Children's analysis of sowing on the microflora from the nose. What shows the tank sowing from the throat. Where to go to donate and where to get the results of bacteriological culture

Determining the sensitivity of infectious agents to antibiotics is a vital study, due to the rapid growth and wide spread of antibiotic resistance in bacteria. This research allows:

evaluate the effectiveness of new antibacterial drugs against the studied pathogen:
determine the feasibility of using old drugs (due to the growth of resistance to antibiotics);
control the spread of antibacterial resistance in certain regions, countries, etc.

At the moment, antibiotic therapy is prescribed either empirically or etiotropically. When empirically prescribed, the natural sensitivity of the pathogen, data on its resistance, as well as epidemiological information on the resistance of bacteria in a given region are taken into account. The main advantage of this principle of antibiotic prescribing is the ability to quickly initiate antimicrobial therapy. Etiotiropnaya therapy can be carried out only after the isolation and identification of the pathogen, as well as after establishing its sensitivity to antibiotics.

Determining the degree of sensitivity of pathogenic microorganisms to various antibacterial drugs is called an antibiogram. This study is carried out in order to evaluate the effectiveness of an empirically selected antibiotic and, if necessary, replace the drug, change it to the one to which the pathogen is most sensitive.

The importance of antibiotic susceptibility testing is due to the rapid increase in acquired resistance among bacteria, as well as the wide choice of antibacterial drugs.

Throat swab for microflora and sensitivity to antibiotics

A tank of sowing mucus from the throat and nose allows you to conduct a qualitative and quantitative assessment of the composition of the microflora and identify:

pathogens of acute and chronic diseases (tonsillitis, pharyngitis, rhinosinusitis, etc.);
clinically significant chronic carriage of staphylococci, pneumococci, etc.

Normally, in healthy people, saprophytic or conditionally pathogenic flora are determined in low titers (less than 10 3 CFU / ml). Values greater than 10 4 CFU are considered clinically significant.

A swab from the pharynx and nose for flora and sensitivity to antibiotics makes it possible to isolate not only the causative agent of an infectious and inflammatory disease, but also to determine which antibacterial drugs are most detrimental to it.

It must be remembered that two days before sowing mucus, it is forbidden to use antimicrobial sprays, rinses, and nasal ointments. It is also forbidden to treat tonsils with Lugol's solution ® .

The sampling of material should be carried out in the morning, on an empty stomach. To obtain reliable results, it is not recommended to brush your teeth and rinse your mouth.

When taking the material (taking a swab from the throat), it is necessary that the sterile swab with which the sample is taken does not come into contact with the tongue and lips. To do this, the patient is asked to open his mouth wide and press his tongue with a spatula. Scraping is taken only from the pharynx, from both tonsils. If there are visible raids on the tonsils, then the scraping is taken first of all from the inflamed area.

Deciphering culture from the pharynx for flora and sensitivity to antibiotics includes a conclusion from a bacteriological laboratory with an established type of pathogen, its titers and antibiogram results (performed if the growth of bacterial colonies in the culture was diagnostically significant).

Sputum culture

Many patients confuse throat culture with sputum culture. It is important to understand that sputum is not saliva, it reflects the microflora of the respiratory tract itself. Therefore, sputum sampling should be carried out after rinsing the mouth (this will reduce the likelihood of contamination of the sample with saliva). It is preferable to collect sputum in the morning, after a deep cough.

Sputum culture for microflora and sensitivity to antibiotics is carried out for tuberculosis, pneumonia, chronic bronchitis, bronchiectasis, etc. Values greater than 10 6 are considered diagnostically significant.

At low titers due to saprophytic or opportunistic flora, there is a possibility that the test sample is represented mostly by saliva, that is, the material was collected incorrectly.

It should also be borne in mind that all microflora cultures taken against the background of ongoing antibiotic therapy are uninformative, since the results obtained will be false-negative.

When decoding the analysis, information is given:

presence or absence of bacterial colony growth in the sample;
how many microorganisms grew in the crop;
what genus and species the cultivated pathogens belong to;
to what antibacterial preparations these bacteria are sensitive;
which antibiotics are not effective (acquired or natural resistance).

