Helicobacter pylori antigen is negative. Stool antigen test no. In what situations is it prescribed

The classification of methods for detecting Helicobacter pylori infection is presented in the table.

Invasive methods require an endoscopic examination (FEGDS) with a biopsy and further study of gastrobiopsy samples. Non-invasive methods of endoscopic examination do not require.

Histological method

The histological method for studying gastric biopsy samples is microscopy of gastrobiopsy smears stained in various ways (hematoxylin-eosin, Giemsa, toluidine blue, Warthin-Starry). This method allows you to determine the severity of inflammation of the coolant, the presence of atrophy, intestinal metaplasia and the presence (degree of contamination) of HP.

Rapid urease test (Helpil test)

Rapid urease test (Helpil test) - determination of HP by the urease activity of a microorganism in biopsy specimens of the coolant. Helicobacter pylori produces urease, under the influence of which urea is hydrolyzed to form ammonium ion. At the same time, the pH of the medium increases, which can be recorded by changing the color of the indicator. Gastrobioptates are placed in a solution containing urea and an indicator, the color change of which indirectly indicates the presence of HP.

Molecular genetic method - PCR in biopsy specimen

The molecular genetic method for studying gastric biopsy specimens using PCR makes it possible to isolate highly pathogenic and low-pathogenic HP strains.

Bacteriological method

It is important to carry out a bacteriological method for studying biopsy specimens of the gastric mucosa: cultural examination and determination of the sensitivity of HP to antibiotics before first-line therapy in regions with high resistance to clarithromycin (more than 15-20%), if it is planned to use standard three-component eradication therapy, one of the components of which is clarithromycin. A bacteriological method with determination of sensitivity to antibiotics should also be used if second-line eradication therapy is ineffective.

Examination of stool for the presence of HP antigen (ELISA)

ELISA (especially using monoclonal antibodies) for detecting the HP antigen in feces is a highly sensitive and specific method for both the primary diagnosis of HP infection and for monitoring the outcome of treatment.

Serological method

The serological method (ELISA) - determination of IgG antibodies to HP in blood serum - is a simple and accessible method for primary screening of infection. Considering that antibodies to HP persist for many months after eradication of the microorganism, the use of a serological method is not recommended for assessing the effectiveness of eradication therapy.

Urease breath test with 13C-urea

Urease breath test is a study of the composition of exhaled air after taking a solution of urea labeled with a carbon isotope (13C). If HP is present in the stomach of the subject, urea, under the influence of urease produced by the bacterium, undergoes hydrolysis to Nh5+ and HCO3-, followed by the formation of carbon dioxide from HCO3-, which, entering the bloodstream, is then released through the lungs and can be determined by a spectrometer in the exhaled air. This test can be used both for the primary diagnosis of HP and for assessing the effectiveness of eradication.

Against the background of Helicobacter pylori infection, inflammatory diseases of the gastrointestinal tract develop, such as gastric or duodenal ulcers, erosive gastritis, and gastroduodenitis.

Norms

• Histological method for examining biopsy specimens of the coolant - normally, pathological changes are not detected.
• Rapid urease test (Helpil test) - normally the test is negative.
• A molecular genetic method for studying biopsy specimens of the gastric mucosa using PCR - normally the result is negative.
• A bacteriological method for examining biopsy specimens of the coolant - normally the result is negative.
• ELISA (especially with the use of monoclonal antibodies) to detect the HP antigen in stool - the result is normally negative.
• Serological method (ELISA) - normally the result is negative.
• Urease breath test - normally the test is negative.

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Helicobacter pylori (helicobacteriosis), antigen, feces

Helicobacter pylori antigen, stool

Description of the study

Helicobacter pylori is a spiral-shaped bacterium that attacks the wall of the stomach and duodenum, causing atrophic gastritis, peptic ulcers and malignancies. About 50-60% of the population is infected with Helicobacter pylori, infection usually occurs in childhood. Thanks to its form, Helicobacter pylori can damage the protective layer of the gastric mucosa. The bacterium produces the enzyme urease, which is capable of neutralizing hydrochloric acid in the stomach. Thus, the stomach wall becomes susceptible to the damaging effects of hydrochloric acid and pepsin, which leads to gastric or duodenal ulcers. Helicobacter pylori can act directly on the cells of the stomach, weakening the protective mechanism and causing inflammation of the mucosa. Helicobacter pylori is capable of increasing the secretion of hydrochloric acid in the stomach, although the mechanism of this process has not been studied. The route of transmission of infection is oral-fecal and household. Infection usually occurs from person to person through close contact (kissing). The source of infection can be saliva or water. Often the infection can occur latently, without causing any symptoms. Duodenal ulcer is associated with Helicobacter pylori in almost 100% of cases. Antibacterial therapy, which is aimed at destroying bacteria, leads to a complete cure for peptic ulcer. Helicobacter pylori is found in 90% of people suffering from gastric ulcer. Antibacterial treatment leads to scarring of the ulcer in 70-90% of cases. A severe disease of the stomach - adenocarcinoma - in 70-90% of cases is caused by infection with Helicobacter pylori. The antigen of the bacterium can be detected in the stool of an infected person with Helicobacter pylori. A week after symptoms of active infection appear, the number of bacteria in the feces decreases, which reduces the diagnostic value of the method. The absence of antigen to Helicobacter 4 weeks after therapy indicates the eradication of Helicobacter pylori.

This analysis allows you to determine the antigen of Helicobacter pylori, the causative agent of diseases of the stomach and duodenum. The analysis allows you to diagnose Helicobacter pylori infection.

Enzyme immunoassay - ELISA

Information regarding the reference values ​​of indicators, as well as the composition of the indicators included in the analysis, may differ slightly depending on the laboratory!

Normally, the test result is negative, that is, Helicobacter pylori antigen is not detected.

• Diagnosis of Helicobacter pylori
• Evaluation of the effectiveness of anti-Helicobacter therapy

• Helicobacter pylori infection

• No Helicobacter pylori infection.
• If clinical manifestations of diseases associated with Helicobacter pylori persist, it is recommended to repeat the analysis after 2 weeks.

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Diagnosis of chronic gastritis type B (GP)

GASTRITIS - inflammation of the gastric mucosa, accompanied by dystrophic and necrotic changes.

Causes: poor quality and diet, chemicals and drugs, infection, and above all, Helicobacter pylori (HP). In this case, lymphocyte-plasma cell infiltration of the mucous membrane is noted. In the initial stages, the process involves only the antrum of the stomach, which preserves its basic functions. Subsequently, disturbances in the regeneration and differentiation of epithelial cells occur, which leads to atrophy of the mucous membranes and a decrease in the secretory function of the stomach.

