Staphylococcus group a. Staphylococcus - what is it, types, symptoms and treatment for staphylococcal infection in adults

Back in 1878, Pasteur and Koch isolated and described a new microbe, which they called staphylococcus. This is a spherical microorganism, up to 1 micron in size, located in clusters, which is why it got its name, which translated from Greek means “bunch of grapes.” Stains well on Gram. Colonies of staphylococcus are capable of producing a pigment substance, which leads to coloration from cream to bright yellow and golden. It is a facultative anaerobes and can be easily grown on nutrient media.

All types of staphylococcus are capable of producing specific toxins and secreting aggressive enzymes. It is these properties that determine the high pathogenicity of microorganisms. Factors of aggression of staphylococcus are:

Exotoxins. To date, four of their species are reliably known. When they enter the macroorganism, all of them lead to the destruction of red blood cells, have necrotic properties, and are capable of causing the death of various cells.
Leukocidins. There are 4 known types of these aggressive enzymes, which are secreted by staphylococci and lead to changes in blood leukocytes and are capable of causing an immune response from the body.
Enterotoxins. Formed in food products contaminated with staphylococci. If it enters the human body, it causes intoxication.

What sets staphylococcal enterotoxin apart is its stability at high temperatures. That's why even after heat treatment products contaminated with staphylococcus, enterotoxin remains aggressive and can cause poisoning:

A special type of exotoxin that triggers necrotic, exfoliative changes in the skin, especially in infants– pemphigus of newborns, skin rashes similar to scarlet fever.
Aggression enzymes. These include plasmacoagulase, hyaluronidase, fibrinolysin and others.
Penicillinase enzyme. Thanks to this substance, staphylococci can pass from active vegetative forms to the L-form, easily modify, becoming resistant to antibacterial drugs, which makes healing difficult.

These microorganisms are among those resistant to various environmental conditions. They easily tolerate the process of freezing and drying, retaining pathogenic properties for many years.

Types of microorganisms

Today's medical science knows more than 30 types of staphylococcus. Fourteen of them are saprophytes, permanent inhabitants skin. Three varieties have aggressive pathogenic properties:

The most dangerous is Staphylococcus aureus, in Latin S. aureus. It is highly pathogenic and has all the aggressive factors characteristic of this type of microbe.
Staphylococcus epidermidis – S. epidermidis. It is a permanent inhabitant of the skin of any person. However, when weakening immune defense, is the source of such deadly dangerous conditions like sepsis. It is this that most often causes infection of the inner lining of the heart - endocarditis.
The least aggressive is saprophytic staphylococcus S. saprophyticus. Lives on the surface of the skin, mucous membranes of the urogenital tract. Can cause severe inflammatory diseases of the urinary system.

All of these types of microbes cause purulent-inflammatory diseases and foodborne toxic infections. They are highly pathogenic.

Main routes of transmission

The following routes of infection are typical for all varieties of staphylococcus:

Endogenous. The microbe is activated against the background of a decrease in the body's immune defense.
Contact. More typical for Staphylococcus aureus. The infection is transmitted through household items and toys.
Airborne. Infection occurs through dust, as well as through contact with a sick person.
Food. The disease manifests itself when products containing staphylococcal enterotoxin enter the body.

According to studies conducted by WHO doctors, Staphylococcus aureus tops the list of microorganisms that cause nosocomial infections.

Staphylococcus aureus

The Latin name for Staphylococcus aureus is Staphylococcus aureus, and it is the most common type of microbe, causing severe, purulent lesions in almost any organ. Under the influence of inadequate antibacterial therapy, it can transform into the L-form, which complicates the treatment process, making the microbe resistant to the treatment. Can cause in the body severe violations life activity, leading to death.

The favorite habitat of this type of microbe is the ENT organs: oral and nasopharynx, mucous membranes of the nasal cavity, sinuses.

This pathogenic species is the most common cause such dangerous diseases as:

Pneumonia.
Infectious endocarditis, accompanied by damage to the heart valve apparatus.
Osteomyelitis.
Purulent mastitis.
Meningitis.
Damage to the skin of newborns.
Sepsis. Foci of purulent inflammation can be detected in any organ: liver, kidneys, membranes and brain matter.

It is with Staphylococcus aureus that the concept “ toxic shock”, often with fatal consequences.

Staphylococcus epidermidis

In Latin - Staphylococcus epidermidis. Less aggressive than the previous species. The main target organs are the skin and soft tissues. It shows its activity when immunity decreases. Staphylococcal infection is accompanied by purulent-inflammatory rashes on the skin, characterized by the appearance of erosions and ulcers. Children get sick more often, which is due to imperfection immune mechanisms protection in this category of patients. In women it causes damage to the genitourinary system.

There is a particular danger in postoperative period, causing early postoperative inflammatory complications, wound infections.

Saprophytic staphylococcus

S. saprophyticus is the least aggressive of the species considered. This pathogen causes cystitis, urethritis, inflammatory diseases of the kidneys, and external genitalia. Adults are more susceptible to the disease; children rarely get sick. Local manifestations are typical; the clinical picture of intoxication syndrome is not typical for infections caused by this type of microbe.

Pregnancy and infection

Staphylococcal infection poses a particular danger to women during pregnancy, when the hormonal background and immunity decreases. Timely sanitation of the source of inflammation and adequate antibiotic therapy will help to avoid undesirable consequences for mother and fetus.

Prevention

Staphylococci are opportunistic microorganisms. According to various studies, carriers are from 40 to 60 percent of the population of all countries of the world. It is necessary to distinguish between the concepts of an infection that has clear clinical symptoms and the detection of staphylococcus based on the results of culture on nutrient media and microbiological studies that are not accompanied by a clinical picture of any disease. Measures to prevent pathological processes caused by this insidious microbe are:

Compliance with basic hygiene standards and rules: regular wet cleaning, ventilation, treatment contact surfaces, toys.
Timely sanitation of foci of infection, carrying out adequate therapeutic measures.
Compliance with hygienic standards in food.
Measures aimed at increasing immune defense, hardening, playing sports.
Compliance with the sanitary and protective regime in medical institutions.

Timely contact medical institution at the first signs of illness, strict adherence to the doctor’s recommendations during treatment, simple measures aimed at strengthening the immune system and prevention are elementary ways to protect the body from the occurrence of staphylococcal infection.

Type: Firmicutes
Class: bacilli
Order: Bacillales
Family: Staphylococcaceae (Staphylococcal)
Genus: Staphylococcus
International scientific name: Staphylococcus

Staphylococcus(lat. Staphylococcus) is a non-motile spherical bacterium belonging to the Staphylococcus family (Staphylococcaceae).

Staphylococcus belongs to the group of positive, immobile, anaerobic, opportunistic microorganisms for the human body. The type of metabolism is oxidative and enzymatic. They do not form spores or capsules. The diameter of a staphylococcus cell is 0.6-1.2 microns, depending on the strain (species). The most common colors are purple, gold, yellow, and white. Some staphylococci are capable of synthesizing characteristic pigments.

