Staphylococcus aureus is a gram-positive spherical bacterium that causes a wide range of different diseases: from mild acne on the skin to the most severe staphylococcal sepsis. Its carriers are almost 20% of the population, parasitizing on the mucous membrane of the upper respiratory tract or the skin.
The danger of Staphylococcus aureus is that it produces various toxins that cause harm to our body, for example:
- α-toxin causes skin necrosis (necrosis),
- Δ-toxin - stops the 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 occurrence of burn 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 penicillin. For this reason, it causes serious outbreaks of nosocomial infections.
Golden Streptococcus can cause the following superficial skin diseases:
Hair follicles with small erythematous nodules without spreading inflammation to the deep-lying layers are folliculitis.
If, in addition to the hair follicles, the sebaceous glands and deeper tissues are involved in the inflammatory process, this is a furuncle. A favorite place for the formation of boils is the areas of the body with a high degree of pollution and maceration (neck, face, armpits, thighs and buttocks). At the initial stage, it is characterized by itching, slight soreness, which is later replaced by intense pain during movement, swelling and marked redness. Recovery occurs after opening the boil.
Carbuncle is a type of superficial staphylococcal infection localized on thick, non-elastic, fibrous skin areas (for example, upper back or back of the neck). Poor permeability of the skin 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 many purulent cells. At the same time, local changes in the skin are accompanied by fever and deterioration of the general condition.
Staphylococcal impetigo is less common than streptococcal, and generally resembles one. However, for staphylococcal impetigo, there are multiple localized surface elements that are covered with a gray crust. The temperature rise is rarely observed.
Local warming compresses, antibiotic therapy (dicloxacillin, cloxacillin) are prescribed for a week, as well as ointments that promote rapid release of a purulent rod. If the boil is localized in the area of the sockets or another part of the face, then the drugs are injected intravenously. With a carbuncle 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 up to 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, similar to that observed with ARVI.
Then the ACS can accept the following flow options:
- Staphylococcal scarlet fever - scarlet-like rash is observed on all parts of the trunk and extremities, peeling later develops.
- The appearance of large and flabby bubbles, the bottom of which, after opening, acquires a purple tinge, giving the skin a burnt appearance. If at the same time rub a relatively healthy area of the skin, then wrinkling and exfoliation of the epidermis occurs (a positive symptom of Nikolsky).
In staphylococcal ACS, the pathogen is isolated from the nasopharynx or the surface of the skin. It is treated topically, as well as with the help of antibacterial drugs, to which Staphylococcus aureus is sensitive.
Toxic shock syndrome (TSS)
TSS is another disease caused by the toxins of Staphylococcus aureus. TSS is manifested by an increase in temperature, reddening of the skin like sunburn and subsequent desquamation, as well as a sharp decrease in blood pressure. Severe cases of the disease are accompanied by vomiting, nausea, diarrhea, the development of kidney and liver failure, muscle pain, DIC and disorientation.
Most often, CTC occurs in menstruating women who use intravaginal hyperabsorbing tampons. In this case, the disease begins in the first days of menstruation with the release of the pathogen from the vagina and the absence of such in the blood.
Treatment is complex, often in resuscitation. The introduction of antistaphylococcal antibodies, drainage of staphylococcal clusters, antibiotic therapy, and the exclusion of the use of tampons during menstruation are shown.
Staphylococcal bacteremia and endocarditis
The source of bacteremia caused by Staphylococcus aureus can be almost any site of infection: furuncle, carbuncle, abscess, osteomyelitis , arthritis, an infected intravenous catheter, shunt for dialysis, non-sterile needle of an addict, etc.
In bacteremia, pathogens enter the bloodstream and dissipate throughout the body, eventually causing DIC (disseminated intravascular coagulation), which clinically resembles meningococcemia. Due to high fever, vascular collapse and tachycardia, death can occur within a day.
As a result of bacteremia, further spread of Staphylococcus aureus occurs throughout 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. Most often develops and persons with weakened immune systems, as well as among drug addicts.
The development of the disease is characterized by the appearance of heart murmurs, signs of heart failure against the background of high fever, embolism, progressive anemia and extracardiac complications of a septic nature. As a rule, staphylococcal endocarditis is characterized by the formation of abscesses in the myocardium and in the region of the corresponding opening, where one of the heart valves is located.