For opportunistic pathogens, concentrations from 10 6 obtained repeatedly with an interval of 3-5 days are considered clinically informative values. An antibiogram is compiled only for pathogens that are diagnostically significant. That is, an analysis for sensitivity to antibiotics is carried out after the pathogen is sown (group A streptococci, pneumococci, Klebsiella, staphylococci, Haemophilus influenzae, chlamydia, mycoplasma).

Blood for sterility and sensitivity to antibiotics

Blood cultures for sterility are performed if bacteremia is suspected. To obtain reliable results, blood sampling should be carried out before starting treatment with antibacterial drugs.

Blood for sensitivity to antibiotics is examined only after studying the blood for sterility and identifying pathogenic microorganisms in it (staphylo- and streptococci, enterococci, meningococci, etc.).

It is impossible to determine the presence of bacteria in the blood using microscopy of a freshly taken sample, since it does not contain the required amount of bacteria.

To confirm or exclude bacteremia, the blood is placed in a special cultural nutrient medium and incubated, subject to a temperature regime of 37 0 C (this temperature is optimal for the growth of pathogenic microorganisms). This is necessary in order to ensure visible bacterial growth. Depending on the type of microorganism (fast-growing or slow-growing), the obvious growth of bacteria becomes noticeable after 18-72 hours. As a general rule, if there is no appreciable growth of microorganisms in the sample after three days, then bacteremia is unlikely, but the culture should continue to be monitored in case it contains slow-growing microorganisms.

If colony growth is detected, the culture is stained and examined under a microscope. Due to this, the type of pathogens is determined (gram-, gram+ cocci, bacilli, etc.). Further, for a more accurate identification of the pathogen, seeding is carried out on special dense media in a Petri dish. With the help of special chemical tests, the type of microorganism is determined.

After identifying the pathogen, a blood test is performed for sensitivity to antibiotics. This is necessary in order to determine which antibiotic will be most effective.

It is important to understand that bacteremia is a life-threatening condition that requires the immediate administration of antibacterial drugs. In this regard, the doctor cannot wait for the results of the antibiogram (usually the answer comes in three days) and is forced to empirically prescribe broad-spectrum antibiotics. Antibiotic susceptibility culture data is vital if the disease is caused by a flora with acquired resistance to one or more antibiotics. In this case, the empirically prescribed drug may not be effective and a drug change will be required, which is already performed on the basis of the results of the study.

How is blood taken for sterility?

The blood sample is placed in a blood culture bottle, avoiding any contamination (contact with the skin of the patient or staff, objects, etc.). The blood culture bottle is removed from the refrigerator immediately before material sampling and warmed to room temperature. After opening the outer (plastic cap), the inner cap of the bottle is treated with seventy percent alcohol (ethyl) for a minute. The patient's skin, directly above the puncture site, is treated with seventy percent ethyl alcohol and 1-2% iodine.

After the treated area has dried, it is necessary to perform venipuncture without touching the treated surface with your hands.

Blood for research should be taken before starting antibiotic therapy. In acute sepsis, it is necessary to perform 2-3 material samplings with an hourly interval. Taking multiple samples increases the chances of detecting bacteria, and also allows you to differentiate between true bacteremia (bacteria in both samples) and contamination of the sample with bacteria (bacteria in one sample due to poor sampling technique).

In febrile patients, blood should be taken when the temperature rises, either immediately or after the temperature peak has passed.

What does the analysis show?

When deciphering the analysis, intermediate (daily) and final conclusions are taken into account. Responses from the bacteriological laboratory are classified into three types:

negative (no growth of microorganisms);
net growth detected (growth of only one species);
mixed growth was detected (as a rule, this indicates a violation of the rules for taking the material and contamination of the sample).

In the final result, when bacteria are detected, their type and the result of the study on sensitivity to antibiotics are indicated.

A throat swab for microflora and sensitivity to antibiotics is a standard bacteriological examination. It is carried out in order to study the composition of the microflora of the nasopharynx and allows you to obtain reliable information about the presence of any pathology, identify its cause and pathogen, and also determine the body's response to certain medications. With this information, the doctor can prescribe the necessary treatment and appropriate medications.

