Abstracts of lectures

Infection (infectio-infection) - a complex interaction of host and pathogen in certain conditions of external and social environment, including the dynamically developing pathological, protective adaptive and compensatory reactions.

Infection (infection process) - a set of physiological and pathological processes that occur in the body when introducing pathogens that cause a violation of the internal environment and the flow of physiological reactions (Timakov).

Infectious disease - is the ultimate manifestation of the infection process.

Similar processes are caused by protozoa called. invasions necessary to have 3 participants: microorganism, pathogen and the environment in which the interaction of macro-and micro-organism.

differences from non-communicable diseases:

- are micro-cause

-contagious

-specific immunity

-periods of illness

Pathogenicity of microbes - the potential ability of a microorganism to induce infectious process, which is characterized by complex pathological specificity, pathophysiological and clinical manifestations caused by this microorganism. This is a sign of the species depends on the existence of microbes in the genes responsible for various signs of pathogenicity (kapusly, enzymes, toxins). pathogens have specificity - the ability of certain species to cause some pathological process (pneumococci -lung) or a quantitative measure of the degree of pathogenicity - virulence, measured in special units (dlm, dlc, ld50)

Activity is determined by virulent microbes, toxins and the amount of action.

Virulence of microbes - is the degree of pathogenicity (Strain sign).

Pathogenicity of microbes - the potential ability of a microorganism to induce infectious process, which is characterized by complex pathological specificity, pathophysiological and clinical manifestations caused by this microorganism. This is a sign of the species depends on the existence of microbes in the genes responsible for various signs of pathogenicity (kapusly, enzymes, toxins). pathogens have specificity - the ability of certain species to cause some pathological process (pneumococci-lung) or a quantitative measure of the degree of pathogenicity - virulence, measured in special units (dlm, dlc, ld50)

Activity is determined by virulent microbes, toxins and the amount of action.

Virulence of microbes - is the degree of pathogenicity (Strain sign).

Microbial pathogenicity factors:

1. ADHERENCE - adhesion. Associated with the presence of microbial adhesins, specialized receptors for different host cells (epithelium dyh.putey, kishech.trakta, urogenital system, etc.)

-pili

- teichoic acids from Gram (+) bacteria

From LPS-lipoproteins from Gram (-) bacteria

Capsule, outer membrane proteins from the cell wall

2. COLONIZATION - multiplication of bacteria on the mucosal surface, the formation of "microbial layer" to a critical mass that can cause pathological. n virulence microbial activity is determined, and the amount of toxin action.

process.

3. PENETRATION - Infiltration of microorganisms into the epithelial cells, leukocytes or lymphocytes. Associated with resistance to lysosomal enzymes, protective proteins, insufficient oxygen content. Activity is determined by virulent microbes, toxins and the amount of action.

These microbes are moving to neighboring cells without going okr.sr, destroying cells and compromising the integrity of epithelium, which gives rise to pathological. process.

4.INVASION - penetration through the mucous membranes and connective tissue barriers in the underlying tissues. Invasion of microbes associated with the development of enzymes that break down connective tissue and thus contribute to the spread of the pathogen in the body.

ENZYMES PATHOGENICITY:

Hyaluronidase (cleaves hyaluronic acid intercellular substance increases the permeability of the mucous membranes, and connective tissue)

Neuraminidase (overcome mucosa, penetrate cells distributed in the intercellular space

Coagulase (coagulated blood plasma)

Plasmin (converts plasminogen blood enzyme and dissolves fibrin clots

Leicocidin

Urease

Lecithinase (lecithin)

Protease (destroy AT)

DNA

Decarboxylase

Enzymes pathogenicity:

-primary cause cell destruction and fibers (hyaluronidase, neuraminidase, protease)

-causing the formation of toxic substances (metabolites produced in the body by the hydrolysis of urea (urease microbial) protein (amino acid decarboxylase, contribute to the accumulation in the intestine in-toxic in the biogenic amines, etc.)