(SEE BOTTOM OF PAGE FOR DIAGNOSIS OF CHRONIC GASTRITIS)

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Diagnosis of the disease

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Additional studies to help clarify the diagnosis

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Main symptoms: chronic gastritis can be asymptomatic, the most typical are pain in the upper abdomen and an ulcer-like syndrome (hungry epigastric pain, nausea, feeling of fullness in the stomach, anxiety, depression). Often chronic gastritis B develops into peptic ulcer of the stomach and duodenum. HP, forming ammonia from urea, constantly alkalizes the antrum of the stomach, which leads to hypersecretion of gastrin and hyperproduction of hydrochloric acid, which affects the gastric mucosa, leading to the formation of erosions and ulcers. At the same time, HP releases special toxic substances that damage the mucous membrane stomach. The double damaging effect causes stimulation of the immune system, depleting the lymphocytic and phagocytic components of the immune system. Increased aggression combined with decreased mucosal protection leads to chronic gastritis and peptic ulcers, as well as gastric cancer and lymphoma. Gastroscopy as a diagnostic technique followed by examination of a biopsy to identify HP may not be reliable due to the difficulties of accurately reaching the site of infection in the altered mucous membrane. Therefore, at present, modern diagnosis of chronic gastritis B is carried out with mandatory immunological laboratory testing of the infectious agent, i.e. detection of HP antigen in feces, antibodies to HP in blood serum, as well as disorders of systemic and local immunity (immunogram and secretory IgA). In addition, changes in intestinal microflora also play a diagnostic role.

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How to do a stool test for Helicobacter

The bacterium Helicobacter pylori lives in the cells of the mucous tissues of the stomach and duodenum. Some varieties of this “inhabitant” of the gastrointestinal tract, under certain circumstances, are capable of destroying healthy cells of the human body and causing diseases. This bacterium is the most common cause of gastritis, daudenitis and enterocolitis. Correct treatment of such ailments depends on accurately identifying the “culprit.” To determine the presence and amount of Helicobacter in the body, several methods are used, one of which is stool analysis or, in medical language, a coprogram.

Types and mechanisms of research

A stool test is the most non-traumatic test option for the patient, in contrast to blood sampling or a biopsy. That is why it is so common in the diagnosis of not only Helicobacter pylori infection, but also other diseases affecting the gastrointestinal tract. It is preferable to conduct a direct stool test for Helicobacter, since it directly identifies the bacterium itself or its DNA, and indirect methods are not so reliable.

There are three types of direct stool examination:

1. Cultural analysis.
2. Immunological analysis.

Each of them has its own characteristics, norm criteria and disadvantages.

PCR

The polymerase chain reaction (PCR) method is a molecular genetic diagnostic method and guarantees maximum information content of the analysis. The essence of such research is to identify the DNA of a certain pathogenic organism, repeatedly increase its number and subsequent identification of the species.

In order for such an analysis to be as reliable as possible, several preparation conditions must be met:

• do not use antibacterial drugs and other medications with similar effects at least 3 days before donating biological material;
• Also, 3-4 days before the study, you should not use rectal suppositories, laxatives and other drugs that affect gastrointestinal motility;
• during the same period of time before taking the test, you should not take medications or food products that can change the color of stool (iron supplements, beets, etc.);
• the container for biological material must be sterile, and it is advisable to deliver it to the laboratory as quickly as possible.

On average, the result of a PCR test will be ready after 24 hours.

Cultural analysis

This option refers to microbiological research methods and consists of the following: the biological material taken is placed in a special environment that is favorable for the growth of certain microorganisms. After a certain period of time, which for Helicobacter pylori is 7 days or more, the grown culture is carefully examined under a microscope. To determine the most likely type of microorganism, scientists use additional methods: they stain the culture with special dyes, conduct studies on interaction with other substances, and study the ability of the identified bacteria to enter into one or another biochemical reaction.

Cultural analysis allows not only to determine the Helicobacter pylori antigen, but also to find out which antibacterial drugs this bacterium is sensitive to. This circumstance becomes extremely important in the case of long-term treatment of Helicobacter pylori infection and its immunity to previously prescribed drugs. However, to the great regret of doctors, the results of sensitivity to certain antibiotics do not always coincide with reality, and those medications that “worked” in a test tube turn out to be useless or insufficiently effective in life.

Immunological analysis

This test option is based on the ability of antibodies to bind to antigens. To do this, special labels are applied to the selected antibodies, which, sticking together with Helicobacter antigens, form entire complexes. Based on their number, a conclusion is drawn about the results of the analysis.

The peculiarity of this study is the risk of obtaining a false result in the analysis, the biological material for which was taken after eradication. The test may be false positive because bacteria may still be found in the stool.

Immunological analysis is usually prescribed before instrumental examination methods, if the clinical picture corresponds to Helicobacter pylori infection and there are characteristic symptoms. If a false positive or false negative result is suspected, additional tests are performed in other ways.

The role of PCR analysis in the correct treatment of disease associated with Helicobacter Pylori

Unfortunately, the widespread use of antibacterial drugs is widespread in our country. This leads to an increase in the number of microorganisms that are resistant to even the most modern medications, which threatens human health and life in case of serious illnesses that require intensive antibiotic therapy. This also applies to the treatment of Helicobacter pylori infection, because not all strains of this bacterium are dangerous and not all require immediate “expulsion”.

PCR analysis allows not only to reliably identify the bacterium, but also to determine its strain, which radically affects treatment tactics and the need for therapy in general.

Advantages of this research method:

• non-invasiveness and ease of collection of biological material;
• high sensitivity, which reduces the risk of obtaining a false result to a minimum;
• maximum information content;
• safety;
• the ability to identify different types and strains of Helicobacter.

That is why specialists are increasingly resorting to the polymerase chain reaction method. However, this analysis also has disadvantages, and one of the most important is the rather high cost, especially if genotyping is necessary.

Analysis of stool for Helicobacter pylori antigen can be carried out in different ways and complemented by other research methods, both laboratory and instrumental. The choice of a specific option is the prerogative of the doctor, who will also tell you how to correctly submit biological material, evaluate the results of the study and, in accordance with them, select adequate therapy.

Problems in the gastrointestinal tract cause discomfort and interfere with living a normal life. Painful spasms, nausea, heaviness, belching - symptoms that destroy any plans that unsettle you. The culprit of the manifestations is the bacterium Helicobacter pylori, which can infect the mucous membrane of internal organs.

Compared to similar bacteria, Helicobacter pylori feels comfortable in an acidic environment. Therefore, the stomach is her favorite place to stay. Rotating flagella and a spiral shape allow the elements to move through the thick mucous membrane.

Under unfavorable conditions, bacteria take the shape of a circle and subside in the body.

Stool analysis for Helicobacter is carried out using the following methods: PCR, cultural, immunological. PCR accuracy is up to 95%. This is the simplest type of diagnosis, recommended for children, seriously ill patients, and the elderly.

PCR analysis

Provoking factors

100% indication for analysis is stomach and duodenal ulcers. In addition, similar diagnostics are prescribed in the following cases:

• oncology;
• lymphoma of the stomach;
• atrophic, Helicobacter gastritis;
• dysplasia of part of the digestive tract;
• history of stomach cancer (first line);
• Ménétrier's disease;
• dyspepsia longer than 6 months;
• long-term use of proton pump inhibitors;
• blood diseases.

