What are protozoan cysts: photo and definition. Stool analysis: how to collect and why it is so important to do it

Cyst (cista) is an intermediate stage or form of existence of most microorganisms, during which they are covered with a kind of protective shell. The process of cyst formation starts at the moment when the simplest organism finds itself in unfavorable conditions. The shell temporarily “freezes” the metabolism.

What is a cyst in biology?

The formation of a cyst is encystment. This form of life is temporary. From a biological point of view, it is necessary for reproduction and for protecting a particular population from extinction.

Some simple organisms, under certain circumstances, can remain in a cyst-like state for hundreds of years.

There are 3 forms of cyst:

The cyst is a protective layer that allows microorganisms to survive even without oxygen. The appearance of cysts can be seen in the photo using Giardia as an example. They look like microscopic oval-shaped grains with two kernels on the sides.

Cyst – formation of a protective shell around a microorganism

Conditions for cyst formation

In the natural environment, cysts form predominantly at extremely high or low temperatures. For example, amoebas stop feeding and reproducing in the fall. With the arrival of cold weather, their bodies become rounded and covered with a thick membrane - a cyst. The same process occurs when rivers and lakes dry up.

The cercariae of the liver fluke encyst as soon as they enter the grass along with the feces of domestic animals (mainly cats). Cattle subsequently eat the cysts along with the greens. This process of transporting helminths is the most common.

Analysis for cysts

Pathogenic microorganisms are much easier to detect if they are in the shell. For analysis you will need biological material - feces. Adults do not survive in feces, as they die almost immediately and instantly decompose under the influence of environmental conditions.

It is possible that the first analysis will show a false negative result in a person, since the infection itself has a wave-like nature. That is, at different periods of the course of the disease there are fewer or more cysts in the biological material, and sometimes they may not exist at all. Therefore, it is much more advisable to take several intermediate tests.

To detect protozoa in the patient's stool, a microscopic examination method is used. On the day of the test, you should not take medications, especially laxatives, or do enemas. The material for research should be as fresh and “clean” as possible.

Cyst forms that can be found in feces:

• cilia (ciliated);
• spore;
• rhizomes;
• ciliates;
• flagella (flagellates)
• intestinal coccidia (cryptosporidium).

The most common pathogenic microorganisms found in cyst form: Entamoeba coli (entamoeba coli, intestinal amoeba), Chilomastix mesnili (chilomastix), Lamblia intestinalis (giardia), Entamoeba histolytica (dysenteric amoeba).

Dysenteric amoeba in cystic form

Do I need treatment?

Almost all healthy people have blastysts in their intestines. Under unfavorable conditions, these protozoan organisms transform into cysts. Blacysts are opportunistic pathogens, so in some people they can cause the disease blastocystosis. But in most cases, these microorganisms do not cause any harm.

Usually, an infected person exhibits symptoms, expressed by general intoxication of the body. Therefore, the patient himself feels when he needs to go to the doctor and get tested. Another characteristic feature is the presence of small dots in the stool.

Many experts believe that the body of an adult and even a child is able to cope with protozoa without additional treatment.

During a general examination, a child may be found to have asymptomatic giardiasis. This will indicate that he is a carrier of the disease and is potentially dangerous for the children's team. Therefore, a sick child will not be accepted into kindergarten until he is completely cured.

Treatment

• Preparation;
• taking essential medications;
• rehabilitation.

If therapy is incomplete or incorrect, the disease will recur, so treatment must be taken seriously.

Preparatory stage

At this stage, the patient must follow the following medical recommendations:

1. Follow a strict diet. You should saturate your diet with cereals, cereals, vegetables, fruits and complex carbohydrates. Do not consume: alcoholic drinks, soda, sweets, fatty foods.
2. Take cleansers. Medicinal preparations and enterosorbents (Smecta, activated carbon) are suitable. Adult patients are recommended to have a fasting day once a week. All this will help cleanse the body of toxins formed due to the activity of pathogenic microorganisms.
3. Maintain cleanliness. You need to regularly wash clothes and bedding, wash your hands after going outside, and handle food. Many patients after therapy are re-infected with cysts due to poor personal hygiene during treatment.