Endocarditis can lead to heart defects and signs of heart failure.
The diagnosis of bacteremia or endocarditis is made on the basis of the detection of antibodies to the components of the shell of Staphylococcus aureus by three-fold blood culture (in the case of antibiotic treatment, the number of cultures may be more). Also, the contents of pustules on the skin and urine are subject to bacteriological examination.
Intravenous administration of an antibiotic to which Staphylococcus aureus is sensitive. Most often it is nafcillin, oxacillin, gentamicin, methicillin, cefalotin, cefazolin, doxacillin, vancomycin (in penicillin allergy). Uncomplicated bacteremia can be performed within 2 weeks, and in the case of endocarditis - up to 4-6 weeks.
Osteomyelitis is a purulent lesion of bone tissue, caused in most cases of Staphylococcus aureus. Mostly children suffer from this disease, although in adults it occurs quite often, for example, osteomyelitis of the spine. By the nature of the flow, it is customary to distinguish between acute and chronic forms of staphylococcal osteomyelitis.
How osteomyelitis occurs
Staphylococcus aureus, causing infection of the skin or internal organs, spreads deep and reaches the periosteum or bone marrow cavity near the epiphysis of the bone. Then a purulent focus is formed, which causes the periosteum to detach from the bone, and a subperiosteal abscess is formed, which breaks out and infects the 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 new growth and the formation of corn. In some cases, osteomyelitis can proceed almost painlessly for the patient, forming necrotic cavity sections in the center (Brodie abscesses).
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 (the child spares the leg and tries not to move it),
- swelling, reddening of the skin and hyperemia of the tissues surrounding the affected bone,
- development of anemia.
Osteomyelitis of the spine in adults
In adults, spinal osteomyelitis is less acute, occurs mainly in the lumbar spine and leads to the fusion of the vertebrae between themselves and obliteration of the interdisc spaces.
It should be suspected if back or neck pain is accompanied by high fever. It is worth paying attention to the presence of early skin infection, local pain when pressing on the affected skin area and the release of Staphylococcus aureus from the blood.
The diagnosis of staphylococcal osteomyelitis is based on data from bacteriological examination of blood and other body fluids, as well as x-ray data of altered bones. From the second week of the disease, on the X-ray images one can see the detachment of the periosteum, the rarefaction of the old bone tissue and the formation of a new one. In chronic osteomyelitis, fistulous passages are also often found.
Osteomyelitis is treated for 6 weeks with penicillin-resistant synthetic penicillin, which is injected parenterally. In children with uncomplicated osteomyelitis, antibacterial agents are administered intravenously for 2 weeks, and then transferred to ingestion over the next 2-4 weeks.
Pneumonia Staphylococcus aureus is quite rare (approximately 1 in 100 cases of bacterial pneumonia). Most often it occurs after suffering flu and in infants.
Staphylococcal pneumonia is characterized by high fever, unproductive cough, and multiple thin-walled abscesses (pneumatological goals) detected on the radiograph, very often accompanied by purulent lesion (empyema) of the pleura. Due to the fact that sputum cultures often do not detect the pathogen, the diagnosis is established on the basis of 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 influenza-like respiratory infection, accompanied by a sudden chill, high fever, progressive shortness of breath, cyanosis, chest pain and cough with an admixture of pus or blood.
In some cases, Staphylococcus aureus causes inflammation of the lungs, which is manifested at the initial stage only by tachycardia, increased respiration and fever. With endocarditis of the right heart, cavities may form in the lungs, purulent pleurisy and empyema develop.
The treatment is carried out with antibiotics, to which staphylococcus is sensitive. Drugs are prescribed for 2 weeks as an injection, and then taken orally for 2-4 weeks. With a properly selected antibacterial agent, the temperature begins to decline from the third or fourth day and gradually returns to normal. When empyema is injected 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:
- urinary disorder (increased frequency, soreness),
- small fever (sometimes it may be absent)
- the presence of pus, blood admixture and the detection of Staphylococcus aureus in general and bacteriological examination of urine.
Without treatment, staphylococcus is able to infect the surrounding tissues (prostate gland, pararenal cellulose) and cause pyelonephritis or form kidney abscesses.
Treatment is carried out with antibacterial drugs, which predominantly accumulate in the urine or have a systemic effect.