesion to the tooth surface. Colonization by a constant part of the microflora is facilitated by fibronectin, which covers the epitheliocytes of the mucous membranes. It has an affinity for Gram-positive bacteria. When fibronectin levels are low, gram-positive bacteria are replaced by gram-negative ones.

Microflora of the vagina includes lactobacilli, bifidobacteria, bacteroids, propionibacteria, porphyrinomonas, prevotella, peptostreptococci, coryneform bacteria, etc. Anaerobes predominate: the ratio of anaerobes / aerobes is 10/1. During the reproductive period of life, gram-positive bacteria predominate, and during menopause it is replaced by gram-negative bacteria. Approximately 5-60% of healthy women have Gardnerella vaginalis; 15-30% - Mycoplasma hominis; 5% have bacteria of the genus Mobiluncus.

The composition of the microflora depends on many factors: the menstrual cycle, pregnancy, etc. Glycogen accumulates in the cells of the vaginal epithelium (endogenous estrogens contribute), which is broken down by lactobacilli to form lactic acid. The resulting organic acids acidify the medium to pH 4-4.6. Acidification of vaginal secretions by lactobacilli, their production of hydrogen peroxide and bacteriocins leads to suppression of the growth of foreign microflora.

Uterine cavity and urinary bladder normally sterile.

The value of the microflora of the human body

Normal microflora is one of the factors of nonspecific resistance of the body. It has antagonistic properties against pathogenic and putrefactive microflora, as it produces lactic, acetic acids, antibiotics, bacteriocins; competes with foreign microflora due to higher biological potential.
- Normal microflora is involved in water-salt metabolism, regulation of intestinal gas composition, metabolism of proteins, carbohydrates, fatty acids, cholesterol, nucleic acids, as well as in the production of biologically active compounds: antibiotics, vitamins (K, group B, etc.), toxins and etc.
- Normal microflora is involved in the digestion and detoxification of exogenous substrates and metabolites, which is comparable to liver function.
- Normal microflora is involved in the recycling of steroid hormones and bile salts as a result of excretion of metabolites from the liver to the intestine and subsequent return to it.
- Normal microflora performs a morphokinetic role in the development of various organs and systems of the body, participates in the physiological inflammation of the mucous membrane and the change of the epithelium.
- Normal microflora performs an antimutagenic function, destroying carcinogenic substances in the intestine. At the same time, some bacteria can produce strong mutagens. Enzymes from gut bacteria convert the artificial sweetener cyclomate into an active bladder carcinogen (cyclohexamine).
- Exopolysaccharides (glycocalix) of microorganisms, which are part of the biological film, protect microbial cells from various physical and chemical influences. The intestinal mucosa is also protected by a biological film.
- The intestinal microflora has a significant impact on the formation and maintenance of immunity. The intestine contains approximately 1.5 kg of microorganisms whose antigens stimulate the immune system. Muramyl dipeptide, which is formed from bacterial peptidoglycan under the influence of lysozyme and other lytic enzymes in the intestine, is a natural nonspecific stimulant of immunogenesis. As a result, there is an abundant saturation of the intestinal tissue with lymphocytes and macrophages, i.e., normally, the intestine is, as it were, in a state of chronic inflammation. Animal gnotobionts grown in an environment free of microorganisms differ from ordinary animals in poorly developed lymphoid tissue. The thin lamina propria is especially distinguished. The intestinal tissue is poorly saturated with lymphocytes and macrophages, as a result of which animal gnotobionts are unstable to infections.
- The most important function of normal microflora is its participation in colonization resistance. Colonization resistance is a combination of protective factors of the body and competitive, antagonistic and other properties of the normal microflora (mainly anaerobes) of the intestine, which give stability to the microflora and prevent colonization of the mucous membranes by foreign microorganisms. With a decrease in colonization resistance, the number and spectrum of aerobic opportunistic microbes increase. Their translocation through the mucous membranes can lead to the development of an endogenous pyoinflammatory process. To prevent infectious complications, with a decrease in body resistance and an increased risk of autoinfection (in cases of extensive injuries, burns, immunosuppressive therapy, organ and tissue transplantation, etc.), it is advisable to maintain or restore colonization resistance using selective decontamination. Selective decontamination is the selective removal of aerobic bacteria and fungi from the digestive tract to increase the body's resistance to infectious agents. Selective decontamination is carried out by prescribing poorly absorbed chemotherapy drugs for oral administration that suppress the aerobic part of the microflora and do not affect anaerobes (for example, the complex administration of vancomycin, gentamicin and nystatin).
- Representatives of the normal microflora, with a decrease in the body's resistance, cause purulent-inflammatory processes, i.e., the normal microflora can become a source of autoinfection or endogenous infection. When commensal microbes translocate to unfamiliar habitats, they can cause various disturbances. For example, bacteroids normally found in the gut can cause abscesses by infiltrating various tissues as a result of trauma or surgery. Staphylococcus aureus, normally found on the skin, tends to colonize intravenous catheters, causing blood flow disturbances. Such intestinal commensals as Escherichia coli affect the urinary system (cystitis, etc.).
- As a result of the action of microbial decarboxylases and LPS, additional histamine is released, which can cause allergic conditions.
- Normal microflora is a repository and source of chromosomal and plasmid genes, in particular genes for drug resistance to antibiotics.
- Individual representatives of normal microflora are used as sanitary indicative microorganisms, indicating environmental pollution (water, soil, air, food, etc.) with human secretions and, therefore, their epidemiological danger.

