Pseudomonas aeruginosa( Pseudomonas aeruginosa) - Causes, symptoms and treatment. MF.

Pseudomonas aeruginosa infection is quite dangerous and aggressive, with a high incidence among the population. Up to 20% of all intra-hospital or nosocomial infections are caused precisely by Pseudomonas aeruginosa. Up to 35% of infections of the urinary system is caused by this rod, as well as 25% of purulent surgical processes. A quarter of cases of primary bacteremia are also caused by P. aeruginosa.

Pseudomonas infection is an acute infectious disease caused by microorganisms of the genus Pseudomonas, affecting the respiratory system, gastrointestinal tract, soft tissues, nervous and other body systems.

Pseudomonas aeruginosa is a conditionally pathogenic microorganism of the genus Pseudomonas( pseudomonas).This gram-negative( Gram stain does not cause violet staining), a bacterium in the form of a rod with rounded ends, a size of 0.5 to 1 micron.

Pseudomonas aeruginosa

It is mobile, does not have a dense capsule, it does not form a spore. It is an obligate aerobic( multiplies with access to oxygen, high humidity).During bacteriological examination, it grows on special nutrient media( meat-peptone agar - MPA, meat-peptone broth - MPB and others), where it grows bluish-greenish colonies with luminescence( fluorescent), which have the smell of jasmine. Has somatic O-and flagellate H-antigens, as well as capsular K-antigen. H-antigen( flagellate) allows to isolate about 60 serovars of Pseudomonas aeruginosa. It is sufficiently resistant to the action of many disinfecting solutions, in some of which it can multiply. It is fatal to it only 5% solution of chloramine, 3% solution of hydrogen peroxide and 2% solution of phenol( carbolic acid).In nature it is found in soil, in water in open reservoirs, on plants. The optimum growth temperature is 37 ° С.

Pseudomonas aeruginosa can be pathogenic to humans. Often occurs in inflammatory processes( purulent wounds, abscesses), often causes infections of the urinary tract and intestines. With high frequency, it causes nosocomial infections due to the prevalence in people with immunodeficiencies( chronic diseases, surgical interventions, infections, etc.).Pseudomonas aeruginosa can be found in the airways of a person, the large intestine, in the external auditory canal, as well as on the surface of the skin in the area of ​​folds( axillary, inguinal).Under normal immunity, Pseudomonas aeruginosa meets a competitive resistance from the representatives of normal flora, which suppresses its growth and causes death( for example, in the intestine).

Factors of pathogenicity of Pseudomonas aeruginosa are:
1) mobility due to flagella;
2) the ability to produce toxins( endotoxin, exotoxin, endogemolysin, enzyme leukocidin), which cause damage to erythrocytes, liver cells, initiation of intoxication, death of leukocytes in the outbreaks;
3) high resistance to a number of antibacterial agents due to the ability to form around their colonies a mucilaginous capsule - glycocalyx( in particular, resistant to beta-lactams, aminoglycosides, fluoroquinolones), which complicates the effectiveness of therapeutic measures in such patients.

Causes of Pseudomonas aeruginosa infection

The source of Pseudomonas aeruginosa infection is a human and animals, both patients and carriers of Pseudomonas aeruginosa. The greatest risk of infection is borne by patients with pneumonia and open purulent wounds.

Paths of infection - is contact-household, airborne, food. Transfer factors - food products( milk, meat products), water, as well as objects of the environment( mostly hospital) - sinks, cranes, handles of taps, doors, toilets, shared towels, hands of medical personnel and poorly processed medical instruments. It is these common factors that explain the high risk of infection with Pseudomonas aeruginosa during hospitalization and the occurrence of intrahospital infections. The risk group for Pseudomonas aeruginosa is burn hospitals, surgical departments of hospitals, obstetric and pediatric hospitals. Here, even epidemic outbreaks of Pseudomonas aeruginosa may occur( in the case of violations of the sanitary-epidemiological regime of the departments).