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Preparing for a swab collection

An analysis for a swab from the pharynx and nose requires some preparation and the implementation of certain rules, the violation of which can lead to an unreliable result. To avoid this, you must follow the following rules:

Stop taking antibacterial drugs five days before the test.
A few days before the study, exclude the use of oral rinses containing antiseptics, as well as ointments and sprays, which contain antimicrobial substances or antibiotics. This can lead to the destruction of most of the microbes, and the analysis will not reveal the bacteria that caused the disease in the smear.
It is recommended to take the analysis in the morning and on an empty stomach. Do not eat, drink or use toothpaste for several hours before the procedure.
Chewing gum is strictly prohibited immediately before taking a smear.
Nasal sampling is also performed on an empty stomach. If the patient managed to eat, you need to wait a few hours, after which you can perform the procedure.

Based on the above, pathogenic bacteria must be allowed to multiply freely in the mucosa for 3-5 days. This will allow you to get a real picture and the most reliable result.

Indications for diagnostics

The procedure for taking material for research is assigned in the following cases:

For preventive examination when applying for a job in the food industry, as well as in children's and medical institutions.
As a complete examination of pregnant women, to prevent the development of infections that threaten the patient or child.
When children enter a kindergarten or school, to exclude the possibility of infectious outbreaks in groups.
In the preoperative and postoperative periods, as well as before hospitalization of the patient.
With bacterial angina. The analysis allows you to identify the pathogen and determine the severity of pathogenicity to prevent complications such as rheumatism, glomerulonephritis and myocarditis.
In case of inflammation of the nasopharynx to exclude suspicion of diphtheria infection.
If you suspect a meningococcal infection or whooping cough (this disease is quite difficult to recognize by the clinical picture, since the symptoms are very blurred).
To search in the nasopharynx for Staphylococcus aureus, which is the cause of the formation of boils and pyoderma.
As seeding for antibiotic susceptibility. Since as a result of prolonged independent use of drugs, bacteria are able to develop resistance to them.
To diagnose mononucleosis, stenosing laryngitis and abscesses that are near the tonsils.

Therefore, a smear on the flora is taken to confirm or exclude a certain pathology.

Smear procedure

Taking a smear of microflora is a simple and painless procedure in which the patient needs to relax and endure just a few seconds. Some discomfort is felt only by people with a well-developed gag reflex.

The algorithm for obtaining material from the patient's throat is as follows:

1. The patient needs to tilt his head back and open his mouth wide so that the doctor can see the posterior pharyngeal wall (when taking a smear in children, a specialist may need help).
2. Next, the tip of the tongue is fixed with a spatula, and using an elongated loop with a sterile cotton-gauze tip, material is taken from the pharyngeal wall, arches and tonsils.
3. After that, the loop is quickly placed in a special test tube, which contains a solution that prevents the death of bacteria during transportation of the material to the laboratory. If there is no test tube with such a solution, the taken analysis must be delivered for examination within two hours.
4. It is necessary to take a smear with extreme caution to avoid touching other surfaces of the oral cavity (tongue, teeth, cheeks).

When taking a swab from the nose, the patient is placed opposite the doctor and asked to tilt his head back. Next, the nose is cleared of mucus, and the skin of the nostrils is treated with 70% alcohol. After that, the material is taken alternately from each nostril. To do this, a sterile cotton swab is inserted into the nasal passage, and tightly pressed against its walls, the instrument is turned. The swab must also be quickly placed in a special tube and sent for microbiological and microscopic examination.

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Procedure capabilities

With the help of a swab from the throat and nose, the following pathogenic flora can be detected:

Hemolytic streptococcus, which is the cause of most diseases. It can cause pneumonia, tonsillitis, pharyngitis, scarlet fever and other pathologies.
Staphylococcus aureus. It can not only cause inflammation in the nasopharynx, but also cause systemic lesions. It is usually activated as a result of a decrease in immunity and contributes to the development of diseases of the genitourinary system, skin, digestive tract, bone tissue damage, otitis media, tonsillitis and sinusitis.
Leffler wand. It is the causative agent of diphtheria. A swab from the throat is also able to determine the degree of its toxicity to the patient's body.
Eosinophils. These cells are released as a result of allergic reactions and indicate the non-infectious nature of the inflammation.

The presence in the smear of Candida fungi (in small quantities), epidermal staphylococci, non-pathogenic pneumococci, Neisseria, viridescent streptococci, herpes simplex virus is considered the norm.