Most types of staphylococcus bacteria are purple in color and spread in bunches similar to grapes, which is why they got their name, which translated from ancient Greek means “σταφυλή” (grapes) and “κόκκος” (grain).

Staphylococci in a certain amount are almost always found on the surface of the human body (in the nasal and oropharynx, on the skin), but when this infection gets inside, it weakens the body, and some of the types of staphylococcus can even cause the development of various diseases, including almost all organs and systems, especially if the immune system is weakened. The fact is that staphylococcus, when ingested, produces a large amount of endo- and exotoxins (poisons) that poison the body's cells, disrupting their normal functioning. The most common pathologies caused by staphylococci are pneumonia, toxic shock, sepsis, purulent skin lesions, disturbances in the functioning of the nervous, digestive and other systems, and general poisoning of the body. It is not uncommon for a staphylococcal infection to occur as a secondary disease, as a complication of others.

The conditional pathogenicity of this type of infection suggests that staphylococci have a negative effect on human or animal health only under certain conditions.

There are quite a large number of types of staphylococcus - 50 (as of 2016). The most common are Staphylococcus aureus, hemolytic, saprophytic and epidermal staphylococci. Each of the strains of these bacteria has its own severity and pathogenicity. They are resistant to many antibacterial drugs, as well as various harsh climatic conditions, but are sensitive to aqueous solutions of silver salts and its electrolytic solutions.
Staphylococcal infection is widespread in soil and air. It is by air that a person is most often infected (infected). It is also worth noting that this type of infection can affect not only people, but also animals.

It has been noticed that children are most susceptible to infection with staphylococcus, which is due to the fact that they are not fully formed immune system and non-compliance with personal hygiene rules, as well as elderly people.

Causes of staphylococcus

The cause of the development of almost all staphylococcal diseases is a violation of the integrity of the skin or mucous membranes, as well as the consumption of contaminated food. The level of harm also depends on the strain of the bacterium, as well as the functioning of the immune system. The stronger the immune system, the less harm staphylococci can cause to human health. Thus, we can conclude that in most cases, staphylococcal disease requires a combination of 2 factors - infection inside and disruption of the normal functioning of the immune system.

How is staphylococcus transmitted? Let's look at the most popular ways of contracting staphylococcal infections.

How can staphylococcus enter the body?

Airborne path. During the season of respiratory diseases, frequent stays in places large cluster people also increases the risk of infection, not only staphylococcal, but also many other types of infection, incl. viral, fungal. Sneezing, coughing - such symptoms serve as a kind of beacons, from which healthy people, if possible, need to stay away.

Airborne dust path. Household and street dust contains a large number of different microscopic particles - plant pollen, exfoliated skin particles, hair of various animals, dust mites, particles of various materials (fabric, paper), and all this is usually seasoned with various infections - fungi. Staphylococcus and other types of infection are very often found in dust, and when we breathe such air, it does not have the best effect on our health.

Contact and household path. Infection usually occurs when sharing personal hygiene items, bed linen, especially if one of the family members is sick. The risk of infection increases when the skin and mucous membranes are injured.

Fecal-oral (nutritional) route. Infection occurs when eating food with dirty hands, i.e. - in case of non-compliance. It is also worth noting here that infection through nutritional means is also a common cause of diseases such as - and other complex ones.

Medical path. Infection with staphylococcus occurs through contact with insufficiently clean medical instruments, both during surgical interventions and during certain types of diagnostics, which imply a violation of the integrity of the skin or mucous membranes. This is usually due to the treatment of instruments with a product to which the staphylococcus has developed resistance.

How can staphylococcus seriously harm human health, or what weakens the immune system?

Presence of chronic diseases. Most diseases indicate a weakened immune system. If pathological processes are already occurring in the body, it is more difficult for it to protect itself from other diseases. Therefore, any disease increases the risk of a secondary infection, and staphylococcal one of them.

The most common diseases and pathological conditions, in which staphylococcus often attacks the patient, are: tonsillitis, pharyngitis, laryngitis, tracheitis, bronchitis, pneumonia, diseases of other systems, as well as other chronic diseases.

In addition, the risk of infection with staphylococcus increases:

Bad habits: smoking, drinking alcoholic drinks, consumption narcotic drugs;
, lack of healthy sleep;
Sedentary lifestyle;
Use;
(vitamin deficiency);
Abuse of certain medications - vasoconstrictors (violate the integrity of the nasal mucosa), antibiotics;
Violations of the integrity of the skin, mucous membranes of the nasal cavity and mouth.
Insufficient ventilation of rooms in which a person often stays (work, home);
Work in enterprises with high air pollution, especially without protective equipment(masks).

Symptoms of staphylococcus

The clinical picture (symptoms) of staphylococcus can be very diverse, which depends on the organ affected, the strain of the bacterium, the age of the person, and the functionality (health) of the immune system of the potential patient.

Common symptoms of staphylococcus can be:

Increased and high body temperature (often local) - up to, ;
(a rush of blood to the site of inflammatory processes);
General malaise, soreness;
Swelling;
Pyoderma (develops when staphylococcus gets under the skin), folliculitis, carbunculosis,;
Decreased appetite, abdominal pain, ;
- , And ;
Respiratory tract diseases:, and;
Purulent discharge from the nasopharynx and oropharynx is yellow-green;
Impaired sense of smell;
Difficulty breathing, shortness of breath, sneezing;
Changing the timbre of the voice;
Toxic shock syndrome;
Drop in blood pressure;
"Scalded Baby Syndrome";
Impaired functioning of certain organs and tissues, which have become a source of infection;

Complications of staphylococcus:

Lung abscess;
Empyema of the pleura;
Loss of voice;
Fever;
Convulsions;

Scientists have divided most types of staphylococcus into 11 groups:

1. Staphylococcus aureus (Staphylococcus aureus)— S. aureus, S. Simiae.

Staphylococcus aureus is the most pathogenic for human body. Once inside, they can cause inflammation and damage to almost all human organs and tissues, as well as form a golden pigment. Staphylococcus aureus has the property of producing the coagulase enzyme, which is why it is sometimes called coagulase-positive staphylococcus.

2. Ear staphylococci (Staphylococcus auricularis)- S. auricularis.

3. Staphylococcus carnosus- S. carnosus, S. condimenti, S. massiliensis, S. piscifermentans, S. simulans.

4. Epidermal staphylococci (Staphylococcus epidermidis)- S. capitis, S. caprae, S. epidermidis, S. saccharolyticus.

Staphylococcus epidermidis is most often found on human skin and mucous membranes. It is a common cause of diseases such as endocarditis, sepsis, purulent lesions of skin wounds and urinary tract. With the normal functioning of the immune system, the body does not allow epidermal staphylococci to multiply inside the body and infect it.

5. Hemolytic staphylococci (Staphylococcus haemolyticus)- S. devriesei, S. haemolyticus, S. hominis.

Hemolytic staphylococcus is most often the cause of diseases such as endocarditis, sepsis, inflammatory processes with suppuration on the skin, and urethritis.

6. Staphylococcus hyicus-intermedius- S. agnetis, S. chromogenes, S. felis, S. delphini, S. hyicus, S. intermedius, S. lutrae, S. microti, S. muscae, S. pseudintermedius, S. rostri, S. schleiferi.