Dysbacteriosis

Conditions that develop as a result of the loss of normal functions of the microflora are called dysbacteriosis and dysbiosis. These disorders occur under the influence of environmental factors, stressful influences, widespread and uncontrolled use of antimicrobial drugs, radiation therapy and chemotherapy, malnutrition, surgical interventions, etc. With dysbacteriosis, persistent quantitative and qualitative changes occur in bacteria that are part of the normal microflora. With dysbiosis, changes also occur among other groups of microorganisms (viruses, fungi, etc.). Dysbiosis and dysbacteriosis can lead to endogenous infections. Dysbiosis is classified by etiology (fungal, staphylococcal, proteic, etc.) and localization (dysbiosis of the mouth, intestines, vagina, etc.). Changes in the composition and functions of the normal microflora are accompanied by various disorders: the development of infections, diarrhea, constipation, malabsorption syndrome, gastritis, colitis, peptic ulcer, malignant neoplasms, allergies, urolithiasis, hypo- and hypercholesterolemia, hypo- and hypertension, caries, arthritis, liver damage, etc.
To restore normal microflora, the following is carried out: a) selective decontamination; b) prescribe probiotic preparations* ( eubiotics ) obtained from freeze-dried living bacteria - representatives of the normal intestinal microflora - bifidobacteria (bifidumbacterin), E. coli (colibacterin), lactobacilli (lactobacterin), etc.

* Probiotics - drugs that, when taken per os, have a normalizing effect on the human body and its microflora.

Before we consider, directly, the microflora of the skin, we have to dwell on several concepts. We will briefly talk about what microorganisms, biocenosis, ecosystem, symbiosis and microflora are.

Microorganisms (germs)

Microorganisms, (microbes) - the collective name for a group of living organisms that are too small to be visible to the naked eye (their characteristic size is less than 0.1 mm).

Microorganisms include bacteria, archaea, some fungi, protists, etc., but not viruses, which are usually classified as a separate group.

Most microorganisms consist of a single cell, but there are also multicellular microorganisms. Microbiology is the study of these organisms.

Biocenosis and ecosystem

Biocenosis (from the Greek βίος - “life” and κοινός - “general”) is a collection of animals, plants, fungi and microorganisms that inhabit a certain land area or water area, they are interconnected and with the environment. Biocenosis is a dynamic, self-regulating system, the parts of which are interconnected.

