Pseudomonas aeruginosa bacterium. Pseudomonas aeruginosa. Is victory possible?

What microorganism are all doctors afraid of and don’t want to see it in test results? Of course, this is Pseudomonas aeruginosa, or Pseudomonas aeruginosa. It is so dangerous and elevated to the rank of terrible and unpredictable that when it is discovered, experts clutch their heads. There are very good reasons for this. What to do if this unfortunate bacterium is detected in a patient?

Pseudomonas aeruginosa in children and adults

We show you this predator because any enemy agent must be visualized and its existence must be remembered. It is quite difficult to confuse it with any other microorganism. A patient in whom Pseudomonas aeruginosa has settled will have an indescribable disgusting aroma. This smell will be more terrible when the process goes very far in its development.

There are several types of Pseudomonas aeruginosa:

• Wild look. Usually such a microbe enters hospitals together with a patient from the outside world;
• Hospital view. This bacterium lives in hospital conditions and is the most dangerous because it is resistant to a wide range of antibacterial drugs;

Habitats of Pseudomonas aeruginosa

Most often, the microbe is located in warm and humid places, and these are various reservoirs, sinks, containers with disinfectants, furacillin, anesthesia machines and dialysis fluids. Thus, when sowing Pseudomonas aeruginosa in a department, it is necessary to replace all plumbing equipment, as well as floor coverings around sinks, toilets, bathtubs, and showers. At the same time, you should not use furacillin with a production time of more than a day. Drying of tubing components for artificial lung ventilation equipment should be prohibited.

Where does the microbe live in the human body?

A person consists of 70% water and is warm enough for the normal functioning and reproduction of Pseudomonas aeruginosa. The bacterium takes root well in patients with:

• tracheostomy tubes;
• wet wound surfaces;
• fistula tracts;
• bedsores and cystostomies;
• burn wounds;
• catheters.

These conditions are extremely attractive for the stick. It is also worth noting that the cornea of ​​the eye is an excellent substrate for the proliferation of Pseudomonas aeruginosa bacteria. It can damage the eye so much in a few hours that it can no longer be saved.

What can the activity of Pseudomonas aeruginosa lead to?

At the moment, the following pathological conditions are known that arise as a result of the pathological activity of this microbe:

• gangrenous pneumonia;
• empyema and otitis externa;
• septicemia and endocarditis;
• infectious eye diseases, more often after surgical interventions and injuries;
• furunculosis and meningitis.

Pseudomonas aeruginosa leads to infection of fistulas, ulceration of bedsores, and infection of burn surfaces.

Under what conditions does Pseudomonas aeruginosa infection occur most often?

The most common reasons for the proliferation of Pseudomonas aeruginosa in the human body are immunodeficiency states or massive antibacterial therapy. Pseudomonas aeruginosa is resistant to many antibiotics. This is her natural feature. By destroying its competitors, we ourselves give the bacteria strength and a selective advantage.

The use of the latest generations of cephalosporins in hospitals leads to the breeding of new, even more resistant and evil microbes that are more pathogenic and insatiable.

For the most part, Pseudomonas aeruginosa spreads in hospital settings through the shortcomings of medical personnel and doctors.

Where does Pseudomonas aeruginosa come from in clinics?

The pathogen is spread through hands, phonendoscopes, towels in procedural, resident, manipulation rooms, mobile phones, ballpoint pens, etc.

If a patient appears in the department with this microbe and if the medical staff violates the rules of antisepsis and asepsis, after 12 hours the contamination of the entire department will reach 100%.

Further development opportunities will depend on the patient’s body. However, infection often occurs and develops into trouble. How can this disease be cured?

Possible treatment of Pseudomonas aeruginosa

In the presence of a wild strain of the bacterium, the greatest preference should be given to ceftazidime, amikacin, carbopenems, ciprofloxacin, cefepime. It is worth saying a few words about cefoperazone, which is an antipseudomonal drug according to teachers at medical institutes.

In fact, there is no evidence that cefoperazone cefoperazone/sulbactam are highly effective treatments for Pseudomonas aeruginosa infection. At the moment, only ceftazidime, which is in first place in the treatment of infection, has a proven similar effect.

In fact, it is not very clear where Russian ideas about sensitivity to these drugs came from. It must be said that the combination of cefoperazone and sulbactam is available only in Turkey and Russia, and in other countries these drugs are not used together for Pseudomonas aeruginosa infection. FDA registration of this combination was quickly withdrawn.