7. Staphylococcus lugdunensis— S. lugdunensis.

8. Saprophytic staphylococci (Staphylococcus saprophyticus)– S. arlettae, S. cohnii, S. equorum, S. gallinarum, S. kloosii, S. leei, S. nepalensis, S. saprophyticus, S. succinus, S. xylosus.

Saprophytic staphylococcus is often the cause of urinary tract diseases such as cystitis and urethritis. This is due to the fact that saprophytic staphylococcus is found mainly on the skin of the genitals, as well as the mucous membranes of the urinary tract.

9. Staphylococcus sciuri– S. fleurettii, S. lentus, S. sciuri, S. stepanovicii, S. vitulinus.

10. Staphylococcus simulans– S. simulans.

11. Staphylococcus warneri– S. pasteuri, S. warneri.

Degrees of staphylococcus

To determine the exact treatment regimen, doctors divided the course of staphylococcal disease into 4 conventional degrees. This is due to the fact that different types of infection, as well as their pathological activity V different times and vary under different conditions. In addition, this approach to diagnosis distinguishes between a staphylococcal infection and which group it belongs to - a completely pathogenic effect on the body, an opportunistic one, and saprophytes, which practically do no harm to humans.

Degrees of staphylococcus

Staphylococcus stage 1. Localization of infection for collection for diagnosis - nasopharynx, oropharynx, skin, genitourinary system. Clinical manifestations are absent or minimal. With a healthy immune system, drug therapy not required.

Staphylococcus stage 2. Clinical manifestations (symptoms) are minimal or absent. If there are complaints, a thorough diagnosis is carried out for the presence of other types of infection. If it is determined that another type of bacteria is present in the body, antibacterial therapy is prescribed privately.

Staphylococcus 3 degrees. The patient has complaints. In most cases, antibiotic therapy is necessary, unless the attending physician considers the use of antibiotics to be unjustified. Treatment of stage 3 staphylococcus is usually aimed primarily at strengthening the immune system. If within 2 months the body does not recover, an individual treatment regimen for the infection is developed, incl. using antibacterial agents.

Staphylococcus stage 4. Therapy is aimed at strengthening the immune system, eliminating... Before using antibacterial therapy, a thorough diagnosis is carried out to determine the reaction of a particular type of staphylococcus to the drug.

Diagnosis of staphylococcus

Testing for staphylococcus is carried out from smears taken usually from the surface of the skin, mucous membranes of the upper respiratory tract or urinary tract.

Additional examination methods may include:

How to treat staphylococcus? Treatment of staphylococcus usually consists of 2 points - strengthening the immune system and antibacterial therapy. If there are other diseases, their treatment is also carried out.

The use of antibiotics based on diagnosis is very important, since it is almost impossible to determine the type of staphylococcus from the clinical picture, and the use of antibiotics wide range actions can cause a large number of side effects.

However, the following most popular antibiotics are used to treat staphylococcus.

Antibiotics for staphylococcus

Important! Before using antibiotics, be sure to consult with your doctor.

"Amoxicillin". Has the property of suppressing infection, stopping its reproduction and negative impact on the body. Blocks the production of peptidoglycan.

"Baneotsin". Ointment for the treatment of staphylococcus in skin lesions. It is based on a combination of two antibiotics - bacitracin and neomycin.

"Vancomycin". Promotes the death of bacteria by blocking a component that is part of it cell membrane. It is used intravenously.

"Clarithomycin", "Clindamycin" And « » . They block the production of proteins by bacteria, without which they die.

"Cloxacillin". Blocks the proliferation of staphylococcus by blocking their membranes present during the stage of cell division. Usually prescribed at a dose of 500 mg/6 hours.

"Mupirocin" – antibacterial ointment for staphylococcal skin lesions. Used for external use. The ointment is based on three antibiotics - Bactroban, Bonderm and Supirocin.

"Oxacillin". Blocks bacterial cell division, thereby destroying them. Method of administration: oral, intravenous and intramuscular.

— In hot weather, avoid eating confectionery, meat, dairy and other products that are not stored in proper conditions;

— If the skin is injured, be sure to treat the wound with antiseptic agents, then cover it with a band-aid;

— Try not to visit beauty salons, tattoo parlors, solariums or dental clinics of dubious nature, where they may not adhere to sanitary standards for processing medical instruments.

Which doctor should you contact if you have a staphylococcal infection?

β-toxin or sphingomyelinase is detected in approximately a quarter of all pathogenic staphylococci. β-toxin is capable of causing the destruction of red blood cells ( red blood cells), and also lead to the proliferation of fibroblasts ( migration of fibroblasts into the inflammatory focus). This toxin becomes most active at low temperatures.

γ-toxin is a two-component hemolysin that has moderate activity. It is worth noting that the bloodstream contains substances that block the action of γ-toxin ( sulfur-containing molecules are capable of inhibiting one of the components of the γ-toxin).

δ-toxin is a low molecular weight compound with detergent properties. Exposure of a cell to δ-toxin leads to disruption of cell integrity by various mechanisms ( basically there is a disruption of the relationship between the lipids of the cell membrane).

Exfoliative toxins. In total, there are 2 types of exfoliative toxins – exfoliant A and exfoliant B. Exfoliative toxins are detected in 2–5% of cases. Exfoliants are capable of destroying intercellular connections in one of the layers of the skin ( granular layer of the epidermis), and also lead to detachment of the stratum corneum ( the most superficial layer of skin). These toxins can act locally and systemically. In the latter case, this can lead to scalded skin syndrome ( the appearance of areas of redness on the body, as well as large blisters). It is worth noting that exfoliants are able to bind several molecules involved in the immune response at once ( exfoliative toxins exhibit properties of superantigens).
Toxic shock syndrome toxin (formerly called enterotoxin F) is a toxin that causes the development of toxic shock syndrome. Toxic shock syndrome refers to acutely occurring multisystem organ damage ( several organs are affected at once) with fever, nausea, vomiting, stool disorders ( diarrhea), skin rash. It is worth noting that toxic shock syndrome toxin can be produced in in rare cases only Staphylococcus aureus.
Leukocidin or Panton-Valentine toxin capable of attacking some white blood cells ( neutrophils and macrophages). The effect of leukocidin on the cell leads to disruption of the water-electrolyte balance, which increases the concentration of cyclic adenosine monophosphate in the cell ( cAMP). These disorders underlie the mechanism of occurrence of staphylococcal diarrhea in food poisoning from products infected with Staphylococcus aureus.
Enterotoxins. In total, there are 6 classes of enterotoxins - A, B, C1, C2, D and E. Enterotoxins are toxins that attack human intestinal cells. Enterotoxins are low molecular weight proteins ( proteins), which are well tolerated elevated temperature. It should be noted that it is enterotoxins that lead to the development of food poisoning by type of intoxication. In most cases, these poisonings can be caused by enterotoxins A and D. The effect of any of the enterotoxins on the body is manifested in the form of nausea, vomiting, pain in the upper abdomen, diarrhea, fever and muscle spasms. These disorders are caused by the superantigenic properties of enterotoxins. In this case, excessive synthesis of interleukin-2 occurs, which leads to this intoxication of the body. Enterotoxins can lead to an increase in the tone of intestinal smooth muscles and increase motility ( contractions of the intestines to move food along) gastrointestinal tract.

