Methods for diagnosing Helicobacter pylori: blood test for antibodies, stool analysis by PCR, urease tests (with FGDS, respiratory), biopsy with cytology. Analysis for Helicobacter pylori Where to get stool tests for Helicobacter

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

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

3-4 days before you need to stop taking antibiotics, laxatives, rectal suppositories. It is important to notify your doctor about the use of medications.
The material for analysis must be collected in a clean container. The pharmacy sells a special container for this purpose. It is prohibited to collect material after enemas or taking laxatives, as the results will be unreliable.
After collection, the material can be stored for 12 hours at a temperature of 2-8 degrees, but for research it is better to submit it 4-5 hours after the bowel movement.
If stool collection is performed after antibiotic therapy for helicobacteriosis, then this should be done only a month after the end of taking antibiotics.

In the laboratory, the resulting material is examined using the 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 adhesion to antigens. This research method is carried out with severe symptoms and before instrumental method examinations. The choice of a specific method is made by the doctor, taking into account various factors.

When examining stool using the PCR method, 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 analysis involves qualitative and quantification 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. Reproduction and growth of microflora certain type 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.

Presence 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 histological examination.

Helicobacter during pregnancy: danger to the fetus and treatment methods

During pregnancy gastrointestinal tract subjected 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 during pregnancy and lactation of helicobacteriosis is prohibited, due to the possible negative influence antibiotics for 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 in acute period. It is prohibited to consume fatty meats and fish, rich broths, smoked foods, cabbage, spinach, radishes, etc.

Helicobacteriosis: treatment

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:

From antibacterial drugs Metronidazole, Clarithromycin, Tetracycline, Amoxicillin, etc. are used.
In addition to antibiotics, anti-acid drugs are prescribed: Esomeprazole, Lansoprazole, Omeprazole, etc. When using these drugs, the production of of hydrochloric acid.
To reduce acidity, the use of Almagel, Maalox, Alumag and other similar drugs is indicated. These medicines 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 diseases are the same: avoid fatty, fried, salty foods, spices, marinades, alcohol and carbonated drinks.

The bacterium Helicobacter pylori (Helicobacter pylori) lives in the cells of the mucous membrane of the human stomach and duodenum. Some strains (genetic types) of the microorganism secrete specific toxins that destroy cells and increase the risk of pathologies such as chronic gastritis and duodenitis, gastric and duodenal ulcers, and some types of malignant tumors. Such strains must be identified and treated promptly. One way to determine Helicobacter pylori infection is to perform a stool test.

The mechanism for determining Helicobacter using stool analysis

PCR (polymerase chain reaction), cultural and immunological stool tests are direct research methods. In contrast to indirect methods, when the presence of a pathological agent is judged by the presence of its metabolic products or reaction immune system organism (production of antibodies), direct methods directly detect the microorganism itself or its DNA.
All types of stool tests for helicobacteriosis are non-invasive (non-traumatic) types of research, unlike blood sampling or gastroduodenoscopy.

Molecular diagnostics

To carry out PCR, a special device is used - an amplifier.

The PCR method is one of the types of molecular genetic diagnostics and allows you to determine the presence of Helicobacter pylori even if a small fragment of bacterial DNA is present in the material.

The essence of the method is to repeatedly multiply the analyzed sample of the pathogen. To carry out the reaction, a kind of “framework” is required, consisting of two primers - obtained through artificial synthesis of DNA fragments identical to the nucleic acid of Helicobacter pylori. During the reaction between the primers, the DNA chain grows if a fragment of microorganism biomaterial is present in the feces. If it is absent, no reaction occurs.

The reaction is carried out at certain temperatures and acidity of the environment, consists of several dozen repeating cycles, and a special enzyme, polymerase, is used for catalysis (acceleration of the reaction). Over 30 cycles, the DNA fragment of the pathological agent present in the biomaterial is multiplied a billion times, which makes it possible to accurately diagnose the infection.

