Microflora of the animal body. Normal microflora of humans and animals
The animal body is populated (colonized) by numerous types of microorganisms that make up its normal microflora, which colonizes body surfaces and cavities communicating with the external environment. Normally, microorganisms are absent in the lungs, uterus and all internal organs. In the body of animals and humans, a distinction is made between permanent (resident) and non-permanent (transient) microflora. Resident microflora is represented by microbes that constantly live in the body. Transient microflora is not capable of long-term existence in the macroorganism, but it plays a significant role in its protection from pathogens. For example, bacteria of the genus Bacillus subtilis, Being representatives of the transient microflora of the intestines of animals and humans, they are capable of synthesizing dozens of different antibiotic-like substances. These bacteria are harmless to the body, have antagonistic activity against a wide range of pathogenic and opportunistic microbes, are characterized by high enzymatic activity, and are capable of exerting antiallergic and antitoxic effects. Medical specialists consider it advisable to use supernatants obtained during deep cultivation B. subtilis to create new generation metabolite probiotics based on them.
Normal microflora plays an important role in the life of the body. The microflora of the gastrointestinal tract is involved in the digestion of roughage (fiber) in herbivores, is an additional source of protein, is involved in the synthesis of vitamins, and is an antagonist of putrefactive, opportunistic and some pathogenic microorganisms. Representatives of normal microflora - lactobacilli, bifidobacteria, E. coli, etc. contribute to the formation of animal immunity to infectious diseases, being a factor in the body's nonspecific defense. It is known that lactic acid bacteria, in addition to bacteriocins, synthesize antibiotic substances with a wide spectrum of action - microcins. Many lactobacilli (L. acidophilus, L. plantarum, L. casein etc.) have an inhibitory effect on Salmonella, Staphylococcus, Pseudomonas aeruginosa, Listeria, etc. Disruption of the vital activity of normal microflora occurs under the influence of various factors (antibiotics, radiation exposure, unbalanced feeding, etc.), which leads to dysbiosis and development pathological processes. To restore normal intestinal microflora, various drugs have been proposed - pro-, pre- and synbiotics, etc.
Skin microflora. The skin is inhabited by staphylococci, streptococci, yeast, sarcina, actinomycetes, yeast-like fungi, micrococci, putrefactive bacilli, Escherichia coli and Pseudomonas aeruginosa, Proteus and other microbes. In the hair follicles, the lumens of the sebaceous and sweat glands, anaerobes are “housed”, of which there are 2-10 times more than aerobes. The skin is a mechanical barrier to the penetration of microbes into the body. The number of microbes on the skin of animals with poor maintenance and care of the skin can reach 1-2 billion per 1 cm 2. With a decrease in the body's resistance and a violation of the integrity of the skin, various pathological processes of both a local and general nature can occur.
Microflora of the respiratory tract. Dust particles “loaded” with microbes enter the upper respiratory tract, most of which settle in the nasopharynx. The permanent inhabitants of the mucous membranes of the upper respiratory tract are strepto-, staphylo- and micrococci, Haemophilus influenzae, lactobacilli and other microbes. The trachea and bronchi are usually sterile.
Microflora of the digestive canal. It is the most representative in terms of qualitative and quantitative composition. Microorganisms live freely in the digestive tract and colonize mucous membranes in the form of a biological film. IN oral cavity detect bifidobacteria, lactobacilli, spirochetes, strepto- and staphylococci, fungi of the genus Candida and protozoa.
Microflora of the stomach. Represented by lactobacilli, yeasts, sarcins, bacilli, acid-fast bacteria. It is much poorer than other parts of the intestine due to the high acidity of gastric juice.
Ruminal microflora of ruminants. Very numerous, since a huge amount gets into the rumen with food. different types epiphytic and soil microorganisms. In the contents of the rumen there are from several thousand to several million and even billions of microbial bodies per 1 cm3. In the rumen of ruminants, complex microbiological and biochemical processes of fiber digestion occur, which are carried out by cellulose-degrading microorganisms: Rutinococcus flavefaciens, R. albus, Bact. succinogenes, S. celolyticum etc. Pectin substances break down You. macerans, Atylobakter, Cranylobacter petinovoruffi. Streptococci living in the rumen ferment starch and glucose with the formation of lactic acid, and propionic acid bacteria - lactates with the formation of propionic acid, partially butyric and acetic acid. Microbes inhabiting the rumen produce all vitamins, especially group B, with the exception of A, E, D.
Microflora of the small intestine. It is much poorer than rumen, which is due to the effect of bile on microbes. Enterococci, E. coli, lactobacilli, and spore microbes live in the jejunum and duodenum.
Microflora of the large intestines. It is divided into M-flora (mucosal) and P-flora (cavitary). M-flora is considered parietal, since its representatives are fixed on the receptors of the intestinal mucosa (bifidumflora) or through indirect interaction with other microorganisms attached to bifidobacteria. P-flora is less stable; its representatives live without attachment to the mucous membrane, in the contents of the intestines. The main inhabitants of the large intestine are enterobacteria, enterococci, acidophilus, bifidobacteria, actinomycetes, yeast, molds, putrefactive and some pathogenic anaerobes (C. sporogenes, C. putrificus, C. petfringens, C. tetani, F. necropliorum). In 1 g of herbivore excrement there can be up to 3.5 billion different microorganisms. The microbial mass makes up about 40% of the dry matter of feces. The abundance of microorganisms is explained by the presence in the large intestine of large volumes of digested food, sufficient humidity, optimal temperature, conducive to the growth and reproduction of microbes.
Microflora of the gastrointestinal tract. It is usually divided into obligate bacteria (lactic acid bacteria, E. soy, enterococci, C. petfringens, C. sporogenes etc.), adapted to living conditions and being constant, and facultative, changing depending on the type of food, feeding regime, watering and other factors.
