Staphylococcus aureus is a gram-positive globular bacterium that causes a wide range of various diseases: from light acne on the skin to severe staphylococcal sepsis. Its carriers are almost 20% of the population, parasitizing the mucosa of the upper respiratory tract or skin.
The danger of Staphylococcus aureus is that it produces various toxins that harm our body, for example:
- α-toxin - causes necrosis of the skin,
- Δ-toxin - stops absorption of water from the intestine, "responsible" for the development of diarrhea,
- leucocidin - destroys the membranes of immune cells,
- enterotoxins - cause food poisoning,
- exfoliative toxins - cause the onset of burns skin syndrome,
- toxin-1 - leads to the development of toxic shock syndrome.
One of their negative features of Staphylococcus aureus is its resistance to treatment with many antibiotics, including the penicillin series. For this reason, it causes serious outbreaks of nosocomial infection.
Golden streptococcus can cause the following superficial skin diseases:
Hair follicles with small erythematous nodules without spreading inflammation to the underlying layers are folliculitis.
If the sebaceous glands and deeper tissues are involved in the inflammatory process in addition to the hair follicles, this is a furuncle. Favorite place of furuncle formation - areas of the body with increased degree of contamination and maceration (neck, face, axilla, hips and buttocks). At the initial stage it is characterized by itching, insignificant soreness, which is then replaced by intense pain during movement, swelling and marked reddening. Recovery occurs after opening the boil.
Carbuncle is a type of superficial staphylococcal infection located on thick, inelastic, fibrous skin areas (for example, the upper back or the back of the neck). Poor skin permeability in these areas leads to the fact that inflammation easily spreads in breadth, leading to the formation of a dense and painful large conglomerate, which consists of a lot of purulent cells. In this case, local changes in the skin are accompanied by an increase in temperature and a worsening of the general condition.
Staphylococcal impetigo is less common than streptococcal, and generally resembles it. Nevertheless, staphylococcal impetigo is characterized by multiple localized surface elements, which are covered with a gray crust. The temperature rise is quite rare.
Local warming compresses, antibiotic therapy (dikloxacillin, cloxacillin) are prescribed for a week, as well as ointments that promote the rapid release of the purulent stem. If the furuncle is located in the area of the eye sockets or other part of the face, then the drugs are administered intravenously. In carbuncles, in some cases, hospitalization is indicated.
Staphylococcal burn-like skin syndrome (ACS)
Staphylococcal ACS is a generalized dermatitis caused by exfoliative staphylococcal toxin. Mostly sick children under 5 years of age, as well as adults with severe forms of immunodeficiency. The onset of the disease is characterized by the appearance of a local skin infection, which is accompanied by general weakness, malaise, fever, like that observed in ARVI.
Then ACS can accept the following flow variants:
- Staphylococcal scarlet fever is a scarlatina-like rash on all parts of the trunk and extremities, and then desquamation develops.
- The appearance of large and flabby bubbles, the bottom of which, after opening, becomes crimson, giving the skin a burned look. If the relatively healthy area of the skin is rubbed, the epidermis is wrinkled and exfoliated (a positive symptom of Nikolsky).
With a staphylococcal ACS, the causative agent is secreted from the nasopharynx or the surface of the skin. They are treated locally, and also with the help of antibacterial drugs, which are sensitive to Staphylococcus aureus.
The toxic shock syndrome (TSS)
STS is another disease caused by toxins of Staphylococcus aureus. It manifests itself as a temperature increase, reddening of the skin like sunburn and subsequent desquamation, as well as a sharp drop in blood pressure. Severe cases of the disease are accompanied by vomiting, nausea, diarrhea, development of renal and hepatic insufficiency, muscle pain, DIC syndrome and disorientation.
Most often, STS occurs in menstruating women who use intravaginal hyperabsorbent tampons. In this case, the disease begins in the first days of menstruation with the excretion of the causative agent from the vagina and the absence of that in the blood.
Treatment is complex, often in conditions of resuscitation. The introduction of antistaphylococcal antibodies, drainage of the foci of staphylococcal congestion, antibiotic therapy, exclusion of the use of tampons during menstruation.
Staphylococcal bacteremia and endocarditis
The source of bacteremia caused by Staphylococcus aureus can be practically any focus of infection: furuncle, carbuncle, abscess, osteomyelitis , arthritis, infected intravenous catheter, shunt for dialysis, non-sterile drug addict needle, etc.
With bacteremia, the pathogens come out into the blood and dissipate throughout the body, eventually causing the DIC syndrome (disseminated intravascular coagulation), which clinically resembles meningococcemia. Because of high fever, vascular collapse and tachycardia, death can occur within a day.
As a result of bacteremia, there is a further spread of Staphylococcus aureus in the body and the formation of metastatic abscesses in the kidneys, myocardium, bones, spleen, brain, lungs and other organs.
Bacterial endocarditis is one of the complications of staphylococcal bacteremia. The most frequently developed and individuals with weakened immune system, as well as drug addicts.