Symptoms of Helicobacter pylori infection

Signs of the presence of bacteria may not appear immediately. The development of the disease is facilitated by factors such as:

• unbalanced diet;
• stressful situations;
• low immunity.

Infection occurs through food, liquid, and contact with a patient (sneezing, coughing). If Helicobacter pylori is activated, then the person feels nausea, heartburn, poor appetite, heaviness after eating, and an unpleasant odor from the mouth.

One of the signs of Helicobacter infection is bad breath.

The symptoms are similar to gastritis, so to detect pylori it is important to undergo an examination and tests.

Preparing to submit material

30 days before the study, it is undesirable to drink synthetic drugs and medications that stimulate contraction of the stomach walls. In addition, 3 days before collecting the material, it is recommended not to eat coloring foods (red wine, beets, black currants).

Also, you should not eat carrots, cabbage, bran, as they contain coarse fiber.

Feces are collected in a special container for analysis. It can be purchased at a pharmacy. Feces should fill a third of the container, this will be enough for research. Do not take stool from the toilet as it may contain disinfectants.

The excrement should be delivered to the laboratory as quickly as possible (within the next two hours). They can be stored for up to 12 hours at temperatures from -8°C to +2°C.

Culture method

The spiral-shaped bacterium is almost never found in feces. Feces are an unsuitable environment for harmful microbes. Once in the large intestine, pylori takes the shape of a circle. In feces it is rarely observed in this form.

Cultural type of research - sowing stool on a comfortable environment for further propagation of Helicobacter pylori. Next, the colonies grow, are studied by laboratory assistants, stained with chemicals and sent for examination under a microscope. Such manipulations make it possible to grow pathogenic microorganisms and analyze them.

In addition to detecting pylori, the method is able to determine the sensitivity of the infection to a specific drug. If during the research process an antibacterial agent is added to the bacterium and the growth of the colonies remains the same, then we can talk about resistance. When microorganisms die, it makes sense to prescribe this medication to a person for treatment.

The action will be correct if a spiral-shaped Helicobacter pylori is detected. Cultural testing is not popular for reasons such as:

Immunological method

Human stool is examined to detect Helicobacter pylori antibodies. To do this, certain protein compounds are taken that are capable of detecting a foreign antigen. Parts of Helicobacter pylori and its metabolic products may be found.

When interacting with an antigen, the bacteria's antibodies create their own complex. This is precisely what the immunological method determines. Such analysis of microbes is rarely carried out in the Russian Federation, although laboratories are equipped with everything necessary.

PCR

A popular way to detect Helicobacter pylori in excrement. The accuracy is high, so all clinics use almost only it. The analysis process involves isolating a section of bacterial DNA from feces. After this, the selected part is duplicated on a machine that restores the genetic code.

When the required size is reached, the remaining bacteria are compared with the standard and Helicobacter pylori is determined. A positive PCR is a sign of the presence of bacteria in the intestines; parts of the DNA match the original.

Reliability of analyzes

PCR is the most reliable method of recognizing bacteria of the three described. In some cases it is inferior to endoscopy and biopsy. The chain reaction rarely gives a false positive response and has high specificity. In addition, the method makes it possible to study coccal forms of Helicobacter pylori.

On a note! Cultural and immunological methods are less reliable than PCR. The reason is frequent false positive responses. But if they are used in conjunction with similar studies, they will be a good help in establishing a diagnosis.

Decoding

If stool is tested using the chain reaction method, the result will be negative or positive. Accordingly, in the first case, no bacteria will be detected in the feces, while in the second case, a specific molecule, Helicobacter pylori, will be detected.

Analysis for inoculation of biomaterial involves assessing the quality and quantity of microorganisms in a specific environment.

Bacterial growth has 4 stages

1. Suitable, watery medium. Slight microbial growth. Solid medium - no organisms in sight.
2. A certain type of bacteria can disperse up to ten colonies.
3. Solid medium. Significant growth of pylori.
4. The growth of bacteria creates more than a hundred colonies.

Grades 3 and 4 indicate inflammation caused by a certain bacterium.

If Helicobacter pylori is found in the stool, this does not mean that there is an ulcer or similar diseases. Only the presence of the pathogen is determined. When the gastric mucosa is abundantly colonized by Helicobacter pylori, we can talk about gastritis, peptic ulcer, pancreatitis.

After indicating the degree, infestation is written, denoted by pluses:

• + the number of bacteria is less than 20 in the field of view;
• ++ no more than 50;
• +++ show more than 50 bacteria.

Table. Degree of infection

The test results are influenced by many factors, including preparation for the study, storage time of the material before sending it to the laboratory. To get the most reliable answer, it is important to follow all the doctor’s instructions and recommendations.

Video - Stool analysis for Helicobacter

In 2005, Australian scientists Robin Warren and Barry Marshall refuted the doctrine of the role of poor nutrition, hyperacidity, heredity and chronic stress in the origin of gastritis and peptic ulcers. They were able to prove that often a variety of stomach problems have a specific culprit - the bacterium Helicobacter pylori.

The bacterium easily adapts to an aggressive environment. In some cases, the immune system copes with infection; if not, the doctor diagnoses “gastritis” or “ulcer”. In 1994, WHO even recognized the connection between the bacterium and cancer of the digestive system, so the presence of Helicobacter pylori in the body is a reason to undergo complex therapy. But how to get tested for Helicobacter pylori, where?

Prevalence of Helicobacter pylori

It is believed that almost 70% of the world's population is infected with Helicobacter. Many people carry the bacteria without knowing it and pass it on to healthy people. Helicobacter pylori can indeed hide in the body for years and begin its “subversive” activities in extremely favorable circumstances: with chronic stress and fatigue, exhaustion of the body, decreased immunity, concomitant diseases, unhealthy diet and unhealthy lifestyle.

As for Russia, registered cases of infection in Moscow alone amount to 60% of the total population of the capital. And this is one of the most developed cities in Russia. Doctors say that in different regions the prevalence of the bacterium reaches 70-90%, which is much higher than in Europe or the United States. This high prevalence is explained by the relatively low standard of living of the majority of the population, neglect of hygiene standards and living in unsanitary conditions.

Indications for diagnosis

Doctors recommend regularly taking basic tests in order to detect and treat disorders in a timely manner. But not everyone does this. As a rule, we only go to the hospital if we are already sick. This is what happens with Helicobacter pylori.