If necessary, at this stage you can take medications to relieve the symptoms of the disease. These can be choleretic or antiallergic drugs.

Drug treatment

At this stage, drugs that remove protozoa from the body are added to therapy. The choice of medication depends on the type of infectious agent. The most commonly used medications for treatment are:

1. Trichopolum. Available in the form of tablets and suppositories. Until recently, the medicine was used only for the treatment of Trichomonas infections (pathogen: Trichomonas). Now the drug is also used for the treatment of giardiasis, helicobacteriosis (the causative agent is the bacterium Helicobacter pylori), and amoebiasis. The medication is prohibited for use in children under 3 years of age. Daily dose for children under 10 years of age: 125 mg 2 times a day (course of treatment: week). For adult patients and children over 10 years of age: 500 mg 2 times a day for a week. Cost of 20 tablets: from 130 rubles.
2. Azithromycin. A semi-synthetic antibiotic, available in the form of tablets and capsules. The medicine is used to treat anaerobic infections, inflammatory and infectious pathologies. The drug is approved for use by children. Daily dosage: 5 mg per 1 kg (for children), 0.5 g per 1 kg (for adults). Course of treatment: 5 days. Price of tablets: from 120 rubles.
3. Ornidazole. Available in tablet form. The medication is used for the treatment of amoebiasis, trichomoniasis, and giardiasis. The drug is also used to prevent anaerobic infections. The medicine is prohibited for use in children whose body weight is less than 12 kg. Daily dose for children under 12 years of age: 1 g (divided into two doses). Course of treatment: week. Dosage for adults and children over 12 years of age: from 1.5 to 2 g per day (the daily rate depends on the patient’s body weight). Course of treatment: 2–4 days. Cost of medicine: from 150 rubles.

You need to choose and take medications very carefully, since they all have a lot of side effects and contraindications. Therapeutic agents for pregnant and lactating women are selected by the doctor on an individual basis.

Rehabilitation

Do not forget that various cysts can be transmitted sexually and domestically. There are no preventive methods that can 100% protect a person from this unpleasant phenomenon. Therefore, it is worth observing basic hygiene rules to prevent infection.

The human body, outside and inside, is a “home” for many microorganisms. There are especially many of them in human beings. Some of them relate to beneficial microflora, which helps us cope with various problems and also contributes to many digestive processes.

However, pathogenic microorganisms, helminths and protozoa also often enter our body and become the cause of a variety of infectious diseases, some of which can be very dangerous to human health. Since intestinal pathogens, worms and protozoan microorganisms mainly live in the intestines, traces of their activity, life forms, cysts and eggs are found in the contents of human intestines - feces. To identify protozoa and helminth eggs, special tests are carried out.

There are a large number of pathogenic protozoa that live in the lower sections. They enter the human body through drinking, food, dirty hands and other ways. Protozoa can provoke a number of diseases, some of which are very dangerous to human health and even life. These microorganisms are capable of spreading throughout many organs of the human body, destroying them, causing a sharp deterioration in health and the appearance of a number of unpleasant symptoms, adversely affecting the entire body as a whole.

When is the test ordered?

In most cases, stool analysis for protozoa is a planned procedure and is carried out for children upon admission to kindergarten, school and other educational institutions.

For adults working in catering establishments, manufacturing and selling food products, medical and educational institutions, such an analysis is mandatory, as it helps to identify carriage in a timely manner and prevent further infection.

Also, stool samples for protozoa are taken as prescribed by a doctor after the following patient complaints:

1. Sudden sharp weight loss without significant reasons (with a normal diet), especially if it is accompanied by digestive disorders, diarrhea, nausea, vomiting, and in some cases blood in the stool.
2. If a person swam in open natural reservoirs, especially small freshwater ones, and could swallow this water, or when drinking well and contaminated water.
3. Returning from tropical or other countries with poor hygiene and a high risk of infection by helminths and other microorganisms.
4. Also the basis for the study are the patient’s subjective complaints, which may allow one to suspect the presence of protozoa.