If appropriate primers are available, infection with cytotoxic (damaging cells of the gastric mucosa) Helicobacter pylori species can be detected.

Cultural analysis

Cultural analysis (bacteriological culture) is a microbiological research method.

Biological material is placed in a specific environment favorable for the growth of a bacterial colony. After a certain period of time (for Helicobacter pylori - more than a week), the culture is examined under a microscope, using colonies to correctly identify various methods– color, ability to enter into certain biochemical reactions.

In addition to identifying the pathological antigen (the causative agent of the disease), the method allows you to test for its sensitivity to antibacterial drugs, which reduces the time and cost of treatment and increases the effectiveness of therapy.

Unfortunately, in some cases, the results of an in vitro sensitivity test (“in vitro”) may not coincide with the results of treatment in vivo (a living organism): in real life, antibiotics selected by a laboratory method may not be so effective.

Immunological methods of analysis

Immunological methods are based on the property of antibodies to stick to antigen. For research, antibodies with special labels are combined with the sample being analyzed, as a result, if Helicobacter pylori is present in the material, antigen-antibody complexes are formed.

Indications for examination

All types of diagnosis of Helicobacter pylori infection have their advantages and disadvantages. The advisability of using a particular method depends on various factors and stages of treatment. The optimal method of examination is chosen by a gastroenterologist.

Indications for PCR analysis of stool:

ulcers, and duodenum;
atrophy of the gastric mucosa;
polyps, stomach tumors;
gastroesophageal reflux (reflux of stomach contents into the esophagus), esophageal ulcer;
genetic predisposition: malignant tumors of the stomach in close relatives (parents, siblings);

A PCR study is optimally prescribed to assess the feasibility of specific treatment with antibacterial drugs for existing organic damage.

Indication for cultural analysis is to determine sensitivity to drugs when empirical treatment is ineffective. Since the test is complex (culture requires a special environment and lack of oxygen) and long-term, this test is not prescribed to diagnose an infection.

Bacteriological culture is capable of isolating only spiral forms of Helicobacter pylori, but not coccal forms, which received Lately widespread. This fact further reduces the value of the study.

Indications for immunological methods:

symptoms of functional and organic pathologies of the stomach and intestines:
- , belching;
- pain that occurs periodically throughout the day with exacerbations in spring and autumn;
- diarrhea or constipation;
- feeling of discomfort, fullness of the stomach;
before prescribing long-term therapy with non-steroidal anti-inflammatory drugs or proton pump inhibitors (drugs to reduce the production of hydrochloric acid);
iron deficiency anemia or thrombocytopenia of unknown etiology;
genetic predisposition;
infection of the immediate environment;
monitoring the effectiveness of antibiotic therapy.

Immunological methods and PCR without genotyping are prescribed for screening purposes - due to its simplicity and relatively low cost, the study is carried out to the general public to identify groups at risk of developing organic and tumor lesions of the stomach and intestines.

Unfortunately, screening for Helicobacter pylori is not widespread in Russia.

Immunological analysis is carried out before instrumental research methods with appropriate symptoms and suggests infection with Helicobacter pylori. Based on the results of the analysis, if necessary, other research methods are prescribed.

Advantages and disadvantages of PCR analysis of stool

Specific therapy of helicobacteriosis with antibacterial drugs is a long process, accompanied by poor tolerability in many patients and a high risk of complications.

Prescribing antibiotics to everyone infected with Helicobacter pylori is a bad practice. Specific antibiotic therapy is indicated only for patients with a tendency to progression of organic lesions - erosions, ulcers, atrophic process - usually infected with certain strains of Helicobacter. These patients require antibiotic therapy in order to achieve remission of peptic ulcer disease and prevent the risk of developing malignant neoplasms.

Cytotoxic types of Helicobacter pylori can only be detected using the PCR method.