It is imperative to turn to diagnostic methods for bacteria in the body as soon as possible if you have the following symptoms:

1. Periodic abdominal pain, usually during or after eating. This is due to stagnation and problems with digestion due to low enzyme levels.
2. Painful sensations on an empty stomach, which subside when eating. In this case, you can feel how food goes down the esophagus, and if you drink a glass of water, you can feel how the water flows - this sensation appears more clearly and indicates that there are damaged places on the walls.
3. The appearance or increase in heartburn. Single heartburn (thrust of gastric juice into the esophagus with irritation of its walls) is a normal variant, but repeated heartburn requires consultation with a doctor and testing.
4. Feeling of heaviness even after eating a small amount of food. In this case, the person feels as if the food has stood up and is not digested, “staying in the throat.”
5. Frequent nausea and periodic vomiting that is not caused by other reasons (for example, toxicosis in early pregnancy).
6. Constant discomfort in the stomach, aching pain, slight heaviness, loss of appetite. If symptoms appear, but then quickly pass, this may indicate the initial stage of the adverse effects of Helicobacter pylori on the mucous membrane.
7. Blood and other unusual impurities in the stool. If an adult can determine what hurts, then in the case of children everything is not so simple. That is why you need to pay attention to the baby’s stool, his general condition and movements.
8. Frequently recurring diarrhea, constipation, defecation disorders.
9. Increased flatulence and rumbling in the stomach.

All of the above signs do not indicate one hundred percent presence of infection in the body. Such symptoms, both in combination and individually, may indicate the presence of a completely different problem, or even be a variant of the norm in a particular case.

Diagnostic methods for Helicobacter pylori

What test should I take for Helicobacter pylori? There are several methods for diagnosing bacteria, which differ in accuracy, the need for preparation, processing time for results, and so on. The first thing the doctor will do is take a medical history. The patient will be asked about symptoms, diet and nutrition, concomitant diseases, medical history, pathologies that close relatives have and can be inherited. Only then will the doctor give a direction for a certain type of analysis.

The presence of harmful bacteria in the body can be detected in various ways. If Helicobacter pylori is suspected, the following tests may be prescribed:

1. Laboratory blood test for the presence of antibodies to Helicobacter pylori. If antibodies are detected, it means that the body recognizes the bacterium.
2. Stool antigen test. The stool test is aimed at identifying the genetic material of the pathogen in the stool.
3. Breath test. A rapid analysis will determine the activity of Helicobacter pylori in the stomach based on the composition of exhaled air.
4. Gastroscopy for Helicobacter.
5. Cytological examination. The method is the most accurate among those listed.

What test should be taken for Helicobacter pylori? To increase the accuracy of diagnosis, it is advisable to take at least two tests. If a bacterium has been identified, then after a course of therapy it is necessary to do a repeat study.

How to get tested for Helicobacter pylori? Preliminary preparation (both the activities themselves and its necessity in principle) depends on the type of research.

Enzyme immunoassay blood test for antibodies

This type of study is prescribed to determine the presence of antibodies to Helicobacter pylori in the patient’s blood. In medical practice, it is generally accepted that antibodies to certain bacteria and infections appear for a reason, but only in case of infection as a response of the body’s immune system.

An enzyme immunoassay can only determine Helicobacter if one to three weeks or more have passed since the infection. If the infection occurred just a few days ago, the test may give a false negative result, since the body has not yet had time to react properly to the appearance of the bacteria.

A false positive result can be given for two reasons:

1. The human factor, i.e. the mistake of a laboratory assistant who mixed up the research material, wrote the conclusion incorrectly, and so on.
2. Recent therapy, during which a person was cured of Helicobacter, but antibodies are still present in the blood. A control test can be carried out no earlier than a month after complex therapy, but even in this case you can get a positive result in the absence of bacteria in the body. In some cases (depending on individual characteristics and some other factors), antibodies remain in the blood for life.

How to take a blood test for Helicobacter pylori? Is advance preparation necessary? On the eve of the study, you should avoid eating excessively fatty foods and drinking alcoholic beverages, and avoid nervous and physical stress. Blood is drawn from a vein in the morning, on an empty stomach. The procedure is painless, but different patients tolerate it differently, so after the analysis it is better to drink sweet tea and eat a piece of dark chocolate.

Where to get a blood test in Moscow

Where can you get tested for Helicobacter pylori in Moscow? First, you can go to a public clinic. A therapist or gastroenterologist, if deemed necessary, will give a referral to a laboratory for testing. Secondly, you can donate blood to identify the bacteria in any private clinic, for example, Invitro or Litech.

In both cases, the results will be ready the next day, however, in private medical centers you can make an additional payment for urgency and receive a specialist’s conclusion within 1-2 hours. The cost of the analysis will be 500-1000 rubles, depending on the pricing policy of the clinic and the urgency of preparing the results. The test can be done free of charge in a public hospital.

Stool antigen test for Helicobacter

The stool test is one of the most patient-friendly methods for diagnosing Helicobacter pylori. Firstly, the study does not require personal presence in the outpatient clinic, and secondly, the material is collected painlessly (non-invasively, that is, without damaging the skin, as when drawing blood), in conditions that are comfortable for the patient. So there is a definite answer to the question of what test to take for Helicobacter pylori, for example, for a child - this is a stool test. This analysis is especially convenient for diagnosing the disease in children, the elderly and seriously ill patients.

However, the effectiveness of stool examination in determining the presence of Helicobacter pylori is insufficient. The number of harmful bacteria, if they exist in the digestive system, decreases when passing through the intestines, and the pathogen is exposed to acids. As a result, the test may give a false negative result. But currently, a special method is used with which specialists can determine even particles of Helicobacter genetic material in feces.

How to take a stool test for Helicobacter pylori? For three days, you must completely stop using suppositories; before collecting the material, you cannot stimulate stool with an enema, castor or other oil. A few days before the analysis, you should exclude from your diet foods rich in fiber, containing a lot of dyes and salts, and you should stop using medications that stimulate intestinal function.

Where to get a stool test for Helicobacter pylori

In Moscow, you can do a stool test to detect Helicobacter in both private medical centers and public clinics. Where to get a stool test (Helicobacter pylori) in the capital if you choose a private clinic? At the service of patients are "OnClinic", MC in Maryino, "Capital Medical Clinic", "Capital" Clinic, "Family MC", "Paracelsus", "Good Doctor", "Medical On Group", "Clinic of Expert Medical Technologies", " ABC Medicine", "Prima Medica", "Eden", St. Andrew's Hospitals, "K+31" and so on.

A gastroenterologist at the clinic will tell you how to get tested for Helicobacter pylori. You can get a consultation in any private clinic, but for reasons of economy it is better, of course, to get tested in any state clinic - the method is not innovative, so you don’t need special equipment, and there are qualified doctors in district clinics.

As for the cost, the study will cost 500-4000 rubles. The most expensive clinics: “Stolitsa” on Letchika Babushkina, MC on Botkinsky, “Stolitsa” on Arbat. The cheapest places are “ABC Medicine”, “Doctor Ozone”, “Good Doctor”.

How to get tested for Helicobacter pylori? Change your diet a little a few days before the test, give up alcohol and some medications. The material must be collected in a clean container; special medical kits for stool analysis can be purchased at pharmacies.

When to get tested after Helicobacter pylori treatment? A repeat study can be carried out 3 weeks after the end of the course of therapy. The attending physician will give specific recommendations.

Breathing urease Helic test

Breath analysis is based on the fact that the bacterium produces special enzymes that can be detected when exhaled. How to get tested for Helicobacter pylori? The patient is asked to breathe through a tube located deep in the mouth. From time to time, the doctor reminds you to swallow saliva so as not to spoil the test results. Typically, two samples of exhaled air are taken.