A biological system consisting of a community of living organisms (biocenosis), their habitat (biotope), a system of connections that exchange matter and energy between them is called an ecosystem. Ecosystem- one of the basic concepts of ecology.

An example of an ecosystem is a pond with plants, fish, invertebrates, microorganisms that make up the living component of the system, a biocenosis living in it.

Symbiosis (from the Greek συμ- - “together” and βίος - “life”) is a close and prolonged coexistence of representatives of different biological species. At the same time, in the course of joint evolution, their mutual adaptation takes place.

Microflora

Microflora - a set of different types of microorganisms that inhabit any habitat.

Human microflora - the collective name of microorganisms that are in symbiosis with humans.

The formed microbiocenosis exists as a whole, as a community of species united by food chains and connected by microecology.

Amazing fact!

Normal microflora accompanies its owner throughout his life.

At present, it is firmly established that the human body and the microorganisms inhabiting it are single ecosystem.

Currently, the normal microflora is considered as an independent extracorporeal (ie outside the body) organ.

This is an amazing fact! Bacteria - these independent, separate lives from us, are part of ourselves, one of our organs.

This is the Unity of All Living Things!

Normal human microflora

The totality of microbial biocenoses found in the body of healthy people is normal human microflora.

It has been established that the normal microflora has a sufficiently high species and individual specificity and stability.

The normal microflora of individual biotopes (biotope - habitat) is different, but obeys a number of basic patterns:

She is quite stable;
forms a biofilm;
represented by several species, among which there are dominant species and filler species;
anaerobic (existing without air) bacteria are predominant. Even on the skin in its deep layers, the number of anaerobes is 3-10 times higher than the number of aerobic bacteria.

On all open surfaces and in all open cavities, a fairly stable microflora is formed, specific for a given organ, biotope or its area - an epitope. The richest in microorganisms:

Oral cavity;
colon;
upper parts of the respiratory system;
external sections of the genitourinary system;
skin, especially its scalp.

Permanent and transit microflora

As part of the normal microflora, there are:

permanent or resident microflora, - is represented by a relatively stable composition of microorganisms, usually found in certain places of the human body in people of a certain age;

transient, or temporary microflora, - gets on the skin or mucous membranes from the environment, without causing diseases and not permanently living on the surfaces of the human body.

It is represented by saprophytic opportunistic microorganisms that live on the skin or mucous membranes for several hours, days or weeks.

The presence of transient microflora is determined not only by the entry of microorganisms from the environment, but also by the state of the host's immune system and the composition of the permanent normal microflora.

Microflora in numbers

The surfaces of the skin and mucous membranes of the human body are abundantly populated by bacteria.

The total number of microorganisms found in an adult reaches 10 14 , which is almost an order of magnitude greater than the number of cells of all tissues of the macroorganism.

On 1 cm 2 skin accounts for less 80000 microorganisms.

The quantitative fluctuations of bacteria in the biocenosis can reach several orders of magnitude for some bacteria and, nevertheless, fit into the accepted standards.

The body has tissues that are free from microflora

Normally, many tissues and organs of a healthy person are free from microorganisms, that is, they are sterile. These include:

Internal organs;
brain and spinal cord;
lung alveoli;
inner and middle ear;
blood, lymph, cerebrospinal fluid;
uterus, kidneys, ureters and urine in the bladder.

Sterility is ensured by the presence of immunity that prevents the penetration of microbes into these tissues and organs.

Normal human microflora is a combination of many microbiocenoses. Microbiocenosis is a collection of microorganisms of the same habitat, for example, microbiocenosis of the oral cavity or microbiocenosis of the respiratory tract. Microbiocenoses of the human body are interconnected. The living space of each microbiocenosis is a biotope. The oral cavity, large intestine or respiratory tract are biotopes.