Drugs with real antipseudomonas activity

1. Ceftazidime. The drug belongs to the 3rd generation cephalosporins. Its antipseudomonal activity is very high. From the moment the drug was introduced and for several years, he was the most active fighter against gram-negative flora. However, after some time, bacteria producing beta-lactamases reduced its effectiveness and at the moment its use is narrowed - it is used to test for the presence of extended spectrum beta-lactamases. For example, if ceftazidime has no effect on any bacteria, then neither cefotaxime nor ceftriaxone will be taken into account. In the absence of an antibiogram, the patient still receives treatment. If ceftazidime does not work, then all 3rd generation cephalosporins will be ineffective and you should not start using them. Vice versa. If the patient was treated with 3rd generation cephalosporins (cefotaxime, ceftriaxone), treatment with ceftazidime may be possible and effective, because it is not destroyed by beta-lactamase cefuroximase and destroys Pseudomonas aeruginosa. Ceftazidime can also penetrate into the cerebrospinal fluid and create a therapeutic concentration there. Thus, it is also used to treat meningitis that was caused by gram-negative microflora;
2. Cefepime. This drug represents a group of 4th generation cephalosporins. Its antipseudomonas activity is very pronounced, but this drug is quite expensive compared to ceftazidime, and it cannot be used as a test for extended-spectrum beta-lactamases;
3. Carbopenems. These drugs are much weaker than ceftazidime, but also have antipseudomonas activity. Most often they are used in combination with other antipseudomonal antibiotics;
4. Amikacin is, along with ciprofloxacin, the most effective drug in the fight against such microorganisms as Pseudomonas aeruginosa in children and adults. Its bactericidal effect is more powerful compared to the drugs described above, and allergic reactions with its use are negligible and rare. However, it should not be used in the first stages of treatment of Pseudomonas aeruginosa infection, that is, the drug should be considered as a reserve medicinal substance. It is important for us to maintain the sensitivity of the bacterium to a given antibiotic for as long as possible;
5. Ciprofloxacin. This drug is one of the safest and most effective antibacterial drugs. Only soon will the sensitivity of pathogenic bacteria to it be reduced to a minimum, because outpatient doctors prescribe it very often and sometimes unreasonably. In addition, the drug is quite affordable in cost. It is in connection with these actions that the drug is prescribed at 800-1200 mg, and not at 400 mg as recently. Ciprofloxacin should remain a reserve drug, like amikacin. Its use can only be administered under the supervision of a clinical pharmacologist.

Pseudomonas aeruginosa is resistant to all antibiotics

You wouldn’t wish anyone in practice to encounter this type of microorganism. This Pseudomonas aeruginosa is immune to any known antibiotic, so there are no remedies or protection against it. The main task is to prevent its occurrence in a hospital setting. To do this, it is worth following the well-known and simple rules of antisepsis and asepsis, and observing personal hygiene for health workers and patients.

Pathogenic microorganisms can cause serious damage to human health. It is impossible to completely protect yourself from infection, since new dangerous infections appear every day. Bacteria live everywhere; traces of Pseudomonas aeruginosa infection can be found not only on the ground or in the air. Microorganisms closely interact with the human body, so their presence in the skin microflora is considered normal. However, any deviation in the functioning of the immune system gives impetus to the active development of bacteria.

What is Pseudomonas aeruginosa

In Latin, this type of infection is called Pseudomonas aeruginosa. This mobile microbe is a gram-negative rod-shaped bacteria whose habitat is soil, air and water. A necessary condition for the development of Pseudomonas aeruginosa infection is oxygen, since without it it cannot exist. The above pathogenic organisms have a capsule that protects them from leukocytes. A distinctive feature of the rod-shaped bacterium is its resistance to most antimicrobial drugs. Pseudomonas aeruginosa does not form spores.

Under certain conditions, an opportunistic bacterium that lives in the human body can lead to the development of infectious diseases. The microflora of some areas of the skin (parotid, axillary, groin area) normally contains a small amount of microbes of this type. Pseudomonas aeruginosa infection causes health problems only in people with weakened immune systems. During their life, microorganisms secrete exotoxins, endotoxins and some enzymes, which cause pathological changes in the human body.

A striking example of the negative impact of the above microorganisms is necrosis of liver cells, destruction of leukocytes and erythrocytes, and vascular damage. The bacterium often leads to damage to various organs and systems; the localization of the infection depends on the route of penetration of the microbes. The habitat of the pathogens Pseudomonas aeruginosa is considered to be open water bodies, soil and the gastrointestinal tract of mammals (animals, birds, people).

Routes of transmission of Pseudomonas aeruginosa

Pseudomonas aeruginosa infection is transmitted in several ways, the main source of infection being bacteria carriers - infected people or animals. Patients with purulent wounds and patients suffering from pneumonia pose a particular danger to others. The infection enters the human body through the skin, conjunctiva of the eyes, gastrointestinal tract, respiratory system, umbilical wound or urinary system.

Pseudomonas aeruginosa bacteria are not characterized by a seasonal pattern; young children and the elderly are at risk. A gram-negative bacillus develops in two cases - when microorganisms are insensitive to disinfectant solutions or when sanitary and hygienic standards in the room are not observed. Infection occurs in one of three ways - airborne, household contact or food.

1. Contact-household transmission of rod-shaped microbes is more common than others, since people use household items every day. These include door handles, toilets, towels, and sinks. Rarely, the infection is transmitted through tools and equipment. Sometimes microorganisms enter the human body through the hands of personnel in medical institutions, even after pre-treatment with disinfectants.
2. Infection through food occurs through consumption of water or food (milk, meat, fish) containing Pseudomonas aeruginosa bacteria.
3. Sometimes microbes penetrate by airborne droplets during the respiratory process, which is explained by the content of gram-negative rods in the air.