Enzymes

Staphylococcal enzymes have a diverse effect. Also, the enzymes that staphylococci produce are called “aggression and defense” factors. It should be noted that not all enzymes are pathogenicity factors.

The following staphylococcal enzymes are isolated:

Catalase is an enzyme that can destroy hydrogen peroxide. Hydrogen peroxide is capable of releasing the oxygen radical and oxidizing the cell wall of the microorganism, leading to its destruction ( lysis).
β-lactamase is able to effectively combat and neutralize β-lactam antibiotics ( a group of antibiotics that are united by the presence of a β-lactam ring). It is worth noting that β-lactamase is very common among the population of pathogenic staphylococci. Some strains of staphylococci exhibit increased resistance to methicillin ( antibiotic) and other chemotherapy drugs.
Lipase is an enzyme that facilitates the attachment and penetration of bacteria into the human body. Lipase is capable of destroying fat fractions and, in some cases, penetrating through sebum into hair follicle (location of the hair root) and into the sebaceous glands.
Hyaluronidase has the ability to increase tissue permeability, which contributes to the further spread of staphylococci in the body. The action of hyaluronidase is aimed at the breakdown of complex carbohydrates ( mucopolysaccharides), which are part of the intercellular substance connective tissue, and are also found in the bones, vitreous body and cornea of the eye.
DNAase is an enzyme that cleaves double-stranded DNA molecule ( deoxyribonucleic acid) into fragments. During exposure to DNase, the cell loses its genetic material and the ability to synthesize enzymes for its own needs.
Fibrinolysin or plasmin. Fibrinolysin is a staphylococcal enzyme that is capable of dissolving fibrin threads. In some cases, blood clots serve a protective function and prevent bacteria from entering other tissues.
Staphylokinase is an enzyme that converts plasminogen to plasmin ( when exposed to staphylokinase, the proenzyme plasminogen transforms into its active form - plasmin). Plasmin can extremely effectively break down large blood clots, which act as an obstacle to the further advancement of staphylococci.
Phosphatase is an enzyme that accelerates the breakdown of esters phosphoric acid. Staphylococcal acid phosphatase is generally responsible for the virulence of the bacterium. This enzyme can be located on the outer membrane, and the location of the phosphatase depends on the acidity of the environment.
Proteinase staphylococcus is capable of breaking down proteins into amino acids ( protein denaturation). Proteinase has the ability to inactivate certain antibodies, suppressing the body's immune response.
Lecithinase is an extracellular enzyme that breaks down lecithin ( fat-like substance, part of the cell wall) into simpler components ( phosphocholine and diglycerides).
Coagulase or plasmacoagulase. Coagulase is the main factor in the pathogenicity of staphylococcus. Coagulase can cause blood plasma clotting. This enzyme can form a thrombin-like substance that interacts with prothrombin and envelops the bacterium in a fibrin film. The formed fibrin film has significant resistance and serves as an additional capsule for staphylococcus.

Groups of staphylococci depending on the presence of coagulase

Pathogenicity	Coagulase-positive staphylococci	Coagulase-negative staphylococci
Opportunistic staphylococci that live on the skin and mucous membranes of humans and animals	S. intermedius, S. hyicus	S. capitis, S. warneri, S. cohnii, S. xylosis, S. sciuri, S. simulans, S. arlettae, S. auricularis, S. carnosus, S. caseolyticus, S. gallinarum, S. kloosii, S. caprae, S. equorum, S. lentus, S. saccharolyticus, S. schleiferi, S. lugdunensis, S. chromogenes.
Pathogenic staphylococci, causing diseases in humans	S. aureus ( Staphylococcus aureus)	S. saprophyticus ( saprophyticstaphylococcus), S. epidermidis ( epidermalstaphylococcus), S. haemolyticus ( hemolytic staphylococcus).

Adhesins

Adhesins are surface layer proteins that are responsible for attaching staphylococcus to mucous membranes and connective tissue ( ligaments, tendons, joints, cartilage are some of the representatives of connective tissue), as well as to the intercellular substance. The ability to attach to tissues is associated with hydrophobicity ( property of cells to avoid contact with water), and the higher it is, the better these properties are manifested.

Adhesins have specificity for certain substances ( tropism) in the body. So, on the mucous membranes this substance is mucin ( a substance that is part of the secretion of all mucous glands), and in connective tissue – proteoglycan ( intercellular substance of connective tissue). Adhesins are capable of binding fibronectin ( complex extracellular substance), thereby improving the process of attachment to tissues.

It is worth noting that most of the components of the cell wall of pathogenic staphylococci, as well as their toxins, can lead to delayed and immediate allergic reactions ( anaphylactic shock, Arthus phenomenon, etc.). Clinically this manifests itself in the form of dermatitis ( inflammatory skin disease), bronchospastic syndrome ( spasm of bronchial smooth muscles, which manifests itself as shortness of breath), etc.

Method of infection with staphylococcus

Diseases caused by staphylococci can be of the nature of autoinfection ( entry of bacteria into the body through damaged areas of the skin and mucous membranes), since staphylococci are permanent inhabitants of human skin and mucous membranes. Infection can also occur through contact with household items or by eating contaminated food. This method of infection is called exogenous.

It is worth noting that important In the mechanism of transmission of staphylococci, they are attributed to the carriage of pathogenic staphylococci. The term "carrier" refers to the presence pathogenic bacteria in the body that do not cause any clinical manifestations diseases. There are two types of carriage of pathogenic staphylococci - temporary and permanent. The main danger is posed by people who are constant carriers of pathogenic staphylococcus. In this category of people, pathogenic staphylococci are detected in large quantities, which are present for a long time on the mucous membranes and in the skin. It is still not entirely clear why long-term carriage of pathogenic staphylococcus occurs. Some scientists associate this with a weakening of local immunity with a decrease in the titer of immunoglobulin A ( a decrease in the concentration of one of the types of antibodies that are responsible for the immune response). There is also a hypothesis that explains the long-term carriage of pathogenic staphylococcus with impaired functioning of the mucous membrane.

The following mechanisms of transmission of staphylococci are distinguished:

contact and household mechanism;
air-droplet mechanism;
air-dust mechanism;
nutritional mechanism;
artificial mechanism.

Contact and household mechanism

The contact-household mechanism of transmission of infection occurs due to the transfer of bacteria from the skin and mucous membranes to various household and household items. This route of transmission of infection is associated with the use of common household items ( towel, toys, etc.). To implement the contact-household route of transmission, a susceptible organism is required ( When bacteria are introduced, the human body reacts with a clinically significant disease or carriage). The contact-household transmission mechanism is a special case contact path transmission of infection ( direct contact with skin).

Airborne mechanism

The airborne transmission mechanism is based on inhalation of air containing microorganisms. This transmission mechanism becomes possible when bacteria are isolated in environment along with exhaled air ( for diseases of the respiratory system). Pathogenic bacteria can be released through breathing, coughing and sneezing.