The biotope is characterized by homogeneous conditions for the existence of microorganisms. Thus, biotopes have been formed in the human body, in which a certain microbiocenosis is settled. And any microbiocenosis is not just a certain number of microorganisms, they are interconnected by food chains. In each biotope, there are the following types of normal microflora:

characteristic of a given biotope or permanent (resident), actively reproducing;
uncharacteristic for this biotope, temporarily trapped (transient), it does not actively reproduce.

Normal human microflora is formed from the first moment of the birth of a child. Its formation is influenced by the microflora of the mother, the sanitary condition of the room in which the child is located, artificial or natural feeding. The state of normal microflora is also affected by the hormonal background, the acid-base state of the blood, the process of production and release of chemicals by the cells (the so-called secretory function of the body). By the age of three months, a microflora is formed in the child's body, similar to the normal microflora of an adult.

All systems of the human body that are open to contact with the external environment are seeded with microorganisms. Closed for contact with the microflora of the environment (sterile) are blood, cerebrospinal fluid (CSF), articular fluid, pleural fluid, lymph of the thoracic duct and tissues of internal organs: heart, brain, liver, kidneys, spleen, uterus, bladder, lungs.

Normal microflora lines the human mucous membranes. Microbial cells secrete polysaccharides (high molecular weight carbohydrates), the mucous membrane secretes mucin (mucus, protein substances) and a thin biofilm is formed from this mixture, which covers hundreds and thousands of microcolonies of normal flora cells from above.

This film with a thickness of not more than 0.5 mm protects microorganisms from chemical and physical effects. But if the factors of self-defense of microorganisms exceed the compensatory capabilities of the human body, then violations may occur, with the development of pathological conditions and adverse consequences. Such consequences include

— the formation of antibiotic-resistant strains of microorganisms;
— formation of new microbial communities and changes in the physicochemical state of biotopes (intestines, skin, etc.);
- an increase in the spectrum of microorganisms that are involved in infectious processes and an expansion of the spectrum of human pathological conditions;
- the growth of infections of various localization; the appearance of individuals with congenital and acquired reduced resistance to pathogens of infectious diseases;
- decrease in the effectiveness of chemotherapy and chemoprophylaxis, hormonal contraceptives.

The total number of microorganisms of normal human flora reaches 10 14, which exceeds the number of cells of all tissues of an adult. The basis of the normal human microflora is anaerobic bacteria (living in an oxygen-free environment). In the intestines, the number of anaerobes is a thousand times greater than the number of aerobes (microorganisms that require oxygen to live).

The meaning and functions of normal microflora:

- Participates in all types of metabolism.
- Participates in the destruction and neutralization of toxic substances.
- Participates in the synthesis of vitamins (groups B, E, H, K).
- It releases antibacterial substances that suppress the vital activity of pathogenic bacteria that have entered the body. The combination of mechanisms ensures the stability of normal microflora and prevents the colonization of the human body by foreign microorganisms.
- Makes a significant contribution to the metabolism of carbohydrates, nitrogenous compounds, steroids, water-salt metabolism, and immunity.

Most contaminated by microorganisms

- skin;
- oral cavity, nose, pharynx;
- upper respiratory tract;
- colon;
- vagina.

Normally, few microorganisms contain

- lungs;
- urinary tract;
- bile ducts.

How is the normal intestinal microflora formed? First, the mucosa of the gastrointestinal tract is seeded with lactobacilli, clostridia, bifidobacteria, micrococci, staphylococci, enterococci, E. coli and other microorganisms that have accidentally entered it. Bacteria are fixed on the surface of the intestinal villi, in parallel, the process of biofilm formation takes place

As part of the normal human microflora, all groups of microorganisms are detected: bacteria, fungi, protozoa and viruses. Microorganisms of normal human microflora are represented by the following genera:

- oral cavity - Actinomyces (Actinomycetes), Arachnia (Arachnia), Bacteroides (Bacterioids), Bifidobacterium (Bifidobacteria), Candida (Candida), Centipeda (Centipeda), Eikenella (Eikenella), Eubacteriun (Eubacteria), Fusobacterium (Fusobacteria), Haemophilus (Hemophilus), Lactobacillus (Lactobacillus), Leptotrichia (Leptotrichia), Neisseria (Neisseria), Propionibacterium (Propionibacteria), Selenomonas (Selenomonas), Simonsiella (Simonsiella), Spirochaeia (Spirochea), Streptococcus (Streptococcus), Veillonella (Veillonella), Wolinella (Volinella), Rothia (Rothia);
- upper respiratory tract - Bacteroides (Bacterioids), Branhamella (Branhamella), Corynebacterium (Corinebacterium), Neisseria (Neisseria), Streptococcus (Streptococci);
- small intestine - Bifidobacterium (Bifidobacteria), Clostridium (Clostridia), Eubacterium (Eubacteria), Lactobacillus (Lactobacillus), Peptostreptococcus (Peptostreptococcus), Veillonella (Veylonella);
- large intestine - Acetovibrio (Acetovibrio), Acidaminococcus (Acidaminococcus), Anaerovibrio (Anerovibrio), Bacillus (Bacilli), Bacteroides (Bacterioids), Bifidobacterium (Bifidobacteria), Butyrivibrio (Butyrivibrio), Campylobacter (Campylobacter), Clostridium (Clostridia), Coprococcus (Kopropropococci), Disulfomonas (Disulfomones), Escherichia (Escherichia), Eubacterium (Ebacteria), Fusobacterium (Fuzobacteria), Gemmiger (Hemmiger), Lactobacillus (lactobacteria), Peptoccus (Pepto Kokki), PeptostReptococcus (Peptostosteroptococci), Propionibacterium (Propionibacteria), Roseburia (Roseburia), Selenomonas (Selenomone), Spirochaeta (Spirochete), Succinomonas, Streptococcus (Streptococci), Veillonella (Veylonella), Wolinella (Volinella);
- skin - Acinetobacter (Acinetobacter), Brevibacterium (Brevibacteria), Corynebacterium (Corinebacteria), Micrococcus (Micrococcus), Propiombacterium (Propionebacterium), Staphylococcus (Staphylococcus), Pityrosponim (Pitirosponim - yeast fungus), Trichophyton (Trichophyton);
- female genital organs - Bacteroides (Bacterioids), Clostridium (Clostridia), Corynebacterium (Corinebacteria), Eubacterium (Eubacteria), Fusobacterium (Fusobacteria), Lactobacillus (Lactobacillus), Mobiluncus (Mobilunkus), Peptostreptococcus (Peptostreptococcus), Streptococcus (Streptococcus), Spirochaeta (Spirochete), Veillonella (Veylonella).

Under the influence of a number of factors (age, sex, season, food composition, illness, the introduction of antimicrobial substances, etc.), the composition of the microflora can change either within physiological boundaries or beyond them (see Fig.