Nosocomial infection

Typical companions of medical institutions are nosocomial infections. Any person can catch a hospital illness, but more often than others this happens among patients in intensive care or the following departments: cardiac surgery, intensive care, burns, general surgery. The presence of pathological microorganisms inside the hospital also indicates poor organization of the sanitary and anti-epidemic regime, but much more often a gram-negative bacillus occurs for other reasons.

Pseudomonas aeruginosa bacteria occupy a leading place among hospital infections due to resistance to antibiotics and disinfectant solutions. Isolated cases of hospital-acquired illnesses are not dangerous, but during an outbreak of an epidemic there is a real threat to the health of patients. According to medical statistics, Pseudomonas bacteria cause at least half of nosocomial infections. The microbe can be found on soap, hand brushes, water taps, changing tables, and anesthesia machines.

There is always a possibility of activation of an opportunistic bacillus in the patient’s body due to decreased immunity. Some features of Pseudomonas bacteria help them adapt to environmental variability. Microorganisms of this type are characterized by:

• the presence of signaling molecules that form quorum sensing (the ability of bacteria to communicate and coordinate their behavior);
• ability to make general decisions for self-defense;
• resistance to large doses of antibiotics;
• the presence of a special protective biofilm;
• the ability to adhesion (sticking of cells to each other and to various substrates).

Symptoms of Pseudomonas Infection

The period of infection development ranges from a couple of hours to several days. Bacteria can affect not only organs and systems, but also cause a combination of several pathologies. One of the most severe manifestations of the disease is damage to the nervous system, which can develop in a primary or secondary way. The latter is characterized by infection through blood from other foci (sepsis). In the primary variant of development, the microbe enters the body during head injuries or during neurosurgical operations, spinal puncture, or spinal anesthesia.

Pseudomonas aeruginosa in children

According to medical statistics, pathogenic microorganisms affect children much more often than adults. Newborns and premature babies whose immune systems are too weak to fight external infections are at risk. Pseudomonas aeruginosa in the urine of a child is a common occurrence, since babies are often carriers of bacteria. In adolescence, children are much less likely to suffer from this disease, with the exception of patients with reduced immunity.

Gram-negative bacteria in children affect the digestive tract, central nervous system, respiratory organs, urinary tract, and skin. Pseudomonas aeruginosa in a child’s stool indicates the spread of pathogenic microorganisms; the conjunctiva of the eyes, the umbilical cord, the gastrointestinal tract, and the skin are considered entry points for infection. Clinical symptoms of infection among children are often toxic in nature, which leads to the appearance of:

• dehydration;
• intestinal paresis;
• sepsis of the digestive tract;
• destruction of lung tissue;
• omphalitis (bacterial inflammation of the bottom of the umbilical wound);
• meningitis;
• meningoencephalitis.

Diagnostics

Due to the lack of specific clinical manifestations, diagnosis of Pseudomonas aeruginosa infection is difficult without a preliminary laboratory examination. Sometimes infection becomes obvious due to certain signs: the affected area is colored blue-green, the course of the disease is prolonged, and resistance to antibacterial drugs is observed. To accurately determine the pathogen, doctors prescribe a bacteriological examination. The material for analysis is:

• blood;
• pus from the wound;
• smears from the vagina and cervix;
• mucus from the nasopharynx;
• sputum;
• cerebrospinal fluid;
• urine;
• vomit;

Sometimes specialists use a serological diagnostic method, which involves detecting antigens against pathogenic microorganisms in the blood. The diagnosis is confirmed by an increase in antibody titer during a repeated blood test. Using special reagents, the doctor isolates microbial plasmids and determines their presence in the resulting sample for diagnosis. Another way to identify bacteria is real-time polymerase chain reaction (PCR). This method significantly reduces the time required to obtain results.

Treatment of Pseudomonas aeruginosa

If a pseudomonas infection is suspected, the patient is immediately hospitalized in a hospital. Such people are prescribed strict bed rest for the entire period of therapy. In the process of fighting gram-negative bacteria, doctors use several types of antibiotics. Additionally, syndromic drugs are used depending on the nature of the manifestation of symptoms of the pathogenic bacillus.

The duration of treatment is from 2 to 6 weeks, sometimes the treatment period takes longer. In special cases, surgical intervention is performed; infected wounds require deep treatment. Dead skin areas must be excised. Sometimes amputation is necessary to save the patient’s life; if necrosis or intestinal abscess is suspected, an urgent operation is performed.

Drug therapy

Treatment of this type of infection requires the use of an integrated approach. One of the main directions of therapy is the use of antibiotics. Based on a laboratory examination, the resistance of the pathogen to the drugs is determined, after which the drug is selected individually for each patient. The course of therapy lasts from 3 to 5 days, the dose and frequency of use is selected by the doctor. Preference is given to the following groups of medications:

• ureidopenicillins (Ticarcillin, Carbenicillin);
• cephalosporins (Cefapirazone, Cefepime);
• carboxypenicillins (Piperacillin, Mezlocillin);
• aminoglycosides (Tobramycin, Netilmicin).

