Nematodes in humans: what is it, symptoms and treatment, photo

Nematodes are parasites from the order of roundworms, which have more than 24 thousand species.

The habitat of nematodes is quite wide.

They are common both in the environment and nature, as well as in humans, animals and even plants.

Currently, there are some types of nematodes that are found in humans:

Roundworms in humans in the body are able to be in quantity 45 kinds at the same time, which threatens with serious complications. Diseases caused by the vital activity of parasites are called nematodes.

Parasite classification

Nematodes are divided into 2 groups:

  • First: free-living, which live at the bottom of reservoirs, in rotten leaves and in moist soil.
  • Second: parasitic, which carry out their vital activity in the human or animal body. Such worms can grow up to 0.5 meters in length.

All nematodes have common distinctive characteristics:

  • have a rounded shape;
  • there is a nervous and digestive system;
  • well-developed reproductive system;
  • basically all species are heterosexual, while the female differs from the male parasite in size and shape.

Development and vital activity of nematodes

During the entire cycle of their development, nematodes do not have metamorphoses. The vital activity of parasites is divided into 4 stages of early development and 1 stage of an adult.

The eggs and larvae of parasites that live in the soil can exist in conditions of unsuitable for the existence of nematodes that live in the body.

They are also adapted to survive without intermediate hosts, which is impossible for individuals living in the body.

The life cycle of nematodes is built along the following chain:

The eggs containing the larvae enter the human body. This stage is called infectious. The larva is then released and trapped in the small intestine. Then it penetrates into the mucous membrane and begins to develop.

After a certain amount of time in the large intestine, the parasites become adults and begin to multiply.

Then comes the diagnostic period when helminth eggs are found in the feces. Together with feces, eggs enter the environment, and the second cellular stage of nematode development begins. Then, increased cell division occurs and a larva forms in the egg. And the process is repeated in the same circle.

Causes of occurrence

Despite the fact that nematodes are a fairly common type of worms, there are the following reasons for infection:

  • the ingress of parasites into the gastrointestinal tract through dirty hands and unwashed vegetables and fruits;
  • with an insect bite. With this route, infection occurs with eggs or larvae of parasites;
  • through the skin, even without damaged areas, in direct contact with water and soil that is contaminated.

As a rule, representatives of adults enter the body, where they continue their vital activity.

Organs where nematodes can be located

Human nematodes can be found in organs such as:

  • muscle tissue;
  • gastrointestinal tract;
  • respiratory system;
  • liver;
  • kidneys.

Symptoms

You can suspect the presence of parasites (see photo above) when a person has symptoms such as:

  • pronounced itching in the anus and genitals;
  • nausea and urge to vomit, arising in the form of seizures;
  • after eating foods containing protein, satiety appears;
  • pain syndrome appears in the muscles;
  • fatigue and mood swings;
  • disruption of the gastrointestinal tract;
  • decreased immunity.

Disease types

Roundworms can cause some diseases in humans.

Ascariasis - appears when infected with roundworms. This type of parasite can only exist in the human body.

In length, this type of nematode can grow up to 0.5 meters ... Eggs can exist in a hostile environment.

Ascaris live in the small intestine. Infection occurs through dirty products. Larvae emerge from the eggs, which can migrate through the body and enter the vessels.

Through the means of blood, they can enter the lungs, liver or atrium.

For a full-fledged existence, roundworms need oxygen, in this regard, they migrate to the bronchi and trachea.

This type of disease is characterized by symptoms such as:

  • headache;
  • fast fatiguability;
  • irritability.

Intestinal obstruction can develop as a complication.

Ascariasis can cause changes in the organs of the digestive and respiratory systems. In the latter case, mechanical asphyxia may occur.

Enterobiasis - infection occurs when pinworms enter the body. A fairly common disease. Pinworms are small worms with a white color. A male individual reaches a length of 3 mm, and a female 12 mm.

Infection with this type of parasite occurs in violation of hygiene and in most cases is recorded in childhood.