Air-dust mechanism

The airborne dust mechanism of transmission of staphylococcal infection is a special case of the airborne droplet mechanism. The air-dust mechanism is realized when bacteria remain in dust for a long time.

Nutritional mechanism

With the alimentary mechanism ( fecal-oral mechanism) transmission, the release of staphylococci occurs from an infected organism through bowel movements or vomiting. Penetration of bacteria into a susceptible organism occurs through the oral cavity when consuming contaminated food ( presence of microorganisms in food). After this, the staphylococcus again colonizes the digestive tract of the new host. As a rule, contamination of food products with staphylococci occurs due to non-compliance with personal hygiene rules - insufficient hand washing. Also, this mechanism can be carried out as a result of carriage of a staphylococcal infection in a food industry worker.

Artificial mechanism

The artificial transmission mechanism is characterized by the penetration of pathogenic staphylococcus into the human body through insufficiently sterilized ( sterilization is a method of processing medical instruments and equipment to completely destroy all microorganisms) medical instruments. As a rule, this can happen during the use of various instrumental methods diagnostics ( for example, bronchoscopy). Also, in some cases, the penetration of staphylococcus into the body is observed during surgical operations.

It is worth noting that medical equipment and instruments may not be completely sterile due to the fact that staphylococcus is resistant to some types of disinfectants ( chemicals that have an antimicrobial effect). Also, the cause of the artificial transmission mechanism may be the incompetence or negligence of medical personnel.

What diseases does Staphylococcus aureus cause?

Staphylococcus aureus is capable of infecting most tissues of the human body. In total, there are more than a hundred diseases that are caused by staphylococcal infection. Staphylococcal infection is characterized by the presence of many different mechanisms, routes and transmission factors.

Staphylococcus aureus can extremely easily penetrate through minor damage to the skin and mucous membranes into the body. Staphylococcal infection can lead to various diseases, ranging from acne ( acne ) and ending with peritonitis ( inflammatory process of the peritoneum), endocarditis ( inflammation of the inner lining of the heart) and sepsis, which has a mortality rate of around 80%. In most cases, staphylococcal infection develops against the background of a decrease in local or general immunity, for example, after an acute respiratory viral infection ( ARVI).

The following symptoms are characteristic of staphylococcal sepsis:

increase in body temperature to 39 – 40°C;
intense headache;
loss of appetite;
nausea;
vomit;
increased sweating;
skin pustular rash;
increase in heart rate to 140 beats per minute;
an increase in the size of the liver and spleen;
loss of consciousness;
rave.

In sepsis caused by staphylococcal infection, purulent lesions of the intestines, liver, membranes of the brain, and lungs are often observed ( abscesses). Mortality in adults can reach significant numbers in the case of inadequate antibiotic therapy without taking into account the antibiogram.

Staphylococcal infection is a complex pathological process of interaction between staphylococcus and the human body with a wide range of manifestations - from asymptomatic carriage to severe intoxication and the development of purulent-inflammatory foci.

Due to the high resistance of the microbe to antibacterial drugs, diseases of staphylococcal etiology occupy a leading place among all purulent-inflammatory pathologies.

Staphylococcus causes the following diseases:

Furunculosis,
Pyoderma,
Abscesses,
Sore throat,
Osteomyelitis,
Enterocolitis.

Etiology

The cause of the disease is staphylococci, which are gram-positive cocci belonging to the Micrococcaceae family. These bacteria have a regular spherical shape and are immobile. Staphylococcus in the smear is located in the form of clusters or bunches of grapes.

To staphylococci, causing pathology in humans, there are only three types:

S. aureus is the most harmful,
S. epidermidis – less dangerous, but also pathogenic,
S. saprophyticus is practically harmless, but can cause disease.

These are opportunistic bacteria that are permanent inhabitants of the human body, without causing any illnesses.

When exposed to adverse external or internal factors the number of microbes increases sharply, they begin to produce pathogenicity factors that lead to the development of staphylococcal infection.

Staphylococcus aureus is the main representative of this group, causing severe illness in humans. It coagulates blood plasma, has pronounced lecitovetylase activity, ferments anaerobic mannitol, and synthesizes a cream or yellow pigment.

Properties of bacteria:

Staphylococci are facultative anaerobes that can live and reproduce both in the presence of oxygen and without it. They obtain energy through oxidative and fermentative pathways.
Bacteria are resistant to freezing, heating, sunlight and the effects of some chemicals. Staphylococcal enterotoxin is destroyed by prolonged boiling or exposure to hydrogen peroxide.
Microbial resistance to antibacterial drugs is a problem modern medicine. New multidrug-resistant strains are constantly being formed in medical institutions. Methicillin-resistant staphylococci are very important epidemiologically.

Pathogenicity factors:

Enzymes – hyaluronidase, fibrinolysin, lecitovitellase;
Toxins – hemolysins, leukocidin, enterotoxins, exfoliatins.

Enzymes break down fats and proteins, destroy body tissues, and supply staphylococci nutrients and ensure their movement deep into the body. Enzymes protect bacteria from the effects of immune mechanisms and contribute to their preservation.

Fibrinolysin promotes the penetration of microbes into the blood and the development of sepsis - blood poisoning.
Hemolysins suppress the activity of immunocompetent cells and help staphylococci survive in areas of inflammation for a long time. In children and the elderly, due to these factors, the infection acquires a generalized form.
Exfoliatin damages skin cells.
Leukocidin destroys leukocytes - white blood cells.
Enterotoxin– a strong poison produced by staphylococci and causing foodborne illness in humans.

Epidemiology

Sources of infection are patients and bacteria carriers. Microbes enter the human body through abrasions and scratches on the skin, as well as the mucous membrane of the respiratory system, genitourinary and digestive system.

The main routes of transmission of the pathogen:

Airborne,
Airborne dust,
Contact-household,
Nutritional.

The airborne route predominates among all others. This is due to the constant release of staphylococci into the air and their long-term preservation in the form of an aerosol.

Staphylococcus is transmitted through contact and household contact in medical institutions through the hands of staff, instruments, medical devices, and patient care items.

In the maternity hospital, newborns become infected with staphylococcus through drinking solutions, breast milk, and infant formula. Nosocomial staphylococcal infection poses a great danger to newborns.

Factors contributing to the development of infection:

Weakened immunity,
Long-term use of antibiotics, hormones or immunosuppressants,
Endocrine pathology,
Viral infections
Exacerbation of chronic diseases,
Long-term chemotherapy or radiotherapy,
Impact of harmful environmental factors.

Staphylococcal infection is usually sporadic, but can occur in small outbreaks. Staphylococcal food intoxication are group diseases that occur when consuming foods contaminated with bacteria.

Pathogenesis

Microbes enter the human body through the skin, mucous membranes of the mouth, respiratory system, digestion, and eyes. At the site of staphylococcus penetration, purulent-necrotic inflammation develops. Further development of the process can occur according to two scenarios:

Intense specific immunity prevents the development of the disease and contributes to the rapid elimination of the outbreak.
A weakened immune system cannot fight infection. The pathogen and toxins enter the bloodstream, bacteremia and intoxication develop. When the process generalizes, staphylococcus affects internal organs with the development of septicemia and septicopyemia.