Preparation for analysis and material for research

Before the analysis, you do not need to undergo any special preparations or procedures, however, to obtain a reliable result, you must follow a few fairly simple rules:

• It is necessary to stop taking a number of medications several days before the test. It is especially important to remove laxatives, including those based on oils, antispasmodics, as well as other medications that can affect the work of the skin, in particular, its peristalsis.
• The use of rectal suppositories, as well as enemas (laxative or medicinal), especially those containing oils, should be excluded.
• It is necessary to remove drugs that can affect the coloring of stool, distorting the normal picture. These are bismuth, iron and barium sulfate.
• In order for the simplest test to be as informative as possible, you need to remove a number of vegetables and fruits from your menu that could affect the test result. It also doesn’t hurt to reduce the amount of meat products, giving preference to light foods, as well as low-fat dairy products.The period of abstinence from all of the above remedies and products is at least three days, unless otherwise recommended by a specialist.

The test requires the patient's stool. To do this, about 20 grams of feces are collected after defecation in the morning, placed in a sterile container and delivered to the laboratory no later than two hours after collection.

In the laboratory, it is done on a glass slide, stained, and then the sample is examined under a microscope.

Staining helps to identify various vegetative forms and cysts, which may belong to opportunistic or symbiotic microflora of the human intestine. Symbiotic microorganisms are very important for the normal functioning of the intestine; their normal presence indicates the full functioning of the immune system, and a decrease in the number indicates the presence of various diseases or the predominance of harmful microbes. Opportunistic microflora in normal quantities does not harm health; these microorganisms are always present in our body. However, a sharp increase in their number indicates the development of various problems and is an alarming sign.

Useful video - Giardiasis in adults and children.

In a stool sample in the laboratory, protozoa can be found in different forms - live and cysts (“naturally preserved”). In most protozoa, cysts are uninformative, they are very difficult to differentiate from each other, so living (vegetative) forms must be studied. To do this, the stool analysis must be as fresh as possible.

Cysts under a microscope

Important! The reproduction function for some protozoa is secondary, when maximum distribution in the environment is the main goal. Certain groups of microbes are generally capable of dividing sexually.

Main causes of encystment

Among numerous laboratory studies, the main reasons for the formation of a thick shell, which ensures the preservation of the viability of microorganisms, were identified. Considering the scale of the spread of protozoa in the environment, the following factors are distinguished:

• temperature factors;
• excess or lack of oxygen in the environment;
• drying out water bodies;
• loss of food resources;
• change in the acidity concentration of the medium.

Diagnostic methods

• excretion of feces naturally (without auxiliary medications, without catheterization);
• biological samples must be fresh (no more than 5-6 hours should pass from the moment of collection to examination);
• following a diet 3-4 days before stool collection;
• exclusion of absorbents and other medications 2 days before the test;
• Before defecation, you should urinate and take a shower;
• collection containers must be hermetically sealed and sterilized.

In the laboratory, protozoan cysts are detected by two main methods for identifying cysts. A popular smear is Lugol's solution or iodine. To do this, a fresh portion of feces is treated with one of these solutions, after which it is placed between pieces of glass and examined under a magnifying glass. Another method is mixing with ether, where the stool sample is run in a centrifuge. After such manipulations, the cysts fall into a natural sediment.

This analysis is done for suspected infection with protozoa and as a preliminary analysis before planned hospitalization, as well as when registering baby to children's institutions, etc.

Preparing for a stool test

Fecal analysis for enterobiasis (pinworm eggs).

A stool test is done in case of suspicion of enterobiasis (pinworm infection) and before planned hospitalization, as well as upon registration baby to children's institutions. Clinical manifestations of enterobiasis are itching in the anal area and intestinal disorders. The causative agent is pinworm. This is a small nematode (roundworm) that lives in the large intestine, and crawling out of the rectum, lays eggs in the folds near the anus.
The source of infection is a sick person. They become infected with the disease through dirty hands. Pinworm larvae, attaching to the skin, cause inflammation, and mature worms disrupt intestinal functions. The waste products of these worms and, especially, their breakdown products have a toxic and allergic effect.