To combat Pseudomonas aeruginosa bacteria, a bacteriophage is used, which contains viruses that are destructive to gram-negative microorganisms. Prominent representatives of the class are the drugs Piocyoneus, Piobacteriophage, Intesti-bacteriophage. The solution is indicated for external and internal use. The course of therapy lasts from 5 to 15 days, the dose and frequency of use is selected by a specialist.

In order to form active immunity against pathogenic microbes, vaccination with the drug Pseudovac is prescribed. In some cases, an autovaccine is used to stimulate the immune system, which is created based on a strain isolated from the patient. Homeopathic remedies are selected individually and used as part of complex treatment along with a balanced diet and vitamin and mineral complexes. During therapy, it is recommended to take prebiotics or probiotics; the course of treatment and dosage is determined by the doctor. These include:

• Probifor;
• Lactobacterin;
• Acylact;
• Linux;
• Bifiform;
• Acipol.

Folk remedies

Treatment of Pseudomonas aeruginosa infection with folk remedies involves the use of herbal medicine. Most recipes are based on an aqueous or oil solution; additional ingredients include medicinal herbs or berries. Alternative medicine drugs are designed to strengthen the immune system, so they are used as preventive measures. The most common folk recipes against gram-negative rods are:

1. Viburnum infusion. Grind 1 tablespoon of berries until mushy. Pour the resulting mixture into 0.5 liters of boiled water and let it brew. Take half a glass 4 times a day before meals.
2. A decoction of aspen, plantain, lingonberry or horsetail leaves. They can be taken separately or all at once (in equal proportions). Chop the leaves (2 tablespoons) and pour in 200 g of boiled water, then cook for 20 minutes over low heat. Infuse the decoction for an hour. Drink the resulting tea before each meal.
3. Tea tree essential oil. Add one drop of natural antibiotic to 1 tsp. sunflower or olive oil. Drink the mixture once a day, 1 tsp, with a glass of water.
4. Calendula infusion. For rinses and lotions, prepare an infusion of fresh (5-6 pcs.) and dried plant flowers (1 tbsp.). Pour the mixture with a glass of boiled water and let it brew for half an hour. Drink the infusion three or four times a day, half a glass. Oil and alcohol solutions from calendula are no less effective.
5. Propolis ointment. For the recipe you will need 10 g of adhesive and half a glass of boiled water. Melt propolis in hot liquid and leave in a thermos for 12 hours. Apply the resulting ointment to the affected areas of the skin daily.

Prevention of Pseudomonas aeruginosa infection

The resistance of the pathogen to most antiseptics and disinfectants makes it difficult to implement preventive measures. However, pathogenic microorganisms are sensitive to a solution of carboxylic acid, chloramine, hydrogen peroxide, bacteria are killed by autoclaving (sterilization with steam under pressure) and boiling. To identify carriers of Pseudomonas aeruginosa in medical institutions, regular examinations of personnel, instruments and premises are carried out.

Microbes often enter the human body through umbilical wounds. To prevent infection, it is necessary to follow the rules of asepsis. In community settings, the risk of infection is low, but to prevent the disease, doctors recommend adhering to certain rules. Timely treatment of chronic diseases, a balanced, fortified diet (with plenty of fiber), and exercise - all this helps to maintain a high level of immunity to fight any pathogenic bacteria.

Video

Part 2

1. Contact your doctor if you are at risk. Pseudomonas aeruginosa is most dangerous for people with weakened immune systems or those being treated in a hospital. Newborns are at high risk. The following groups of people are at high risk:

   • cancer patients;
   • HIV-infected people and people with AIDS;
   • patients with cystic fibrosis;
   • patients using a ventilator;
   • patients who have undergone surgery;
   • people with a catheter;
   • patients observed with extensive burns;
   • patients with diabetes mellitus.

2. Contact your doctor if you suspect an infection. See a doctor as soon as possible - a Pseudomonas aeruginosa infection requires examination by a professional. Depending on the location of the lesion, infection caused by Pseudomonas aeruginosa manifests itself differently. It could be:

   • pneumonia - may be associated with infection entering the ventilator;
   • eye infection;
   • ear infection;
   • urinary tract infections caused by bacteria entering the catheter;
   • infection of a surgical wound;
   • infected bedsores - this condition can occur in people who are forced to lie down for a long time;
   • sepsis, which occurs when bacteria enter intravenous lines.