The main advantages of such a test are its high efficiency, relative safety of the study and convenience for the patient. The test time does not exceed 40 minutes.

How to get tested for Helicobacter pylori? Preparation for a breath test requires serious preparation. First, you should slightly modify your diet on the eve of the study:

• exclude legumes, brown bread, cabbage and apples (foods that can cause increased gas formation in the digestive tract);
• give up alcoholic beverages, and on the day of the study - chewing gum and cigarettes;
• do not drink liquid an hour before the test;
• Only an early and light dinner is allowed; after 10 pm on the day before the test you can no longer eat;
• in the morning before the test, you need to brush your teeth and rinse your mouth with clean water; you should not use mouth fresheners or rinses;
• The attending physician must be informed about all medications that the patient took 2-3 days before the test.

Where to take a breath test in Moscow

The breath test can be taken in private clinics in the capital: “BestClinic”, “MedicCity”, “NearMedic”, “K+31”, “On Clinic”, “Medkvadrat” and so on. The cost of the procedure is from 800 rubles.

Listed above are the most common methods for diagnosing Helicobacter in the human body. There are other methods, such as gastroscopy or biopsy. The need for additional research will be determined by the attending physician.

along with a breath test, the most reliable method for diagnosing a current Helicobacter pylori infection.

Synonyms: helicobacter pylori antigen, EIA.

What is Helicobacter pylori?

The pathogenic microorganism (H. pylori) causes the following diseases:

• - inflammation of the gastric mucosa
• chronic duodenitis - inflammation of the duodenum
• (in 70% of cases) and duodenum (in 90% of cases)
• helicobacteriosis
• stomach cancer
• lymphoma of the stomach

70% of the population is infected, every third!

The constant presence of bacteria in the stomach is accompanied by the following symptoms:

• pain in the stomach after eating or before eating
• occasional nausea and even vomiting
• feeling of heaviness in the stomach
• heartburn and sour taste in the mouth
• bad breath

These symptoms not only reduce the quality of life and force you to take medications for a long time, but can also lead to stomach cancer!

Helicobacter pylori is capable of “triggering” other diseases that at first glance are not associated with the stomach, the permanent habitat of the bacterium. For example, a severe illness with a decrease in the number of b and a high probability of bleeding.

Therefore, correct diagnosis of a current H. pylori infection is extremely important!

Advantages

• high specificity and sensitivity (99%)
• recommended as a method of choice in children and adults
• the procedure is simple for both the patient and medical staff
• low price and availability
• quick results
• without contraindications, complications and side effects

Disadvantages of the method No.

Indications

• diagnosis of Helicobacter pylori infection and monitoring the success of treatment
• symptoms of dyspepsia - pain or feeling of discomfort (heaviness, fullness, early satiety) in the stomach (under the stomach)
• symptoms of chronic gastritis, gastric and duodenal ulcers, gastroesophageal reflux disease (GERD)
• 4-6 weeks after the end of treatment for Helicobacter pylori infection to monitor cure

The Helicobacter pylori stool antigen test is not recommended in the absence of symptoms!

Test principle

Particles of the microbial wall of H. pylori are released with feces, which react with the corresponding monoclonal antibody, which leads to a change in the color of the color indicator.

Preparation

• 2 weeks before testing for H. pylori antigen in stool, you need to stop taking bismuth drugs (De-Nol, Ulcavis), proton pump inhibitors (omeprazole, pantoprazole, lansooprazole), antibiotics (any)
• do not take stool thinners
• loose stools cannot be examined

Performance

Today, Helicobacter pylori antigen in stool can be determined in the laboratory or at home using rapid tests.

A special plastic container is filled 1/3 with feces collected in a chemically clean container (not from the toilet, but from the pot). The container is placed in a bag and taken to the laboratory for testing. The sample can be stored at 2-8C for up to 24 hours.

In a home rapid test, stool is collected in a test tube with a solvent, shaken thoroughly, and a few drops are applied to the window of the test cassette. If two stripes appear - the result is positive, if one is at the control level - negative, if one is opposite the test or none - the test is invalid. Analysis time 10 minutes.

Norm

• Normally, the antigen to Helicobacter pylori is not detected in the stool or the result is negative

Some manufacturers also indicate a “gray zone” - when the result cannot be assessed as positive/negative. In this case, it is recommended to repeat the analysis after 2 weeks.

Additional Research

Decoding the result

1. positive

• H. pylori is present in the body, indicating acute or chronic infection
• the bacterium has not yet been completely eliminated from the body; a 4-week pause has not been observed between the end of treatment and analysis

2. negative

• no Helicobacter pylori infection
• complete cure

P.S. The article was written according to the recommendations for the diagnosis of Helicobacter pylori infection - American Gastroenterology Association (AGA), the American College of Gastroenterologists (ACG), Infectious Diseases Society of America (IDSA) / the American Society for Microbiology (ASM).

Study of Helicobacter pylori antigen in stool was last modified: November 24th, 2017 by Maria Bodyan

In addition, the advantage of the method is its non-invasiveness - there is no need to use more or less traumatic procedures to collect material (puncture of a vein to draw blood, insertion of a duodenal tube).

Conducting a stool test does not require the presence of the patient; timely delivery of stool to the laboratory is sufficient. This is especially important for examining children.

There are different methods for identifying Helicobacter pylori, each with its own advantages and disadvantages.

The attending physician determines the need and choice of research method. The availability of the analysis for a particular patient due to price is of considerable importance. Most of it is performed only in private clinics and laboratories, as it requires expensive equipment.

The purpose of the study is to identify the causal relationship of the disease with Helicobacter and prescribe a targeted course of treatment to get rid of the pathogen.

What is Helicobacter?

The name Helicobacter pylori translates as “spiral pyloric.” It is tied to the characteristic shape of the bacterium, localization in the pyloric region (the border zone of the stomach with the duodenum). The microorganism has flagella that help it move even in thick mucus.

Helicobacter is able to withstand the acidic environment of gastric juice. For life support, it uses the energy of hydrogen molecules produced by intestinal bacteria.

The bacterium synthesizes about 20 enzymes

The most famous Helicobacter enzymes:

The characteristics of the microorganism include:

• the difficulty of isolating by culture, since Helicobacter does not grow on conventional nutrient media;
• a long period of absence of symptoms indicating infection;
• the ability in a “dangerous” situation to transform into a spherical shape and be covered with a protective film.

It is impossible to detect a spiral shape in feces, since the intestinal environment is unfavorable for the existence of Helicobacter. There is no necessary acidity, little oxygen, and strong destructive enzymes of bile and pancreas. Therefore, the coccal form of the bacterium is found in the stool.

Symptoms of gastric damage caused by Helicobacter may be minimal or correspond to the clinical picture of an exacerbation of the disease. The patient has:

• bloating;
• belching;
• heartburn;
• pain syndrome, especially during exacerbations in spring and autumn;
• constipation or diarrhea;
• feeling of heaviness in the epigastrium;
• decreased appetite;
• sudden weight loss.