Nonspecific changes, which are a consequence of disrupted metabolic processes in the body and the accumulation of microbial decay products, contribute to the development of infectious-toxic shock.

Staphylococcal toxins penetrate into the blood from the source of inflammation, which manifests itself as intoxication– vomiting, fever, loss of appetite. Erythrogenic toxin causes scarlet fever syndrome.

The result of the breakdown of microbial cells is allergic reaction body to foreign proteins. This is manifested by fever, lymphadenitis, allergic rash and a number of complications - inflammation of the kidneys, joints and others.

An allergic reaction and a toxic component reduce immunity, increase vascular permeability, lead to the development of a septic process, which is accompanied by the formation of many purulent foci and the formation of sepsis.

Pathomorphological changes

Symptoms

Clinical signs of pathology are determined by the site of introduction of the bacterium, the degree of its pathogenicity and the activity of the human immune system.

When the skin is damaged by staphylococcus, pyoderma develops. The pathology is manifested by inflammation of the skin at the roots of the hair or folliculitis - an abscess with hair in the central part. Purulent-necrotic skin diseases of staphylococcal etiology include furuncle and carbuncle, which are acute inflammation of the hair follicle, sebaceous gland, surrounding skin and subcutaneous fat. A particular danger to human health is the location of purulent-inflammatory foci on the face and head. If the course of the pathology is unfavorable, the formation of abscesses in the brain or the development of purulent meningitis is possible.
Purulent melting of deep tissues is called. In an abscess, inflammation is limited to the capsule, which prevents the process from spreading to surrounding tissues. Cellulitis - spilled purulent inflammation subcutaneous fat tissue.

Subcutaneous phlegmon

Pneumonia of staphylococcal etiology is a severe but quite rare pathology. Manifestations of pneumonia - intoxication and pain syndromes, respiratory failure with severe shortness of breath. Complications of the pathology are lung abscesses and pleural empyema.
Purulent inflammation meninges Staphylococcal origin develops through the penetration of microbes through the bloodstream from foci of infection on the face, in the nasal cavity or paranasal sinuses. Patients develop pronounced neurological symptoms, signs of meningism, seizures, impaired consciousness.
Osteomyelitis is a purulent infectious and inflammatory disease that affects bone tissue, periosteum and bone marrow. Purulent foci located in the bone often break out. Signs of pathology are pain, tissue swelling, formation of purulent fistulas.
Staphylococci often affect large joints with the development of purulent arthritis, which is manifested by pain, stiffness and limited movement, joint deformation, and the development of intoxication.
Staphylococcal endocarditis is an infectious inflammation of the connective tissue of the heart lining its internal cavities and valves. Symptoms of the disease are fever, pain in muscles and joints, chills, sweating, pale skin, the appearance of small rashes and dark red nodules on the palms and soles. Auscultation reveals a heart murmur. Endocarditis is a severe pathology leading to the development of heart failure and characterized by high mortality.
Infectious-toxic shock is an emergency condition caused by exposure to bacteria and their toxins on the human body. It is manifested by severe intoxication, dyspepsia, confusion, signs of cardiovascular and renal failure, and collapse.
Food toxicosis develops as a result of eating food containing staphylococcal toxins and often occurs as follows: acute gastritis. Incubation is fast - 1-2 hours, after which severe intoxication and dyspepsia appear. Vomiting often results in dehydration.

Features of staphylococcal infection in children

Staphylococcal infection in children occurs in the form of epidemics, sporadic, group, and family diseases. Epidemic outbreaks are usually recorded in maternity hospitals or neonatal units. Epidemics can affect schools, kindergartens, camps and other organized children's groups. This is due to children eating food contaminated with bacteria. Usually food poisoning happen in the warm season.

Newborn children become infected with staphylococcus through contact from the mother or hospital staff. The main route of transmission of infection for infants is nutritional, in which microbes enter the child’s body with the milk of a mother with mastitis.

Preschoolers and schoolchildren become infected by consuming low-quality food. Staphylococcus, multiplying in a living organism, secretes an enterotoxin that causes gastroenterocolitis.

Staphylococcal respiratory diseases occur when infected by airborne droplets. The microbe enters the mucous membrane of the nasopharynx or oropharynx and causes inflammation of these organs.

Factors causing high susceptibility of newborns and infants to staphylococcus:

Insufficiently strong local immunity of the respiratory and digestive organs,
Lack of immunoglobulin A, which is responsible for local protection of the body,
Vulnerability of mucous membranes and skin,
Weak bactericidal effect of saliva,
Associated pathologies - diathesis, malnutrition,
Long-term use of antibiotics and corticosteroids.

Symptoms in children

There are two forms of staphylococcal infection - local and generalized.

Local forms in children include: rhinitis, nasopharyngitis, conjunctivitis. These pathologies are mild and rarely accompanied by intoxication. They usually manifest themselves in infants as loss of appetite and weight loss. In some cases, local forms are manifested by fever, general deterioration condition and extensive local symptoms.

Skin diseases of staphylococcal etiology in children occur in the form of folliculitis, pyoderma, furunculosis, hidradenitis, and phlegmon. They are accompanied by regional lymphadenitis and lymphangitis. Epidemic pemphigus- pathology of newborns, manifested by symptoms reminiscent of erysipelas: a rash or focal redness of the skin with clear contours. With pemphigus, the skin peels off in entire layers, under which large blisters form.
Staphylococcus in the throat can cause acute tonsillitis or pharyngitis in children, often against the background of an acute respiratory viral infection. Staphylococcal tonsillitis manifests itself as a sore throat, intoxication, fever and the appearance of a continuous coating on the tonsils, arches and uvula. The plaque is usually yellow or white, loose, purulent, and easily removed. When examining a child, the doctor discovers diffuse hyperemia of the throat mucosa without clear boundaries.

Inflammation of the larynx of staphylococcal origin usually occurs in children 2-3 years old. The pathology develops rapidly and has no specific symptoms. Often combined with inflammation of the bronchi or lungs.
Staphylococcal pneumonia is a serious pathology, especially in young children, often complicated by the formation of abscesses. Catarrhal and intoxication signs appear simultaneously in children, while the general condition sharply worsens, signs appear respiratory failure. The child is lethargic, pale, sleepy, refuses to eat, often spits up and even vomits. Pneumonia does not always end in recovery; death is possible. This is due to the formation of bullae in the lungs, in place of which abscesses can form, leading to the development of purulent or.
Scarlet fever-like syndrome in children accompanies infection of wounds, burns, the development of lymphadenitis, phlegmon, and osteomyelitis. The manifestation of the disease is a scarlet-like rash that appears on the hyperemic skin of the torso. After the rash disappears, lamellar peeling remains.
Symptoms of Staphylococcus aureus in cases of damage to the digestive tract depend on the location of the pathology and the condition of the macroorganism. Gastroenteritis begins acutely with symptoms of intoxication and dyspepsia. Children experience vomiting, usually repeated and uncontrollable, abdominal pain, fever, weakness, and dizziness. With inflammation of the small intestine, diarrhea begins up to 5 times a day.
Staphylococcal sepsis usually develops in newborns, often premature children. Infection occurs through the umbilical wound, damaged skin, respiratory organs and even ears. The disease develops rapidly and occurs with severe intoxication, the appearance of rashes on the skin, and the formation of abscesses in the internal organs.