Microflora of the genitourinary tract. The lower parts of the genitourinary tract are inhabited by staphylo- and streptococci, acid-fast mycobacteria, etc. The most permanent inhabitant of the vaginal mucosa is Bact. vaginal vulgare. This microorganism is an antagonist to other microorganisms. In healthy animals, microflora is found only in the lower parts of the genitourinary tract. The uterus, ovaries, testes, and bladder are free of microbes. In a healthy female, the fetus in the uterus is sterile. Microbes colonize the fetus's body during childbirth, and then during the process of adaptation of the animal to the conditions external environment.
In diseases of the genitourinary organs, the microbial “landscape” changes and is represented by pathogenic and opportunistic microorganisms.
The role of normal microflora in animals. Normal microflora plays an important role in the life of the animal’s body. It performs the following essential functions:
♦ participates in the formation of the body’s immunological reactivity, stimulating the immune system;
♦ colonizes organs communicating with environment, has antagonistic activity against many pathogenic microbes, preventing their penetration and reproduction in the body;
♦ has a pronounced morphofunctional effect in relation to the mucous membrane of the small intestine, which contributes to the normal manifestation of the physiological functions of the digestive canal;
♦ promotes hepatic-intestinal circulation of important components of bile - bile salts, cholesterol, bile pigments;
♦ synthesizes some enzymes, vitamin K and B vitamins;
♦ produces enzymes that break down fiber and other difficult-to-digest components of feed;
♦ participates in water-salt metabolism;
♦ regulates the gas composition of the intestines and other cavities of the host’s body;
♦ produces enzymes involved in the metabolism of proteins, carbohydrates, lipids and nucleic acids;
♦ performs a mutagenic and antimutagenic role;
♦ carries out detoxification of exogenous and endogenous substrates and metabolites;
♦ is a source of microbial, plasmid and chromosomal genes;
♦ synthesizes antimicrobial substances, pectins and short-chain fatty acids, which have a healing effect on the body.
Pathogenic microbes can also live in the gastrointestinal tract of animals and humans. For example, Heliobacter pylori- spiral-shaped gram-negative bacteria that live on the epithelium of the human stomach are considered the most common cause chronic gastritis and are associated with peptic ulcers and stomach cancer. Infection occurs in childhood, spontaneous elimination of the microbe is extremely rare, so people are doomed to lifelong carriage.
In recent years, a new branch of biology has begun to develop - gnotobiology, which studies the germ-free life of macroorganisms. In special chambers using sterile food, germ-free chickens, rats, mice, guinea pigs, piglets and other animals are raised, used for a more detailed elucidation of the role of normal microflora in the pathogenesis of infectious pathology, the vital activity of the macroorganism, in the manifestation of innate and acquired immunity.
Related information.
Description of presentation 1 Normal microflora of the animal body. The role of microorganisms on slides
2 INTRODUCTION. Species composition and quantitative characteristics of microflora various areas animal body. Differences in the body microflora of different animal species. Normal microflora of the body and pathogenic microorganisms that cause dysbacteriosis. Mechanisms that prevent colonization (settlement) pathogenic microflora animal body. The role of microorganisms in the cycle of substances in nature. CONCLUSION.
3 1. Veterinary microbiology and immunology: Textbook / Ed. N. A. Raduka. — M.: Agropromizdat. - 1998. 2. Intizarov M. M. Antibiotics and colonization resistance // Coll. tr. VNIIA. -1990. — Vol. 19. - pp. 14 -16. 3. Intizarov M. M. Introduction to gnotobiology: Lecture. — M.: MBA. - 1991. - 12 p. 4. Kozhevin P. A. Microbial populations in nature. - M.: Publishing house of Moscow State University. — 1989. -175 p. 5. Kostenko T. S., Rodionova V. B., Skorodumov D. I. Workshop on veterinary microbiology and immunology. - M.: Kolos. - 2001. 6. Chakhava O. V. et al. Microbiological and immunological foundations of gnotobiology. — M.: Medicine. - 1982. - 159 p.
4 1885 - Escherich isolated from the feces of children an obligatory representative of the intestinal microflora - E. coli, found in all mammals, birds, fish, reptiles, amphibians, insects, etc. 1893 - Jensen found that different types and strains of E. coli can be both pathogenic for animals and non-pathogenic and even beneficial inhabitants of the intestines of animals and humans. 1900 - Tissier discovered bifidobacteria in the feces of newborns, obligatory representatives of the normal intestinal microflora of the body during all periods of animal and human life. 1901 - Moreau isolated lactic acid bacteria - Bacillus acidophilus. 1976 - Petrovskaya V.G. and Marco O.P. developed the concept of the importance of normal microflora for humans and animals.
5 Normal microflora of the body is an open biocenosis of microorganisms found in healthy people and animals. 1. A set of many microbiocenoses characterized by certain relationships and habitat. 2. Together with the macroorganism, it is a single ecosystem. 3. Formed from birth.
661. 1. Resident (permanent, endogenous, indigenous, local, autogenous, autochthonous, indigenous) - developed in phylogeny and ontogenesis in the process of evolution and is characteristic of a given animal species. 2. 2. Transient (exogenous, facultative) – temporarily introduced, uncharacteristic for a given species, not actively reproducing in the body.
77 Organs and tissues free from microorganisms (normally sterile) 1. 1. Internal organs. 2. 2. Brain and spinal cord. 3. 3. Alveoli of the lungs. 4. 4. Inner and middle ear. 5. 5. Blood, lymph, cerebrospinal fluid. 6. 6. Ovaries, uterus, testes. 7. 7. Kidneys, ureters and urine in the bladder.