Preparing for analysis

The material should be taken in the morning. Before taking the test you should not wash baby. The nurse uses a cotton swab dipped in glycerin to scrape the surface of the perianal folds and lower parts of the rectum. The stick is placed in a plastic test tube and tightly closed with a lid.

As a result of the analysis, pinworm eggs are not found or found. Normally they are not detected.

Analysis of feces for helminth eggs (worm eggs).

Preparing for a stool test

Feces are collected in a disposable container with a screw cap and a spoon in an amount of no more than 1/3 of the container's volume or in a clean glass jar - no more than one spoon in volume. On the container or jar it is necessary to clearly indicate the patient's surname and initials, date of birth, date and time of collection of the material, which must be delivered to the laboratory on the same day. During collection, avoid contamination of urine and genital secretions. Before being sent to the laboratory, the material must be stored in a refrigerator at 4-8 degrees C. On the result form, it is indicated whether helminth eggs were not found or helminth eggs were found, and if found, then what exactly. Normally, worm eggs are not found in feces.

Fecal occult blood tests

The analysis is done if there is a suspicion of bleeding from any part of the gastrointestinal tract. Used to detect “hidden” blood that is not visible during microscopic examination. It is highly sensitive to hemoglobin, a substance contained in red blood cells (erythrocytes). For three days before the analysis, meat, liver, fish, apples, bell peppers, spinach, white beans, green onions, tomatoes, all types of green vegetables, turnips, horseradish, beets, blueberries, pomegranates are excluded from the diet - these are foods containing iron, and also foods that color stool, as well as taking iron-containing medications. It is advisable to use the diet: Milk, dairy products, cereals, mashed potatoes, white bread with butter, 1-2 soft-boiled eggs, some fresh fruit. This food is given for 4-5 days. It is also not recommended to brush your teeth for 2 days due to the possibility of injury to your gums. The stool should be free of enemas and laxatives. For the study, you need about 1 teaspoon of feces. Normally, occult blood is not detected. A positive reaction to “occult” blood in the stool is observed when:

• bleeding from the gums;
• bleeding from varicose veins of the esophagus, stomach, intestines;
• ulcerative and inflammatory processes in the stomach and intestines;
• hemorrhagic diathesis - a group of diseases, the common manifestation of which is hemorrhagic syndrome (a tendency to repeated intense long-term, most often multiple, bleeding and hemorrhage);
• polyposis - multiple benign tumors of the mucous membrane of various parts of the intestine;

Coprogram

The test is done to collectively describe the physical, chemical, and microscopic examination of stool. It is prescribed for diagnosing diseases of the digestive system and assessing the results of treatment. Stool examination allows you to diagnose:

• violation of acid-forming and enzymatic functions of the stomach;
• violation of intestinal enzymatic function;
• violation of the enzymatic function of the pancreas;
• liver dysfunction;
• the presence of accelerated evacuation from the stomach and intestines;
• malabsorption in the duodenum and small intestine;
• inflammatory process in the gastrointestinal tract;
• dysbacteriosis – disruption of the normal intestinal microflora;
• ulcerative, allergic, spastic colitis - inflammation of the intestines.

Microscopic examination determines the main elements of feces: muscle fibers, plant fiber, neutral fat, fatty acids and their salts, leukocytes, red blood cells, intestinal epithelial cells, malignant tumor cells, as well as mucus, helminth eggs, and protozoa.

Preparing for the study

Discontinuation of medications is recommended. You cannot conduct scatological studies after an enema. After an X-ray examination of the stomach and intestines, stool analysis is indicated no earlier than two days later, since this study is carried out using X-ray contrast agents that are excreted in the feces. Feces are collected in a disposable plastic container with an airtight lid and a spatula for sampling or in a clean glass container. Mixing urine into stool should be avoided. The container must be delivered to the laboratory on the same day, and before shipment it must be stored in the refrigerator at a temperature of 3-5 degrees C. For children over 1 year old, the following coprogram indicators are typical:

Discoloration is an important diagnostic sign of many diseases. So, with obstructive jaundice, when the flow of bile into the intestines stops, the stool becomes discolored. Black, tarry stool is a sign of bleeding from the upper digestive tract. The red color is most often due to the admixture of unchanged blood during bleeding from the colon. Among the pathological impurities in the feces, mucus, blood, pus, as well as helminths, etc. can be found. A large number of muscle and connective tissue fibers (creatorhea) is evidence of insufficiency of pancreatic function or a decrease in the secretory function of the stomach. The detection of digested fiber and starch (amilorhea) is characteristic of diseases of the small intestine. The detection of neutral fat in the feces (steatorrhea) is evidence of insufficient lipolytic function of the pancreas; neutral fat and fatty acids are characteristic of impaired bile secretion. A large number of leukocytes indicates an inflammatory process in the intestines (dysentery - an infectious disease of the gastrointestinal tract, etc.).

The test is used mainly for diagnosing lactase deficiency (impaired absorption of lactose and poor tolerance to foods containing milk sugar) in children of the first year of life. Lactase deficiency can be primary and secondary. Primary or true lactase deficiency is a congenital deficiency of the enzyme. True lactase deficiency is rare. Secondary lactase deficiency is especially common among children in the first year of life and is often a consequence of intestinal dysbiosis or immaturity of the pancreas. Secondary lactase deficiency disappears after correction of dysbiosis or with age (transient), and in older age, milk sugar is normally absorbed. Lactase deficiency can be confirmed or refuted by taking a stool analysis baby for carbohydrate content.

Preparing for the study:

Feces should be collected in a separate, clean container. The amount of material should not be less than a teaspoon of feces. The feces must be delivered to the laboratory within 4 hours from the moment of collection. If the delivery time exceeds 4 hours, then the feces must be frozen at -20 degrees C. Repeated thawing/freezing is not allowed. Normal values ​​for carbohydrates in feces:

• Children under 1 year – 0 – 0.25%
• Children over 1 year and adults 0%

If carbohydrate levels increase, lactase deficiency may be suspected.

Protozoa - (Protozoa) - a group of microscopic unicellular animals.

Enzymes of the gastrointestinal tract are biologically active substances, due to which food is digested to a greater extent.

Moreover, some types of protozoa can survive in the form of cysts for up to several years.

Protozoa live in the small or large intestine of humans. They are single-celled microorganisms. The ways they penetrate the host’s body are raw water, unwashed hands and food.

To detect protozoa, stool is examined for the presence of cysts. They can be detected in excrement and in vegetative form, when single-celled microorganisms are mobile and active. But when microorganisms leave the intestines, they lose their own structure and quickly die.

When protozoa take the form of a cyst, they are covered with a special membrane. In this form, it is much easier to diagnose their presence in human feces. But what types of single-celled organisms take the form of cysts, and how can they be found in stool?

Many varieties of protozoa can be identified in human excrement. Cysts of the following classes are often localized in the intestine:

1. amoebiasis;
2. flagella;
3. ciliated;
4. coccidia;
5. amoebic.

Amoebiasis. This disease is caused by dysenteric amoeba. This simple microorganism lives in the intestines of the host and is excreted from it as a cyst or trophozoite.

But most amoebas are not pathogenic microorganisms. These are Hartmann's, Bütschli's, intestinal amoeba, entamoeba coli and en nana cysts. Determining their presence in feces is not easy.

But the dysentery amoeba cyst is easier to detect. If it was found in feces, it indicates the development of dysenteric or ulcerative colitis in a person.

The following forms of amoebas are hatched in feces:

• luminal;
• fabric;
• encysted.

If during the diagnostic process luminal amoeba cysts are identified, this indicates that the disease has acquired a chronic form.

Complications of amoebiasis are:

1. bleeding from the anus;
2. peritonitis;
3. intestinal abscess;
4. tumor-like formations.

Balantidiasis. Balantidium is a circumlocal microorganism belonging to the ciliated family that lives in the intestine.

It is noteworthy that sometimes balantidia cysts are detected in the stool of healthy people.