Sick children are hospitalized in a hospital for antibacterial and symptomatic treatment.

Video: about staphylococcus – Doctor Komarovsky

Staphylococcus during pregnancy

During pregnancy, a woman's immune system is weakened, protective forces reduced. At this time, the female body is most vulnerable and open to various microbes, including staphylococcus.

Every pregnant woman, after registering with antenatal clinic must undergo a number of mandatory examinations, including tests for staphylococcus in a microbiological laboratory. The bacteriologist counts the number of grown colonies that correspond in morphological, cultural and biochemical properties to Staphylococcus aureus. If their number exceeds the norm, then the pregnant woman is prescribed appropriate treatment, which consists of sanitizing the nasopharynx with antiseptics, using immunomodulators, local antibiotics or staphylococcal bacteriophage. Staphylococcus in the nose in pregnant women is treated by instillation antiseptic solutions into the nasal passages. In order to prevent infection of the child, pregnant women are immunized with staphylococcal toxoid.

Preventive measures during pregnancy:

Personal hygiene,
Regular walks in the fresh air
Balanced diet,
Ventilation of the room,
Gymnastics for pregnant women.

When the first symptoms of staphylococcus appear, you should rinse your nose with a warm water-salt solution every three hours.

Diagnosis

Diagnosis of staphylococcal infection is based on epidemiological history, patient complaints, characteristic clinical picture and laboratory test results.

Laboratory diagnostics

The main diagnostic method is microbiological examination of nasopharyngeal discharge. To do this, patients usually take a swab from the throat for staphylococcus. The material for research can be blood, pus, discharge from the ears, nose, wounds, eyes, exudate of the pleural cavity, feces, gastric lavage, vomit, discharge from the cervical canal in women, urine. The purpose of the study is to isolate and fully identify the pathogen to genus and species.

A series of tenfold dilutions are prepared from the test material and the required amount is inoculated onto one of the elective nutrient media - milk-bile-salt or yolk-salt agar. The number of grown colonies is counted and studied.

Significant differential features staphylococcus:

Pigment,
Lecitovitellase,
Plasmocoagulase,
Catalase activity
DNAase,
Ability to ferment mannitol under anaerobic conditions.

The number of bacteria less than 10 3 indicates asymptomatic carriage of Staphylococcus aureus. More high performance indicate the etiological significance of the isolated microbe in the development of the disease.

To determine staphylococcal enterotoxin in the test samples, the method is used enzyme immunoassay or gel precipitation reaction.

Serodiagnosis involves detecting antibodies to staphylococcal antigens in blood serum. To do this, use the hemolysis inhibition reaction, the passive hemagglutination reaction, and ELISA.

Staphylococcal infection should be differentiated from streptococcal infection. Staphylococcus is manifested by inflammation, which tends to suppurate, the formation of thick greenish pus and fibrinous deposits. Staphylococcal infection is characterized by inconsistency of temperature reaction, return of temperature, and low-grade fever. Blood parameters are more constant - neutrophilic leukocytosis and increased erythrocyte sedimentation rate.

Streptococci also cause mucous membranes of the nose, lymph nodes, ears, and lungs. Both infections have similar pathogenesis and pathomorphology. They are characterized by the development of purulent-necrotic inflammation. The clinical picture of diseases caused by staphylococcus and streptococcus includes intoxication, pain and allergic syndromes.

Distinctive signs of streptococcal infection are:

Severe hyperemia, swelling and soreness of inflamed mucous membranes,
Rapid development of acute inflammation with damage to the tonsils, ears, lymph nodes,
Streptococci do not affect intestinal tract, do not cause diarrhea, boils and carbuncles,
Penicillin in moderate doses works well for streptococcal lesions.

Staphylococcal infection is characterized by:

Hyperemia of the mucous membrane with a cyanotic tint,
Inflammation of the nasopharynx is always accompanied by regional lymphadenitis,
Weaker effect from large doses of penicillin.

Treatment

Local forms of staphylococcal infection are treated at home. Hospitalization is indicated in cases of generalization of the process with sepsis, meningitis, endocarditis, or if necessary surgical treatment purulent-necrotic skin lesions - boils or carbuncles.

Treatment of Staphylococcus aureus is complex, including antibacterial therapy, the use of immunotherapy drugs and sanitation of purulent foci.

Antibacterial treatment

Antibiotics are prescribed to the patient after receiving the results of a microbiological examination of the discharge from the pharynx or nose. Patients are prescribed:

Semi-synthetic penicillins – “Ampioks”, “Oxacillin”;
Combined penicillins – “Amoxiclav”;
Aminoglycosides – “Gentamicin”;
Cephalosporins - Cefepime.

Currently, there are microbes whose enzymes destroy these drugs. They are called MRSA - methicillin-resistant Staphylococcus aureus. Only a few antibiotics will help cope with such strains - Vancomycin, Teicoplanin, Linezolid. "Fuzidin" is often prescribed with "Biseptol".

Antibiotics should be used only as prescribed by a doctor. Antibacterial therapy must be justified and thoughtful.

Irrational use of drugs:

Destroys healthy microflora of the body,
Has a detrimental effect on the functioning of internal organs,
Harmful to health
Provokes the development of dysbacteriosis,
Complicates the course of staphylococcal infection.

Bacteriophages

Bacteriophages – biological weapons against bacteria. These are viruses that act very specifically, attack harmful elements and do not have a negative effect on the entire body. Bacteriophages multiply inside bacterial cells and lyse them. Having destroyed dangerous bacteria, bacteriophages die themselves.

To destroy Staphylococcus aureus, the bacteriophage is used locally or orally for 10-20 days, depending on the location of the pathology. To treat purulent skin lesions, lotions or irrigations with liquid bacteriophage are used. It is injected into the articular or pleural cavity, vagina, uterus, taken orally, instilled into the nose and ears, and given enemas with it.

Immunostimulation

Autohemotransfusion - intramuscular injection the patient's own venous blood. This procedure is widely used to treat furunculosis. After intramuscular injection, the blood is destroyed, and the breakdown products stimulate the immune system.
Subcutaneous or intramuscular injection of antistaphylococcal antitoxic serum or intravenous administration antistaphylococcal plasma.
Herbal immunostimulants – "Schisandra", "Echinacea", "Eleutherococcus", "Ginseng", "Chitosan". These drugs normalize energy and basal metabolism, have an adaptogenic effect - help cope with stress and stress.
For patients with severe signs of immune dysfunction, synthetic immunomodulators are indicated - “Polyoxidonium”, “Ismigen”, “Timogen”, “Amiksin”.
Vitamin therapy.

Surgical treatment

Surgical treatment is indicated for the formation of infectious foci with purulent melting - carbuncles, abscesses, boils in cases where conservative therapy does not produce results.