88 Organs and tissues rich in microorganisms 1. Skin. 2. 2. Upper sections respiratory system. 3. 3. Oral cavity. 4. 4. Ruminant tripe. 5. 5. Large intestine. 6. 6. External parts of the genitourinary system.
9 1. Represented by several species, among which dominant species and filler species are distinguished. 2. Anaerobic bacteria are predominant. 3. Forms a biofilm with a thickness of 0.1 to 0.5 mm. 4. Quite stable. 5. Each ecological niche of an animal’s body has its own species composition of microorganisms. Basic patterns of functioning of the normal microflora of the animal body
1111 About 400 types of microorganisms Anaerobic bacteria - 95 - 99%. Aerobic and facultative anaerobic – 1 – 5%. Recently discovered bacteria in the cecum and colon of rodents are filamentous, segmented bacteria. Bacteria unknown to science.
1313 Escherichia coli and filamentous segments—PP bacteria
1414 Microflora of the stomach Acid-resistant microflora – – lactobacilli, streptococcus, yeast. Number of bacteria - 1010 33 /g /g contents
17171. Cellulose-degrading bacteria: Ruminococcus flavefaciens Ruminococcus albus Bacterium succinogenes Clostridium cellobioparum Clostridium cellolyticum 2. Breaking down pectin: You illus macerans You illus asterosporus Amylobacter Cranulobacter pectinovorum 3. Fermenting starch and glucose: Streptococcus bovis Str eptococcus faecalis 4. Propionic acid bacteria: Propionipecti novorum Veillonella Peptostreptococcus elsdenii Butyribacterium E. coli
1919 protective (antagonism to others, including pathogenic microbes); immunostimulating (antigens of microorganisms stimulate the development lymphoid tissue); digestive (metabolism of cholesterol and bile acids); metabolic (synthesis of B vitamins, nicotinic, pantothenic, folic acids).
21 Microflora of the lower parts of the gastrointestinal tract of animals Name of microbial groups (genus or species) Number of microorganisms in 1 g of material from the intestines Escherichia 10 7 Bifidobacteria 10 7 -10 9 (up to 10 10) Lactobacilli, enterococci 10 6 -10 7 Bacteroides 10 10 (up to 10 11) Eubacteria, clostridia 10 4 - 10 5 Klebsiella, Proteus, Citrobacter, Enterobacter 0 - 10 5 Pseudomonas 0 - 10 8 Staphylococci 10 3 - 10 4 Streptococci up to 10 7 Diphtheroids 0 - 10 6 Spore anaerobes, fungus s, actinomycetes 10 3 —
22 Name of microbial groups (genus or species) Number of microorganisms in 1 g of material from the intestines Escherichia Bifidobacteria Lactobacilli Enterococci Bacteroides Clostridia Vaillonella 10 7 -10 9 (up to 10 10) 10 6 -10 7 10 10 (up to 10 11) 10 4 - 10 5 More transiently may be represented: Other representatives of enterobacteria (Klebsiella, Proteus, Citrobacter, Enterobacter) Pseudomonas Staphylococci (S. epidermidis, S. aureus, etc.) Other streptococci (S. mitis, S. salivarius, etc.) Diphtheroids Aerobic bacilli (B subtilis, B. licheniformis, B. megatherium) Fungi, actinomycetes 0 - 10 5 0 - 10 8 10 3 - 10 4 to 10 7 0 - 10 6 10 3 - 10 4 10 3 Microflora of the large intestine of different animal species
23 Microcolonies of bacteria in rectal biopsy are located around epithelial cells or in the form of separate aggregates Epithelial cells Live bacteria Dead bacteria
30 Lactobacilli in fermented milk
31 Skin microflora Diphtheroids (corynebacteria, propionic bacteria). Mold fungi. Yeast. Spore aerobic bacilli (bacilli). Staphylococci (S. epidermidis and S. aureus).
34 In the nasal passages: diphtheroids (corynebacteria), staphylococci (S. epidermidis), neisseria, hemophilus bacteria, streptococci (alpha-hemolytic). In the nasopharynx: corynebacteria, streptococci (S. mitts, S. salivarius), staphylococci, neisseria, vilonella, hemophilus bacteria, enterobacteria, bacteroides, fungi, enterococci, lactobacilli, Pseudomonas aeruginosa, Bacillus subtilis
35 Microflora of the mucous membrane of the trachea and large bronchi of pigs Name of microbial groups (genus or species) Number of microorganisms in 1 g of scrapings and in mucus Neisseria 10 3 - 10 5 Staphylococci 10 3 Streptococci 10 4 Corynebacteria 10 4 - 10 5 Haemophilus influenzae bacteria 10 4 -
36 Name of microbial groups (genus or species) Frequency of occurrence in the vagina and cervix, % Obligate anaerobic microorganisms Bacteroides Bifidobacteria Peptococci, peptostreptococci Clostridia 17 80 20 1 Facultative anaerobic and aerobic microorganisms Lactobacilli Escherichia and other enterobacteria Corynebacteria Sta phylococci (S. epidermidis, S aureus) Non-hemolytic Streptococci Enterococci Candida Pseudomonas aeruginosa 85 5 -15 80 55 35 41 14 1 Microflora of the birth canal of different animal species
38 Factors influencing the state of normal microflora 1. Endogenous (secretory function of the body, hormonal levels, acid-base state). 2. Exogenous (feeding and keeping of animals, environmental, climatic conditions).
