microbiology lectures of fourth semester

microbiology

1. Lecture 1 ,2 Normal microflora of the gastrointestinal tract.  The microflora of the digestive tract it is heterogeneously mix of microorganisms. If have moving from top to bottom of GIT, we can see that the stomach is less colonized than other sections of the gastrointestinal tract, due to the action of hydrochloric acid. Already in intestine the concentration of microorganisms increases. In the large intestine, the number microorganisms reaches peak values ​​- 1010-1012 CFU / ml and anaerobes prevail over aerobes in a ratio of 1000:1. The relationship between intestinal microflora and the human have been established in the process of evolution . Role of the GIT microflora very importantly for regulated the protective mechanisms? in the form of gastric secretion, in peristalsis, in epithelial desquamation ( flaking,peel off) secretion of antimicrobial peptides and maturation of the immune system. Normal autoflora - a associations of microorganisms presents in the body a particular ( определенный ) human , animal , p lant organisms , whose natural role is to ensure the interrelationship of microorganisms of organs and tissues with the external environment (the total surface of the gastrointestinal tract is about 300 m, respiratory system - 80 m skin - 2 m

2. Saprophytes - microorganisms, the nutrient medium for which are intermediate or end products of life microorganism . Symbionts - organisms of various biological species with interconnected and mutually beneficial joint life activity. The entire microflora of the digestive tract is divided into obligate (main microflora), facultative (conditionally pathogenic and saprophytic microflora) and transient (временный, приходящий) (random ( causal) microorganisms). It should be noted that the natural form of existence in nature of any microorganisms is an immobilized state (V . L Paikov , 1999). The symbiotic community of human organisms and microorganisms can viewed as a regulatory system. Optimal relationship unicellular microflora and human organism guarantees a long-term stability and, ultimately (в конечном счете) human health. For example, the mucous of the digestive tract is a good example of regulatory system model. The microflora of the digestive tract of a child is different limited species diversity and, as a result, “decrease biological stability”, insufficient ability (недостаточная способность) of the system microflora-mucous to self-regulation.

3. Their number and species diversity increase gradually (постепенно) as the range of expands (в зависимости от диапазона, по мере расширения) of food products or feeding and the process of microbial digestion in the large intestine . Due to the relative immaturity of the enzyme and barrier systems in young children, corresponding to the peculiarities of nutrition, metabolism and assimilation of waste products normal microflora are relatively imperfect. So opportunities( возможности) for manifestation of pathogenic properties of microbial metabolites of even normal microflora, in the internal environment organism is more great than in adult body. For the same reasons, young children are pronounced the relationship between functional and microecological disorders is obvious intestines. In addition, under the influence of adverse factors and lack of breastfeeding risk of colonization of opportunistic and pathogenic microflora of the intestines of an infant is especially . It has been established that the intestinal microflora of a woman in the period pregnancy have a major physiological role in the formation of microflora of newborn organism .

4. In last years, attention pediatricians more often attracted to questions related to the role of microflora mothers in the development of immunity in a newborn child, which provides tolerance to those microorganisms that, to the maximum extent( степени ), induced in the fetus (у плода) . Memory of the fetal immune system for microbial antigens from mother through the placenta, persists( сохраняется) after birth and even in adulthood organisms. The following main factors of formation can be distinguished microbiocenosis :  I. Before and during childbirth: • Genetic; • Mother's microflora; • Microflora of medical person а l; • Hospital microflora; • Medicines. II. After birth: • Composition of breast milk; • The composition of the milk formula; • Pro- and prebiotics food.  

5. There are three phases of "physiological" colonization of the gastrointestinal tract: 1) The first phase - aseptic (up to 10-20 hours); 2) The second phase - colonization by microorganisms (up to 2-4 days); 3) Third - stabilization of microflora. In the first hours and days in the intestines of newborns, micrococci, staphylococci, enterococci and clostridia are predominantly found, then enterobacteria (primarily Escherichia coli), lactobacilli, bifidobacteria appear. For 1.5-2 weeks after birth, the number of bifidobacteria and lactobacilli increases, which in primarily due to the unique biological, immunological and other properties of human milk, causing the formation in the intestines of the newborn of the most physiologically favorable( благоприятный) microbial flora. One of the clinical criteria for "physiological" colonization intestinal microorganisms is the content in feces of bifidflora . With milk formula, not form ed the predominance of any group of microorganisms/

6. Early brest feeding of newborns , including in the first minutes after birth, is not only the basis for the formation of the microflora of the gastrointestinal tract, but also the « key » to the future health of the child in subsequent years of its development.  Despite( несмотря на) the fact that the total number of microorganisms from the first days life of a child is practically approaching (приближенно) the microflora of older children ages and adults, and after 2 years the composition of the intestinal flora of the child practically does not differ from an adult, certain types of microbes still undergo changes (претерпевать изменения). The microflora of the digestive tract protects a person from colonization by exogenous pathogenic microorganisms and inhibits (тормозит) the growth already present in it pathogenic microorganisms. The mechanism of this phenomenon is the competition of microflora for nutrients and binding sites (участки связывания) , as well as in the production of normal microflora certain pathogen-inhibiting substances. In the process of a child's growth, there are certain "critical" periods of development of immunobiological reactivity, when antigenic exposure ( воздействие) to the immune system gives inadequate or even paradoxical answer: it may not be enough to protect or excessive (чрезмерный) - hyperergic (allergic).

7. The first critical period is the neonatal period (the first 4 weeks - 28 days of life). The system of phagocytosis is not developed . The newborn shows weak resistance to opportunistic ( contingently , on probation )(условно-патогенный) , pyogenic, gram-negative flora. Characterized by a tendency to generalization of microbial-inflammatory processes, to septic ( putrefactive ) (гнилостный) states.   The second critical period - 3-6 months of life - is characterized by weakening of passive humoral immunity due to catabolism maternal antibodies. The content of immunoglobulins in the blood falls to critical values. Mostly antigens (infections) develop primary immune response (ответ) with predominant synthesis (с преимущественным синтезом) of IgM antibodies, not leaving immunological memory. This type of immune response occurs also with vaccination against infectious diseases, and only revaccinations form a secondary immune response with the production antibodies of the IgG class. There is an insufficiency of the system (недостаточность системы) of local immunity (repeated SARS, intestinal infections and dysbacteriosis , skin diseases). Susceptibility( восприимчивость) to allergic and infectious processes in the intestine with the development of microecological disorders (расстройства) . It is less pronounced (выражена) with breastfeeding.

8. The third critical period is the 2nd year of life . In this period significantly expand (значительно расширяются) the child's contacts with the outside world (freedom movement, socialization). The primary nature of the immune response to many antigens (IgM synthesis), although the immune response is more degree switches ( в большей степени переключается) to the formation of antibodies of the IgG class. However, the synthesis antibodies of the IgG2 and IgG4 subclasses is limited. CD immunophenotypes leukocytes and lymphocytes circulating in the blood, almost no change, but they become more sensitive to cytokines and interleukins. Cytokines - interleukins and interferons - are well known, if not as highly effective, but practically as the only antitumor agents in melanoma and kidney cancer. Endogenous interleukin-2 activates T-lymphocytes and NK-cells, which recognize and destroy tumor cells, increases the production of antibodies by B-lymphocytes, Recombinant interleukin-2 has the same biological activity as the endogenous cytokine. Aldesleukin action includes activation of cellular immunity with marked lymphocytosis, eosinophilia, and thrombocytopenia

9. According to immunobiological characteristics, a significant part (значительная часть) of the children of the second year of life is not ready for the conditions of being( существовать , находиться) in a children's team ( group). The fourth critical period is the 6-7th years of life . Content formed elements of the blood there is a second cross (absolute and the relative number of lymphocytes decreases and is established the predominance of neutrophils). Lymphocytes circulating in the blood have a wide immune memory, the intensity decreases processes of proliferation (процесс распространения) of unspecialized lymphocytes. Medium the concentration of IgG and IgM in the blood corresponds to the level of adults, however the plasma level of IgA has not yet reached the final values.  The content of IgE in blood plasma is characterized by a maximum level in compared( в спавнении ) with other age periods, which is partly ( обусловленно ) due to frequent (частыми) parasitic infections during this period – giardiasis ( lambliosis ), helminthiases. This period is characterized by an increase in the frequency of atopic, immunocomplex , parasitic diseases, manifestations of late immunodeficiencies . Many chronic diseases develop polygenic nature ( полигенный характер, полигенная природа).

10. Polygenic diseases (formerly diseases with a hereditary predisposition) are caused by both hereditary factors and, to a large extent, environmental factors. In addition, they are associated with the action of many genes, so they are also called multifactorial. The most common multifactorial diseases include: rheumatoid arthritis, coronary heart disease, hypertension and peptic ulcer disease, liver cirrhosis, diabetes mellitus, bronchial asthma, psoriasis, schizophrenia) . The fifth critical period is adolescence (in girls from 12 to13 years old, in boys from 14-15 years old) . The pubertal growth spurt is associated with a decrease in the mass of lymphoid organs. organs of the immune system, first of all, the thymus gland - begin to undergo reverse development - involution. The secretion of sex hormones (androgens) leads to suppression cellular link of immunity and stimulation of its humoral link. The content of IgE in the blood decreases. Finally formed a strong and weak types of immune response (expression of Ir - and Is-genes). growing the impact of exogenous factors (smoking, xenobiotics , etc.) on immune system. Increased sensitivity to mycobacteria(tuberculosis).

11. As you know, the intestinal microflora is currently considered (в настоящее время считается) as an important metabolic organ of the body, the state of which determines the health of not only the intestines, but the whole organism. Microorganisms are involved (вовлеченный) in physiological, biochemical and immunological processes in the host organism. microbial flora, inhabiting (заселяющий) the gastrointestinal tract, is involved in the metabolism of proteins, carbohydrates, fats and other substances entering the body, or formed during digestion. Established detoxifying role microorganisms in relation to both endogenous and exogenous substrates. Detoxification (med.) - natural and artificial removal of toxins from the body Gastrointestinal tract, along with skin, mucous membranes and respiratory system, represents the main routes of entry into xenobiotics in the human body. ( Xenobiotics (from the Greek. ξένος - alien and β ίος - life) - chemicals alien to living organisms that are not included in the biotic cycle. As a rule, an increase in the concentration of xenobiotics in the environment is directly or indirectly associated with human economic activity. These include: pesticides, some detergents, synthetic dyes (красители) ) .