The most susceptible patients with reduced immune protection due to concomitant acute or chronic diseases, as well as certain age groups - elderly persons and children. Children in times more often suffer this infection. The most vulnerable children's groups are newborns and babies of the first 2-3 months of life, as well as premature babies.

risk of developing Pseudomonas infection
№ Patients with certain conditions Possible manifestations of Pseudomonas infection
1 frequent intravenous Osteomyelitis procedures endokrdit
2 Leukemia Sepsis, perirectal abscess
3 Diseases malignant growth Pneumonia
4 Burns sepsis, cellulitis
5 Operation CNS organsMeningitis
6 Tracheostomy Pneumonia
7 Corneal ulcers Panophthalmites
8 Vascular catheteris Purulent thrombophlebitis
9 Urinary tract catheterization Urinary tract infectionsSystem 10 minutes
period neonatal meningitis, diarrhea

Step occurrence

Pseudomonas infection infection infection and the emergence of stage 3 occurs:

1) attachment of Pseudomonas aeruginosa to the damaged tissue and proliferation at the site of its attachment, that is the primary site of infection;
2) the spread of infection in the deep tissue - the so-called local infection( it is still restrained by immunity);
3) the penetration of the pathogen into the blood with the development of bacteremia and the spread of infection to other organs and tissues( septicemia).

Symptoms of Pseudomonas aeruginosa infection

Pseudomonas aeruginosa can cause inflammation of many organs and systems, we will consider only its most frequent manifestations.

Pseudomonas aeruginosa infection of the gastrointestinal tract is characterized by the appearance of acute enterocolitis or gastroenterocolitis. The severity of manifestations depends both on the patient's age and on the initial state of immunity and on the intestine itself. Thus, in children of older age and adults, acute onset of vomiting, pain in the stomach( epigastrium), and then throughout the stomach, there is weakness, poor appetite, nausea, fever is often subfebrile( up to 38 °), stool up to 5-7 timesa day mushy, with pathological impurities( slime, blood), the color is brownish-greenish. Duration of the disease is no more than 3-4 days. Children of early childhood carry the infection more severely - a temperature higher( up to 39 °), frequent regurgitation or vomiting, refusal to eat, lethargy, frequent loose stool to 6, and sometimes up to 10-15 times a day, stools are also greenish with pathologicalimpurities( mucus, blood), has a characteristic fetid odor, bloating, loud rumbling. Along with the acute course, there are variants with little symptoms, but the disease itself lasts up to 4 weeks. A feature in early childhood is the danger of developing intestinal bleeding, dehydration, and in the older age of appendicitis and cholecystitis. Concomitant disease with intestinal damage - the development of dysbiosis, which requires long-term therapy during rehabilitation.

Pseudomonas aeruginosa infection of the urinary tract ( MVP) is manifested by the occurrence of cystitis, urethritis, pyelonephritis. An infection is introduced into the urinary system more often with a catheterization of the bladder. Symptoms of specific diseases are similar to those of other infections. In most cases, the infection of the MFI is chronic for several months and even years. In rare cases, the infection from this primary focus is spread to other organs and tissues.

Pseudomonas aeruginosa infection of the respiratory system often develops on the background of chronic bronchopulmonary disease( bronchitis, cystic fibrosis, bronchiectatic disease), and at the risk group also patients with resuscitation and intensive care units( on artificial ventilation after endotracheal intubation).Perhaps the development of both primary pneumonia and secondary pneumonia, characterized by protracted course, poor efficacy of antibiotic therapy, a propensity for destructive processes. Symptoms of pneumonia are similar to those in other infectious lung lesions.

Pseudomonas infection of soft tissues and skin occurs in places of open wound, burn surfaces, wounds after surgical interventions, trophic ulcers on the limbs. To understand that the Pseudomonas aeruginosa infection can be removed from the wound, which acquires a blue-green color. It is this color will be a wound dressing in the patient.

Also, with the wounds, development of of Pseudomonas osteomyelitis ( bone tissue damage) is possible.

Pseudomonas de novo infection of the ear manifests itself in the form of purulent external otitis, in which there is pain in the ear, purulent discharge with an admixture of blood, less often develops the middle otitis and mastoiditis( inflammation of the mastoid process).

Pseudomonas aeruginosa develops as a result of eye surgery or traumatic injury. It may develop purulent conjunctivitis, possibly damage to the cornea and the eyeball itself. In this case, patients have a sense of "foreign body" in the eye, pain, impaired vision, purulent discharge.