3939 Differences in the body microflora of different animal species Type of animal Distinctive features Low quantity High quantity Rats and mice Escherichia coli, bifidobacteria Lactobacilli, streptococci, clostridia Guinea pigs E. coli Lactobacilli Rabbits E. coli, lactobacilli bacteroides Dogs Streptococci (S. lactis, S. mitis), enterococci, clostridia Bifidobacteria Pigs Similar to human microflora Ruminants Cellulolytic and fibrolytic bacteria - fiber digesters
40 Pathogenic microorganisms constantly enter the animal’s body. They coexist in the body for a long time as part of the automicroflora (carriage of pathogenic microbes is formed, but the normal microflora predominates quantitatively). They are forced out of the body by normal microflora and eliminated (removed). They displace normal microflora, multiply rapidly and can cause the corresponding infectious disease.
41 - qualitative and quantitative change in the composition of the normal microflora of the body 1. 1. Irrational antibiotic therapy. 2. 2. Intoxication. 3. 3. Infectious diseases. 4. 4. Somatic diseases (diabetes mellitus, oncological diseases). 5. 5. Hormone therapy. 6. 6. Radiation injuries. 7. 7. Immunodeficiency and vitamin deficiency conditions.
43431. 1. Decrease in the total number of bacteria - representatives of normal microflora or its individual species. 2. 2. An increase in the number of normally rare microorganisms or the appearance of species that are not typical for a given biotope. 3. 3. The appearance of altered variants of microorganisms - representatives of normal microflora (change biochemical properties, their acquisition of certain virulence factors). 4. 4. Weakening the antagonistic activity of microorganisms that are part of the normal microflora.
47 Production of volatile fatty acids. Formation of free bile metabolites. Lysozyme production. Acidification of the environment during the production of organic acids. Production of colicins and bacteriocins. Synthesis of various antibiotic-like substances. Competition of non-pathogenic microorganisms with pathogenic species for the same receptors on the cells of the macroorganism. Absorption by normal microflora of important components of nutrients necessary for the life of pathogenic bacteria. Mechanisms of antagonism towards pathogenic and opportunistic microflora
481. Preparations from a monoculture of living microorganisms (bactisubtil, bifinorm, lactobacterin, bifidobacterin). 2. Preparations containing several types of living microorganisms (Bifikol, Immunobak, Bifilak, Biod-5, KD-5, Tang, OLIN, SUB-PRO). 3. Preparations from monocultures or a complex of microorganisms, including substances that stimulate their engraftment, growth and reproduction (lactobifidol, streptofide). 4. Preparations from genetically modified strains of microorganisms (vetom -1. 1, subalin). 5. Preparations containing, in addition to microorganisms or agents that stimulate their growth and reproduction, other compounds that affect the functions of cells in animal organs and tissues (cellobacterin). Probiotics are biological products that contain live “beneficial” bacteria that are antagonistically active against pathogenic and opportunistic microorganisms and are used for the prevention and treatment of gastrointestinal diseases in humans and animals.
4949 Gnotobiology (from the Greek gnosis - knowledge and biota - flora and fauna) is a science that studies the germ-free life of animals. Gnotobiotes (gnotobionts) are animals completely free from microflora or carriers only certain types microorganisms. Gnotophores (from the Greek for - carrier) are gnotobiotes that have species of microorganisms known to the researcher.
5050 Gnotobiological animals Common animals Germ-free gnotobiotes Gnotophores. Antigen-free Holobiots Conventional Monognotophores Dignotophores Trignotophores Polygnotophores SPF-animals (SPF - specific pathogen free) - carriers of non-pathogenic microflora
5252 Cycle is a cycle of various transformations of substances, thanks to which their reserves in nature are not depleted and are inexhaustible. Microorganisms play a huge role in the circulation of substances. Such colossal work of microorganisms is due to their extremely wide distribution in nature, the extreme speed of reproduction, and the wide variety of types of their nutrition and enzyme systems.
5353 Destructors - bacteria (including actinomycetes) and fungi that decompose dead animals and plants; in this case, organic substances are converted into inorganic ones, that is, mineralization occurs. Microorganisms use the products of decomposition of organic matter as a source of nutrition and energy.
5454 Among the various processes of transformation of substances in nature, in which microorganisms take an active part, the cycle of nitrogen, carbon, phosphorus, sulfur, and iron is of utmost importance for the life of plants, animals and humans on Earth.
5555 Nitrogen cycle There is a huge amount of nitrogen in nature. 44 // 55 of the volume of air around us is nitrogen. The entire living world (plants, animals) contains 20-25 billion tons of nitrogen, a huge amount of it is found in the arable layer of soil - in podzol about 6 g, and in chernozem up to 18 g per 1 hectare. But all this nitrogen, free in the atmosphere and bound in organic matter, in soil humus, in peat, is not absorbed by plants, and therefore by animals. Thus, nitrogen cannot directly participate in the biogenic cycle of substances.
5656 Ammonium occupies a central place in the nitrogen cycle. It is a product of the decomposition of proteins and amino acids that enter the soil along with residues of animal and plant origin. In well-aerated soils, ammonium undergoes nitrification; bacteria of the genera Nitrosomonas and Nitrobacter occus reduce it to nitrite and nitrate.
5757 Stages of the nitrogen cycle with the participation of microorganisms 1. Nitrogen fixation (fixation of atmospheric nitrogen, representatives of the genera Azotobacter, Rhisobium, Clostridium are involved). 2. Ammonification (rotting, breakdown of nitrogenous organic compounds with the formation of ammonia, representatives of the genera: Bacillus, Pseudomonas, Clostridium are involved). 3. Nitrification (oxidation of ammonium salts to nitrous acid salts - carried out by representatives of the genera Nitrosomonas, Nitrosovibrio, Nitrosococcus, representatives of the genera Nitrobacter, Nitrococcus, Nitrospira participate in the oxidation of nitrites to nitrates). 4. Denitrification (the reverse process of nitrification, representatives of the genera Thiо bacillus, Pseudomо nas, Paracoccus participate).