12. Neutralization mechanisms - neutralization followed by elimination of non-toxic or low-toxic metabolites are due to overall activity of the digestive system. Of decisive importance functional state of the liver. Serves as a powerful barrier to toxins muco -epithelial layer of the intestine. The microbial flora of the gastrointestinal tract, in addition to a variety of effects on the macroorganism , is able to protect the latter from endogenous and exogenous toxic substances - amines, salts of heavy metals, pesticides, drugs, in particular antibiotics . Microorganisms play an important role in the metabolism and neutralization of nitrates entering into the body with food and water Beneficial microflora, primarily bifidobacteria , synthesis of a number of vitamins, produces some biologically active substances (for example, amines). Microorganisms complement or support the functionality of the macroorganis .   The specific action of microbial flora determines their participation in etiology and pathogenesis of pyoinflammatory and other diseases.

13. Microbial flora is involved in the regulation of the state intestinal motility (моторика кишечника) : stimulates gastric emptying (опорожнение) and peristalsis intestines and reduces the transit of food. Beneficial microflora prevents intestinal contamination (загрязнение) with pathogenic microorganisms . It has been established that (установлено, что) the disappearance or significant (значительное) decrease microbial flora leads to changes in the functional state digestive organs. Mechanisms of action of microbial flora on the motor function of the gastrointestinal tract are complex (сложны) and are ambiguous (неоднозначны) . The activity of the intestine can be influence (влиять) by amines formed in the life process of microorganisms. Such highly active (высокоактивные) biologically substances like histamine and serotonin change the function of the sphincters of the digestive tract, more than 2/3 of which located in the intestine. As can be seen from the above, none of the functions of the gastrointestinal tract can be implemented ( реализована) without the participation of microflora.

14. The microbial flora of the intestine is involved in enterohepatic circulation of bile acids. It has been established that the intestinal microflora have been an active role in induction of food tolerance to food allergens, which is based on lies the balance in the Th1/Th2 system (Th1 is a subpopulation that determines anti-infective orientation of the immune response, Th2- polarization of the immune response towards the development of atopy) . Bifido - and lactobacilli, having a pronounced antagonistic activity against pathogenic bacteria, regulate quantitative and qualitative composition of the intestinal microflora, slow down the growth and reproduction of pathogenic and opportunistic microbes in it. Bifidobacteria and lactobacterin are among the most favorable microorganisms for human health Bifidobacteria (BF) - gram-positive bacilli, strict anaerobes( строгие анаэробы) . In the large intestine of children, bifidobacteria are the main group of saccharolytic bacteria and is for up to 95% of the total microbial populations ( Kawase K., Suzuki T, 1981). Dominant position bifidobacteria in the intestine protects the body from pathogenic microflora, especially in children during the first year of life.

15. Summarizing the results of the research, the following can be given child-friendly properties of BF: 1) the end products of BF ( bifidobacteria ) metabolism are strong acids lactic and acetic, which lower the pH of intestinal contents and therefore have antibacterial properties . 2) produce vitamins, mainly group B and some enzymes, such as casein phosphatase and lysozyme;  3) some components of BF cells act as immunomodulators , as they, increase(strengthen the immune response to malignant cells and pathogenic .   4) BF are able to restore the normal balance of intestinal microflora after antibiotic therapy. Formula-fed childs have higher LB(lactobacilli) levels and is 108 CFU(colony forming units) / ml. In 73% of adults, LB ranges from 109 CFU / ml, and for vegetarians - 1011 CFU / ml ( Finegold S.M., 1977). to bacteria, belonging (принадлежит) to the group of gram-negative obligate anaerobic bacteria primarily bacteroids and fusobacteria .

16. Bacteroids - Gram-negative , non-spore-forming, polymorphic bacillus. Strict anaerobes ( строгие анаэробы ). Colonize the intestines of newborns by 6-7 days of life. At breastfeeding stand out in about 50% of children, their level is 1010 CFU / ml. In adults, their level reaches 109-1010 cfu /ml. It has been established (установлено) that bacteroids take part (принимают участие) in digestion, as well as inbreakdown ( fission , disintegration )(расщепление) of bile (желчных) acids. Some strains (штамм) are able to synthesize enterotoxin, 5-10% of diarrhea is caused by enterotoxigenic strains bacteroids . Moreover, children from 1 to 5 years of age most often suffer diarrhea provoked by bacteroids . In the elderly, bacteroids can cause colon cancer . Fusobacteria - gram-negative non-spore-forming polymorphic rod-shaped (палочковидный) bacteria. Strict anaerobes. They are characteristic for the intestinal microflora of adults, their concentration is 108- 109 cfu /ml. Fusobacteria are often isolated from pathological material with purulent complications (при гнойных осложнениях) of various localization . Veillonella are gram-negative obligate anaerobic cocci. Their the level in children of the first year does not exceed (превосходит) 105 CFU / ml, and approximately ( nearly) (примерно) in50% of children. In children receiving( получение) artificial nutrition, their concentration higher and often exceeds 10s CFU/ml. Their distinguishing feature is the ability to produce gas, which can cause dyspeptic disorders .

17. Basis for comparison Gram-positive Gram-negative bacteria Meaning Bacteria that test positive for Gram stain and appear as dark purple or purple when viewed under a microscope Bacteria that test negative for Gram stain and appear as red or pink when viewed under a microscope Examples Streptococci , Clostridium, Lactobacillus, Bacillus subtilis, Leuconostoc . Vibrio, Rhizobium, Escherichia coli, Acetobacter. Cell wall. Single layer. Double layer Straight and straight. Wavy and uneven Less elastic and more rigid More elastic and less rigid The rigidity of the cell wall is due to the high content of peptidoglycan, which is about 80%. The elasticity of the cell wall is due to a smaller amount of peptidoglycan, which is about 2-12%. The cell wall contains muramic acid, which makes up about 16-20% of the total dry weight of the cell.. The content of muramic acid is only 2-5% of the total dry weight.. The cell wall exhibits alkali resistance. The cell wall is sensitive to alkali. Cell wall contains teichoic acid Teichoic acid is absent from the cell wall. The thickness of the cell wall can be up to 15-30 nm, or sometimes it can be 80 nm. The thickness can be up to 8 - 12 nm in the range of the cell wall. The lipid content is low, which is about 1-4%. The lipid content is high, which is about 11-22%. The outer membrane is missing. The outer membrane is present. Produce exotoxins. Produce endotoxins. Antibiotic affects The cell is less sensitive to chloramphenicol, tetracyclines, streptomycin and highly sensitive to sulfonamide and penicillins, antibiotics. Cells show high sensitivity to sulfonamide, penicillins and low sensitivity to chloramphenicol, streptomycin and tetracyclines .

18. Lecture 3. Ecology of microorganisms. Normal microflora. Microorganisms are ubiquitous. They inhabit the soil, water, air, plants, animal and human organisms - the ecological habitats of microbes.  There are free-living and parasitic microorganisms. Wherever there are at least some sources of energy, carbon, nitrogen, oxygen and hydrogen (the building blocks of all living things), microorganisms are necessarily found . Soil microflora.   Soil is the main habitat for microbes. The composition of the microflora consists of many thousands of species of bacteria, fungi, protozoa and viruses. Pathogenic microorganisms enter the soil with human and animal bioexcretions (feces, urine, sputum, saliva, pus, sweat, etc.), as well as with corpses. The spore-forming pathogenic microorganisms that cause anthrax, tetanus, gas gangrene, and botulism remain in the soil for the longest time, which determines the epidemic significance of the soil in these infections. Sapronosis pathogens can autonomously inhabit soil and water and be associated with soil and water organisms, i.e. this natural habitat for them is the main reservoir of pathogens. Soil and water in the case of sapronoses acts as a source of infection for animals and humans

19. Water microflora. A serious environmental problem is wastewater containing a significant amount of microorganisms and organic substances that do not have time to self-purify. Sanitary and hygienic water quality is assessed in various ways. More often determine the coli-titer and coli-index, as well as the total number of microorganisms in ml. Coli-index- the amount of E.coli (E. coli) in one liter, coli-titer- the smallest amount of water in which one cell of Escherichia coli is found. The sanitary and epidemiological significance of determining microorganisms in various objects is studied by sanitary microbiology. Its main principles include the indication (detection) of pathogens in environmental objects, indirect methods - the identification of sanitary-indicative microorganisms, the determination of the total microbial contamination. Water is essential in the epidemiology of intestinal infections. Their pathogens can enter the external environment (soil) with feces, with wastewater - into water bodies and, in some cases, into the water supply network. 

20. water microflora

21. Marine water microflora

22.   Air microflora.   Air as a habitat is less favorable than soil and water - few nutrients, sunlight, drying. The main source of air pollution by microorganisms is the soil, less - water. In terms of species, cocci (including sarcins ), spore bacteria, fungi, and actinomycetes predominate. Of particular importance is the microflora of enclosed spaces (accumulates when excreted through the human respiratory tract). Airborne (due to the formation of persistent aerosols) spread many respiratory infections (flu, whooping cough, diphtheria, measles, tuberculosis, etc.). The microbiological purity of air is of great importance in hospital conditions (special operating rooms and other surgical departments). Normal (i.e., in a healthy body) microflora is quantitatively and qualitatively represented in different parts of the body ( ecotopes ) differently. The reasons are different living conditions.  Autochthonous (i.e., inherent in a given area) microflora can be divided into resident (permanent) and transient (non-permanent). On the mucous membranes, especially the gastrointestinal tract, representatives of the normal microflora live in the form of two forms - some of them are located in the lumen (luminal), the other is enclosed in a mucosal parietal matrix that forms a biofilm (parietal microflora). Colonization resistance of the intestine is associated with it - a natural barrier to protect the intestines (and the body as a whole) from infectious agents .

23. Normal microflora of the skin.   The most populated by microorganisms are places protected from the action of light and drying. The composition of the microflora is most constant in the region of the mouths of the sebaceous-hair follicles. Staphylococcus epidermidis and S. saprophyticus , fungi of the genus Candida are more often detected, less often diphtheroids and micrococci. The microflora of the respiratory tract.   The mucous membranes of the larynx, trachea, bronchi and alveoli of a healthy person do not contain microorganisms. The bulk of the microflora of the oropharynx and nasopharynx falls on the green streptococcus, Neisseria, diphtheroids and staphylococci are less common.   Microflora of the urinary tract.   The microbial biocenosis is poor, the upper sections are usually sterile. The vagina of a healthy woman is dominated by Doderlein lactobacilli (lactobacilli), which create an acidic pH that inhibits the growth of gram-negative bacteria and staphylococci, and diphtheroids . There is a balance between lactobacilli on the one hand and gardnerella and anaerobes on the other.