3. Discuss treatment with your doctor. A smear (scraping) is taken from the site of the lesion and sent to the laboratory to determine the pathogen. It is also possible to determine the sensitivity of an infection to a specific group of antibiotics. Often, Pseudomonas aeruginosa is widely resistant to most antibiotics. To prescribe effective antibiotics, your doctor needs to know about all your medical conditions, especially if you are pregnant or have kidney disease. For treatment, the doctor may prescribe:

   • Ceftazidime. For most Pseudomonas aeruginosa infections, this antibiotic is effective. It is usually given intravenously or intramuscularly. If you are allergic to penicillin, the drug is contraindicated.
   • Piperacillin + Tazobactam (“Tazocin”). This combination drug is also effective against Pseudomonas aeruginosa. Provide your doctor with a complete list of medications you take, including over-the-counter medications, dietary supplements, and vitamins.
   • Imipenem. This is a broad-spectrum antibiotic that is usually prescribed together with cilastatin. Cilastatin increases the half-life of imipenem and improves tissue penetration of the antibiotic.
   • Aminoglycosides (gentamicin, tobramycin, amikacin). The dosages of these drugs depend directly on your weight and the functioning of your kidneys. To monitor side effects related to the kidneys (nephrotoxicity) and hearing, the concentration of the drug in the blood and fluid consumed is monitored.
   • Ciprofloxacin. The drug is prescribed orally or intravenously. It is not advisable to take this drug if you have epilepsy, kidney disease, or pregnancy.
   • Polymyxin B. This drug is prescribed orally, intravenously, intramuscularly (in some countries the drug is available for use by inhalation).

4. Follow the diet and physical activity recommended by your doctor. Some patients, such as those with cystic fibrosis, need to adjust their diet and exercise levels to improve nutrition and tissue healing.

   • When receiving mechanical ventilation, you must eat a high-fat, low-carbohydrate diet. Excess carbohydrates in the diet increases the formation of carbon dioxide, which makes breathing difficult.
   • It is necessary to limit physical activity during a systemic infection. This does not apply to cases where the infection is limited in nature.

Pseudomonas aeruginosa P. aeruginosa is a gram-negative rod that is a strict aerobe and is capable of utilizing almost any carbon source, so moist places where there are minimal amounts of organic matter are suitable for its reproduction.

Strains isolated from patients can cause ß-hemolysis on blood agar; over 90% of strains produce blue-green phenazine pigment (this is responsible for the bluish color of pus) and fluorescein, which is yellow-green in color and fluoresces. These pigments diffuse into the nutrient medium, so the color of the latter around the colonies changes. In epidemiological studies, Pseudomonas strains are distinguished using serotyping, phagotyping and pyocin typing, as well as restriction fragment length polymorphism analysis (using pulsed-field gel electrophoresis).

Epidemiology

In a study conducted in Israel, the incidence of Pseudomonas aeruginosa bacteremia in children was 3.8 cases per 1000 patients over 10 years, and the mortality rate was 20% (these rates varied depending on concomitant diseases). Pseudomonas aeruginosa and other pseudomonas are often introduced into hospital conditions on the clothes, shoes and skin of patients and staff; other ways are with plants and vegetables that are brought to the hospital. Pseudomonas aeruginosa can colonize the gastrointestinal tract of patients. As a result, contamination of any wet or liquid substances occurs. Thus, pseudomonads can be found in distilled water, in the kitchen and laundry of a medical institution, in some antiseptic solutions and on ventilator equipment. At the time of admission to the hospital, the frequency of colonization of the skin, pharynx, nasal mucosa and feces of patients is low, but it increases to 50-70% with a long hospital stay, the use of a wide spectrum of antitumor chemotherapy, mechanical ventilation and the introduction of urinary catheters. Broad-spectrum antibiotics inhibit the intestinal microflora, resulting in reduced resistance to colonization, which allows Pseudomonas aeruginosa from the environment to colonize the gastrointestinal tract. Destruction of the intestinal mucosa by certain drugs, especially cytostatics, and hospital enteritis provide an opportunity for P. aeruginosa to enter the lymph or blood.

Pathogenesis

Pseudomonas require oxygen to grow, which explains why these bacteria do not colonize or infect the skin. The invasiveness of Pseudomonas aeruginosa is mediated by virulence factors. Pseudomonas aeruginosa produces endotoxin, which is quite weak compared to other gram-negative bacteria.

Pseudomonas aeruginosa also produces a number of exotoxins. Exotoxin A causes local necrosis and facilitates dissemination of infection. Exoenzyme S acts both as an adhesin and as a cytotoxin. The development of infection caused by pseudomonas goes through three stages. Bacterial attachment and colonization are facilitated by fimbriae, as well as epithelial damage due to trauma or other infection. Mucopolysaccharide inhibits phagocytosis, and extracellular proteins, proteases, elastases and cytotoxin (formerly called leukocidin) digest cell membranes and antibodies, and also increase capillary permeability and suppress the functions of leukocytes. Local tissue spread is followed by penetration into blood vessels and dissemination. This stage is facilitated by endotoxin and mucous exopolysaccharides (prevent phagocytosis), as well as protease (breaks down IgG) - The macroorganism responds to infection by producing antibodies to exotoxin A. The dominant position of Pseudomonas aeruginosa among the causative agents of opportunistic infections is explained by the weakening of immune mechanisms due to injury, neutropenia, inflammation of the mucous membranes , immunosuppression, inhibition of mucociliary transport.