58 Groups of microorganisms living in the soil 1. Ammonifier bacteria, causing rotting of animal corpses, plant remains, decomposition of urea with the formation of ammonia and other products: aerobic bacteria - B. subtilis, B. mesentericus, Serratia marcescens; bacteria of the genus Proteus; fungi of the genus Aspergillus, Mucor, Penicillium; anaerobes - C. sporogenes, C. рutrificum; urobacteria - Urobacillus pasteuri, Sarcina urea, which break down urea; 2. Nitrifying bacteria: Nitrobacter and Nitrosomonas (Nitrosomonas oxidize ammonia to nitrous acid, forming nitrites, Nitrobacter convert nitrous acid into nitric acid and nitrates);
59 Groups of microorganisms living in the soil 3. Nitrogen-fixing bacteria: absorb free nitrogen from the air and, in the process of life, synthesize proteins and other organic nitrogen compounds used by plants from molecular nitrogen; 4. Bacteria participating in the cycle of sulfur, iron, phosphorus and other elements - sulfur bacteria (oxidize hydrogen sulfide to sulfuric acid), phosphorus bacteria (form easily soluble phosphorus compounds), iron bacteria (oxidize iron compounds to iron oxide hydrate), etc.; 5. Bacteria that break down fiber and cause fermentation (lactic acid, alcoholic, butyric, acetic, protionic, etc.). 6. Pathogenic and opportunistic microorganisms (pathogens of fungal diseases, botulism, tetanus, gas gangrene, anthrax, brucellosis, leptospirosis, intestinal infections, etc.) - with human and animal secretions, with fecal wastewater.
6363 Carbon cycle The interconnection of living organisms on Earth is especially clearly expressed in the carbon cycle. Atmospheric air contains about 0.03% C022, but the productivity of green plants is so great that the entire supply of carbon dioxide in the atmosphere (2600 -10 99 t C02) would be spent in 20 years - a period that is negligibly short on the scale of evolution. Photosynthesis would cease if microorganisms, plants and animals did not ensure the return of C022 to the atmosphere as a result of the continuous mineralization of organic substances. The cyclic transformations of carbon and oxygen are realized mainly through two differently directed processes: oxygen photosynthesis and respiration (or combustion in non-biological reactions).6464 Carbon is removed from the cycle in various ways. Carbonate ions contained in sea water, combine with Ca ions dissolved in it. Ca 2+2+ and precipitate as Ca. C 0 33 (calcium carbonate). The latter is also formed biologically in the calcareous structures of protozoa, corals and mollusks, deposited as limestone rocks. The deposition of non-mineralized organic residues under conditions of high humidity and lack of oxygen leads to the accumulation of humus, the formation of peat and coal. Another type of removal of organic carbon from the cycle is the deposition of oil and gas (methane).
6666 Phosphorus cycle In the biosphere, phosphorus is presented almost exclusively in the form of phosphates. In living organisms, phosphoric acid exists in the form of esters. After the cells die, these esters quickly decompose, which leads to the release of phosphoric acid ions. The form of phosphorus available to plants in the soil is the free ions of orthophosphoric acid (H 33 P 0 P 0 44). Their concentration is often very low; Plant growth, as a rule, is limited not by a general lack of phosphate, but by the formation of poorly soluble phosphate compounds, such as apatite and complexes with heavy metals. Phosphate reserves in deposits suitable for development are large, and in the foreseeable future, agricultural production will not be limited by a lack of phosphorus; however, the phosphate must be converted into a soluble form. In many places, phosphate from fertilizers ends up in flowing waters and lakes. Since the concentration of iron, calcium and aluminum ions in water bodies is low, phosphate remains in dissolved form, which leads to eutrophication of water bodies, which is especially favorable for the development of nitrogen-fixing cyanobacteria. . In soils, due to the formation of insoluble salts, phosphates most often quickly become unavailable for absorption.
6767 Sulfur Cycle In living cells, sulfur is represented mainly by sulfhydryl groups in sulfur-containing amino acids (cysteine, methionine, homocysteine). In the dry matter of organisms, the proportion of sulfur is 1%. During anaerobic decomposition of organic substances, sulfhydryl groups are cleaved off by desulfurases; formation of hydrogen sulfide during mineralization in anaerobic conditions also called desulfurization. Largest quantities naturally occurring hydrogen sulfide are formed, however, during the dissimilatory reduction of sulfates carried out by sulfate-reducing bacteria
6868 Sulfur bacteria live in soil, water, and manure. During the decomposition of organic sulfur-containing substances in the soil, as well as during the reduction of salts of sulfuric, sulfurous and sulphurous acids, hydrogen sulfide is formed, which is toxic to plants and animals. This gas is converted into harmless compounds accessible to plants by sulfur bacteria.
7272 The role of bacteria in the cycle of iron and manganese Iron bacteria have been known for a very long time. In 1836, Ehrenberg suggested that these organisms take part in the formation of bog and turf iron ores. Due to the difficulties of cultivating iron bacteria in laboratory conditions, the physiological properties of these microorganisms have been poorly studied.
The human body normally contains hundreds of species of microorganisms; bacteria dominate among them. Viruses and protozoa are represented by a significantly smaller number of species.
The term “normal microflora” combines microflora that are more or less often isolated from the body of a healthy person.
The blood and internal organs of a healthy person and animals are practically sterile. They do not contain germs or cat. cavities in contact with the external environment - the uterus, bladder. Microbes in the lungs are quickly destroyed. But in the mouth. cavities, in the nose, in the intestines, in the vagina there is a constant norm. microflora characteristic of each area of the body (autochthonous). In this case, a person serves as a source of income to the environment. environment of many m-s.