Advantages of PCR stool analysis:

high sensitivity of the method;
high specificity of the test;
simplicity and non-invasiveness of material collection;
safety;
the ability to isolate both spiral and coccal forms of Helicobacter pylori;
the ability to isolate different strains of bacteria.

Test sensitivity is the ability to produce true positive results. The higher the sensitivity, the lower the proportion of false positive results, when the antigen is allegedly detected in uninfected individuals.

The specificity of the test is an indicator that depends on the number of false negative (when the antigen is not released in an infected patient) test results. The PCR method for testing stool for Helicobacter pylori is characterized by a sensitivity of 64–94% and 100% specificity.

Collecting feces is easy and simple. Unlike blood sampling or gastroduodenoscopy, the collection of material does not require the use of local anesthetics, which can develop allergic reaction, does not cause pain or discomfort, and is safe from infection with a “dirty” instrument. The study does not require any special effort, such as the breathing method, which makes it accessible even to small children.

Disadvantages of PCR stool analysis:

inability to determine sensitivity to antibacterial drugs;
inability to distinguish between a current infection and a successfully cured one, when DNA fragments of the bacterium can remain in the feces for about a month;
lower sensitivity compared to the study of a biopsy (tissue sample or cell mass) of the gastric mucosa;
relatively high cost of analysis with genotyping;
strict requirements for personnel: qualifications, strict adherence to rules, accuracy.

One of the main disadvantages of the PCR method is a continuation of its main advantage: the high sensitivity of the test causes false positive results in the event of contamination (“contamination” from the outside) of the analyzed material.

Preparing for the test

The reliability of the result of any analysis depends on the strict fulfillment of certain conditions at all stages, and sampling of material is no exception.

Rules for taking material:

three days before the analysis, antibiotics, laxatives, drugs that slow down peristalsis, rectal suppositories and some other medications are discontinued according to the doctor’s instructions, so you should warn the doctor about the use of certain medications;
Feces are collected in containers issued by the laboratory; it is recommended to take samples from three different points;
It is advisable to deliver the biomaterial to the laboratory immediately; if this is not possible, the sample should be stored at a temperature of 2–8 degrees for no longer than 24 hours;
if the test is performed to evaluate the effectiveness of previously prescribed antibiotic therapy against Helicobacter pylori, stool is collected no earlier than four weeks after the end of treatment.

Slowing the passage of feces and constipation can lead to the destruction of Helicobacter in feces, which causes false negative results. To increase the reliability of the result, the doctor may prescribe a mild laxative - lactulose - before the analysis.

How and where to get tested

The tests are prescribed by a gastroenterologist, so his consultation is necessary before testing for Helicobacter pylori.

Approximate cost of stool examination:

PCR method with genotyping – 1200 rubles;
PCR without genotyping – 600 rubles;
sensitivity to antibiotics – 600 rubles;
immunological methods – 400–650 rubles (depending on the method).

For the most accurate diagnosis of Helicobacter pylori, it is necessary to choose a medical institution that has earned a good reputation.

Research results

The processing time of tests and their reliability depend on the method of antigen determination.

Timing of completion, reliability and interpretation of the results of stool tests for helicobacteriosis.

	Deadlines	Credibility	results
PCR	from 5–6 hours (express method) to 2 days	high	1) negative – not a single declared genotype of the bacterium has been identified; 2) positive – helibacteriosis (current or in history), at least one of the declared genotypes has been identified
Bacteriological analysis for sensitivity to antibiotics	7–10 days	high – for sensitivity; low – for antigen detection	1) number of bacteria 0 – Helicobacter was not isolated; 2) number >0 - helibacteriosis; 3) S – sensitivity to the specified antibiotic; 4) R – resistance (resistance) to the antibiotic; 5) I – moderate sensitivity to the antibiotic.
Immunological methods	1 day	low	1) negative - the pathogen has not been identified; 2) positive - helicobacteriosis

The low reliability of immunological and cultural analysis is explained by the low content of antigen in feces: if the PCR analysis is sensitive even in the presence of 10 cells, then for a reliable result of other methods there must be at least 10 times more cells.