5. ANTI PHAGOCYTIC ACTIVITY:

- capsule composed of polysaccharides, polypeptides, prevents the capture of bacteria by phagocytes, prevents digestion (pneumococci, bacillus plague, Klebsiella)

-components of bacterial cell walls

(protein A of Staphylococcus aureus, M protein pyogenic streptococci, cord factor tubercle bacillus).

6. AGRESSINS - substances that suppress the body's defenses and enhancing pathogens

7.TOXINS (proteins, LPC):

Protein toxins:

- completely secreted (exotoxins)

- a partially secreted

- nesekretiruemye

- LPS (endotoxin)

EXOTOXIN:

Chemical nature - proteins, heat-labile. Properties-virulence, Organotropona, antigenicity, immunogenicity.

Produced predominantly gram (+) bacteria can pass into toxoid

The toxin has two center:

One-molecule captures toxin receptor cell

-2nd penetrates cell blocks vital metabolic reactions

Mechanism of action are divided:

- CYTOTOXIN – inhibit protein synthesis at the subcellular level (diphtheria bacillus)

- MEMBRANOTOKSINS: - increase the permeability of the surface membrane to form a channel in it, which is hydrophilic and hydrophobic inside out, which leads to disruption of self-control cells are killed by osmotic shock

a) leukocidin (leukocytes) - Staphylococcus

b) hemolysin (RBCs)-Clostridium perfringens

Toxin - "FUNCTIONAL BLOCKERS" a) enterotoxins (TL, TS) - activate cell adenylate cyclase, leading to increased permeability of the walls of the small intestine and increases the yield of liquid in its lumen (diarrhea), E. coli

b)-neurotoxins block the transmission of nerve impulses in the cells of the brain and spinal cord, tetanus bacillus, botulism, etc.

- Eksfoliatin, ERITROGENINY - affect the interaction of cells with each other and with the intercellular substance - Staphylococcus aureus, Streptococcus scarlatinal

ENDOTOXINS

By chemical. nature - LPS

More resistant to high temperatures, less toxic, have low specificity of action. Weak antigenicity and immunogenicity.

With a large dose-inhibition of phagocytosis phenomenon pronounced toxicity, incidence of heart activity and low body temperature.

When administered small doses indicated the opposite effect: stimulation of phagocytosis, less severe toxemia, fever

Excel at destroying bacteria concentrated in the cell wall of Gram (-) bacteria.

- PERSISTENCE

Modes of transmission:-трансплацентарный (вертикальный) - краснуха

and sex - Gonorrhea

pin - Frenzy

-transmissible - malaria

-fecal-oral - typhoid

-airborne-diphtheria

-parenteral (iatrogenic) viral hepatitis in

TRANSMISSION ROUTES:

digestive tract, mucous

mucous-urinary organs

-intact skin

-damaged skin

mucous-eye

airway mucous-

transmission factors:

-insects

-food

water-

and the air-dust

feces-

Medical tools

blood-

water-droplets in the air

sources of infection:

-soil

-household items

-germ carrier

-food

air-

forms of infection:

on the manifestations:

-typical

-atypical

ON THE NATURE OF AGENT:

1 - bacterial

2 viral

3 fungal

4 protozoal

BY DESCENT:

1) Heteroinfection (pathogens) - infecting microbe outside with food, water, air

2) Endogenous infection (EI) - activation UP flora in the body weakened immune deficiency conditions (stress, trauma, starvation, the effect of ionizing radiation, chronic frequent infections and other diseases)

3) Autoinfection (a kind of endogenous infection) - autoinfection, pathogen transfer from one habitat to another (usually hands)

On localization of the pathogen in the body:

1) spot (alopecia) - boil (hair follicles), sore throat (tonsils)

2) total (generalized) - decrease reactivity, the microbe in the blood:

-Bacteremia (without multiplication) - br.tif, brucellosis, typhus, relapsing fever, plague, tularemia

-viremia

-Toxemia (endotoxin) - salmonellosis, esherihioz meningitis

-TOKSINEMIYA (exotoxin) - diphtheria, botulism, tetanus

-SEPTICAEMIA (sepsis) - (multiplication with a sharp oppression of the basic mechanisms of immunity) - sib.yazva, plague, coccal disease.