Deciphering the results

The results of the analysis are written out on a special form, then the response of the throat swab is deciphered. The name of the microorganism consists of two Latin words (they denote the genus and species of the pathogenic microbe). Opposite it, in the corresponding column, the number of bacterial cells is indicated, which is expressed in special colony-forming units - CFU / ml. This indicator is calculated as follows:

1. The collected material (pharyngeal swab) is delivered to the laboratory, where nutrient media are preliminarily prepared (they are intended for bacterial growth).
2. Next, a cotton-gauze swab is carried out over the surface of these media and left in a thermostat. This allows you to start the process of bacterial growth, which subsequently form whole colonies that look like spots of various shapes and sizes.
3. After that, the bacteriologist counts their number. If the indicator of the content of opportunistic microbes does not exceed 104 CFU / ml, this indicates that the mucous membrane of the patient's nasopharynx is normal. If the result of the analysis exceeded the value of 104, then there is a rapid growth of bacteria, and, consequently, the balance between pathogenic and beneficial bacteria is disturbed. All this leads to the development of the disease.

In the case when the definition of "confluent growth" is written in the results instead of the CFU indicator, it means that a large number of bacilli were found that form colonies as a result of confluence. It is impossible to accurately calculate their number.

The general results of the analyzes are summarized in a special form and have the following options:

Positive result. He speaks of the growth of pathogenic and opportunistic microbes that can cause such inflammatory and infectious diseases as diphtheria, acute pharyngitis, whooping cough and others. If there is an increase in the fungal flora, candidiasis develops in the oral cavity.
Negative result. There are no fungal or bacterial pathogens in the smear. Therefore, viruses are the cause of the disease, not fungus or bacteria.

In the case of passing a smear for flora and sensitivity to antibiotics, an antibiogram is attached to the results, which is a table or list with the names of drugs. Opposite each of them is a certain number of "+" signs, meaning the following:

one sign "+" indicates the low sensitivity of the pathogenic microbe to this antibiotic;
two "+" signs - average sensitivity;
three "+" signs - high sensitivity.

The higher the sensitivity, the more effective the antibiotic on this microorganism. A dash is placed in front of those antibiotics that are completely ineffective against the pathogen in question, and, therefore, their use is inappropriate. Based on the antibiogram, the most appropriate drug is selected and the necessary therapy is prescribed.

Usually, the doctor who prescribed this analysis is responsible for deciphering the results.

Conclusion

A swab from the pharynx and nose for flora is a quick and absolutely painless diagnostic method, which at the same time is able to detect the presence of pathogenic microbes and pathogens. It allows the doctor to get a complete picture of the pathological process and prescribe effective treatment.

A swab from the throat is taken for a standard bacteriological study to study the microbial composition and the quantitative ratio of the microflora of the nasopharynx. This is a laboratory diagnostic method that allows you to identify pathogens of infectious and inflammatory diseases of the upper respiratory tract. To determine the etiology of infection, it is necessary to conduct a bacteriological examination of the discharged nose and throat for microflora.

Specialists refer patients with chronic, and to the microbiological laboratory, where biomaterial is taken from the nose and throat with a sterile cotton swab and examined. Based on the results of the analysis, the specialist determines the causative agent of the pathology and its sensitivity to antibiotics.

Reasons and goals for taking a smear on the microflora from the throat and nose:

Diagnosis caused by beta-hemolytic streptococcus and leading to the development of severe complications - glomerulonephritis, rheumatism, myocarditis.
The presence of Staphylococcus aureus in the nasopharynx, which provokes the formation of boils on the skin.
Bacteriological culture of clinical material in case of inflammation of the nasopharynx is carried out in order to exclude diphtheria infection.
Suspicion of meningococcal or pertussis infection, as well as respiratory ailments.
Diagnosis of stenotic, abscesses located near the tonsils, includes a single analysis.
Persons in contact with an infectious patient, as well as children entering a kindergarten or school, undergo a preventive examination in order to detect bacterial carriage.
A complete examination of pregnant women includes taking a swab from the pharynx for microflora.
A prophylactic swab from the throat and nose for staphylococcus aureus is taken by all medical workers, kindergarten teachers, cooks and grocery store sellers.
A swab from the throat to determine the cellular composition of the discharge. The studied material is applied to a special glass slide. Under a microscope, a laboratory assistant counts the number of eosinophils and other cells in the field of view. A study is underway to determine the allergic nature of the disease.

Patients are sent to the bacteriological laboratory to study the material from the nasopharynx in order to exclude or confirm a specific infection. In the direction indicate the microorganism, the presence of which must be confirmed or refuted.