Testing stool for helibacteriosis is safe, non-traumatic and can be carried out using different methods to detect infection, determine virus strains and pathogen sensitivity to antibiotics.

Based on the test results, it is possible to form a risk group, whose representatives have a high probability of developing stomach and duodenal ulcers, and malignant stomach tumors; assess the degree of risk and minimize it by timely antibacterial treatment of cytotoxic strains of helicobacteriosis.

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 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 can withstand acidic environments 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:

need to check before long course therapy with non-steroidal anti-inflammatory drugs, proton pump inhibitors, as 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;
analysis requires long term(7–10 days) for complete implementation.

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 artificial synthesis individual parts 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 current acute illness And 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 results diagnostics

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 the method enzyme immunoassay with standard serums

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, 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

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.

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

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 They allow you to learn a lot about a person’s health 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 medicinal product colony growth is maintained - 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 stool is rarely used in Russia; not many laboratories are equipped necessary reagents and necessary tests.

But in the future it is possible to include this method detection of Helicobacter as screening tests: studies of large groups of the population for infection with the bacterium.

PCR stool analysis for Helicobacter pylori

This is the most common method for examining feces for this bacterium, with high accuracy.

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 doctor laboratory diagnostics 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.

[09-053 ] Helicobacter pylori, DNA [real-time PCR]

1025 rub.

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Detection of Helicobacter pylori (H. pylori), during which the genetic material (DNA) of the microorganism in a sample of biomaterial is determined using the real-time polymerase chain reaction (RT-PCR) method.

Synonyms Russian

Helicobacter [real-time polymerase chain reaction].

English synonyms

H. pylori, Helicobacter pyloridis, DNA.

Research method

Real-time polymerase chain reaction.

What biomaterial can be used for research?

Biopsy, cal.

General information about the study

H. pylori is a Gram-negative, motile bacterium that is resistant to hydrochloric acid and can colonize the mucous membrane of the stomach and duodenum. As a rule, primary infection occurs in childhood and is asymptomatic, but in some people it leads to the development of serious diseases over time. H. pylori is found in the vast majority of cases of gastritis and peptic ulcers and, in addition, greatly increases the risk of developing adenocarcinoma and B-cell lymphoma of the stomach. Modern diagnostics of these diseases is impossible without accurate and rapid identification of H. pylori.

H. pylori can be detected using several methods. Currently, non-invasive diagnostic methods are available, which have the advantage of simplicity and safety of taking a sample for research (stool examination), which is of particular importance when examining the elderly, children, and also in outpatient settings.

Helicobacter is very sensitive to the effects of bile acids and low oxygen content, therefore, when the chyme passes through the duodenum and colon, the number of bacteria is significantly reduced. In addition, active spiral-shaped bacteria undergo morphological changes, providing greater stability in unfavorable conditions. The result of this is a low concentration of microorganisms and a predominance of coccal forms in the feces, which should be taken into account when choosing laboratory method research of this biomaterial. Among many non-invasive methods, research using real-time polymerase chain reaction occupies a special place.

Real-time polymerase chain reaction (RT-PCR) is a molecular diagnostic method that allows the detection of fragments of genetic material (DNA) of an infectious agent in biological material (for example, in feces). RT-PCR is characterized by very high sensitivity (93-95%), which is an advantage when analyzing stool. Unlike bacteriological culture, this test can detect both spiral and coccal (non-culturable) forms of H. pylori. Due to the fact that the reaction reveals the DNA of a microorganism, the test is not used for differential diagnosis current infection or infection in history - the test result will be positive for some time after the complete eradication of H. pylori, which is due to the identification of fragments of destroyed DNA of the microorganism.