Normal human microflora is a combination
many microbiocenoses characterized by certain
mi relationships and habitat.
In the human body in accordance with environmental conditions
biotopes with certain microbiocenoses are formed. Liu-
battle microbiocenosis is a community of microorganisms that exist
as a whole, connected by food chains and microeco-
logic.
Types of normal microflora:
1) resident - permanent, characteristic of a given species;
2) transient - temporarily trapped, uncharacteristic for
given biotope; She doesn't actively reproduce.
Normal microflora is formed from birth. On her form
microflora influence the microflora of the mother and intra-
no environment, character.
Factors affecting the state of normal microflora.
1. Endogenous:
1) secretory function of the body;
2) hormonal background;
3) acid-base state.
2. Exogenous living conditions (climatic, household, eco-
brain teaser).
Microbial contamination is characteristic of all systems that have
contact with the environment. In the human body,
The correct ones are blood, cerebrospinal fluid, articular fluid, pleura
oral fluid, thoracic duct lymph, internal organs:
heart, brain, parenchyma of the liver, kidneys, spleen, uterus, urinary
bubble, alveoli of the lungs.
Normal microflora lines the mucous membranes in
de biofilms. This polysaccharide backbone consists of a polysaccharide
reads of microbial cells and mucin. It contains micro-
37
cells of normal microflora. Biofilm thickness -
0.1-0.5 mm. It contains several hundred to several
thousand microcolonies.
The formation of a biofilm for bacteria creates an additional
protection. Inside the biofilm, bacteria are more resistant to
influence of chemical and physical factors.
Stages of formation of normal microflora of the gastric
but-intestinal tract (GIT):
1) accidental seeding of the mucosa. Varnish enters the gastrointestinal tract
tobacilli, clostridia, bifidobacteria, micrococci, staphi-
lococci, enterococci, E. coli, etc.;
2) formation of a network of ribbon bacteria on the surface
villi. It is fixed mainly rod-shaped
bacteria, the process of biofilm formation is constantly going on.
Normal microflora is considered as an independent
ny extracorporeal organ with a certain anatomical
structure and functions.
Functions of normal microflora:
1) participation in all types of exchange;
2) detoxification in relation to exo- and endoproducts, trans-
formation and release of medicinal substances;
3) participation in the synthesis of vitamins (groups B, E, H, K);
4) protection:
a) antagonistic (associated with the production of bacterioci-
new);
b) colonization resistance of mucous membranes;
5) immunogenic function.
The highest contamination is characterized by:
1) large intestine;
2) oral cavity;
3) urinary system;
4) upper respiratory tract;
5) skin.

2. Dysbacteriosis

Dysbacteriosis (dysbiosis) is any quantitative or
qualitative changes in the normal
human microflora, resulting from exposure to
effects on a macro- or microorganism of various adverse
factors.
38
Microbiological indicators of dysbiosis are:
1) a decrease in the number of one or more permanent
species;
2) loss by bacteria of certain signs or acquisitions
new ones;
3) increase in the number of transient species;
4) the emergence of new species unusual for this biotope
dov;
5) weakening of the antagonistic activity of normal
microflora.
The reasons for the development of dysbacteriosis can be:
1) antibiotic and chemotherapy;
2) severe infections;
3) severe somatic diseases;
4) hormone therapy;
5) radiation exposure;
6) toxic factors;
7) deficiency of vitamins.
Dysbacteriosis of various biotopes has various clinical
sky manifestations. Intestinal dysbiosis can manifest itself
in the form of diarrhea, nonspecific colitis, duodenitis, gastroenteritis
rita, chronic constipation. Dysbacteriosis of the respiratory organs
flows in the form of bronchitis, chronic diseases
ny lungs. The main manifestations of oral dysbiosis
are gingivitis, stomatitis, caries. Dysbacteriosis sexual
system in women proceeds as vaginosis.
Depending on the severity of these manifestations, there are
several phases of dysbacteriosis:
1) compensated, when dysbacteriosis does not accompany
with any clinical manifestations;
2) subcompensated, when, as a result of an imbalance of normal
small microflora, local inflammatory
changes;
3) decompensated, in which there is a general
process with the occurrence of metastatic inflammation
body foci.
Laboratory diagnosis of dysbacteriosis
The main method is bacteriological research. Wherein
in the evaluation of its results, quantitative indicators prevail.
Not specific identification is carried out, but only to the genus.
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An additional method is fatty acid spectrum chromatography.
acids in the test material. Each genus corresponds
its spectrum of fatty acids.
Correction of dysbacteriosis:
1) elimination of the cause that caused the imbalance of the normal
microflora;
2) the use of eubiotics and probiotics.
Eubiotics are preparations containing live bactericides.
nogenic strains of normal microflora (colibacterin, bi-
fidumbacterin, bifikol, etc.).
Probiotics are substances of non-microbial origin
and food products containing additives that stimulate the self-
natural normal microflora. Stimulants -
oligosaccharides, casein hydrolyzate, mucin, whey,
lactoferrin, dietary fiber.