Symptoms of Pseudomonas aeruginosa

Most infections caused by Pseudomonas aeruginosa are opportunistic or associated with the presence of shunts and indwelling urinary catheters. Pseudomonas aeruginosa can penetrate small wounds of healthy individuals as a secondary pathogen and cause the formation of phlegmons or abscesses, the distinctive feature of which is the green or blue color of the pus. A characteristic skin lesion of Pseudomonas is ecthyma gangrenosum. It occurs as a result of the introduction of a pathogen from the outside or as a complication of sepsis. A pink spot appears on the skin, which turns into hemorrhagic nodules, and then into crusted ulcers, surrounded by a bright halo of hyperemia. Hemorrhages and foci of necrosis are found at the bottom of the ulcers

Infections caused by Pseudomonas aeruginosa

Outbreaks of urinary tract infections and dermatitis have been reported in healthy people associated with the use of public swimming pools, as well as bathtubs shared by multiple family members. Folliculitis developed within a few hours to 2 days after contact with water from the listed sources. The skin rash may be erythematous, macular, papular, or pustular. In some cases, the lesions were single and scattered, in others they involved the entire body. In some children, skin lesions were accompanied by malaise, fever, vomiting, pain and congestion of the pharynx, conjunctivitis, rhinitis and swelling of the mammary glands.

Other types of pseudomonas (not Pseudomonas aeruginosa) rarely serve as causative agents of infections in healthy children, however, pneumonia and abscesses caused by B. cepacia have been described; otitis media caused by P. Putrefaciens or P. stutzen; phlegmon, osteomyelitis and sepsis caused by 5. maltophilia. In addition, injection drug addiction predisposes to the development of sepsis and endocarditis, the causative agent of which is S. maltophilia.

Burn and wound infection.

The burn and wound surface is often colonized by pseudomonas and other gram-negative bacteria; this initial colonization with a low number of adherent microorganisms serves as a necessary precondition for invasion. Antibacterial agents reduce the amount of sensitive microflora, which allows relatively resistant pseudomonads to multiply rapidly. The proliferation of bacteria in necrotic tissues, as well as associated with long-term use of venous and urinary catheters, increases the risk of sepsis caused by Pseudomonas aeruginosa, a serious complication in burn patients.

Cystic fibrosis. Pseudomonas aeruginosa is present in many children with cystic fibrosis, and the frequency of its detection increases with age and severity of lung damage. In patients with cystic fibrosis, mucus-forming strains of Pseudomonas aeruginosa predominate, which are rare in other diseases. The infection begins gradually or even asymptomatically, but its rate of progression varies greatly. Against the background of cystic fibrosis, antibodies do not lead to eradication of the pathogen, and antibiotics have only a moderate effect, thus the infection becomes chronic. Repeated courses of antibiotic therapy can lead to the emergence of highly resistant P. aeruginosa strains.

Persons with impaired immunity. Children with leukemia or other immune-weakening diseases, especially those on immunosuppressive therapy or who are neutropenic, are extremely susceptible to sepsis. Sepsis develops as a result of penetration into the bloodstream of Pseudomonas aeruginosa, which previously colonized the respiratory tract or gastrointestinal tract. Sepsis is often combined with generalized vasculitis and foci of necrosis and hemorrhages in almost all organs. On the skin, such lesions look like purple nodes or ecchymoses that become necrotic (gangrenous ecthyma). Possible hemorrhagic or gangrenous, which leads to intestinal obstruction and severe arterial hypotension.

Hospital-acquired pneumonia. Although Pseudomonas aeruginosa does not play a significant role in the etiology of pneumonia in children, it is an important cause of hospital-acquired pneumonia, especially in patients on mechanical ventilation. In the past, Pseudomonas aeruginosa was often found on ventilators, connecting tubes and humidifiers, but these days, thanks to improved disinfection and regular equipment changes, this has become rare. However, colonization of the upper respiratory tract and gastrointestinal tract can lead to aspiration of secretions containing Pseudomonas aeruginosa and severe pneumonia. The greatest difficulty is in the differential diagnosis between colonization and pneumonia in intubated patients. Typically, this issue can only be resolved by culture of material obtained using invasive methods, such as bronchoscopy with brush biopsy.

Infections in infants. In some cases, Pseudomonas aeruginosa causes hospital-acquired bacteremia in newborns; When culturing the blood of newborns who are in intensive care units, this microorganism is detected with a frequency of 2-5%. The development of bacteremia is often preceded by conjunctivitis. Increasingly, P. aeruginosa is cultured from the peritoneal fluid of infants with necrotizing enterocolitis. In children approaching 1 year of age, sepsis may very rarely occur due to community-acquired infection with Pseudomonas aeruginosa. Only a few cases have been described in which sepsis developed following ecthyma-like skin lesions, transient neutropenia due to a viral infection, OR prolonged exposure to a bath with contaminated water.

Diagnostics

Infections caused by Pseudomonas aeruginosa do not have clinical features (with the exception of ecthyma gangrenosum). Skin lesions similar to gangrenous ecthyma are observed in sepsis caused by Aeromonas hydrophila, other gram-negative bacteria, as well as Aspergillus spp.