Other representatives of the Helicobacter genus (H. suis, H. baculiformis) may also be present on the gastric mucosa. Although their importance in the development of gastrointestinal diseases has not yet been fully established, they play a role in the identification of H. pylori. For example, laboratory research, based on the identification of an antigen common to all Helicobacter species, will be characterized a large number false-positive results for H. pylori due to detection of other species (as is the case with ELISA). This is practically excluded in a study using RT-PCR, since the reaction is based on the detection of a DNA fragment specific to H. pylori.

Diagnosis of helicobacteriosis in children presents certain difficulties. This is due to the child’s failure to perform the breathing maneuver when using the urease breath test, as well as the need for anesthesia when using invasive methods. Stool testing using RT-PCR is a good alternative to these methods and therefore can be successfully used in pediatric practice.

High content of inorganic salts (phosphates, calcium), gastrointestinal enzymes, polysaccharides, bile acids and salts, plant fibers, mucus and other components of feces can inhibit RT-PCR, so preparation for the test requires due attention on the part of the patient and the doctor. The interpretation of the analysis result is carried out taking into account additional laboratory and instrumental data.

What is the research used for?

To diagnose diseases caused by H. pylori:

atrophic or antral gastritis;
ulcers of the stomach and duodenum.

When is the study scheduled?

If you suspect gastritis or peptic ulcer in children and the elderly.
If it is impossible to use invasive methods for identifying H. pylori in patients of any age.

What do the results mean?

Reference values: negative.

Positive result:

current H. pylori infection;
History of H. pylori infection.

Negative result:

absence of H. pylori infection.

What can influence the result?

The presence of blood, bile, excess inorganic salts and other components in the stool sample can lead to a false negative result.
Treatment with tetracycline, penicillin (aminopenicillins), macrolides (clarithromycin, azithromycin) and metronidazole may lead to a false negative result.

Important Notes

Helicobacter pylori

Polymerase chain reaction (PCR) increases the DNA copy number of bacteria or viruses by millions of times using the enzyme DNA polymerase. One DNA molecule is enough for diagnosis. The synthesized amount of DNA is identified by enzyme immunoassay or electrophoresis. PCR diagnostics allows you to detect the pathogen at the earliest stages of the infectious process, in any biological environment of the body, with the possibility of quantitative determination of viruses or bacteria.

Helicobacter pylori is a spiral gram-negative bacteria that was discovered on the gastric mucosa more than half a century ago, but it did not attract much interest until the early 1980s, when a method was developed to culture the organisms from mucosal biopsies.

In 1983, Australian physician Barry Marshall discovered that H. pylori was almost always present in the stomachs of patients suffering from chronic gastritis or an ulcer. Bacteria, by themselves, do not cause stomach or duodenal ulcers, however, they provoke inflammatory processes in the stomach and weaken natural protection mucous membrane from exposure acidic environment stomach; at the same time, H. pylori stimulates hypersecretion of hydrochloric acid, affecting the mechanisms of its regulation. If the therapy leads to a decrease in stomach acidity, the ulcer may heal, but after stopping treatment there is a possibility of its recurrence. Long-term observations have shown that in patients who did not receive treatment against H. pylori, the ulcer recurs after 2 years in 100%, and in treated patients it recurs (usually due to reinfection with H. pylori) in only 5-10%. The source of H. pylori infection is an infected person, cats, pigs, large cattle and monkeys (rhesus macaque). More often, infection occurs through water and food contaminated with feces (vegetables that were watered with contaminated water). The object of transmission of the infectious principle can be contaminated hands, saliva, drops of saliva or sputum during coughing. Studies conducted by doctors from the USA have shown that H. pylori can be considered a familial infection, and if a carrier of H. pylori is identified in a family, then the probability of other family members being infected is 95%. Detection of Helicobacter by PCR makes it possible to establish a diagnosis much faster and monitor treatment. Materials for research can include gastric aspirates, feces, and saliva.

Please note that taking a urogenital smear, smear from the throat, nose, and oral cavity is paid.