Surgical intervention consists of opening abscesses and boils, excision of necrotic tissue, removal of purulent contents and foreign bodies, drainage of lesions to create an unimpeded outflow of pus, local administration antibiotics. Often, surgeons remove the source of infection itself - the catheter, artificial valve or implant.

Traditional medicine

Folk remedies complement basic drug treatment pathology.

It is strictly forbidden to use any thermal procedures at home to speed up the process of ulcer maturation. Hot baths, steam baths and saunas will only worsen the patient’s condition and lead to further spread of the infection.

Heat treatments can only be used during the recovery period.

Prevention

Preventive measures aimed at preventing staphylococcal infection:

Term staphylococcal infection includes a group of infectious diseases caused by various types of staphylococci. The main characteristic of staphylococcal infection is the occurrence of a purulent process at the site of penetration of the microbe into the body.

Group of staphylococci. Staphylococcus aureus

The name staphylococcus comes from Greek word staphyle, meaning bunch and kokkos, meaning grain. Staphylococcus microbes received this name because of the characteristic appearance of their colonies under a microscope. Indeed, colonies of staphylococci under a microscope resemble bunches of grapes or small clusters of grains. This type of staphylococcal colony is formed because after division the microbes do not separate from each other, but remain attached to each other.

The group of staphylococci includes many various types microbes, most of which are practically harmless to humans, or cause illness only under certain conditions. Many of these microbes inhabit various areas of the human body (skin, mucous membranes, oral cavity and intestines) forming the so-called microflora of the body.

For medicine, the most interesting types of staphylococci are: Staphylococcus aureus(S. aureus), Staphylococcus epidermidis(S. epidermidis) and Saprophytic staphylococcus(S. saprophyticus), since these are the types of staphylococci that most often cause diseases in humans.

Microbiological properties of staphylococci

Staphylococci are small, round-shaped bacteria. Staphylococci feed mainly on decaying food, as well as dying body tissues. There are a huge number of staphylococci on the human skin and mucous membranes, but if the person is healthy and his skin and mucous membranes are not damaged, these microbes do not cause any diseases. Their aggressive properties appear only in conditions of a weakened organism or if there is damage to the skin or mucous membranes.

Staphylococcus aureus so named because of the specific “golden” color of the colonies of this microbe, which grow on nutrient media. There are many options in nature Staphylococcus aureus, which differ from each other in aggressiveness (pathogenicity) and other microbiological characteristics.

A common characteristic of all bacteria from the group of staphylococci is their high resistance to various antibiotics. Such resistance appears after contact of a bacterial strain with a specific antibiotic. Most of the microbes that do not have time to adapt to the antibiotic, of course, die, but a small part manages to adapt to the antibiotic (or rather, finds a way to neutralize it) and continues to multiply, restoring the size of the microbial population in a short time. This feature of staphylococci must be taken into account when planning tactics for treating diseases caused by these microbes. Currently, the incidence of staphylococcal infections has increased significantly precisely because of the immunity of these microbes to a number of antibiotics.

How do staphylococci cause disease?

When talking about how staphylococci cause disease, we must first mention their pathogenicity factors, that is, those abilities and characteristics of microbes that are directly involved in damage to tissues and organs of the body.

The group of staphylococci in general and Staphylococcus aureus in particular have the following pathogenicity factors:

Enzymes, destroying body tissues (hyaluronidase, fibrinolysin, lecithinase) - these enzymes are capable of breaking down proteins and fats that are part of body tissues. With the help of these enzymes, staphylococcus, firstly, supplies itself with nutrients (staphylococci feed on destroyed tissues), and secondly, moves deeper into the body. Thanks to fibrinolysin, staphylococci are able to penetrate the blood and spread throughout the body, causing blood poisoning (sepsis).

Hemolysins and toxins, inhibiting the activity of cells of the immune system are important factors in the pathogenicity of staphylococci. We can say that with the help of these factors, staphylococci are able to for a long time survive in areas of inflammation, and also spread quickly throughout the body. These factors are of particular importance in the development of the disease in persons with weakened immune systems (children or elderly people), who experience generalized ( general forms) infections caused by staphylococci.
Enterotoxins- these are special substances that are produced by staphylococci during their life. For staphylococci themselves, these toxins are intermediate metabolic products or substances with which they fight for existence with other bacteria. For humans, enterotoxins are the strongest poisons that can cause food poisoning. According to modern data, the most common culprit of food poisoning is Staphylococcus aureus. In this case, the microbe can get into food with dirty products or from the body of people who are carriers of this microbe. Due to the fact that Staphylococcus aureus is present on the skin and mucous membranes of almost all people, it is sometimes impossible to determine the source of microbes in case of poisoning. Most often, food poisoning occurs due to low-quality dairy products, meat, and sweets. It should be noted that enterotoxin (enterotoxin means poison acting in the intestines) of staphylococcus is quite resistant to high temperatures and is destroyed only by prolonged boiling.

All of the pathogenicity factors described above are manifested by staphylococci depending on existing conditions. People most susceptible to infection by Staphylococcus aureus (and other types of these microbes) are people with impaired metabolism, such as diabetics, immunocompromised patients, children and the elderly.

What happens at the site of staphylococcus infection?

purulent processes

Staphylococcus aureus and immunity

Staphylococcus aureus is an immunogenic microbe, that is, after past infection The patient develops immunity (immunity to the microbe). Newborn children are protected from staphylococci by maternal immunity during the first 6 months of life. Further, due to contact of the child’s body with staphylococcus (in particular with Staphylococcus aureus), his body independently develops antimicrobial immunity. Due to the fact that in nature there are many varieties of staphylococci, immunity acquired during an illness caused by one specific type of staphylococcus cannot protect the body from all types of this microbe, therefore, staphylococcal infections occur with different frequencies in almost all people.

Also, as a result of long-term contact of the human body with staphylococcus (mainly Staphylococcus aureus), so-called tolerance occurs, that is, the body does not respond to the microbe.

Prevention of staphylococcal infection

Prevention with a vaccine?

However, doctors still have means of specific protection against staphylococci in their arsenal - these are specific anti-staphylococcal serums, which are produced on the basis of the blood of people who have suffered the disease or immunized animals. Fortunately, nowadays, thanks to antibiotics, the need to use such serums has decreased significantly.

Personal hygiene is the best means of prevention

dangerous infections

clean skin

In the case of newborns or young children, parental hygiene of the child is the most important factor protecting the child from such types of infection as staphyloderma, that is, bacterial skin lesions that occur with suppuration.

In older people, good personal hygiene may also be helpful in preventing microbial infections. As you know, most often staphylococci infect already damaged areas of the skin and mucous membranes (wounds, ulcerations). Therefore, proper initial treatment and further care play a primary role in preventing wound suppuration.

A certain role in the prevention of staphylococcal infection is played by proper nutrition and sufficient intake of vitamins and minerals. As you know, vitamin and mineral status directly determines the effectiveness of immune defense and the metabolic process. Thus, prophylactic intake of vitamin and mineral preparations can be called a nonspecific means of preventing infections.

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