To make a diagnosis, it is necessary to isolate Pseudomonas aeruginosa from the blood, CSF, urine, aspirate from the lung or pus (the latter is obtained by puncture of a subcutaneous abscess or phlegmon).

Treatment of Pseudomonas aeruginosa

For systemic infections, it is necessary to begin administering antibiotics, to which Pseudomonas is sensitive in vitro, as early as possible. Often the effectiveness of antibiotics is limited. For generalized infections against the background of immunodeficiency, long-term antibiotic therapy is necessary.

For sepsis and severe Pseudomonas aeruginosa infections, one or two bactericidal drugs are prescribed. Most data indicate that in patients with normal immunity, one drug is sufficient. Two antibacterial drugs are necessary for synergy; such treatment is indicated for patients with immunodeficiencies, as well as for unknown sensitivity of Pseudomonas aeruginosa. Of the drugs active as monotherapy, it is worth noting ceftazidime, cefoperazone, ticarcillin/clavulanate and piperacillin/tazobactam. The listed drugs can be combined with gentamicin and other aminoglycosides that have a synergistic effect. Carbenicillin, ticarcillin and mezlocillin should not be prescribed, since the blue pus bacillus quickly becomes resistant to them.

Ceftazidime has been proven to be highly effective in patients with cystic fibrosis. Azlocillin, mezlocillin and piperacillin/tazobactam in combination with an aminoglycoside are active against sensitive strains of Pseudomonas aeruginosa. Among the alternative agents, it is worth mentioning imipenem/cilastatin, meropenem and aztreonam. Ciprofloxacin is also effective, but it can only be prescribed to people over 18 years of age. Long-term antibiotic therapy should always be based on the results of susceptibility testing of P. aeruginosa, since the prevalence of resistant strains is increasing.

For meningitis, it is most advisable to prescribe a combination of ceftazidime and gentamicin intravenously. If this treatment is unsuccessful, it should be supplemented with intraventricular or intrathecal administration of gentamicin (regardless of body weight, 1-2 mg is administered once a day until CSF cultures become negative). Intraventricular and intrathecal drugs are administered only when indicated.

Forecast

The prognosis largely depends on concomitant diseases. If sepsis caused by Pseudomonas aeruginosa occurs against the background of severe immune disorders, the prognosis is poor (with the exception of reversible neutropenia and hypogammaglobulinemia).

The prognosis improves when several antibacterial agents are prescribed. In addition, the prognosis is better in the absence of neutropenia or restoration of the number of neutrophils, as well as when foci of local infection are drained. Pseudomonas spp. found in the lungs of most children who die due to cystic fibrosis; it is possible that this microorganism is responsible for the slow deterioration of these patients. An association has been found between B. cepacia, which is often resistant to standard antibacterial agents, and faster decline in lung function as well as lower survival. Those few infants who manage to survive meningitis caused by Pseudomonas aeruginosa usually exhibit developmental abnormalities.

Prevention

Healthy individuals who are away from medical facilities should not worry about contracting Pseudomonas aeruginosa infection, but they should be aware of the possibility of bacterial contamination of medical equipment and prevent transmission of the infection to patients. Sources of bacterial contamination must be identified and eliminated as quickly as possible, which requires effective hospital infection control programs. As already mentioned, Pseudomonas spp. capable of multiplying in distilled water, some solutions for disinfection, parenteral administration and in medications. In neonatal units, infection is usually transmitted to children through the hands of staff, washbasins, catheters, and suction catheter rinsing solutions.

To prevent and combat an outbreak of infection, it is necessary to thoroughly wash your hands before contacting a child, preferably using ethanol or iodine-containing solutions. Frequency of contamination with Pseudomonas spp. and other gram-negative bacteria is significantly reduced with careful care and sterilization of endotracheal tubes, as well as when installing and caring for permanent catheters, preparing solutions for intravenous administration, especially for parenteral nutrition; In addition, IV tubing needs to be replaced regularly.

To prevent pseudomonas follicular dermatitis, which occurs upon contact with contaminated water from swimming pools or hot baths, it is necessary to maintain the pH of the water within the range of 7.2-7.8, and the concentration of free chlorine at the level of 70.5 mg/l.

Infection in burn patients can be minimized by isolating the patient, removing nonviable tissue, and topical application of sulfadiazine cream or 10% mafenide acetate. The possibility of creating a vaccine, also against Pseudomonas spp.

When infected with Pseudomonas spp. passages communicating with the spinal space (occur with median dysraphism), early diagnosis and surgical treatment are necessary. Pseudomonas urinary tract infections can be minimized by early recognition and surgical correction of obstruction.

Pseudomonas aeruginosa is the cause of very serious diseases, especially in patients with weak immunity. Pseudomonas aeruginosa is the most common cause of nosocomial infections in patients hospitalized for one week or more. Read about the symptoms and treatment of this pathology below.

Symptoms of Pseudomonas Infection

Depending on which organ or system was affected, the corresponding diseases develop:

• Respiratory tract - ;
• Bloodstream – bacteremia;
• Heart - ;
• Central nervous system – meningitis, brain abscesses;
• Ears – middle and/or outer;
• Eyes – bacterial keratitis, endophthalmitis;
• Bones and joints - ;
• Gastrointestinal tract – diarrhea, enteritis, ;
• Genitourinary system – , ;
• Skin – gangrenous ecthyma.