During the prenatal period, the organism develops in the sterile conditions of the uterine cavity, and its primary contamination occurs during passage through the birth canal and on the first day of contact with the environment. Then, over a number of years after birth, a characteristic definition is formed. biotopes of his body microbial “landscape”. Among the norms. microflora distinguishes resident (permanent) obligate microflora and transient (non-permanent) microflora, which is not capable of long-term existence in the body.
Main microbial biotopes
Leather. On the skin covers m-s are susceptible to the action of bactericidal factors in sebaceous secretions that increase acidity. In such conditions, mainly Staphylococcus epidermidis, micrococci, sarcina, aerobic and anaerobic diphtheroids live. Following basic hygiene rules can reduce the number of bacteria by 90%.
They are breathing. system. In the upper breath. dust particles loaded with microorganisms enter the pathway, most of which are retained in the nasopharynx and oropharynx. Bacteroides, corynemorphic bacteria, Haemophilus influenzae, lactobacilli, staphylococci, streptococci, non-pathogenic Neisseria, etc. grow here. The trachea and bronchi are usually sterile.
Genitourinary system. Microbial biocenosis of the genitourinary organs. systems are more meager. The upper urinary tract is usually sterile; Staphylococcus epidermidis and diphtheroids dominate in the lower sections; Fungi of the genus Candida are often isolated. Mycobacterium smegmatis dominates in the external sections. The vaginal microbiocenosis includes lactic acid bacteria, enterococci, streptococci, staphylococci, corynebacteria, and Doderline bacilli.
Oral cavity. Mouth. the cavity is a convenient place for the development of tissues. Humidity, abundance nutritious ingredients, optimal temperature, slightly alkaline reaction of the environment. favorable factors for the development of properties. Therefore, the microflora of the oral cavity is extremely abundant and diverse. Streptococci dominate among bacteria, constituting 30-60% of the total microflora of the oropharynx. Less aerated areas are colonized by anaerobes - actinomycetes, bacteroides, fusobacteria and veillonella. The oral cavity is also inhabited by spirochetes, mycoplasmas, fungi of the genus Candida and a variety of protozoa. Normal microflora of the oral cavity can cause inflammatory processes and dental caries, however, with a huge number of microbes in the oral cavity inflammatory processes occur relatively rarely. Protective value have a barrier function of the mucous membrane and enamel of teeth, phagocytosis.
Gastrointestinal tract(Gastrointestinal tract). Bacteria most actively colonize the gastrointestinal tract. There are practically no microbes in the stomach of a healthy person, which is caused by the action of gastric juice. Nevertheless, certain species (for example, Helicobacter pylori) have adapted to living on the gastric mucosa.
The upper parts of the small intestine are also relatively free of bacteria, which is due to the unfavorable effects of alkaline pH and digestive tract. enzymes. However, candida, streptococci and lactobacilli can be found in these sections.
The lower parts of the small intestine and, especially, the large intestine are a huge reservoir of bacteria; their content can reach 1012 in 1 g of feces (30% of the dry weight of feces). The intestinal microflora is represented by three main groups. Group 1 includes gram-positive. non-spore anaerobes - bifidobacteria and gram-negatives. bacteroids, making up 95% of the microbiocenosis. Group 2 (associated microflora) is represented mainly by aerobes (lactobacteria, coccal flora, Escherichia coli) specific gravity it is small and does not exceed 5%. Group 3 includes rare opportunistic or facultative microflora. Its specific gravity does not exceed 0.01-0.001% of the total number of microbes. Representatives of the facultative microflora are Proteus, Pseudomonas aeruginosa, Staphylococcus, Candida, Serracina, Enterobacteria and Campylobacteria.
Representatives of the 2nd and 3rd groups under physiological conditions are symbionts of the 1st group, they coexist perfectly with it, without causing harm, showing aggressive properties only under certain conditions.
The importance of body microflora for humans.
Barrier. The intestinal parietal microflora colonizes the mucous membrane in the form of microcolonies, forming a kind of biological film. At the same time, bacteria prevent harmful microbes and their metabolic products from entering the body.
Protection. Normal microflora is one of the most important factors in the natural resistance (stability) of the body, as it exhibits a highly antagonistic effect towards other bacteria, including pathogenic bacteria, preventing their reproduction in the body.
Metabolism. Microflora, especially the large intestine, is involved in digestive processes, including the metabolism of cholesterol and bile acids. The important role of microflora is also that it provides the human body with various vitamins that are synthesized by its representatives (vitamin B1, B2, B6, B12, K, nicotinic, pantothenic, folic acid, etc.) These vitamins provide most of the needs for them body. Microflora regulates water-salt metabolism and gas composition of the intestine.
Detoxification. Microorganisms inhibit the release of toxins by some microorganisms, take part in the detoxification of xenobiotics (foreign substances) entering the body from the external environment and the resulting toxic metabolic products by converting them into non-toxic products, and destroy carcinogenic substances.
Stimulation immune system. Microflora, with its antigenic factors, stimulates the development of the body's lymphoid tissue, the formation of antibodies and thus helps maintain homeostasis of the mucous membranes.
1. Microflora of the animal body.
2. The concept of sterility of animal tissues and organs.
The microflora of an animal's body is often one of the sources of contamination of meat by microorganisms. Consequently, its quantitative and species composition can significantly influence the composition of the microflora of meat obtained after slaughter of animals. The microflora of an animal's body is understood as a set of groups and species of microorganisms that have adapted to coexistence in the process of evolution. There are normal and random microflora of the animal’s body. Normal microflora is a collection of microorganisms that are permanent inhabitants of the animal’s body. The random microflora of an animal’s body is represented by microorganisms that are temporarily in the animal’s body, i.e., those that come from the soil, air, water, or feed. Among them there may be opportunistic and pathogenic microorganisms, which, when the resistance of the animal’s body weakens, can cause the occurrence of various diseases.