24. Normal microflora of the skin

25. Normal microflora of the respiratory tract

26. Dysbacteriosis - changes in the quantitative and qualitative composition of the microflora, mainly the intestines. Often accompanied by an increase in facultative anaerobic or residual microflora (gram-negative rods - Escherichia coli, Proteus, Pseudomonas), staphylococci, fungi of the genus Candida. These microorganisms are usually resistant to antibiotics and, if the normal flora is suppressed by antibiotics and natural resistance is reduced, they are able to multiply freely. The most severe forms of dysbiosis are staphylococcal pneumonia, colitis and sepsis, candidiasis, pseudomembranous colitis caused by Clostridium difficile. For treatment, biological preparations are used that restore the normal microflora - eubiotics - colibacterin (they use a special strain of E. coli, a Shigella antagonist), lactobacterin , bifidumbacterin , bifikol , bactisubtil and others, as well as special bacteriophages

27. Lecture 4,5 Causative agents of intestinal infections. Dysentery is caused by Shigella, enterobacteria of the genus Shigella (S.dysenteriae, S. flexneri , S.sonnei , S.boydii ) - Gr- motionless rods 2-3 microns long. Spores and capsules do not form. They have fimbriae ( adhesins ). facultative anaerobes. They grow well on simple nutrient media, often dissociate into the avirulent R-form. Break down carbohydrates into acid without gas. Identification of the pathogen is carried out by biochemical and antigenic properties.  The causative agents of dysentery are unstable in the external environment: they die when dried, exposed to sunlight, competitive microflora; sensitive to boiling and the action of conventional disinfectants. Often isolated strains with drug resistance, including polydrug resistant. Shigella - unconditionally pathogenic invasive bacteria, pathogens of anthroponotic infection (dysentery, shigellosis). They are able to colonize the intestinal mucosa, penetrate into epitheliocytes and multiply in them. As a result of invasion and the action of cytotoxins , epitheliocytes die, catarrhal-ulcerative inflammation develops - colitis

28. Shigella dysenteriae

29. The source of infection is a microbe carrier or a sicker person in whom the pathogen is excreted with feces. Infection - by alimentary, less often by household contact (through infected objects, hands). The disease is accompanied by intoxication of the body, abdominal pain, diarrhea (feces mixed with blood), metabolic disorders, intestinal dysbacteriosis . In children, especially when infected with toxigenic S.dysenteriae, dysentery is severe, often fatal. With untimely and inadequate treatment, the infection becomes chronic, and microcarriage is often formed. Immunity is very unstable, species-specific, repeated diseases are possible.  Microbiological diagnostics is based on the isolation of the pathogen and its identification (microbiological method). An additional method is serodiagnosis (detection of serum antibodies to Shigella in RA, RPHA, etc.).  Specific treatment : nitrofuran preparations, antibiotics (according to the sensitivity of the pathogen); dysenteric bacteriophage (in the first days of the disease); drugs to restore normal microflora ( colibacterin , lactobacterin , bifidumbacterin ). Specific prophylaxis : for emergency - dysenteric bacteriophage; a vaccine is being developed for a planned one. Causative agents of typhoid and paratyphoid

30. Typhoid and paratyphoid diseases are caused by enterobacteria of the genus Salmonella (typhoid fever - S.typhi; paratyphoid A and B - S. paratyphi A and S, schottinuelleri (B), respectively. These are gram-negative mobile rods ( peritrichs ) 1-3 microns long; capsules do not form. "Facultative anaerobes. Grow well on simple media, including in the presence of bile, forming transparent colonies with a diameter of 2-4 mm, uniform turbidity in the broth. The biochemical and antigenic properties of Salmonella are diverse and underlie their identification. Sensitive to conventional disinfectants, boiling, pasteurization, in the external environment (in water) can persist for up to several months.They are unconditionally pathogenic, typical invasive bacteria - pathogens of anthroponoses (S. schottmuelleri is also pathogenic for calves, chickens). The source of infection is a sick person or microcarrier , from which the pathogen is excreted in faeces and urine. Infection - alimentary way (often infected water, milk). Adhesins provide Salmonella with attachment to intestinal epitheliocytes , invasins - penetration into the lymphatic apparatus and mesenteric lymph nodes, where they multiply. The onset of the disease coincides with the entry of bacteria into the blood (usually 2 weeks after infection). The period of bacteremia is accompanied by fever and intoxication (when Salmonella dies in the blood, their endotoxin is released). In the future, hematogenous dissemination of the pathogen occurs in the liver, spleen, bone marrow and other organs; in large quantities, salmonella accumulate in the bile ducts and gallbladder.

31. Salmonella typhi

32. With bile, they again enter the intestine and are re-introduced into the already sensitized lymphatic follicles. An allergic reaction develops the Arthus phenomenon with the formation of ulcers in the intestinal wall. With perforation of the intestinal wall or intestinal bleeding, a fatal outcome is possible. Immunity is stable, repeated diseases are rare. The causative agents of salmonellosi   Salmonellosis is caused by numerous representatives of the genus Salmonella - S. typhimurium , S. enteritidis , S. choleraesuis , S. haifa , S. anatum , less often others. They differ from the causative agents of typhoid-paratyphoid diseases in ecological features, antigenic structure and some pathogenic properties.  The source of infection is various animals (cattle, pigs, horses, dogs, cats, rodents) and poultry. Infection occurs more often when eating and writing infected meat (beef), chickens and eggs; infection of meat can be intravital or post-mortem (during slaughter, cutting, storage, transportation, cooking). Pathogens are relatively stable in the external environment, they can multiply at a temperature of -4 (in a domestic refrigerator) without a noticeable organoleptic change in the product; stored in frozen meat and eggs for up to 1 year; boiling kills instantly

33. Salmonella are enterotoxigenic , invasive, and cytotoxic microbes that damage intestinal epitheliocytes ; they multiply in macrophages, penetrate into the lymphatic system, and in some cases - into the blood (with intoxication, dissemination and reproduction in the internal organs). Usually the disease proceeds as acute gastroenteritis (without generalization) and ends with recovery within 3-5 days. Immunity is unstable, type-specific. In hospital conditions, special hospital strains of Salmonella can form. characterized by high virulence, resistance to antimicrobial effects and the ability to cause outbreaks of hospital (nosocomial) infection among patients, the infection of which occurs by contact, household, airborne or food.  Specific treatment : used in the treatment of generalized forms ( levomycetin and other antibiotics).  Specific prevention : planned is not developed; for emergency, a polyvalent salmonella bacteriophage was proposed.

34. The causative agent of cholera   Cholera is caused by vibrio cholerae (Vibrio cholerae biovar cholerae , Vibrio cholerae biovar El-tor, Vibrio cholerae serovar O-139 "Bengal") - Gr - a small curved comma-shaped or straight stick without spores and capsules. Very mobile ( monotrichous ). Facultative anaerobe. Grows on simple media. When isolating a pure culture, elective media are used for inoculation - alkaline peptone water, alkaline nutrient agar, etc., where characteristic growth is noted: after 6 hours on peptone water - a delicate bluish film, on agar (after 12-18 hours) - transparent round smooth colonies with a blue tint in oblique light. Biochemically active. Some of them can cause intestinal infections in humans, and if they have cholera exotoxin, a cholera-like disease. The causative agent of cholera is sensitive to drying, exposure to sunlight, competitive microflora, acids (including weak ones), common disinfectants, and boiling; it can be stored for a long time in flowing reservoirs, sea water, in the body of aquatic organisms (frogs, oysters, crabs). Infection occurs in the alimentary way (more often with infected water). Vibrios that have entered the intestine colonize the epithelium, secrete cholerogen , which, with the participation of neuraminidase, penetrates into the epitheliocytes , activating their adenylate cyclase system, which leads to the release of salts from the cells and the accumulation of fluid in the intestinal lumen. Patients have indomitable vomiting, profuse diarrhea, dehydration of the body, which can lead to the death of the patient. Cholera is characterized by rapid epidemic spread and relatively high mortality, so it is classified as a particularly dangerous infection.

35. Microbiological diagnostics is carried out in accordance with approved instructions in special laboratories and includes: methods of express diagnostics, isolation of a pure culture and its identification (by morphological, cultural, biochemical, antigenic properties and sensitivity to cholera phages) with the determination of the sensitivity of the pathogen to antibiotics.  Specific treatment : with severe dehydration, pathogenetic therapy is most significant (the introduction of saline solutions to restore the water-salt balance of the body); for etiotropic therapy, antibiotics are used - tetracycline, chloramphenicol. Specific prophylaxis : for emergency prophylaxis, antibiotics are prescribed to contacts (in accordance with the sensitivity of the pathogen), cholera bacteriophage; planned prophylaxis is carried out with vaccines (killed cholera vaccine El Tor; cholerogen-anatoxin with O-antigen and vibrio enzymes). Of great importance in the prevention of cholera is the microbiological control of imported products and water bodies, the timely detection of sick and cholera microcarriers , their isolation and sanitation.

36. Causative agents of escherichiosis   Escherichia are typical representatives of the Enterobacteriaceae family. The genus Escherichia is represented by 1 species (E. coli). Escherichiosis is caused by pathogenic variants of E. coli - Gr-rods 2-6 μm long, often mobile ( peritrichous ), without spores. They have pili (fimbria), and some strains have a micro- or macrocapsule . facultative anaerobes. They grow well on simple media, forming a uniform turbidity in nutrient broth after 24 hours, on agar - smooth or rough colonies of medium size. On differential media (Endo, Levin) ferment (sometimes slowly) lactose and form colored colonies. They have pronounced saccharolytic properties (decompose carbohydrates to acid and gas) and proteolytic - they decompose proteins to indole and hydrogen sulfide. In the antigenic structure, 0-, K- and H-antigens (thermostable and thermolabile ) are distinguished, according to which Escherichia are divided into a large number of serogroups and serovars , designated as a formula (for example: E. coli 0126: K60: H2). Resistance in the external environment and to antimicrobial effects is the same as that of most enterobacteria ; Escherichia are sensitive to antibiotics (aminoglycosides, tetracycline), with the exception of multi-resistant strains, for example, hospital ones.  Among the causative agents of escherichiosis , enterotoxigenic (0-1, 0-8), enteropathogenic (0-55. Ol 11) and enteroinvasive Escherichia coli (ETEC, EPEC and EIEC, respectively), enterohemorrhagic (0-1576), enteroaggregative (various groups) . They differ in a set of pathogenicity factors ( adhesins , invasins , cytotoxins ) and in antigenic structure; they cause diseases characteristic of each variant. Cholera-like diseases often cause ETEC of serogroups 01, 015, 0148, etc.; dysentery-like - EICP 0124, 0151, etc.; colienteritis in young children - EPKP 026. 055, 0111.