The development of the disease is characterized by the appearance of cardiac murmurs, signs of heart failure against a background of high fever, embolism, progressive anemia and extracardiac septic complications. As a rule, staphylococcal endocarditis is characterized by the formation of abscesses in the myocardium and in the region of the corresponding orifice, where one of the heart valves is located.
Endocarditis can lead to heart defects and the development of signs of heart failure.
The diagnosis of bacteremia or endocarditis is based on the detection of antibodies to the components of the staphylococcus aureus by threefold blood sowing (in the treatment of antibiotics, the number of crops can be more). Also bacteriological examination is the content of pustules on the skin and urine.
Intravenous administration of an antibiotic to which Staphylococcus aureus is sensitive. Most often, it is nafcillin, oxacillin, gentamicin, methicillin, cephalothin, cefazolin, doxacillin, vancomycin (for allergies to penicillins). Uncomplicated course of bacteremia can be carried out within 2 weeks, and in case of endocarditis - up to 4-6 weeks.
Osteomyelitis is a purulent lesion of bone tissue, caused in most cases by Staphylococcus aureus. Suffer from the disease mainly children, although in adults it is often enough, for example, osteomyelitis of the spine. By the nature of the current, it is customary to distinguish between the acute and chronic form of staphylococcal osteomyelitis.
How osteomyelitis occurs
Staphylococcus aureus, by causing infection of the skin or internal organs, extends inward and reaches the periosteum or bone marrow cavity near the epiphysis of the bone. Then a purulent foci forms, which causes the periosteum to peel off from the bone and form a subperiosteal abscess that breaks out and infects surrounding tissues. If this abscess breaks into the articular cavity, then staphylococcal arthritis develops. Subsequently, Staphylococcus aureus causes the death of bone tissue, leading to a new growth and the formation of calluses. In some cases, osteomyelitis can occur almost painless for the patient, forming in the center of necrotic areas of the cavity (Brody's abscess).
Osteomyelitis in children
In children, the first symptoms of acute osteomyelitis can be:
- acute fever,
- nausea, vomiting,
- pain in the area of bone damage,
- muscle spasms around the lesion (while the child spares the leg and tries not to move it),
- puffiness, redness of the skin and hyperemia surrounding the affected bone tissue,
- development of anemia.
Osteomyelitis of the spine in adults
In adults, the osteomyelitis of the spine proceeds less sharply, it is observed mainly in the lumbar region and leads to the fusion of the vertebrae with each other and obliteration of the interdisk spaces.
It must be suspected if the pain in the back or neck is accompanied by high fever. In this case, it is worth paying attention to the presence of an early transferred skin infection, local soreness with pressure on the affected skin and the allocation of Staphylococcus aureus from the blood.
The diagnosis of staphylococcal osteomyelitis is based on bacteriological examination of blood and other body fluids, as well as radiograph data of altered bones. Since the second week of the disease on X-ray images, one can see a detachment of the periosteum, a rarefaction of the old bone tissue and the formation of a new one. In chronic osteomyelitis, fistulous strokes are also often found.
Osteomyelitis is treated within 6 weeks with penicillin-resistant synthetic penicillin, which is injected parenterally. In children with uncomplicated osteomyelitis, antibacterial agents are given intravenously for 2 weeks and then switched to oral administration for the next 2-4 weeks.
Pneumonia Staphylococcus aureus is rare (approximately 1 in 100 of bacterial pneumonia cases). Most often, it occurs after a flu and in infants.
Staphylococcal pneumonia is characterized by high fever, unproductive cough and detected on the roentgenogram by multiple thin-walled abscesses (pneumatoceles), very often accompanied by purulent lesions (empyema) of the pleura. Due to the fact that sputum cultures often do not detect a pathogen, the diagnosis is established based on the effectiveness of trial treatment with antistaphylococcal drugs.
Older children and adults on the eve of the development of staphylococcal pneumonia note the appearance of an influenza-like respiratory infection accompanied by sudden chills, high fever, progressive dyspnea, cyanosis, chest pain and coughing with pus or blood.
In some cases, Staphylococcus aureus causes pneumonia, manifested initially only by tachycardia, increased respiration, and fever. With endocarditis in the right heart, lungs can form cavities, develop purulent pleurisy and empyema.
Treatment is done with antibiotics, to which staphylococcus is sensitive. The drugs are given for 2 weeks in the form of injections, and then for 2-4 weeks taken internally. With a properly selected antibacterial agent, the temperature starts to decrease from the third or fourth day and gradually normalizes. When empyema is introduced into the pleural cavity drainage (prevention of the formation of bronchopleural fistula and purulent pockets).
Urinary Tract Infections
Urinary tract infection caused by Staphylococcus aureus is characterized by:
- disorder of urination (frequent, painful),
- a small fever (sometimes it may be absent),
- the presence of pus, the admixture of blood and the detection of golden staphylococci in a general and bacteriological study of urine.
Without treatment, staphylococcus is able to infect surrounding tissues (the prostate gland, perinephricular tissue) and cause pyelonephritis or form kidney abscesses.
Treatment is carried out by antibacterial drugs, which mainly accumulate in the urine or have a systemic effect.