Pseudomonas aeruginosa of the nervous system occurs in the patients that have been left behind and is one of the most severe manifestations of this disease. May develop meningitis( inflammation of the mild cerebral membrane), meningoencephalitis( also damage to the brain substance).In most cases, infection from the primary focus during septic process. Primary reproduction of Pseudomonas aeruginosa in the central nervous system is possible after trauma and surgical interventions. A characteristic pattern of purulent meningitis or meningoencephalitis, practically not different from other infections. With lumbar puncture, a high content of cells in the cerebrospinal fluid( pleocytosis) to several thousand per ml, a predominance of neutrophils over lymphocytes, a high protein content, a liquid when flowing cloudy with greenish flakes. The prognosis is more often unfavorable.

Other manifestations of Pseudomonas aeruginosa are endocarditis( cardiovascular damage), arthritis, sinusitis, frontal sinitis, sinusitis and, finally, sepsis, a generalized pseudomonas aeruginosa infection with multiple organs and systems.

Summarizing the above, it is possible to highlight important features of Pseudomonas aeruginosa infection:
- In acute course, a high incidence of adverse outcomes due to the high resistance of P. aeruginosa to a number of antibacterial drugs, which creates difficulties in treatment and is the cause of lost time.
- Propensity to protracted and chronic course of infection with frequent relapses of varying severity, which requires long-term treatment.

Diagnosis of Pseudomonas aeruginosa infection

1) Preliminary diagnosis is difficult, because there are no syncope for clinically specific symptoms for
.The alarming factors in the P. aeruginosa plan are a protracted course of infection despite the ongoing antibiotic therapy, which has no success, as well as the connection of infection with medical manipulations in hospitals, surgical interventions, trauma.

2) The final diagnosis is made after a laboratory examination. The leading method of
examination is bacteriological, followed by bacterioscopy. The material for the study can be any, depending on the clinical form - from mucus of the nasopharynx and feces to urine, cerebrospinal fluid, which is separated from the wounds. It is advisable to take the material before the start of antibacterial research. The material is inoculated on a special nutrient medium where colony of blue-green color with fluorescence is grown, and then they are examined under a microscope.

Colonies P. aeruginosa

Pseudomonas aeruginosa at bacterioscopy

Usually another study is conducted immediately - antibioticogram( sensitivity to certain antibacterial drugs).

An additional method of investigation is the serological examination of blood for antibodies to P. aeruginosa, which is applied mainly retrospectively( i.e., to confirm infection).
General clinical methods( analysis of urine, blood, biochemistry and so on), as well as instrumental methods of investigation, are used to help the doctor to establish only the clinical form of Pseudomonas aeruginosa infection.

Treatment of Pseudomonas aeruginosa infection

1) Organizational-regime measures are reduced to hospitalization of patients with severe manifestations of infection in any hospital by profile. Bed rest for the entire period of intoxication.

2) Drug treatment.
Etiotropic therapy is quite difficult for Pseudomonas aeruginosa infection.
High frequency of antibiotic-resistant P. aeruginosa strains. In spite of this, there are certain groups of antibacterial drugs or some of their representatives within the group who, with pseudomonas aeruginosa, have maintained their effectiveness. These include some cephalosporins( ceftazidime, cefepime), carbapenems( imipinem, carbapine), modern aminoglycoside( amikacin), and some fluoroquinolones( ciprofloxacin).The stability of P. aeruginosa to tetracyclines has been proved, rapid occurrence of resistance to fluoroquinolones( levofloxacin and others).

Pathogenetic therapy and postdromal therapy are prescribed depending on the clinical manifestation of Pseudomonas aeruginosa infection.

Prevention of Pseudomonas infection

The main preventive measures are reduced to the prevention of immunodeficiency( timely treatment of chronic diseases, chronic infections), prevention of colds. Prevention of infection of children, sometimes parents themselves are guilty( strengthening the health of the baby, controlling nutrition, drinking water, swimming in open water).Prevention of nosocomial transmission of infection, as a rule, depends only on the medical staff.

The doctor infektsionist Bykova N.I.