Let's consider the features of symptoms for each system:

1. Endocarditis: fever, heart murmur, positive blood culture for Pseudomonas aeruginosa. Skin symptoms: Roth spots, Osler's nodes, hemorrhages. Enlarged spleen (splenomegaly).
2. Pneumonia: cough, wheezing, fever, pallor and cyanosis, hypoxia, sometimes shock.
3. Gastrointestinal tract: fever, signs of dehydration, stomach and intestinal disorders, signs of peritonitis.
4. Skin and soft tissues: hemorrhages and areas of necrosis surrounded by erythema (an area of ​​reddened skin), subcutaneous nodules, abscesses, cellulite, fasciitis.
5. Musculoskeletal system: pain and decreased range of motion in the affected area.
6. Eye lesions: swelling of the eyelid, lacrimation.
7. Otitis externa: red, swollen, inflamed external auditory canal, swollen lymph nodes.
8. Bacteremia: fever, rapid breathing and heart rate, and shock, jaundice.

Diagnostics

Laboratory research

• Clinical blood test;
• Blood culture for sterility;
• (general and sowing);
• Sputum culture (for pneumonia);
• Puncture and analysis of cerebrospinal fluid.

Imaging studies

• X-ray of the chest organs;
• Computed tomography and magnetic resonance imaging;
• Ultrasonography;
• Echocardiography.

Other tests

• Bronchoscopy;
• Thoracentesis;
• Lumbar puncture;
• Ophthalmological and ENT examinations.

Treatment

The treatment regimen for infections caused by Pseudomonas aeruginosa also depends on which organ is affected. In any case, the main drug remains an antibiotic. Usually, 2 antibacterial drugs are prescribed at once, in order not only to have the maximum effect on Pseudomonas aeruginosa, but also to destroy other possible pathogenic bacteria, this is especially true in cases where the patient caught Pseudomonas aeruginosa in the clinic, already receiving treatment for some other diseases.

Schemes of prescribed drugs for different manifestations of Pseudomonas aeruginosa infection:

1. Endocarditis - high doses of aminoglycosides + penicillin or broad-spectrum cephalosporin. Treatment continues for up to six weeks.
2. Pneumonia - treatment begins with 2 antibiotics; as the patient’s condition improves, one antibiotic is discontinued.
3. Bacteremia - due to the danger and severity of the process, antibacterial treatment is prescribed even before the blood culture results arrive. The patient receives an aminoglycoside + penicillin or a broad-spectrum cephalosporin, sometimes one of the drugs is changed to a fluoroquinolone (for example, ciprofloxacin) or rifampicin.
4. – the drug of choice is ceftazidime, to which an aminoglycoside is added. Antibiotic therapy lasts at least two weeks.
5. Ear damage - usually a combination of an antibiotic and (for example, metypred) is prescribed.
6. Eye damage - conjunctivitis and ulcerations are treated with local antibiotics (aminoglycoside drops). You need to put drops into your eyes every 30-60 minutes. For severe lesions, antibiotic injections into the orbit (in the soft tissue next to the eye) and an oral antibiotic are additionally prescribed.
7. Damage to the genitourinary system - aminoglycosides and fluoroquinolones in tablets are mainly prescribed. Usually, one antibiotic is enough for successful treatment; the main thing is to choose it correctly at the beginning of therapy. If the infection is not susceptible to these drugs, the patient is prescribed cephalosporins, carbapenems, and penicillins.
8. Lesions of the gastrointestinal tract - antibiotics and rehydration therapy (droppers with saline, glucose and vitamins) successfully cope with the disease.
9. Skin and soft tissues - patients are prescribed a regimen of two antibiotics, both topically (to areas of affected skin) and in tablets or injections.

Surgery

1. All probes and catheters should be removed from the patient and replaced with new ones (if necessary) if there is a suspicion that infection has occurred through them.
2. Deep surgical treatment of all wounds that may be infected with Pseudomonas aeruginosa. In some cases, amputation may be necessary to save the patient's life.
3. Foot ulcers in diabetic patients must be carefully treated and all non-viable tissue must be removed immediately.
4. Severe cases of otitis media (malignant otitis externa) must be treated not only with antibiotics, but also with surgery. During the procedure, the ENT specialist removes all necrotic tissue.
5. In cases of damage to the gastrointestinal tract with the development of complications (intestinal perforation, obstruction, necrosis of a section of the intestine, abscess formation), immediate surgical intervention is performed.

Which doctor should I contact?

If any infectious disease occurs, you can consult a therapist or infectious disease specialist. Depending on which organ is affected by Pseudomonas aeruginosa, treatment will be required from a cardiologist, dermatologist, gastroenterologist, nephrologist, urologist, ophthalmologist, ENT doctor and other specialists. Radiologists and endoscopists take part in the diagnosis. Treatment is often carried out with the participation of a surgeon.