Indications for research may be:

• the need to check before a long course of therapy with non-steroidal anti-inflammatory drugs, proton pump inhibitors, since they reduce the production of hydrochloric acid in the stomach;
• signs of iron deficiency anemia;
• unclear thrombocytopenia;
• the possibility of infecting family members;
• control of the course of antibiotic therapy;
• elucidation of the connection with genetic predisposition.

In a child, signs of infection include complaints of nausea, vague abdominal pain, poor appetite and refusal to eat, frequent profuse regurgitation, as well as bloating and rumbling in the abdomen.

Bacteriological culture method

Isolation of a pathogen culture is a microbiological type of research. The classic method requires inoculating the material on a nutrient medium, counting the grown colonies, and examining the microorganism from the colony under a microscope. It is also necessary to conduct biochemical tests to study its properties and additional inoculation on a medium with antibiotics to identify sensitivity to different drugs.

The sowing medium is quite expensive, it is prepared specially

It is difficult to perform a stool test for Helicobacter pylori using a culture method:

• sowing must take place without access to oxygen;
• only spiral-shaped forms can be distinguished, which rarely end up in feces, and not coccal ones;
• the results of the in vitro antibiotic sensitivity test (in vitro means “on glass, in a test tube”) in practice turn out to be misleading and in some cases do not coincide with the actual use in the patient (in vivo), the optimal antibiotic discovered is not effective enough;
• the analysis requires a long period (7–10 days) to complete.

Immunological research methods

The essence of the immunological analysis is the identification of antibody + antigen complexes in which the foreign agent is Helicobacter. More common use is for blood testing. But in fact, indirect signs of the presence of the antigen can be confirmed by the presence in stool, saliva, urine, and in pregnant women in the amniotic fluid.

The methods use ready-made “tagged” antibodies. When they treat the patient's stool containing antigens (remnants of Helicobacter), a compound reaction occurs with standard antibodies. The duration of the study is one day. A stool test for Helicobacter antigen is prescribed if the patient has any symptoms of digestive disorders.

The most common option is primary screening of the population (examination of all applicants or certain groups) who do not have specific complaints. It is not used in Russia due to the lack of a sufficient number of immunological tests in clinic laboratories.

PCR method

Polymerase chain reaction (PCR) refers to molecular genetic diagnostics. With its help, it is not the bacterium that is detected, but its specific DNA. Even with a small amount, in the case of recovery or asymptomatic carriage, the method makes it possible to link changes in the body with the effect of Helicobacter with sufficient accuracy.

The duration of analysis using the express method is 5–6 hours, the usual method is 2–3 days.

The technique is designed for the artificial synthesis of individual parts of DNA, duplication and construction of a chain of 30 cycles. The process does not occur in the absence of the slightest residue of biomaterial. An amplicator device is required for the reaction. Polymerase is an enzyme that speeds up the process.

Stool PCR is prescribed to confirm the role of Helicobacter in pathology and determine the advisability of specific therapy:

• for erosions and ulcers in the stomach, esophagus and duodenum;
• gastroesophageal reflux (reflux of contents in the opposite direction);
• atrophic damage to the gastric mucosa;
• polyps;
• stomach tumors;
• identifying hereditary predisposition in the case of relatives having malignant tumors of the digestive organs;
• monitoring the results of antibiotic therapy.

• high sensitivity and specificity (defined as 94% and 100%, respectively); the reaction is positive even in the presence of 10 bacteria;
• ease of implementation;
• safety for the patient, absence of trauma during material collection;
• the ability to determine DNA in both helical and coccal forms of Helicobacter;
• isolation and study of various genetic modifications and strains.

• it is not possible to determine the optimal antibiotic by sensitivity;
• there is no difference between the ongoing acute disease and the residual effects after an exacerbation, bacterial DNA remains in the stool for almost a month after clinical recovery;
• sensitivity is still lower than when examining a biopsy from the stomach wall;
• relatively high cost;
• the need to train personnel and purchase equipment;
• positive reaction in cases of personnel contamination of material from someone else’s sample (external contamination).

The PCR laboratory has advanced technology that allows you to obtain reliable diagnostic results

How to evaluate test results?

Decoding the research results is the job of a specialist doctor. You should not resort to independent interpretation or use the services of friends. The assessment is carried out based on a set of characteristics. PCR gives the following result:

• negative, if the Helicobacter genotype has not been isolated, is found normally;
• positive if the patient is at the height of the disease or has a history of infection.

During bacteriological examination:

• a zero number of bacteria was detected or Helicobacter is absent;
• if the number of microorganisms is greater than zero, helibacteriosis is confirmed;
• the sign S means sensitivity to the declared antibiotic;
• R - indicates resistance (resistance) to the drug;
• I - moderate sensitivity.

Stool culture allows us to give not only qualitative, but also quantitative characteristics of Helicobacter pylori infection. To do this, the degree of bacterial growth is taken into account:

• 1st degree - weak growth is observed on a liquid medium, on solid samples - no growth;
• 2nd degree - grows up to 10 colonies;
• 3rd degree - the number of grown colonies reaches 100;
• Grade 4 - the prevalence and activity of the pathogen is very active, more than 100 colonies grow.

Testing is carried out using enzyme immunoassay with standard sera

Immunological tests show a negative result if the pathogen antigen is not detected, a positive result in the presence of helicobacteriosis. The reliability of immunological and cultural methods is significantly inferior to PCR; their implementation requires a massive prevalence of the pathogen in feces.

How to prepare for the test?

The doctor will indicate where you can get tested. He must also familiarize the patient with the rules for collecting material and preparing it. Some private clinics provide visitors with printed instructions “How to take tests.” The effectiveness of the study depends on compliance with these conditions.

The general rules for collecting feces to identify Helicobacter are:

• stop taking antibacterial agents three days before the test;
• A control stool test is carried out one month after the end of the course of treatment;
• some tests require three days before the test to switch to a diet without foods with dietary fiber, eliminate pickles, and alcoholic beverages;
• a ban on the use of laxatives and rectal suppositories; if treatment requires daily use, you must notify your doctor;
• Feces should be collected in clean laboratory containers (issued at the clinic or purchased at the pharmacy); it is advisable to take samples from three points;
• Feces with impurities of mucus, pus, blood, urine are considered unsuitable;
• delivery of the material to the laboratory must be ensured within the first 2 hours; if necessary, it is allowed to be stored in the refrigerator for no more than a day at a temperature of 2 to 8 degrees.

A special kit for collecting stool for analysis can be purchased at a pharmacy

Additional Research

During diagnosis, the patient should not insist on an isolated stool examination. Using additional types, the doctor increases the reliability of information about Helicobacter infection.

Urease breath tests are very popular.

An irrefutable type of examination is a cytological examination of a sample of the gastric mucosa obtained by biopsy during a fibrogastroscopic examination. With a high-resolution microscope, the laboratory assistant sees a colored Helicobacter.