When protozoal infections close to sepsis reproduction in the blood of some protozoa (malaria parasites, trypanosomes)

-Pyosepticemia (purulent lesions in internal organs) - staph, strep infection

With mass entering the blood of toxins and bacteria may develop bacterial or toxic and septic shock.

3) wound (tetanus, gas gangrene)

-venereal (syphilis, AIDS, gonorrhea)

-respiratory (flu, pneumonia, bronchitis)

Gastrointestinal (typhoid, dysentery, cholera)

According to the intensity distribution:

1) sporadic - sporadic disease

2) group - a small number of unrelated cases

3) epidemic - a large number of related cases of a single source

4) pandemic-covered continents (influenza, plague, cholera)

The number of species of pathogens:

Monoinfection-one species of microbe infection (diphtheria, tuberculosis)

Mixed infection, infection by several species of pathogens-(+ typhoid dysentery)

When reinfestation:

1) a secondary infection - infection is now available to any new infection (sick with dysentery, joined pneumonia caused by other microbes)

2) re-reinfection disease the same infection after recovery is not completed by the formation of stress immunity (dysentery, gonorrhea)

3) superinfection-patient infected with the disease during the same agent (before recovery)

4) Returns relapse-clinical illness after recovery without re-infection, and by the remaining bacteria (erysipelas, relapsing fever)

duration microbe interactions with the body:

-sharp - a short time, the pathogenesis of certain microbe disappears from the body

-chronic - an infectious disease with long-term presence of the microbe in the body can be released into the environment (tuberculosis, syphilis)

-persistence-long intracellular pathogen multiplication (multiply inside macrophages salmonella)

-bacteriocarrier-(microbe carrier, of virus) - manifestations of infection weak or absent, and the microbe persists in the body after a weak intensity of postinfection immunity (br.tif., dysentery)

Can occur in healthy individuals, contact with patients or carriers.

-abortive infection - ended abruptly, undeveloped form, associated with weak virulence of pathogens, which in a short time disappear from the body

-latent - hidden atypically proceeding without clinical signs of disease (tbc, malaria, herpes)

-asymptomatic - without pronounced wedge. symptoms

-symptomatic - in the presence of the characteristic simptomokmpleksa

Source of infection:

antropos-person infection source

(Convalescent, sick, bacillicarriers) - Gonorrhea

- Zoonoses (zooantroponozam) - a source of animals (brucellosis)

-sopronozy - environment, serving as the natural habitat of some pathogenic bacteria or contaminated secretions from patients or animals (legionellosis)

Periods of infection:

until the first signs of the disease

Duration of envy:

a) The speed of propagation of pathogens

b) Features of the toxic products of pathogens

c) reactivity of microorganism (Salmonella-minute plague-clock skralatina, syphilis-weeks-months rabies, leprosy-years)

Adhesion to sensitive cells (tonsil dyh.puti, gastrointestinal tract, SPE), microbes usually not released into the environment

2. Prodromal period (4-5 days) - nonspecific common manifestations.

Exceptions: measles, smallpox

Colonization of the sensitive cells.

3. Period of development of clinical symptoms (from a few days (flu) to many years (leprosy) - the height of the disease manifestations of specific symptoms: fever, inflammation, CNS, cardiovascular system, respiratory, digestive, reproductive organs (specific manifestations characteristic of the pathogen that caused the disease. serum aT begin to appear, which increases the titer. Intensive microbial growth, the allocation to the environment, danger to others.

4. Period of recovery (convalescence)

-decrease in the frequency and intensity of symptoms

-rapid decline in temperature

-sweating

-often-vascular collapse

Termination of reproduction and death of the pathogen, or the transition to mikrobonositelstvo. The duration depends on the state of the organism, rehabilitation, etc. The antibody titer reaches a maximum. If lethal, infectious diseases corpses be disinfected. Dynamics of infectious process.

Clinical manifestations:

1. Places

2. Nonspecific

3. Specific

4. Reduced

Features of viral infections:

Viruses characterized by obligate parasitism and the ability to induce NK infectious process. Lack of nonpathogenic species allows not to use the term "pathogenicity." Viruses lack the virulence properties as it is inherent in living cells with its own exchange-in. Therefore, instead of the concepts of "pathogenicity and virulence" for virus uses the term "infectivity" or "infectivity." The property is connected with NC virus whose introduction into the sensitive cells is capable of causing infection.