Microflora of the nasopharynx

On the mucous membrane of the pharynx and nose, there are many microorganisms that make up the normal microflora of the nasopharynx. A study of the discharge of the throat and nose shows the qualitative and quantitative ratio of microbes living in this locus.

Types of microorganisms living on the nasopharyngeal mucosa in healthy people:

bacteroids,
veillonella,
Escherichia coli,
branhamella,
pseudomonas,
Streptococcus matans,
Neisseria meningitides,
Klebsiella pneumonia,
epidermal staphylococcus,
green streptococcus,
Non-disease-causing Neisseria
diphtheroids,
corynebacterium,
Candida spp.,
Haemophilis spp.,
Actinomyces spp.

With pathology in a smear from the pharynx and nose, the following microorganisms can be detected:

Beta-hemolytic group A,
S. aureus
Listeria,
Branhamella catarrhalis,
Acinetobacter baumannii,

Preparation for analysis

In order for the results of the analysis to be as reliable as possible, it is necessary to correctly select clinical material. For this you need to be prepared.

Two weeks before the material is taken, systemic antibiotics are stopped, and 5-7 days before, it is recommended to stop using antibacterial solutions, rinses, sprays and ointments for topical use. The analysis should be taken on an empty stomach. Before this, it is forbidden to brush your teeth, drink water and chew gum. Otherwise, the result of the analysis may be false.

A swab from the nose for eosinophils is also taken on an empty stomach. If a person has eaten, you must wait at least two hours.

Taking material

To properly take the material from the pharynx, patients tilt their heads back and open their mouths wide. Specially trained laboratory staff presses the tongue with a spatula and collects the pharyngeal discharge with a special tool - a sterile cotton swab. Then he removes it from the oral cavity and lowers it into a test tube. The tube contains a special solution that prevents the death of microbes during the transportation of the material. The tube must be delivered to the laboratory within two hours from the moment the material was taken. Taking a swab from the throat is a painless procedure, but unpleasant. Touching a cotton swab to the pharyngeal mucosa can provoke vomiting.

To take a swab from the nose, it is necessary to seat the patient opposite and tilt his head slightly. Before analysis, it is necessary to clear the nose of the existing mucus. The skin of the nostrils is treated with 70% alcohol. A sterile swab is introduced alternately first into one and then into the other nasal passage, turning the instrument and firmly touching its walls. The swab is quickly lowered into the test tube and the material is sent for microscopic and microbiological examination.

microscopic examination

The test material is applied to a glass slide, fixed in a burner flame, stained according to Gram and studied under a microscope with immersion oil. Gram-negative or gram-positive rods, cocci or coccobacilli are found in the smear, their morphological and tinctorial properties are studied.

Microscopic signs of bacteria are an important diagnostic landmark. If the smear contains gram-positive cocci located in clusters resembling grapes, it is assumed that the causative agent of the pathology is staphylococcus aureus. If the cocci are positively Gram-stained and arranged in chains or pairs in the smear, these are probably streptococci; Gram-negative cocci - Neisseria; Gram-negative rods with rounded ends and a light capsule - Klebsiella, small Gram-negative rods - Escherichia,. Further microbiological research is continued taking into account microscopic signs.

Seeding of the test material

Each microorganism grows in its "native" environment, taking into account pH and humidity. The environments are differential-diagnostic, selective, universal. Their main purpose is to provide nutrition, respiration, growth and reproduction of bacterial cells.

Inoculation of the test material must be carried out in a sterile box or laminar flow cabinet. The health worker must be dressed in sterile clothes, gloves, a mask and shoe covers. This is necessary to maintain sterility in the work area. In boxing, one should work silently, carefully, ensuring personal safety, since any biological material is considered suspicious and obviously infectious.

A smear from the nasopharynx is inoculated on nutrient media and incubated in a thermostat. After a few days, colonies grow on the media, having a different shape, size and color.

There are special nutrient media that are selective for a particular microorganism.