37. Escherichia colli

38. The source of infection is a sick person or microcarrier . Infection - alimentary way. More often children under 2 years old ( colenteritis ) get sick. Immunity is weak, type-specific. Local immunity in children and adults is provided by secretory IgA; passive immunity in children to dysentery-like escherichiosis is associated with the entry of IgG through the placenta to EICP. Serum IgM against EPC does not pass through the placenta, so children are more susceptible to EPC.  Microbiological diagnostics is based on the isolation of the pathogen from patients in pure culture and its identification by morphological, physiological, antigenic properties and pathogenicity factors. Belonging to one or another serogroup is determined in RA with diagnostic coli-sera. Specific treatment : drugs from antagonist microbes ( lactobacterin , bifidumbacterin , polyvalent coli-protein bacteriophage against serovars 0-55, 0-111); in severe cases - antibiotics in accordance with the sensitivity of the pathogen strain.  Specific prevention : not developed.

39. The causative agent of botulism Botulism is caused by Clostridia (Clostridium botulinum) - large spore-forming Gr+ rods. The oval spore makes the cage look like a tennis racket. Motile ( peritrichous ), does not form a capsule. obligate anaerobe. Grows on special media; on liquid it gives turbidity, on blood agar - an irregularly shaped colony with a zone of hemolysis. Actively ferments proteins and carbohydrates. At a temperature of 22-25 under anaerobic conditions on organic substrates (for example, in food, canned food) it produces a highly toxic exotoxin (neurotoxin) of one of the 7 serovars (A, B, C, D, E, F, G). Botulinum toxin is the most powerful biological poison that affects various animals, birds and humans. Death occurs after taking 0.001 mg or more of botulinum toxin. Vegetative cells of C. botulinum are less stable in the external environment than spores that can withstand drying, freezing, boiling for many hours, and the action of disinfectants. Botulinum toxin is destroyed by boiling within 20 minutes. C. botulinum lives in the intestines of animals, humans, fish, as well as in the soil, where its reproduction is noted. Botulism is a severe toxinemia disease , food toxicosis , accompanied by damage to the bulbar nerve centers. Poisoning occurs after eating foods with botulinum toxin accumulated as a result of the reproduction of C. botulinum (usually home-made canned food: meat, fish, mushrooms, vegetables).

40. Clostridium botulinum

41. The incubation period is 6-24 hours, sometimes up to 10 days. The toxin is not destroyed in the digestive tract, is quickly absorbed into the blood and selectively blocks the functional activity of neurons. There is general intoxication, aphonia , damage to the organs of vision (double vision, "grid before the eyes"), difficulty in swallowing. Lethality reaches 60%. Immunity is weak, type-specific; recurrence is possible.  Microbiological diagnostics is aimed at detecting botulinum toxin and determining its serovar , as well as isolating a pure culture of the pathogen. The toxin is determined in a neutralization reaction on white mice, for which the animals are injected (after a 5-minute contact) with a mixture of an extract from the test material (vomit, feces, blood, suspected product) with antitoxic anti-botulinum sera (polyvalent and the most common types A, B, C, and S). For rapid detection and typing of the toxin, it is recommended to use RPHA with antitoxic erythrocyte diagnosticums . Isolation of the culture is carried out on special liquid media under anaerobic conditions, followed by identification but morphological and physiological properties and determination of the type of toxin in the culture liquid.  Specific treatment : urgent administration of anti-botulinum sera (initially polyvalent - A, B, C, E, and after establishing the type of toxin - the serum of the corresponding serovar ).  Specific prophylaxis : emergency is carried out for persons who have used a product poisoned with botulinum toxin (the same anti-botulinum serum is injected); planned (with the threat of poisoning) - the introduction of polyanatoxins (A, B, E) as part of the preparations " Tetraanatoxin ", " Pentaanatoxin ", " Sextaanatoxin ".

42. The causative agent of brucellosis   The causative agents of this zoonosis - brucella 3 species ( Brucella melitensis , B. abortus , B. suis ) - Gr - small (0.5-1.0 microns) rods or cocci without spores, flagella and capsules. Aerobes. They are cultivated on special media with the addition of blood, glucose and vitamins (usually after 1-3 weeks they form round, colorless, smooth colonies). Identification and differentiation of Brucella is based on biochemical properties, resistance to certain dyes and lysability by bacteriophage. Pathogenicity is associated with the presence of invasive properties, the ability to intracellular parasitism, the action of endotoxin and is most pronounced in B. melitensis . The causative agent is resistant to environmental factors, withstands pasteurization.  Source of infection - animals sick with brucellosis: B- melitensis causes disease in small cattle, B. suis in pigs. Brucella are relatively stable in the environment, especially at low temperatures (in animal secretions, soil, wool, meat, cheese, they persist for up to several months), highly sensitive to conventional disinfectants and boiling. Infection occurs by the alimentary route (when eating milk and other animal products), as well as by contact and aerosol (when caring for sick animals or working with infected raw materials).

43. Brucellosis

44. Brucella are able to penetrate intact mucous membranes. They spread lymphogenously and hemagogenously , can persist and multiply for a long time in the cells of the lymphoid-macrophage system, affecting the musculoskeletal system, nervous, cardiovascular and other body systems. The incubation period is 1-3 weeks. The disease occurs in acute and chronic form, accompanied by prolonged fever, weakness, sweating, joint pain. From the first days, an allergy of the HRT type develops, which persists for a long time. Immunity is cellular and humoral, long-term. It is due to the phagocytic reaction and the action of HRT.   Microbiological diagnostics is carried out by immunological methods: antibodies to Brucella are detected in the blood serum (in RA, RSK, RIGA, etc.), HRT is detected to the Burne skin-allergic test with brucellin . In special laboratories, pure culture is isolated and identified (from blood, urine, bone marrow).   Specific treatment : antibiotics (tetracycline, chloramphenicol, streptomycin), in chronic forms - vaccine therapy (killed brucellosis vaccine).   Specific prophylaxis : for planned prophylaxis (animal breeders working in brucellosis farms), a live brucellosis vaccine is administered.

45. Lecture No. 7,8 . Microbiology of tuberculosis. Mycodacterium tuberculosis. Family – Mycobacteriaceae Genus - Mycodacterium 5 groups of mycobacteria: Group 1 - pathogenic, include: M. tuberculosis, M. bovi , M. Micorti , M. Africanum , M. Avium , M. Leprae . M. lepraemurium . Tuberculosis - "tubercle" - an acute infectious disease of a person and animals, is characterized by the formation of specific inflammatory changes, often looking like small tubercles, with predominant localization in the lungs and lymph nodes and having a tendency to chronic course.  The disease has been known since ancient times. plays a role in the development of the disease social conditions. Pathogens are common in nature: found in soil, water, body heat - and cold-blooded. Discovered by R. Koch in 1882

46. Mycobacteria in milk and beef

47. Micobacteria avium

48. The causative agents of tuberculosis : M. tuberculosis; M. bovis - the causative agent of tuberculosis in cattle - 5-20%, cause a severe, rapid form of tbc (consumption); M. avium - the causative agent of avian tuberculosis - 3% of diseases. Animals get sick with M. tuberculosis and M. bovis . People get infected through food products. Low freezing temperature increases virulence m / o. Pasteurization does not destroy MBT.  Tuberculosis statistics. Since 1995, a TB pandemic has been declared worldwide. In 2007, there were13.7 million reported cases of chronic active tuberculosis; 9.3 million new cases; 1.8 million cases deaths, mainly in developing countries.  Among all newly diagnosed patients with tuberculosis, bacterial excretors accounted for 40%. Morbidity in children under 14 years old - 16.1 per 100 thousand children of this group, and adolescents - 15-17 years old - 33.5 per 100 thousand. (same as in Rwanda, Bangladesh, Afghanistan). 

49. In Russia, the death rate from tuberculosis in 2007 was 18.1 people per 100 thousand inhabitants (7% lower than in 2006), thus dying from tuberculosis about 25,000 people (on average in Europe, mortality from tuberculosis is approximately 3 times less). - Africa - 363 cases per 100 thousand population; 28% of cases of all diseases. - Asia - Bangladesh, India Indonesia China Philippines - accounts for half of all new cases. - China - 250-300; - Turkmenistan, Tajikistan - 200; - New York - 500; - Japan - 30; - Australia up to 40; WHO forecast : by 2020, about 1 billion will be infected with MBT, 200 million get sick. Incidence of tropical diseases, OKZ, AIDS in total less than patients with tbc.

50. Morphology. - gram (+), straight or curved sticks; - in old cultures form filamentous forms; - “Fly grains” - coccoid forms - acid-resistant granules, consisting of methophosphate , can be located outside and intracellularly; - under the influence of chemotherapy drugs form L- and filterable forms, retaining infectivity, leading to long-term persistence bacteria in the body - spores, capsule, mobility - absent; - strict aerobes, temperature optimum 37С, pH 7.0-7.5, range - 4.5-8.0. Generation time 14-18 hours, growth is stimulated by 0.5% glycerol and 5-10% CO2. - M.bovis - short, thick sticks, unlike M. Tuberculosis . According to the degree of pathogenicity are divided into 2 groups: - pathogenic and conditionally pathogenic; -saprophytes.

51. Biological properties: A high lipid content is characteristic - up to 40% of the dry residue of the cell. 3 lipid fractions were found: - phosphatidic (ether-soluble) - fat (soluble in ether and acetone) - wax (soluble in ether and chloroform) Lipids contain specific acid-resistant fatty acids. acids: - tuberculostearic - phthioid - mykolovaya - mycoline

52. The high lipid content determines the properties of tbc: 1. Resistance to alcohols, acids, alkalis; 2. Difficult coloration. The cell wall has a structure similar to that of Gram +, but when stained according to Gram, they are colorless, tk. do not accept alcohol acids. The Ziel-Nilson method is used - tbc are stained ruby ​​red, shaped elements and other m / o are blue. 3. Resistance to drying and exposure to sunlight. Scattered sunlight kills for 8-10 days. Boiling sputum - the death of sticks after 5-7 minutes to 1 hour, they remain in dried sputum few weeks. 4. Resistance to common disinfectants: 5% phenol - death after 6 hours, 0.05% solution of benzylchlorophenol - 15 minutes, 5% chloramine -30 min, 10% lysol , 5% carbolic acid - 6 to 12 hours. 5. High hydrophobicity. On liquid media for 5-7 days they form a film, which thickens over time, the broth remains transparent; on agar - on 14-40 days dry scaly plaque or warty formations with pleasant smell, poorly wetted with water, poorly removed from the agar. 