Viruses have specificity and Organotropona (rabies virus - cell nerve, measles - airways pox - skin cells, liver cells hepatitis, etc.)

Features of viral infections:

-the ability of many RNA and DNA viruses cause infection integrative (virogeniyu) that occurs when integrating into the chromosome NC (provirus) - (hepatitis B, adenovirus, herpes, AIDS).

At no stage virogenii reproduction, assembly output.

In certain circumstances - mutation uncontrolled division.

stage-presence of viremia (circulating in the blood), except viruses that spread through neurogenic (rabies, herpes).

the incidence of virus-immune system cells (lymphocytes), influenza viruses, measles, herpes, polio, AIDS, etc.

Lymphotropic reflected in the pathogenesis and outcome of viral infections (immunodeficiency)

Education intranuclear and intracytoplasmic inclusions - smallpox, rabies, herpes, measles and t.d.Imeyut diagnostic value.

Form of viral infection:

-productive (acute, accompanied by a reproduction of viruses in cells and rapid evolution).

This form may manifest as forms: focal and generalized. Persistent can manifest itself in the form of: latent (asymptomatic) - absence of virus isolation; chronic - virus isolation from the body; infection and slow - no virus isolation; abortive-suspension products; development of neoplastic degeneration of cells (oncogenic viral infection).

Odontogenic (stomatogennye) infection develop in if available in the tooth inflammation spreads to nearby tissue through defects of dental hard tissues or through the root canal. Etiological agents of odontogenic infections are representatives of the normal oral flora: staphylococci, streptococci, gram-positive and gram-negative anaerobic and facultative anaerobic bacteria (peptokokki, peptostreptokokki, Bacteroides, leptotrihii etc.). Leading role played by staphylococci and gram-negative anaerobes nonspore.

Periodontitis – inflammatory periodontal disease (tooth root shell between the root of the tooth and jaw bone). The cause of inflammation is often the infection. Germs penetrate into the periodontal space through root canal (complication pulpit), in the presence of pathological periodontal pocket (periodontitis), hematogenous route for acute infectious disease (angina, scarlet fever, flu). Depending on the extent of the inflammatory process, the following types of odontogenic infections: periodontitis, periostitis of the jaw, jaw osteomyelitis, purulent inflammation of the soft tissues of the tooth (abscess, abscess).

Jaw abscess - an inflammation of the periosteum. In 74-78% of cases is a complication of inflammatory processes in periodontal tissues when exudate from periodontal falls under the periosteum of the jaw.

Osteomyelitis of the jaw - infectious necrotic process that develops in the bone marrow, in all structural parts of the bone and surrounding soft tissues. May be limited (in the range of 2-3 teeth) and diffused (diffuse). Called often pyogenic Staphylococcus aureus.

Abscess - limited suppurative inflammation in the soft tissues of the oral and maxillofacial region. May be caused by streptococci, staphylococci, pneumococci, diplococci, Escherichia coli, etc. fuzobakterii anaerobic microorganisms.

Phlegmon - diffuse suppurative inflammation in the soft tissues of the oral and maxillofacial region (subcutaneous, intramuscular, mezhfastsialnoy loose tissue). Caused by the same organisms as abscess. Risk of disease is determined by the proximity of the brain, the visual analyzer, the initial of the upper respiratory and digestive tracts. The infection can spread along the neurovascular bundle of the neck, throat and esophagus into the mediastinum.

Methods of laboratory diagnosis of infection: microscopic, bacteriological, virological, mycological, immunological, biological, Allergy, biochemical, and genetic.

Immune complex reactions of the organism to preserve its structural and functional integrity when exposed to genetically alien information antigens exogenous and endogenous origin.

Antigen exogenous origin - microbes, graft and other environmental factors

ntigeng endogenous cells of an organism modified by the action of a microbe, a / b; aging and tumor cells.

anti-infective immunity-set of inherited and acquired properties that protect the body from pathogens.