The material is rubbed with a swab into the medium on a small area measuring 2 square meters. see, and then with the help of a bacteriological loop, they are sown with strokes over the entire surface of the Petri dish. Crops are incubated in a thermostat at a certain temperature. The next day, the crops are viewed, the number of grown colonies is taken into account and their character is described. Subculture individual colonies on selective nutrient media to isolate and accumulate a pure culture. Microscopic examination of a pure culture makes it possible to determine the size and shape of the bacterium, the presence of a capsule, flagella, spores, and the ratio of the microbe to staining. The isolated microorganisms are identified to the genus and species, if necessary, phage typing and serotyping are carried out.

Research result

The result of the study, microbiologists write out on a special form. To decipher the result of a swab from the throat, the values \u200b\u200bof the indicators are required. The name of the microorganism consists of two Latin words denoting the genus and species of the microbe. Next to the name indicate the number of bacterial cells, expressed in special colony-forming units. After determining the concentration of the microorganism, they proceed to the designation of its pathogenicity - “conditionally pathogenic flora”.

In healthy people, bacteria that perform a protective function live on the mucous membrane of the nasopharynx. They do not cause discomfort and do not cause the development of inflammation. Under the influence of unfavorable endogenous and exogenous factors, the number of these microorganisms increases dramatically, which leads to the development of pathology.

Normally, the content of saprophytic and conditionally pathogenic microbes in the nasopharynx should not exceed 10 3 - 10 4 CFU / ml, and pathogenic bacteria should be absent. Only a doctor with special skills and knowledge can determine the pathogenicity of a microbe and decipher the analysis. The doctor will determine the appropriateness and necessity of prescribing anti-inflammatory and antibacterial drugs to the patient.

After identifying the causative agent of pathology and its identification to the genus and species, they proceed to determine its sensitivity to phages, antibiotics and antimicrobials. It is necessary to treat a disease of the throat or nose with the antibiotic to which the identified microbe is most sensitive.

throat swab results

Variants of the results of the study of a smear from the pharynx:

Negative culture result- There are no causative agents of bacterial or fungal infection. In this case, the cause of the pathology is viruses, not bacteria or fungi.
Positive microflora culture result- there is an increase in pathogenic or opportunistic bacteria that can cause acute pharyngitis, diphtheria, whooping cough and other bacterial infections. With the growth of fungal flora, oral candidiasis develops, the causative agent of which is biological agents of the 3rd pathogenicity group - yeast-like fungi of the genus Candida.

Microbiological examination of the separated pharynx and nose on the flora allows you to determine the type of microbes and their quantitative ratio. All pathogenic and opportunistic microorganisms are subject to full identification. The result of laboratory diagnostics allows the doctor to prescribe the right treatment.

A swab from the throat for microflora is prescribed for many patients who suffer from a prolonged runny nose or have other symptoms of viral infections.

Thanks to this simple study, it is possible to study the flora of the mucous membrane and identify the causative agent of the pathology. This makes it possible to choose the right therapy.

This diagnostic method is used in such situations:

Thus, a swab from the throat and nose is carried out in two main situations: to determine the carriage of harmful microorganisms and to detect the causative agent of the disease.

Training

In order for a swab for flora and sensitivity to antibiotics to give a reliable result, it is important to follow a number of recommendations. This study needs some preparation. So, before passing the analysis, you should:

Antiseptics for the oral cavity are contraindicated because they help to kill most of the microbes present on the mucous membranes. As a result, the study will not help determine the true number of microorganisms and identify the bacteria that provoked the disease.

The use of drinks and food, as well as the use of toothpaste, will provoke the washing off of some of the microorganisms. This will also distort the results. On the day of the study, it is advisable to completely refuse food and drinks. It is better to exclude even a morning cup of coffee or a glass of water.

Features of the study

The procedure is completely painless. It does not lead to negative health effects. To conduct research, perform the following steps:

An adult needs to open his mouth wide. If the procedure is performed on a young child, the health care provider will need parental assistance.
The end of the tongue is pressed with a spatula, and with the other hand, by means of a loop with a cotton-gauze tip, the mucous secretions are carefully removed from the arches, pharyngeal walls, and tonsils. The material should be taken so that the device does not touch the teeth, cheeks or tongue.
Then the instrument must be immediately placed in a sterile container. The resulting analysis must be sent for research within 2 hours. If this is not possible, the material is immediately placed in a container containing a preservative.

microscopic examination

Tank sowing from the pharynx involves applying the resulting material to a glass slide. It is fixed with a burner, a study is carried out using immersion oil. Gram staining is also often performed. As a result of the procedure, it is possible to identify pathogenic bacilli, coccal flora, coccobacilli. Specialists examine their morphological characteristics.