53. Features are used to differentiate . 1. Fast growing (18 species) - visible colonies appear before 7 days. 2. Slow-growing (20 species) - colonies appear later than 7 days. 3. Not growing on nutrient media or requiring special conditions cultivation (leprosy, lepramurium ).  Cultural properties: Nutrient media: glycerin, potato with bile, egg( medium of Levenshtein -Jensen).  Price method - cultivation of a sputum smear on glass in a vessel with citrated blood. The smear is pre-treated with 5% sulfuric acid to destroy associated microflora. If there is a cord - factor - the growth of sticks in the form of serpentine braids, due to convergence of cells in microcolonies . Smear staining according to C-N .   Antigenic structure. Each species is homogeneous, very different from other species. calls formation of antipolysaccharide , antiphosphatide , antiprotein antibodies. Live and killed MBT induce the development of HRT.

54. Entrance gate: - light - air-dust; - airborne method; -alimentary - the entrance gate of the intestine. M.bovis is transmitted from sick animals, more common in children; -contact (in milkmaids from sick animals); -transplantation (L-forms pass through the villi of the chorion). Diagnostics. 1 . The bacteriological method takes 70 days. Material: sputum, urine, liquor, pus. Material + 37C, 24 hours → centrifugation 15 min 3000 rpm → inoculation 0.2 ml sediment on the media L-I, Finn

55. 2 . Mordovsky under rubber stoppers in tilted → 48 hours 37C → upright → viewing0.05% CHB ( . econtamination and stabilization) → incubation at every 2 weeks for 3 months. With growth → microscopy by C-H, MFA, inoculation on L-I medium with different concentrations of antibiotics(isoniazid, streptomycin, rifampicin, ethambutol, kanamycin, proteinamide , ofloxacin , salivilic acid sodium ( d.b . neg !). Confirmatory tests: niacin test, catalase, nitrate reductase, 5% NaCl ( neg ).  Bacteriological analyzer " Baktek " - growth in 5-7 days, sensitivity to antibiotics - after 2-3 weeks. - confirms the diagnosis of tuberculosis; - determine the type of mycobacteria; - quality control of treatment; - antibiogram .

56. 2. Bacterioscopic . Enrichment methods are used: - homogenization - the material is treated with alkali, shaken, centrifuged. A smear is prepared from the sediment; - flotation: gasoline is added to the homogenized material or xylene, shake. MBT float together with parts of gasoline. smear from films; - LSM; - phase-contrast microscopy.   3. Biological on guinea pigs. 4. Allergic ( Mantoux test). 5. Serological: RSC, RPGA, IFM, immunoblotting. He's not talking about morbidity, but infection. 80% of finds. 6. PCR : in sputum, cerebrospinal fluid - significantly; in blood -?

57. Prevention . BCG (BCG) (IBP p. 6.1) - Calmette and Gerin vaccine. Passed for 13 years M bovis culture (270 passages) on a medium with bile salts. This is live attenuated strains. Lost cord factor, but preserved antigenic properties. It causes cellular immunity and sensitization of the body. Non-sterile immunity is formed. there is M bovis in the body. A vaccinated child can become ill with tuberculosis, develop small form, but there will be no meningitis, TVS of the spine. Treatment: DOTS program. 5 basic principles: - political support; - diagnostics through microscopy; - reliable supply of medicines; - control over treatment; - regular evaluation of results.          

58. Lecture 9 . Facultative anaerobic Gram-positive rods. Especially dangerous infections. Microbiology of diphtheria. Genus Corynebacterium Diphtheria is an acute infectious disease that manifests itself deep intoxication of the body with diphtheria exotoxin and specific fibrinous inflammation at the injection site microorganism. The causative agent was identified by Klebs in 1883. Leffler received the culture in 1884. Roux and Yersin isolated pure exotoxin in 1888. Bering received the serum in 1892. Ramon received the toxoid in 1923. The genus is Corynebacterium . Coryne - mace; diphthera - film, fog. Morphology. Straight or slightly curved sticks. Dimensions - 8 * 0.3 - 0.8 microns. In smears arranged in the form of Roman fives, hieroglyphs, palisade. often haveclub -shaped thickening at the ends - grains of volutin ( metopolyphosphates ) -supply of nutrients formed when a microorganism enters thefavorable conditions. Spore and capsule do not form. Motionless. Gram-positive.

59. Symptoms

60. They are divided into 3 groups: 1. pathogenic for humans 2. plant pathogens 3. saprophytes - normal flora of the skin, mucous membranes of the throat, nose, oropharynx, eyes, urethra, genitals, respiratory tract. These include: -C. xerosis -C. ulcerans -C. minutissimum . They are called diphtheroids . Can cause purulent-inflammatory diseases, stand out from wounds. -C. pseudodiphthericum - false diphtheria bacillus (Hoffmann). To identify volutin grains stain: 1. according to Neisser . This is a complex coloring method. Use acetic acid blue of Neisser , treated with Lugol , stained with vesuvine . Body bacteria turns yellow, volutin grains turn dark purple. 2. Methylene blue according to Loeffler - a simple staining method. cage ends are stained more intensely (dark blue, black), the cell body - blue color. The phenomenon of metachromasia is an uneven coloration.

61. Cultural properties. Aerobes, facultative agaerobes . Temperature range - 25-40°С, optimum - 35-37°С. pH- 7.6-7.8. Demanding on nutrient media, need growth factors: 1. Roux medium- curdled horse serum; 2. Loeffler's medium - ¾ clotted bovine whey and ¼ sugar broth. After 8-10 hours, convex cream-colored colonies are formed, which do not merge - "shagreen leather"; 3. Buchin's quinosol medium. Colonies turn blue, medium under the colonies - in purple. Growth in 24-48 hours; 4. Clauberg's medium - composition: "lacquer blood" with potassium tellurite; 5. KTA - tellurite blood agar. Porlochka diphtheria restores potassium tellurite to metallic tellurite, which accumulates in colonies. Growth in the form of large colonies with a diameter of 2-3 mm grayish-black colors. Potassium tellurite inhibits the growth of associated microflora. Diphtheroids and Hoffmann's bacillus form smaller colonies. antigenic structure.

62. According to cultural and enzymatic properties , C. diphtheria is divided into 3 biovar : - gravis (severe) - causes severe disease with epidemic flash. It is in R-form. On the broth gives a granular sediment and film. On dense media, they form flat matte colonies with a radial striated and jagged edges (daisy flower). - mitis (light) - causes mild sporadic diseases. Colonies 1-2 mm in diameter, smooth, shiny (S-shape), intense black. On the broth - uniform turbidity; - intermedius (intermediate) - small colonies, up to 1 mm. Moves to R- Sshape .   Resistance. 60°C - death in 10-15 minutes; 100°C - after 1 min. Resistant to low temperatures, well withstand drying. They remain viable for a long time in saliva, mucus, dust, in the form of fine aerosol - up to 2 days. Disinfectants at normal concentrations kill within a few minutes.

63. Methods for determining toxigenicity . 1. Precipitation reaction in agar. Per nutrient agar plate layer on a strip of filter paper impregnated with antitoxin(antitoxic serum). A culture is sown along the edges of the strip plaques. The antitoxin diffuses from the strip into the agar, and the toxin diffuses from the plaques. At the place of their connection, a white precipitation line falls out - culture toxigenic. Accounting in 24-48 hours. 2. Bioassay on guinea pigs. i/c – dermonecrotic test; s / c - death from high blood pressure. At autopsy - an increase in the adrenal glands with hemorrhage in the medulla 3. Infection of chicken embryos. Letalis . 4. Infection of cell culture - CPD. 5. DNA probe method. 6. ELISA method. 7. PCR reaction to detect the tox -gene.

64. Epidemiology. Source of infection: sick, convalescent, bacterial carrier. Patients with atypical, erased forms are of the greatest importance. Healthy carriers play a special role. They are a reservoir of conservation microorganism, if there are no epidemics. The reason for the long bacteriocarrier : the presence of antitoxic and the absence antimicrobial immunity.   Way of transmission : airborne, airborne dust, household contact (linen, dishes, toys).   bacteriological method. Examined : - persons with an acute inflammatory process of the upper respiratory tract; - contact with a patient with diphtheria or a carrier of a toxigenic strain; - Persons newly employed in institutions for children, health care facilities. The material (mucus from the pharynx and nose) is taken with two dry swabs. Do sowing on nutrient media and a smear on glass with Gram stain, methylene blue, LSM. Final thr results after 96 hours.

65. Immunity. After the illness, persistent, durable, sometimes lifelong. It has an antitoxic and antimicrobial character. Post-vaccination immunity is antitoxic. Antibodies do not interfere formation of bacteria. Prevention. - DTP vaccine (IBP p. 6.4); -ADS- anatoxin (UPS p. 6.6); -AD-M- anatoxin (IHD p. 6.5); - vaccine " Tetrakok " - contains diphtheria, tetanus toxoids, inactivated polio vaccine 3 types, pertussis microbes (IHD p. 6.9).

66. Lecture No. 10 . Microbiology of plague(murrain). Yersinia pestis . The third plague pandemic began in Hong Kong in 1894 and lasted 20 years. claimed 10 million people. The causative agent of the plague was isolated by Yersin and Kitazato , proved the role of rats in the epidemiology of plague. Family . Enterobacteriaeceae Genus Yersinia The species Y. pestis is the causative agent of plague; Y. pseudotuberculosis - the causative agent of pseudotuberculosis; Y. enterocolitica is the causative agent of intestinal yersiniosis

67. Morphology. - short ovoid Gr (-) rod with bipolar color - detected Leffler's methylene blue - the color is brighter at the poles; - length 1-3 microns, diameter 0.3-0.7 microns; - in smears from broth culture they are arranged in a chain, from agar cultures are disorderly; - polymorphism is characteristic - they form spherical, flask-shaped, filiform(long), L-shaped under suboptimal conditions; - dispute, has no flagella; - forms a capsule of protein nature at 37 C. Morphology. - short ovoid Gr (-) rod with bipolar color - detected Leffler's methylene blue - the color is brighter at the poles; - length 1-3 microns, diameter 0.3-0.7 microns; - in smears from broth culture they are arranged in a chain, from agar cultures are disorderly

68. - polymorphism is characteristic - they form spherical, flask-shaped, filiform(long), L-shaped under suboptimal conditions; - dispute, has no flagella; - forms a capsule of protein nature at 37 C. Cultural properties. - aerobe; - well grows on usual nutrient media; - T range - 0-45 ° C, optimum - 27-28 C. pH 6.9-7.1; -virulent strains form R-forms; on liquid media after 48 hours a delicate film is formed, from which threads (stalactites) descend, there is a loose sediment at the bottom, the broth remains transparent. Shaking causes agglutinogenic growth. Y.pseudotuberculosis gives diffuse haze.