Skin and fur. The skin and especially the coat are most heavily contaminated with microorganisms. On 1 cm 2 of animal skin, from hundreds of thousands to several million microbes are usually found, and on 1 cm 2 of fur, from hundreds of millions to several billion. The quantitative composition of microorganisms in the skin and fur of animals depends on the conditions of feeding, care and maintenance of animals.
A wide variety of microorganisms get onto the surface of the skin from soil, water, air and other environmental objects with which animals come into contact.
The qualitative composition of microorganisms is represented mainly by saprophytic microorganisms (micrococci, diplococci, streptococci, staphylococci, sarcina). In addition to these microorganisms, intestinal, pseudomonas and other coli, as well as yeast, fungi, and actinomycetes were found. These microorganisms are commensals. When the body's resistance decreases, they can be causative agents of abscesses, furunculosis and other suppurative processes. In addition to saprophytes, pathogenic bacteria (salmonella, listeria, etc.) are sometimes found on the skin of animals.
Eyes. On the mucous membrane of the eyes (conjunctiva) there are individual microorganisms (cocci, actinomycetes, yeasts, molds). Their quantity is insignificant, since the secretion of the lacrimal glands contains a bactericidal substance - lysozyme.
Respiratory system. Microorganisms are detected only in the upper parts of the respiratory tract, mainly on the mucous membrane of the nose, larynx and upper parts of the trachea. The lower parts of the respiratory tract (bronchioles and lung tissue) of healthy animals are practically sterile, and only during pathological processes (pneumonia, bronchitis) are pneumococci, pyogenic cocci and other microorganisms found in them. These commensal microbes, when the body's resistance is impaired, can cause secondary (secondary) infections.
Blood, lymph and tissue. The blood, lymph and tissues of practically healthy animals, as a rule, do not contain microorganisms. In infectious diseases (anthrax, swine fever, bird plague, etc.), the pathogen can easily be isolated from blood, lymph and other tissues.
Digestive tract. Various microorganisms live in the oral cavity. Due to the presence of lysozyme in saliva, the number of microorganisms may be insignificant. Most often, various coccal bacteria, diphtheroids, vibrios, spirochetes, lactic acid, putrefactive and filamentous bacteria, molds, yeasts, and actinomycetes are found on the mucous membrane of the oral cavity, teeth, and at the root of the tongue. Some of these microorganisms (putrefactive bacteria, molds, yeasts, actinomycetes) are random microflora that come with food, water, air and soil.
The quantitative and species composition of the microflora of the oral cavity of animals often changes and depends on the type of feed and type of feeding. Thus, when feeding animals rough dry feed, there are fewer microorganisms in the oral cavity than when using succulent feed. The species composition of microflora also depends on the type of animal and its age. For example, spirochetes are constantly found in old pigs, but very rarely in gilts.
In the stomach of animals, the number of bacteria is insignificant, since gastric juice has a bactericidal effect. Basically, acid-fast pathogenic bacteria (mycobacterium tuberculosis, anthrax bacillus), spore-bearing aerobic bacilli (potato bacilli, hay bacilli), sarcina and actinomycetes survive. At low acidity The stomach reveals a large number of different microorganisms (putrefactive bacteria, molds, yeasts).
The species composition of stomach microorganisms is influenced by various factors: the type of animal, feeding conditions, feed composition, etc. Thus, the microflora of the pig stomach is represented by dairy
acidic bacteria, cocci, which ferment carbohydrates. The species composition of the horse's stomach microflora is more diverse: lactic acid bacteria, anaerobic bacteria (putrefactive, butyric acid, etc.), yeast, molds, actinomycetes. In different parts of the stomach, the microflora is distributed unevenly.
A variety of soil and epiphytic microorganisms enter the stomach with food: fluorescent, mushroom, potato bacilli, coliform bacteria, micrococci, sarcina, molds, yeasts, actinomycetes, protozoa, cellulose-degrading microbes, microbes that decompose urea, etc. In ruminants Having a multi-chamber stomach, the rumen is often populated by microorganisms (1 g of rumen contents can contain from tens to several hundred millions of microbial cells). In the rumen, lactic acid bacteria, acidophilus bacillus, mesophilic cheese stick, etc. mainly multiply. Biochemical processes caused by the vital activity of microorganisms occur intensively in the rumen of ruminants. Thus, up to 90% of the feed is fermented in the rumen. In addition, a number of vitamins are synthesized here, especially group B (B1, B12, B6), K, nicotinic and folic acids are formed, as well as other organic compounds.
The small intestine contains a small number of microorganisms compared to the large intestine. It amounts to thousands and tens of thousands of microbial cells in 1 g of intestinal contents. The permanent inhabitants of the small intestine are microorganisms that are most resistant to the action of bile and other digestive juices. They are enterococci, lactic acid bacteria (mainly Bacillus acidophilus, spore-forming soil bacilli, Escherichia coli, actinomycetes, yeast).
The microflora of the large intestine and rectum is the most significant in both species and quantitative composition. In 1 g of the contents of the large intestine, up to 3 billion microbial cells are found. Of these, the permanent inhabitants are enterococci, coliform bacteria, lactobacilli, spore-forming anaerobes (mainly Clostridium perfringens, spore-forming putrefactive bacteria - hay bacilli, potato bacilli, etc.). Small quantities contain bacteria of the genus Proteus, cellulose-destroying microbes, yeast, and actinomycetes. Due to the fact that the large intestine contains various microorganisms, complex biochemical processes associated with the breakdown of various nutritional substrates occur in it.