Microscopic signs of bacterial microorganisms are an important diagnostic criterion. If there are gram-positive cocci in the material, which are located in clusters similar to grapes, it can be suspected that staphylococci are the causative agent of the disease.

If coci stain positively for Gram and form pairs or chains, streptococci are most likely the cause of the pathology. Neisseria are classified as gram-negative coccal flora. If the material contains gram-negative rods with a light capsule and round ends, we are talking about Klebsiella. Escherichia are small Gram-negative rods. This group also includes Pseudomonas aeruginosa.

Sowing material

To identify infectious agents, the material is placed in a special environment, taking into account pH and humidity. Environments can be different - universal, selective. Differential diagnostic environments are also distinguished. In any case, their key task is to ensure life and create conditions for the reproduction of bacteria.

The material is sown in a sterile box. A laminar flow cabinet can also be used for this purpose. The laboratory assistant must wear sterile clothing. Equally important is the use of shoe covers, masks, gloves. Due to this, it is possible to maintain the desired indicators of sterility in the working area.

Care must be taken when working in the box. It is very important to monitor your own safety, as any biomaterials can pose a threat to the health of a healthcare worker.

Materials from the nasopharynx are placed in a special environment in a thermostat. After a few days, whole colonies grow. They may vary in size, shape and shade.

There are special media that are selective for certain microorganisms:

Blood agar is considered the main medium for microbes from the nose and throat. It is highly sensitive and includes nutrients for saprophytes and harmful microorganisms. Pneumococci and staphylococci produce hemolysins and lead to hemolysis of red blood cells. The hemolytic activity of bacteria is considered to be the main factor of pathogenicity. It is typical for most pathogenic microorganisms. Features of growth, shade and area of hemolysis differ depending on the variety of microbes.
Universal options include thioglycol medium and Sabouraud. They are suitable for most harmful bacteria.
For staphylococci, yolk-salt agar is used.
The non-selective medium is warm blood agar. It develops gonococci, bacteria that cause purulent meningitis, and Haemophilus influenzae.
The differential option for growing enterobacteria is Endo medium.
Enterococci develop well in enterococci.

By means of a swab, the material is placed into the medium, after which it is distributed over the Petri dish using a bacteriological loop. Then the crops are sent to the thermostat, selecting the desired temperature. The next day they are viewed, the number of colonies is determined and their character is assessed.

Some colonies are placed in certain media to identify and accumulate pure culture. Thanks to its study under a microscope, it is possible to assess the size and shape of bacteria, to identify the presence of spores, bundles or capsules. Also, experts determine the ratio of bacteria to staining.

It is important to determine the genus and species of isolated bacteria. In addition, the specialist conducts phage typing and serotyping.

Data interpretation

In a normal state, a lot of various microorganisms are present in the pharynx of each person. Some are a variant of the norm, while others are dangerous to health. Sometimes a certain amount of harmful bacteria does not provoke any consequences. Such flora is called conditionally pathogenic. Valid options include:

candidal fungi;
epidermal staphylococci;
herpetic infection;
pneumococci.

Deciphering the analysis allows you to identify the following microorganisms:

Staphylococcus aureus. It can provoke various inflammations. At the same time, such processes affect not only the pharynx, but also lead to systemic pathologies. When the immune system is weakened, bacteria become active and provoke pathologies such as otitis media, diseases of the urinary system, sinusitis, and purulent skin lesions. Often, Staphylococcus aureus causes diseases of the bone tissue and digestive organs.
Hemolytic streptococcus. This bacterium often provokes tonsillitis. Also, its active reproduction causes complex forms of pharyngitis with a large amount of purulent secretion and scarlet fever.
Leffler wand. This microorganism is the causative agent of diphtheria. With the help of the study, it is possible to determine the degree of toxic effect of bacteria on the body.

An increase in the number of fungi also indicates certain disorders in the body, since it is a sign of a weakened immune system. Sometimes a throat swab can detect eosinophils. These cells appear with allergies, so you can suspect the non-infectious nature of the pathology.

A throat swab is considered an informative diagnostic study. Thanks to its implementation, it is possible to detect pathogenic microorganisms and determine their susceptibility to antibiotics. This allows the doctor to choose the appropriate therapy.