69. On dense media - 3 stages: - after 10 hours growth in the form of colorless plates - "broken glass"; - after 18-20 hours - under microscopy, a light lacy zone is visible around the central yellowish part is “lace handkerchiefs”; - after 40-48 hours - a delineated brown center with a pronounced peripheral zone - "adult colony". The need for nutrient media. 1. To accelerate growth (up to 3 days), growth stimulants are added: hemolyzed blood, sodium sulfite, sarcins in lyophilized form, gentian violet - to suppress the growth of putrefactive m / f. 2.weakly expressed proteolytic activity - environments with deep protein digestion: Hottinger agar, spleen hydrolyzate , fishmeal. The medium must contain ready-made amino acids 3. natural auxotroph - parasitizes in the body.

70. Resistance. - in sputum - up to 10 days; - normal sensitivity to disinfectants (5-10 min); - in fleas - 1 year; - in ticks - 5 years; - heating up to 50 C - death in 30-40 minutes; 80 C - death after 5 minutes; 100C - death after 1 min; -UV - 2-3 hours - death; - food products: grain, bread, vegetables (at + T) - 3 months; - water - 47 days; - in sterile soil - up to 1 year, in non-sterile - up to 7 months; -1% solution of chloramine - 3 min; -5% lysol - 5 min; - resistant to low T.

71. Epidemiolog y. Anthropozoonosis . Natural reservoir - rodents: mice, rats, ground squirrels, marmots, tarabagans , gerbils. Outbreaks in humans are preceded by epizootics among rodents. Infection of rodents mainly occurs through flea bites. The causative agent multiplies in the digestive tube of fleas, feeds on blood. Way of transmission to humans: -transmissible (through flea bites) - rubbing feces into the skin wound or flea food cork. When bitten, a flea regurgitates a food cork a large amount of pathogen; - contact - when working with carcasses and skins of rodents and carnivores; -alimentary - meat of sick animals (camels, ground squirrels); - aspiration; - through the mucous membranes.   Natural foci - almost all of Africa, Asia, South America. I.p . -3-6 days 1. skin form - the formation of pustules and carbuncles at the site of implementation;

72. 2. bubonic form. The pathogen enters through the skin migrate to the lymph node, develop serous-hemorrhagic inflammation, a bubo is formed (enlarged lymph node); 3. skin-bubonic; 4. secondary pneumonic plague - hemorrhagic necrosis of l / y, the pathogen enters the bloodstream, then into the lungs - plague pneumonia and sepsis develop. From this moment, the epidemic begins, because. the pathogen is transmitted by airborne droplets; 5. primary pneumonic plague - spreads by airborne droplets from a patient with a pneumonic form of plague; 6. intestinal form - profuse diarrhea with the release of blood and mucus; 7. primary septic - rapid dissemination of the pathogen in the body from the bubo. Bleeding from the kidneys, intestines, hematemesis

73. Clinic : severe headache, fever with chills, hyperemia of the face, its darkening, dark circles under the eyes. Bubo appears on the 2nd day. Pneumonic plague - chills appear quickly, high fever, pain in the side, bloody cough with sputum (sputum comes off basins), delirium, cyanosis, collapse, death. Excreted with sputum amount of pathogen. The main role in the pathogenesis of the disease is the suppression of the activity of phagocytes and the spread of the pathogen with blood throughout the body.  Postinfectious immunity. Durable lifelong, cellular - mediated by T-lymphocytes and macrophages - and humoral. In those who have been ill and vaccinated, phagocytosis is complete. Prevention . Plague live vaccine from an attenuated EV strain. It is administered n / c, s / c, i / c, inhalation according to epidemic indications to persons, living in the epizootic area. Also available in tablet form. Apathogenic to humans, has high immunizing properties.

74.   Laboratory diagnostics. Test material: bubo punctate, blood, sputum. - bacterioscopic method - - coloring according to Gram; - methylene blue Leffler ; - LSM; - bacteriological - sowing on MPA and MPB with growth stimulants and substances that inhibit the growth of associated flora (gentian violet): medium of Tumansky . They put a test with a plague bacteriophage - lysis in place application to the sown culture; - biological - infection of a guinea pig with n / c, s / c, i / b contaminated material. Separate pure culture. To accelerate the death of animals pre-administered glucocorticoids; -serological - RPHA, ELISA; -immunological - determination of antigens using erythrocyte diagnosticum sensitized with antibodies to capsular antigen - RPHA; - allergic test with pestine - retrospective diagnosis.

75. Lecture No. 11 Microbiology of anthrax. Bacillus anthracis . Fam. bacillaceae Genus Bacillus Species Bacillus anthracis1900-1914 15-20 thousand people fell ill annually WHO - up to 9 thousand diseases per year. In Russia - currently single cases. In 1876, Koch first identified a pure culture source of infection. Sick and dead animals, as well as skin, wool, horns, hooves removed from slaughtered or dead farm animals. Storage tank. Polluted soil.   Infection of animals. 1) alimentary way (food, drinking water); 2) transmissible - through the bites of flies, ticks, horseflies; 3) rarely - air.

76. Morphology . - large Gr (+) stick, length - 6-10 microns, diameter - 1-1.5 microns. - aerobe or facultative anaerobe. - the ends are cut off and retracted. In smears are arranged in pairs, chains(bamboo cane). - flagella are absent. Motionless (NB!) - the main diagnostic sign. - in the body of the sick and the fallen form a capsule. Capsulation occurs on special nutrient media enriched with serum or blood. observed in freshly isolated strains. All capsule forms are highly virulent; capsuleless - avirulent . To identify capsules, Ramonovsky -Giemsa, Riebeger stain is used (blue body, pink capsule). - create controversy. With good air access and a certain humidity vegetative forms outside the human or animal body pass into spore. In the body of patients and in an unopened corpse, spores are not formed. The spore is located centrally, does not deform the cell. Well formed when grown on poor nutrient media with access to oxygen. Formed in distilled water, in unfixed smears. This is the protection of the microorganism from the effects of the external environment. The form of infection of humans and animals is a spore. The temperature optimum of spore formation is 30-35 , the range .

77. Spore coloration : Ziel-Nilson , Ramonovsky - Giemsa. cultural properties. it is not demanding on nutrient media. Grows well on Martin's agar Hottinger . T optimum - 37-38, pH 7.2-7.6 (7-8). matte, opaque, rough colonies with uneven edges, 3-5 mm in diameter are formed on dense media - R - shape. Under a low magnification of the microscope, the appearance of a lion's mane, the head of a jellyfish - due to the chain arrangement of sticks that form threads extending from the center. S-shape round smooth colonies with smooth edges. on liquid media in R-form growth in the form of a ball of cotton wool, the broth remains transparent, in the S-shape - uniform turbidity. Bacillus anthracis is virulent in R-shape.

78. Pathogenicity factors. I. capsule . Determines the virulence m / o: - inhibits phagocytosis; - adhesion factor on macroorganism cells; - protection against bactericidal action of blood. Its loss leads to the loss virulence. Synthesis is controlled by a plasmid. II. exotoxin. The main factor of virulence and immunogenicity. It consists of 3 factors that act in synergy: a) lethal - has a cytotoxic effect, causes pulmonary edema; b) edematous - lipoprotein, increases the concentration of cAMP , causes edema; c) protective antigen - protein - interacts with cell membranes, activates other components of the toxin; induces the synthesis of protective antibodies. Used in the manufacture of vaccines/

79. Resistance. 1) vegetative form - medium resistance: at Tº 75 and above - dies after 1 min, 60 ºС - 15 min., disinfectants - after 10 min. In corpses without access oxygen - m / o dies after a few days from the accompanying putrefactive microflora. Dead animals are not opened. 2) Spores in water persist for several years; - in the soil - 10 years; - UV withstand 20 days; - boiling - 45-60 minutes; - dry heat - 180ºС up to 3 hours; - autoclaving -2 atm. - 1 hour; - 10% NaOH or 1-2% formalin solution - 2 hours; - 5% solution of potassium permanganate - 24 hours; - 4% bleach solution -3 min; - are well preserved in tanned skins, salted meat.  

80. Sensitivity to AB. - to penicillin, because little produce penicillinase , go into the L-form ( spheroplasts ). On agar containing 0.05-0.5 IU / ml of penicillin, after 3 hours of growth, the bacilli disintegrate into balls arranged in a chain - the “pearl necklace” phenomenon. -to many ABs: doxycycline, rifampicin, ampicillin, erythromycin, tetracycline. Variability. -the quality of the medium changes the morphology of the colony, cells (color, S-shape); - capsular forms of Bacillus anthracis - STI - anthrax vaccine; - spore-free strain of Davis; - can form a capsule fragments; -may not produce the toxin.

81. Pathological material is destroyed: - dry heat at 180 2-3 hours; - boiling with 2% soda for 1 hour; - corpses are cremated; - crops autoclave 2 atm. - 1 hour. Fixation of smears is carried out with a Nikiforov mixture (equal parts of alcohol and ether), chilled acetone. Alcohol can not be carried out, because. survive in it for up to a day. Epidemiology and clinic. The main source of infection is sick herbivores (cows, sheep, horses, deer, and to a lesser extent pigs). The pathogen is isolated with urine, feces, saliva into the soil. The person gets infected - in direct contact with animal corpses, cutting carcasses, caring for sick animals, working with wool, skins, through cutting boardsinfected with the pathogen or its spores. Occupational Illnessin meat slaughterhouses. 98% of cases - skin form, manifests itself in the form of anthrax carbuncle.

82.   Laboratory diagnostics Material : sputum, carbuncle discharge, blood, faeces , urine, soil, water, food, raw materials of animal origin, blood smears from peripheral veins of the ear of a fresh corpse, the ear of a fallen animal (an incision between two ligatures, the incision site is cauterized). At autopsy: the spleen or liver is taken, from pigs - tissue from the pharynx . bacterioscopic method -according to Gram, C-N, R-G (capsule), LSM. If all (+) , an indicative is given a positive response. bacteriological : Sowing on MPA and MPB. After 18-24 hours, the growth of matte colonies with a rugged periphery (head of a jellyfish), growth in the form of flakes (ball of cotton wool) on the BCH, clear broth Treatment. - anti-anthrax gamma globulin (IBP p. 5.10) - protein gamma and beta-globulin fractions isolated from blood serum immunized horses containing antibodies to the anthrax microbe. For prophylactic purposes - to persons who had contact with an infected person material. - Antibiotics course 7-10 days.  