The species and quantitative composition of the intestinal microflora are influenced to a certain extent by the age of the animal, the composition of the feed, the time of year, and antibiotic therapy. Thus, in the first days of life, the intestines of calves are densely populated with lactic acid bacteria, which make up 85-90% of the total microflora. During the grazing period, the composition of the microflora changes. When feeding roughage, fiber fermentation agents multiply.
At infectious diseases animals, as well as with prolonged or improper use of antibiotics and sulfonamide drugs, a sharp change in the composition of the intestinal microflora (dysbacteriosis) can occur. At the same time, the number of lactic acid bacteria decreases, spore putrefactive aerobic and E. coli completely disappear or their antagonistic effect is lost. Conditions are created for the proliferation of fungi, which can cause candidiasis, pneumonia, laryngotracheitis, in some cases ending in the death of the animal.
In healthy animals, the digestive tract often contains pathogenic microorganisms that can cause pathological changes when the body’s resistance weakens.
Genitourinary system. The bladder, uterus, ovaries, and testes of healthy animals usually do not contain microorganisms. On the outer surface of the urethra (urethra) coccal microorganisms are found, and on the vaginal mucosa - a variety of coccal microorganisms, coliform bacteria, and acid-fast bacilli.
In case of infectious diseases of farm animals (tuberculosis, brucellosis, leptospirosis, etc.), the causative agents of these diseases are usually found in the genitourinary organs.
Blood, lymph and tissue. The blood, lymph and tissues of practically healthy animals, as a rule, do not contain microorganisms. In infectious diseases (anthrax, swine fever, bird plague, etc.), the pathogen can easily be isolated from the blood, lymph and other tissues. The bladder, uterus, ovaries, and testes of healthy animals usually do not contain microorganisms.
Questions for self-control: 1. What is meant by normal and random
Microflora of the animal's body?
Microflora of the animal body and its physiological significance
Some microorganisms are permanent inhabitants of the animal body. Others are temporary - come with water, food, air.
M/f skin. Post-s: staphylococci, streptococci, actinomycetes, sarcina, kish-aya and Pseudomonas aeruginosa. sticks. Depends on the conditions of detention.
M/f breath. ways. In newborns. No. Streptococci, staphylococci, actinomycetes, mycoplasmas, molds. and trembling mushrooms.
M/f stomach. Poor due to gastric juice and acidic environment. Sarcines, lactic acid bacteria, actinomycetes, enterococci.
M/f scar. Richer due to epiphytic and soil m/f. Origin complex biochemical and microbiol. processes involving cellulose-forming bacteria. Putrefactive bacteria and fermentation.
M/f thin. Poorer. Enterococci, acidophilus, spore microbes. actinom., Escherichia coli.
M/f thick. The richest. Enterococci, staph, strept, yeast, mold, actin, putrefactive m/o. In case of pain, they are found in the feces of encounters. pathogen. m/o, which can infect healthy people (convalescents).
M/f genitourinary. organs. In healthy people only in external areas. staf, strep, micrococci, mycobacteria..
The role of m/f: the formation of immune activity, antagonism of pathogenic m/f, affects the functions of the digestive tract, is taken into account in the circulation of bile components, the breakdown of fiber and other feed components.
Distribution of microbes in nature
The spread is facilitated by its small size, negligible weight, enormous reproduction rate, and ability to adapt to changes in the environment. environment, temperature factor.
Microflora of air and water. Quantitative and qualitative determination of air and water microflora
The water is most populated at 10-100 cm depth. The UFL applies above. Self-purification of a reservoir: fast flow, UV rays, organic mineralization. compounds by microorganisms, t. In everyday life - filters. In clean waters, cocci predominate; in polluted waters, rods predominate. May be pathogenic: anthrax, brucellosis, erysipelas, pasteurellosis.. Coli titer - minimum (GOST 333) V of water in which 1 Escherichia coli is detected. Coli index - the number of E. coli in 1 liter of water (GOST 2-3).
Air is an unfavorable environment for m/o. But a short stay of microorganisms in the air is sufficient for the transmission of pathogens from patients. Depends on room ventilation and sanitary and hygienic standards. Saprophytes: micrococci, rods, molds and yeasts, actinomycetes. Opportunistic: fungal spores. Pathogenic: mycobacteria, pneumococci, streptococci.
Determination of air and water microflora:
1. OMC: For water - take a water sample using bathometers, make dilutions of 1:10, 1:100, pour in MPA, put in a thermostat for 24 hours at 37 degrees, then count the grown colonies. Norm for drinking water no more than 100 CFU (colony-forming units).
For air - sedimentation method (Petri dish with MPA, thermostat, counting), aspiration method using Krotov’s apparatus (the device sucks in air, settles on a Petri dish with a dense medium, counting), filtration method, including Dyakov’s method (air is passed through MPA and glass beads, filled with a special medium for staphylococci and streptococci, counted)
2. Sanitary indicator microbes: For water - general (TKB 37 degrees) and thermotolerant (TCB 44 degrees) coliform bacteria - coliform bacteria (coliforms). The coli-titer and coli-index are also determined using membrane filter methods (membrane filters are placed on a Seitz asbestos filter, water is filtered, transferred to Endo in a Petri dish with tweezers, incubated, coliforms are counted (Gr-, oxidase-, spores-, lactose+) ), fermentation meth (inoculation on Kessler's medium with lactose, incubation, subculture on Endo, coliforms are counted). Enterococci - an alkaline-polymyxin environment. Cl. Perfringens - Wilson-Blair medium, iron sulfite agar.
For air - hemolytic streptococci, staphylococci ( salt environments- Chistovich).
3. Pathogenic microorganisms.