The fibrogastroscopic picture of the mucous membrane itself with characteristic erosions, atrophy, and ulceration indicates indirect signs of the presence of a pathogen in the stomach. X-ray diagnostics also makes it possible to judge organic pathology caused by Helicobacter by abnormalities in the direction of the folds and contours of the stomach.

Based on the results of the tests, the doctor can place the patient in a risk group with an increased likelihood of developing a stomach ulcer or malignant tumors. Preliminary use of specific treatment can reduce the risk. When choosing a medical institution to perform paid research, you need to consult about the reputation and responsibility of its employees.

Stool analysis for Helicobacter pylori: preparation and interpretation

Helicobacter pylori is one of the most dangerous bacteria that provokes the development of various diseases of the stomach and duodenum. To diagnose pathology, not only a blood test is prescribed, but also a stool test.

Helicobacter pylori: causes and symptoms

Helicobacter pylori is a pathogenic bacteria that infects the duodenum and stomach

Helicobacter pylori is a pathogenic bacterium that, when it enters the body, causes the development of helicobacteriosis. It is small in size and has a spiral shape. Producing a large amount of toxins, it affects the stomach and duodenum. The bacterium gets its name from the fact that it is found in the pyloric region of the stomach.

By multiplying, Helicobacter affects all cells of the stomach, which leads to inflammatory processes. This bacterium is resistant to acidic environments and can move along the walls of the stomach using flagella.

Signs of infection may not appear immediately. The disease develops with accompanying factors: poor nutrition, stressful situations, decreased immunity. Infection can occur through contaminated water or food, or through contact with an infected person while sneezing or coughing.

The following symptoms are characteristic of Helicobacter pylori infection:

• Heartburn
• Nausea and vomiting
• Smell from the mouth
• Loss of appetite
• Bloating
• Stool disorder
• Discomfort after eating

The listed symptoms are similar to those of gastritis and ulcers, therefore, to identify the pathogen and treat helicobacteriosis, it is necessary to undergo an examination.

Stool analysis: preparation and collection of material

Medical disposable containers for collecting stool for analysis

In the laboratory, the resulting material is examined using the PCR method. This is a molecular genetic diagnosis that allows you to identify Helicobacter even a small fragment of bacterial DNA in the collected material. The study is carried out under certain conditions and temperature conditions.

More information about Helicobacter pylori can be found in the video:

To detect Helicobacter pylori infection, other methods can be used: cultural and immunological analysis. The cultural method is usually understood as bacteriological inoculation of the material under study. It is placed in a special environment for bacterial growth. Usually it is about 10 days. Then the type of bacterium and its ability to enter into biochemical reactions are examined under a microscope. This method allows you to determine the sensitivity of the identified bacteria to antibiotics, which allows you to prescribe correct and adequate treatment.

The immunological method involves the adhesion of antibodies to antigens. This method of examination is carried out in case of severe symptoms and before the instrumental examination method. The choice of a specific method is made by the doctor, taking into account various factors.

Decoding stool analysis

When examining stool using PCR for Helicobacter pylori, the result can be negative or positive. In the first case, no bacteria were detected in the stool, but in the other case, an antigen to Helicobacter was present.

Stool bacterial culture analysis involves a qualitative and quantitative assessment of microorganisms in the test environment. There are 4 degrees of bacterial growth:

• 1st degree. In a favorable liquid environment, the growth of the identified bacteria is weak, and in a solid environment it is not observed at all.
• 2nd degree. The reproduction and growth of a certain type of microflora reaches up to 10 colonies.
• 3rd degree. It is distinguished by significant growth of up to 100 colonies in solid media.
• 4th degree. The growth of the bacterium is very high and exceeds 100 colonies.

The third and fourth degrees indicate an inflammatory process provoked by a specific type of bacteria.

The presence of Helicobacter in feces does not indicate a stomach ulcer or other diseases of the gastrointestinal tract, but only determines the presence of a pathogenic bacterium. If, according to the results of the analysis, the gastric mucosa is colonized with Helicobacter, then in many cases this is accompanied by pathologies such as ulcers, gastritis, irritable bowel syndrome, carcinogenic tumor, pancreatitis, etc.

Laboratory tests alone are not enough to make an accurate diagnosis. The examination must be comprehensive and include a biopsy and histological examination.

Helicobacter during pregnancy: danger to the fetus and treatment methods

The pathogenic bacterium does not affect the course of pregnancy and the condition of the child

During pregnancy, the gastrointestinal tract is subject to heavy load. In this case, heartburn, pain in the epigastric region, etc. are very often observed. The risk of developing an ulcer is very high, so the expectant mother should be examined to identify this infection in order to avoid possible violations.

It is better to carry out the examination in the first months, since diagnosis becomes more difficult as the period increases. Non-invasive research methods are used for diagnosis. An effective diagnostic method for determining Helicobacter is gastric intubation. The procedure is carried out in a gentle way. Endoscopy is performed in rare cases and with great caution, as the pressure on the uterine organs increases.

Treatment of helicobacteriosis during pregnancy and lactation is prohibited due to the possible negative effect of antibiotics on the fetus.

Among the drugs that are allowed are Phosphalugel and Maalox. Among antispasmodics, Drotaverine, Baralgin, Papaverine can be used only with the permission of a doctor.

If Helicobacter pylori infection actively manifests itself during gestation, then the symptoms of toxicosis are pronounced and appear very early. Toxicosis can be observed up to 5 months. A pregnant woman should adhere to a special diet and exclude from her diet foods that irritate the gastric mucosa. Diet No. 1 is prescribed during the acute period. It is prohibited to consume fatty meats and fish, rich broths, smoked foods, cabbage, spinach, radishes, etc.

Helicobacteriosis: treatment

If Helicobacter pylori infection is detected, antibiotic therapy is prescribed

The treatment regimen for Helicobacter pylori is determined by the doctor individually, taking into account the severity of symptoms and test results. Therapy for helicobacteriosis involves the death of the bacterium, as well as the healing of ulcers:

• Antibacterial drugs used include Metronidazole, Clarithromycin, Tetracycline, Amoxicillin, etc.
• In addition to antibiotics, anti-acid drugs are prescribed: Esomeprazole, Lansoprazole, Omeprazole, etc. When using these drugs, the production of hydrochloric acid decreases.
• To reduce acidity, the use of Almagel, Maalox, Alumag and other similar drugs is indicated. These drugs have adsorbent, enveloping and gastroprotective effects.
• To restore the intestinal microflora, after using antibiotics, probiotics are used: Lactoferrin, Vitaflor,

During treatment you should adhere to proper nutrition. Food should be portioned, neither hot nor cold. You should eat food strictly at certain hours. The diet menu must be approved by a doctor, but the recommendations for all patients with gastrointestinal diseases are the same: avoid fatty, fried, salty foods, spices, marinades, alcohol and carbonated drinks.

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How to take a stool test for Helicobacter pylori

Modern diagnostic methods make it possible to learn a lot about a person’s health status from his biological fluids: blood, urine, feces.