83. Symptoms Redness - edema - papule - vesicle - pustule - scab that quickly turns black. Secondary pustules form around it, which merge into one black-brown scab. The affected areas are edematous, with the capture of the entire surface legs, arms or face. There is no pain. T 39-40º C. With treatment, the condition improves after 5-6 days. - inhalation of dust with spores - pulmonary form. flows in the form hemorrhagic pneumonia. Death in 2-3 days. - when eating poorly cooked meat - intestinal form - severe enterocolitis with hemorrhagic manifestations. The illness lasts 2-4 days and letalis . Prevention. In 1881, Pasteur created and applied the vaccine. All vaccinated animals were infected with anthrax. -in 1883 L.S. Tsenkovsky is a live spore-free capsuleless vaccine. - in 1940, Ginsburg received from a virulent culture of the strain "Krasnaya Niva " vaccine-free avirulent STI mutant (IBP p. 5.11 - 5.12). Vaccinate according to professional indications, the duration of immunity is 12 months.  

84. Lecture No. 11,12 . Especially dangerous infections. Microbiology of brucellosis. Genus Brucella . Brucellosis is a disease of humans and animals caused by bacteria of the genus Brucella . Source of infection farm animals: small and large cattle, pigs, camels, deer. For every type of animal Brucella is characteristic . 1. Brucella melitensis - goat - sheep type. Highly pathogenic for humans 95-97% of all cases. Causes epidemics among animals. account for slaughter the whole herd. 2. B. suis . The source of infection is pigs, rodents, hares, deer. Highly pathogenic for humans up to 1% of cases. 3. B. abortus . Bull type. Less pathogenic for humans. calls sporadic diseases 1-3% of cases. 4 Brucella can pass on to other types of animals: wolves, foxes, rodents, horses, saigas , etc.   Morphology . Small gram-negative coccobacteria , 1-1.5 µm long, diameter 0.4-0.6 µm. Spores and capsules do not form. Slow growing (clinically slow infection).

85.   Cultivation. 1. Medium erythritol -agar. The polyhydric alcohol erythritol is included. There are many in amniotic fluid. Optimum pH 7.2-7.4. 2. Meat media supplemented with 1% glucose, 1% glycerol. Optimum pH6.6-6.9. On enriched media growth in 2-3 days. On simple media - up to 10 days. Growth in broth up to 1 month.  Colonies are tender, smooth, whitish, translucent. In the center colonies in sunlight bright glow - "hemisphere". Primary crops grow with an increased content of CO2-10%, subsequent with normal conditions. One portion of the material is cultivated in conventional conditions, two – at 10% CO2.  Biochemically inactive, in our conditions it is possible to determine only urease and oxidase activity. Pathogenicity factors. - endotoxin; - the ability to suppress phagocytosis; - hyaluronidase enzymes, etc.; - allergenic properties; - It is believed that there is an exotoxin.

86. Antigenic structure . There are A-, M-, R - antigens. present in LPS. Distinguish with using brucellosis sera. There is an antigenic relationship with other types of m / o: - cholera (in those vaccinated against cholera, the Heddelson reaction is positive first 3 months) - tularemia; - B. abortus shares antigens with Yersinia enterocolitica , serovar . Serologically they are not differentiated. Can only be distinguished by sampling Burne . Epidemiology. Manifestations of the disease in cattle and small cattle - infectious abortions. They can be massive. From sick animals, the pathogen is excreted in milk, urine, feces, pus, and especially a lot of amniotic fluid.  

87. Ways of human infection: - contact. The causative agent penetrates through the skin of the hands, mucous membranes nose, mouth, eyes - covered with dirty hands; - contact household (livestock workers - shepherds, milkmaids, cattlemen, veterinarians); - alimentary (unpasteurized milk and dairy products from it, water). Pathogenesis . I.p . - 1 week - several months. The causative agent enters the lymph nodes through the lymphatic pathways and breed in them. The tonsils, pharyngeal, cervical, submandibular nodes and l / in the intestine. Further enters the blood → throughout body. The lympho-hematopoietic system is affected. going on severe allergization of the body. Runs like chronic sepsis. Due to incomplete phagocytosis: m / o are not available for AT and AB. Inside the cells transform into L-forms, persist in the body for a long time, canreverse and relapse

88. Clinic. Diverse. Depends on allergization , intoxication of the body and affected organs. Lymphatic, vascular, hepatolienal , nervous and especially musculoskeletal systems. Prolonged course of the disease (up to 10 months). Leads to loss employment, disability . Immunity. Post-infectious - long, strong, cross (against all Brucella species), recurrence is possible. Caused by T-lymphocytes, macrophages. In immune humans and animals phagocytosis is complete. The role of AT is the stimulation of phagocytosis. When infected with large doses and highly virulent strains immunity is broken . Laboratory diagnostics . No clinical diagnosis is made. Material for research: Acute, febrile period: blood, cerebrospinal fluid, punctate of the sternum (with neurobrucellosis ). Chronic period: urine, bile, sputum (rarely), sectional material. Punctate from the joint is useless to take, because. is a symptom of an allergic

89. Reactions. From animals - aborted fetus, stomach contents (easy to get material), milk. - bacteriological method. Culture is hard to pinpoint. Allocate only in patients with B. melitensis in the febrile period, in chronic patients not stands out. - according to Kostaneda : 5-10 ml of blood from the cubital vein is inoculated into 3 vials with 50-100 ml liver broth. Two of them are incubated under 10% CO2 conditions. Growth after 10 days - 1-1.5 months (45 days): turbidity, mucous sediment, in smears for gram-negative cocobacilli . Put RA on glass with agglutinating sera, determine the sensitivity to the phage. - sowing on dense media with foreign m/f inhibitors (gentian violet, penicillin). Advantages: growth in 2-3 days, fast foreign microflora is inhibited sowing min amount of blood. Sow 5-6 cups of 0.2-0.3 ml culture retains Ag composition cannot be isolated from clotting blood.

90. The type of brucella is determined by: -requirements for CO2 ( B.abortus has); - the formation of H2S (B. melitensis does not form); - growth on media with bacteriostatics ( fuchsin , thionine ) - (V. suis does not grow with thionine ); -agglutination with specific sera; -urease activity (not in B.abortus ); -Test with TB. (Only in B.abortus ); - bioassay. To isolate culture from contaminated material. Enter n / c, in / peritoneum, n / c guinea pigs and white mice. Opened after 2030 days. Pieces of organs and l / y are sown on the pit. environment for obtaining h.k . - PCR. - serodiagnosis .  At the beginning of the incubation period and the disease, incomplete antibodies appear, keep for a long time - up to 5-10 years. Complete AT appear one month after diseases, maximum titers reach by 6 months and last up to a year.

91. Sensitivity to AB: - B. abortus and B. melitensis are resistant to penicillins (500 U/ml). Vaccine strains and B. suis are sensitive to penicillin, in contrast to virulent strains. Highly sensitive to tetracycline, rifampicin, gentamicin, streptomycin, chloramphenicol. Specific prophylaxis 1. Live brucellosis vaccine from the B. Abortus strain - LBV. 2. Chemical brucellosis vaccine - CVD. In Russia there is no. 3. Killed therapeutic vaccine - used to treat chronic brucellosis.

92. Lecture number 1 3 . Microbiology of tularemia. Francisella tularensis . The causative agent is Francisella tularensis . Discovered by McCoy and Chapin, studied Francis (genus); View - according to the name of the area (Tulare).  Morphology. Small immobile coccoid encapsulated rods( coccobacteria ). Pronounced polymorphism: in smears of cultures - cocci, in smears from organs - coccobacteria . They do not form spores, the capsule is false, motionless. When stained by special methods, they give a bipolar coloring. Strict aerobes. T optimum 37ºС, pH 6.7-7.2.   Cultural properties. They do not grow on ordinary media, amino acids, thionine , Mg are required

93. Medium are used: - McCoy (coagulated yolk medium); - agar with heart muscle digest and 5% sheep blood; - yolk media with tissue extracts, cystine , glucose, rabbit blood. Colonies are small - 2 mm in 3-5 days. On liquid media superficial growth. They break down some carbohydrates with the formation of acid, form H2S. Virulent forms form S-forms. Tº optimum - 36-37ºС. On medium add penicillin - inhibits the growth of concomitant microflora. Stability in the external environment: - fodder, grain - 4 months; - water - 3 months; - ice - 1 month. - sensitive to UV, high T (100 ° - instantly), 50% alcohol, antiseptics - death after 5-10 minutes. withstands ↓ T: in a frozen state - 10 years, fodder, grain - 8-20 days, rodent corpses - 6 months. - putrefactive microflora is an antagonist, because m/o breed faster than the tularemia microbe.

94. Epidemiology. Widespread in fresh water. It parasitizes humans, mammals, birds, arthropods, fish and amphibians. Basic i.i . for humans - vole, house mouse, water rats, muskrats, hares (hare and hare): -2 gr. - highly susceptible, but less sensitive animals - gray rats, ground squirrels, hamsters, nutria, squirrels, humans. Infection from 1 μb cell, DLM - from 1 billion. mcb . class Infection vectors : blood-sucking arthropods: ixodid , gamasid mites, fleas, horseflies, mosquitoes, mosquitoes.  Ways of infection: - contact - through the skin and mucous membrane of the eyes; - inoculative (transmissible) - when bitten by a carrier; - alimentary - through the gastrointestinal tract; - aspiration - through the respiratory tract (agricultural work). Human susceptibility is high, not transmitted from person to person (biological impasse).

95. Pathogenesis . The pathogen multiplies in the lymph nodes, part of it is destroyed with release of endotoxin - tularemia buboes are formed. The causative agent penetrates into the lymph and bloodstream, new portions are released endotoxin, sensitization occurs. Metastases form in the liver spleen, lungs, bone marrow. Clinic.   I.p . -2-8 days, acute onset. Distinguish 4 clinical forms .  1. bubonic - 70-80% of all cases. Occurs when an insect stings contact with the blood and secretions of a sick animal, contaminated objects (grain, hay) and bathing. On the 7th day, a the primary affect is an ulcer. a)Distinguish the eye – bubonic ; b) anginal -bubonic ; c) ulcerative-bubonic forms . 2. pulmonary - with hematogenous drift into the lungs or airborne dust transmission. Can be spread from person to person through droplets way.  3. generalized - when eating contaminated food. 4. abdominal. Ulcerative foci in the gastrointestinal tract, inflammation of the mesenteric .