Giardia belongs to the flagellates. Their cysts are very tenacious, because they are not afraid of low or high temperatures.

In the external environment, their life cycle is quite long. Moreover, they can remain in active form in unfavorable conditions for no more than 30 minutes.

Giardia cysts have an oval, pear-shaped shape. Their width (6-10 microns) and length (6-10 microns) can be different.

The urinary tract, small intestine, duodenum and bladder are considered favorable environments for the existence of the active form.

Giardiasis is mainly diagnosed before the age of 10 years. In this case, helminthiasis is severe, which is accompanied by skin rashes, weight loss, foamy stools, loss of appetite, vomiting and bloating.

Giardia damages the intestinal mucosa, mechanically blocking the passage, which affects digestion. Thus, the food is not digested and rots, causing a mass of bacteria to form. All this provokes the development of diseases of the bile ducts, pancreas and gall bladder.

Cryptosporidosis. Cryptosporidium are microorganisms that harm the mucous membrane of the gastrointestinal tract and respiratory organs. Ooscysts of Cryptosporidium parvum are spherical in shape, with a diameter of 4.2-5.4 µm.

In HIV-infected people, cryptosporidium lives throughout the gastrointestinal tract, from the mouth to the rectum. Complications of cryptosporidosis include:

• sclerosing cholangitis;
• hepatitis;
• cholecystitis.

To identify amoeba nana cysts and other types of protozoa in human feces, microscopic examination is carried out. To do this, biomaterial is taken from the patient for analysis, to which an ether solution is added and placed in a centrifuge. The centrifuged material is then divided into four parts.

The remaining sediment should contain cysts of unicellular microorganisms. Next, the mixture is applied to a glass slide, stained with a special solution. Thus, protozoan cysts can be seen using an electron microscope.

In addition, to identify certain types of single-celled organisms, products prepared according to Gram are used to stain glass. However, such analysis is ineffective for some species of protozoa (cryptosporidium).

To monitor therapy, tests that detect the presence of cysts of single-celled microbes are done depending on the type of disease. So, for balantidiasis and amoebiasis, the study must be done 48 hours after the start of treatment, and in the case of giardiasis - after seven days.

In preparation for the analysis, you should not eat foods that thin your stool, or drink laxatives. In addition, two days before the test, it is not recommended to use oils, rectal suppositories and agents that stimulate intestinal motility. You should also not eat foods that are colored.

A study to detect protozoan cysts in feces is recommended for children of school and preschool age and people who have been abroad.

Tests must also be taken if you consume low-quality raw water (accidentally swallowed when swimming in an open body of water) and unwashed or poorly heat-treated food.

The medications should be taken 4 times a day. If treatment measures are taken in a timely manner, the prognosis of the disease is favorable.

Amebiasis is treated based on the type of invasion and the condition of the patient’s organs and mucous tissues. Often, treatment of the disease involves taking Nitroimidazole:

• Fasizhin;
• Secnidazole;
• Ornidazole;
• Trichopolum;
• Metronidazole.

Such drugs are used for the treatment of intestinal amebiasis, as well as for all kinds of abscesses. Patients with amoebic dysentery whose course of the disease is severe, in addition to the listed drugs, are prescribed antibiotics. In this way, purulent abscesses can be prevented.

In the case of abscesses, they are drained through the skin (aspiration). Today, amebiasis can be cured completely, but only with timely treatment. But for this it is necessary to carry out early diagnosis and choose competent treatment tactics.

1. Nitazoxadine;
2. Azithromycin;
3. Paromomycin;
4. Mepron.

This infectious disease is often accompanied by diarrhea. To get rid of it, Imodium is often used.

In addition to drug therapy, the patient must adhere to a diet. To normalize the functioning of the digestive system, the doctor prescribes mucoprotectors and enzyme agents. At the same time, it is important to drink enough liquid during therapy.

If Giardia cysts are detected in the stool, multi-stage treatment is carried out:

• preparatory;
• basic;
• rehabilitation.

After contact with animals, you should wash your hands thoroughly. It is important to use only purified water for drinking and cooking. Moreover, you should not use someone else's towel or wear underwear.