By examining stool, you can find out whether the bacterium H. pylori, which can cause gastritis, stomach ulcers and provoke cancer pathology, has settled in the body.

Feces for the presence or absence of this microbe can be studied in three ways: cultural, immunological, and the most reliable and widespread method - the polymerase chain reaction (PCR).

Determination of Helicobacter by cultural method

The bacterium itself is extremely rarely found in feces in its usual S-shape entirely. The large intestine and feces are not a favorable environment for the microorganism, therefore, when it enters them, it can take on a round coccal form, occasionally occurring in feces in this form.

The cultural method involves sowing part of the test material onto a nutrient medium in which the bacteria will feel good and begin to multiply.

Colonies grow, which are analyzed, stained with special reagents and examined under a microscope. In this way, pathogenic microbes are literally grown for the purpose of further study.

In addition to detecting the bacterium itself, the method allows one to determine the sensitivity of the pathogen to a particular antibiotic. If, when adding a drug, the growth of the colony continues - H. pylori is resistant to the antibacterial agent, and if the microorganisms die, it makes sense to prescribe this drug to the patient for the purpose of treatment and eradication, the bacteria are sensitive to it.

The cultural method is very reliable, but only if the S-form of the microbe is found in the biological material taken. The method has its drawbacks, and for this reason is not very widespread:

• The research period takes from 6 to 12 days
• Expensive media for sowing Helicobacter bacteria
• Specific conditions for media that ensure colony growth that are difficult to reproduce in the laboratory
• Rare occurrence of S-shaped bacteria in feces suitable for growth under nutrient conditions (coccal forms are not studied)

Determination of Helicobacter pylori antigen in feces by immunological method

The patient's feces can be subjected to immunological research, which allows identifying not the microorganism itself, but its parts - antigens.

Special antibodies are used aimed at detecting a foreign antigen - parts of a bacterium, its metabolic products, genetic material.

Interacting with a foreign agent, antibodies form a specific complex, which is determined by enzyme immunoassay.

This method of studying feces is rarely used in Russia; not many laboratories are equipped with the necessary reagents and necessary tests.

But in the future, it is possible to include this method of detecting Helicobacter as screening tests: studying broad groups of the population for infection with the bacterium.

PCR stool analysis for Helicobacter pylori

This is the most common method for testing feces for this bacterium and is highly accurate.

The essence of the method is as follows:

A section of bacterial DNA is isolated from the patient’s biological material, which is then artificially duplicated many times on a special apparatus, this is how the genetic code of H. pylori is restored

When the genomic fragment of a microbe reaches a sufficient size, it is compared with the reference one and a conclusion is made about the microorganism under study: whether it is Helicobacter or another pathogen.

A positive PCR test means the presence of Helicobacter pylori infection in the human body: the bacterium is present in the stomach, its DNA fragments were found in the stool and coincided with the reference ones.

• High accuracy: even a small amount of genetic material is enough for research with a high percentage of confidence, approaching 99%.
• Speed ​​of research. 2 days is enough for analysis, but there are express methods that allow you to establish a diagnosis in a few hours.
• Painless. The method is atraumatic and non-invasive. Allows you to examine small children, elderly, debilitated patients for whom FGDS with biopsy and other endoscopic manipulations are contraindicated.
• For an accurate result, it is not necessary to detect DNA fragments of exactly S or helical forms; parts of coccal microbes (most common in feces) are also suitable for analysis.

PCR diagnostics have significantly more advantages than disadvantages. The disadvantages include:

• Relatively high cost of analysis.
• Preservation of microbial DNA fragments in feces and after eradication. Even if the treatment is successful and the bacterium is absent from the body, after some time DNA fragments are found in the biological material and a stool test for Helicobacter may give a positive result. Therefore, in order to monitor cure, PCR diagnostics is recommended no earlier than 1 month after the end of therapy.
• Special expensive high-tech equipment, which requires trained and trained personnel to operate.

In vitro stool test for Helicobacter pylori antigen

All diagnostic studies carried out with patient feces refer to in vitro manipulations - “in vitro”, “in glass”, outside the human body.

They have fairly high accuracy and information content if they pursue the goal of detecting a microbe.

But not all processes occurring “in vivo” - inside the human body, can be recreated “in vitro” with the same reliability. For example, determination of sensitivity to antibiotics, analyzed by culture.

When studying the antibacterial sensitivity of microbial colonies on nutrient cultures, it was revealed that the most suitable drugs for bacteria in vitro “did not work” and turned out to be ineffective in treating the patient.

The results of in vitro studies of bacterial sensitivity to antibiotics are not always accurate.

How to take a stool test for Helicobacter pylori

The information content of a diagnostic test depends not only on the study chosen, the quality of the equipment and the qualifications of the personnel, but also on how the patient prepared for the analysis.

Feces for research must be collected correctly:

• After defecation, part of the fecal matter must be placed in a sterile container for collecting biological material, which must be purchased in advance from a pharmacy or laboratory.
• Prevent the ingress of blood, urine, saliva, pus and other foreign impurities into the biological material, which are likely to distort the results of the analysis.
• The container with the contents must be tightly closed and delivered to the laboratory no later than 4-5 hours before the study.

In addition to observing the technical aspects of collecting material for analysis, for several days before donating stool, you must follow the following recommendations:

• A week before the test, stop taking antibiotics.
• For three days, do not drink alcohol, foods high in fiber, or those that can color stool: beets, drinks with dyes.
• Do not use rectal suppositories or ointments, do not use laxatives.

Compliance with the above rules will allow the laboratory diagnostic doctor to assess the patient’s health status as accurately as possible and draw the right conclusions during the analysis.

Reliability of stool analysis for Helicobacter

PCR - diagnosis of feces is the most reliable of all three methods described above, it is to some extent inferior only to biopsy endoscopic examination.

PCR analysis of feces rarely gives false-positive results, is highly specific, and allows one to examine the DNA material of commonly encountered coccal forms of Helicobacter in feces.

The reliability of the cultural and immunological method is lower than PCR. These methods are prone to false-positive results, but in combination with other methods of detecting Helicobacter pylori, they are an excellent tool for making a diagnosis.

H. pylori antigen in feces

If Helicobacter pylori antigen or a DNA fragment of the microorganism under study is detected in the stool, this means that:

• The person is infected with H. pylori.
• Eradication therapy is not effective enough and the microbe has not disappeared from the gastrointestinal mucosa.
• Less than a month has passed after therapy and antigens of dead pathogens remain in the stool.

To exclude a false positive result after undergoing an anti-Helicobacter therapy regimen (when the test is positive and the human body does not contain H. pylori), you should not rush to find out the effectiveness of the treatment, but wait at least one month after its completion.

If the treatment of the bacteria is successful, 1 month after eradication, antigens and DNA of the microbe are not detected in the stool. The examination result is negative.

If antigens are detected during the initial analysis, the doctor will recommend that the patient undergo a course of special therapy aimed at destroying H. pylori.