96. Post-infectious immunity is strong, persistent, lifelong . Caused by T-lymphocytes, macrophages (leads to the development of HRT) and antibodies. Laboratory diagnostics. Material: pus from buboes, eye discharge, lymphatic punctate nodes, sputum, blood, sectional material. Take any form of blood5-7 ml. 1 . bacterioscopic . Gram stain and methylene blue. MFA. 2. bacteriological. The pathogen is not isolated from the patient, at first use the biological method, and then from blood and organ cultures isolated pure culture. Use of weakened animals (preliminary administration of yolk or hydrocortisone) morphological, cultural, antigenic (RA with specific serum) properties. 3. PCR. 4. biological - guinea pigs, white mice are sensitive. 5. serological

97. Detection of antibodies from the 2nd week of the disease : - RPGA, - test-tube RA, - RNGA, Diagnostic titer 1:100. An increase in titer is obligatory   Prevention. In risk groups, a live tularemia vaccine is used (IBP p. 5.6). 1. Laboratory workers when working in tularemia natural foci; 2. agricultural workers in areas unfavorable for tularemia

98. Lecture No. 14.15 Pathogenic cocci . Staphylococci   Family Staphilococcoceae , genus Staphilicoccus .   - They are the causative agents of staphylococcal pneumonia, neonatal staphylococcus, sepsis, pemphigus. - These are small Gram-positive cocci. - In smears are located in clusters, often grape-like. - They do not form a dispute, they are motionless. They form microcapsules. They are facultative anaerobes. - Undemanding to nutrient media, grow well on simple media, give pigment colonies. The elective medium for staphylococci is yolk-salt agar, less often milk-salt agar. - Staphylococci are resistant to high concentrations of sodium chloride.

99. 2. Streptococci They belong to the family Streptococcaceae , genus Streptococcus. - These are gram-positive cocci, arranged in chains or in pairs in smears. - They are facultative anaerobes. - Do not grow on nutrient media. On blood agar, small-dotted, pigmentless colonies are produced, surrounded by a zone of hemolysis: a - green, b - transparent. In sugar broth, near-wall growth is given, and the broth itself remains transparent. - The disease is more often caused by b-hemolytic streptococcus. - Grow at 37°C. - Streptococci are able to break down amino acids, proteins, carbohydrates. According to biochemical properties, 21 species are distinguished. Most of them are conditionally pathogenic.

100. The most important in the development of infectious diseases are: 1) S. pyogenus , the causative agent of a specific streptococcal infection; 2) S. pneumonia, the causative agent of pneumonia, can cause a creeping corneal ulcer, otitis, sepsis; 3) S. agalactia , may be part of the normal microflora of the vagina; infection of newborns leads to the development of sepsis and meningitis in them; 4) S. salivarius , S. mutans , S. mitis, are part of the normal microflora of the oral cavity; in oral dysbiosis are the leading factors in the development of caries. streptococcal antigens. 1. Extracellular - proteins and exoenzymes . These are variant-specific antigens.

101. 2. Cellular: 1) surface proteins are represented by surface proteins of the cell wall, and in S. pneumonia, by capsule proteins. They are variant-specific; 2) deep - teichoic acids, peptidoglycan components, polysaccharides. They are group specific. 3. Meningococci They belong to the genus Neisseria, genus N. meningitidis .   - These are bean-shaped diplococci, in smears they look like coffee beans. - They do not form spores, they do not have flagella, they form a capsule in the body.  - Gram-negative. Strict aerobes.

102. - Meningococci are demanding on nutrient media - they grow only on media containing human protein (serum agar, ascites agar) at a temperature of 37 ° C. On serum agar form delicate transparent colonies of medium size. In whey broth they grow in the form of turbidity and sediment at the bottom.  - Biochemically inactive, ferment only glucose and maltose, forming an acid, but not forming a gas. Extremely unstable in the environment, sensitive to temperature changes, die at temperatures below 37 °C.  - According to the capsular polysaccharide antigen, meningococci are divided into four main serogroups (groups A, B, C, D) and three additional (X, Y, Z). 

103. 4. Gonococci They belong to the genus Neisseria, species N. gonorrhoeae .  - These are bean-shaped diplococci, in smears they are located intracellularly in the protoplasm of leukocytes, they look like coffee beans.   - Do not form spores, immobile, form a microcapsule, gram-negative. They are obligate aerobes.   - Gonococci are extremely demanding on nutrient media, they grow only on media containing human proteins (serum agar, ascites agar, etc.). On serum agar form small shiny colonies in the form of droplets.

104. Gonococcal antigens: 1) protein antigens of the outer membrane; 2) lipopolysaccharide antigens of the cell wall. There is no generally accepted division into serogroups and serovars .  - Pathogenic only for humans. They cause only specific nosological forms of purulent-inflammatory diseases.   Features of serodiagnosis : the diagnosis is made qualitatively (by the detection of antibodies in the serum of the subject) according to the results of a single reaction (without paired sera). This is due to the fact that post-infectious immunity is not formed in gonorrhea (there are no post-infectious antibodies).

105. Lecture No. 16,17 Gram-negative bacteria - causative agents of purulent-inflammatory diseases   1. Haemophilus influenzae   Family Pasterellaceae , genus Haemophilus, species H. influenza.   - These are small or medium-sized straight rods, non-spore-forming, immobile, gram-negative, aerobes. In the body form a capsule.   - Culture media containing blood (blood agar) or its preparations (chocolate agar) are required.   - In the environment, microorganisms quickly die from the action of temperatures above 55 ° C, sunlight, drying, disinfectant solutions.

106. Antigenic structure: 1) somatic protein O-antigen; 2) capsular polysaccharide K-antigen;   - According to the structure of the capsular K-antigen, the species is divided into five serovars (denoted a, b, c, d, e). Serovar b is the most common causative agent of meningitis.   Pathogenic factors: 1) endotoxin; 2) capsular polysaccharide with antiphagocytic activity. - Does not produce exotoxin.   - Haemophilus influenzae can be part of the normal microflora of the mucous membrane of the oropharynx and upper respiratory tract, so the infection can occur as endogenous.

107. 2. Pseudomonas aeruginosa Belongs to the family Pseudomonadaceae , genus Pseudomonas, species P. aerugenosa . The genus Pseudomonas, in addition to Pseudomonas, includes more than 20 species, many of which can also cause disease in humans. - These are straight or slightly curved rods of medium size, mobile ( lophotrichous or monotrichous ), gram-negative, obligate aerobes. They do not form spores, they have a thin mucous capsule. - Pseudomonas aeruginosa is undemanding to nutrient media, grows well on artificial nutrient media. On meat-peptone broth, it grows in the form of turbidity with a grayish film on the surface. On dense nutrient media, large translucent colonies of a fluorescent greenish color are formed.

108. At the same time, bluish-green water-soluble pigments, pyocyanin or fluorescein, diffuse into the medium. The ability of pseudomonads to form pigments is the most characteristic differential diagnostic feature. The culture of Pseudomonas aeruginosa when cultivated on nutrient media has a sour-sweet aromatic odor (specific odor of jasmine).  - Stable in the environment. It is naturally resistant to antibiotics. Antigenic structure: 1) somatic O-antigen, group-specific, according to its structure it is divided into serogroups ; 2) flagellar H-antigen; 3) M-antigen of extracellular mucus

109. Pathogenic factors: 1) in the body can form a capsule-like substance with protective properties; 2) releases heat-labile exotoxin A, which has cytotoxic and dermonecrotic effects; 3) releases endotoxin; 4) some strains produce hemolysins and leukocidin ; 5) has aggression enzymes such as plasmacoagulase , proteases, antielastase .   - Pseudomonas aeruginosa can live in the human intestine, found on the skin and mucous membranes.

110. 3. Klebsiella   The genus Klebsiella includes several species pathogenic to humans. The most significant are K. Pneumoniae , K. Ozaenae , K. Rhinoscleromatis . - These are Gram-negative, medium-sized rods that do not form spores. facultative anaerobes. In preparations, they are arranged singly, in pairs or in short chains. They do not have flagella, are immobile. - Do not form a dispute. - These are true capsular bacteria: they form a capsule in the body and on nutrient media. The capsule has a polysaccharide structure.

111. Undemanding to nutrient media. On dense nutrient media, they form characteristic dome-shaped turbid mucous colonies. When growing on meat-peptone broth, they cause uniform turbidity, sometimes with a mucous film on the surface. - Klebsiella are resistant to environmental factors, thanks to the capsule they are stored for a long time in water, on objects, in rooms.   Antigenic structure: 1) somatic O-antigen - group-specific; 2) capsular K-antigen. K antigens are shared with Escherichia and Salmonella antigens.  

112. Pathogenic factors: 1) have pronounced adhesive properties; 2) the main factor is a capsule that protects microorganisms from phagocytosis; 3) have a K-antigen that suppresses phagocytosis; 4) secrete endotoxin. - Klebsiella is often found on the skin and mucous membranes, and therefore the development of an endogenous infection is possible. But exogenous infection is more common. Sources of infection can be a patient, a bacteriocarrier , objects of the external environment.   - Ways of transmission - airborne, contact-household.

113. Proteus Genus Proteus. The causative agent of purulent-inflammatory diseases is the species P. mirabilis .   - These are polymorphic gram-negative rods with rounded ends, facultative anaerobes. There is no capsule formation. They have peritrichous flagella. - H-forms of these bacteria are characterized by high mobility, although there are also immobile (O-forms).   - Undemanding to nutrient media. On meat-peptone agar, the H-form of the protea gives a characteristic creeping growth in the form of a delicate bluish-smoky veil (swarming phenomenon), covering the entire surface with a continuous coating without the formation of individual colonies.

114. In a liquid nutrient medium, it grows in the form of diffuse turbidity. During cultivation, a putrefactive odor is characteristic. O-forms form large colonies with smooth edges. Some strains cause hemolysis of erythrocytes in blood media.  - Stable in the environment, can remain viable in weak solutions of disinfectants. Widely distributed in nature. They are inhabitants of the intestines of humans and animals.  Antigenic structure: 1) somatic O-antigen - group-specific; 2) flagellar H-antigen - a specific variant. - According to the H-antigen, proteins are divided into 110 serovars . Within the species, fagovars , bactericinovars , bacteriocinogenovars are distinguished.

115. Pathogenic factors: 1) adhesins - drank; 2) endotoxin; 3) pathogenic amines - indole, skatole ; 4) enzymes of aggression - proteases.   - Proteins in small quantities can be found in the intestines of a healthy person, so a proteus infection can develop as an endogenous one.   - Their main habitat is the objects of the external environment, rotting products, sewage, soil. Sources of infection for a person can be a patient and a bacteriocarrier .   - Bacteria are involved in the development of purulent-inflammatory diseases of the urinary tract, quickly spread over the burn surface, giving a characteristic putrid odor.   - Post-infection immunity is unstable