Due to the special structure, parasites are fixed in the intestine, feeding on its contents and blood.

Symptoms typical for this type of disease:

  • fast fatiguability;
  • sleep changes;
  • allergic reactions;
  • headache;
  • dizziness;
  • acute itching.

With the latter symptom, the child strongly scratches the skin, while pinworm eggs fall on the hands and are carried at the household level.

Trichocephalosis caused by parasites of whipworms. The worm can grow in length up to 5 cm ... the body is filamentous. A distinctive feature of whipworms is the body, where the front half is narrower than the back. The main habitat of the whipworm is the large intestine. The parasite enters the body through water and dirty food.

Symptoms indicating this disease:

  • anemia;
  • pain in the abdomen;
  • disorders of the nervous system.

Hookworm occurs when infected with a crooked head. The nematode is small in size and pink in color. The masculine can grow in length 10 mm , and the female 18 mm.

The habitat of the parasite is usually the duodenum. This nematode species is common in tropical areas.

The parasite can only live in the human body. It has 4 teeth in the mouth, it feeds on blood.

Infection occurs only through contaminated food or water and through the skin.

Symptoms of a crooked head infection:

  • depression;
  • headache;
  • poor memory and attention disorder;
  • disturbance in the work of the gastrointestinal tract;
  • pain in the duodenum;
  • fast fatiguability.

If treatment is not started on time, the patient may die.

Diagnostics

It is believed that if a person has itching in the anus or gritting teeth in a dream, then this is an unambiguous presence of parasites in the body. But this is not the case. To make an accurate diagnosis, it is necessary not only to consult a doctor, but also to undergo a series of studies.

The most accurate diagnosis is the study of feces. It is carried out 3 times for a reliable diagnosis. Nimatodes in humans in the body during their existence produce a huge number of eggs. Their presence in feces and speaks of a particular type of disease.

How auxiliary research methods are used:

  • testing for the presence of antibodies;
  • a blood test, when infected with worms, notes a change in the level of leukocytes;
  • analysis of feces for worm eggs;
  • biopsy;
  • morphological studies;
  • in some cases, X-rays and MRIs are done.

Treatment

When a nematode is diagnosed, treatment is primarily medication. Oxygen therapy is also used.

Means against worms are prescribed exclusively by a doctor, since such drugs have a strong toxic effect and an accurate calculation of the ratio of mass and dose is necessary. Appointments are based on research data.

Oxygen therapy is the introduction of pure oxygen into the intestines. There are some types of worms for which this procedure is fatal. After death, they come out naturally.

In addition, various kinds of laxatives are used.

Drug treatment

Various anthelmintic drugs are used to treat worms:

  • Nemosol - the most effective drug against worms of various types. This drug slows down the metabolism of parasites, inhibits the output of glucose, which leads to the complete destruction of nematodes;
  • Pirantel - paralyzes parasites, after which they die. The advantage of the drug is the absence of toxic substances and safety. This drug can be used during pregnancy, during breastfeeding, as well as in children;
  • Nourished - one of the most effective means for treating parasites of almost all types. This drug has a number of contraindications;
  • when the parasites are located outside the intestine, Diethylcarbamazine or Ivermectin .

Surgery

Surgical intervention is performed only when the parasites are located in the liver, heart, biliary tract, brain, eye.

In other cases, surgical treatment is not used.

Complementary home treatments

In addition to drug treatments for nematodosis, there are a large number of folk recipes for fighting parasites. They are herbal and herbal based.

But it is worth remembering that in no case is it possible to self-medicate, since you can not only not be cured, but also harm and aggravate the disease.

Before taking any infusion, you should consult your doctor.

Herbs and fees

Wormwood herb has long been considered an excellent remedy for the fight against worms. It is used in different forms.

  • To prepare the powder you will need: 0.3 g of well-crushed wormwood leaves, which are placed in a capsule. It is necessary to use the product before dinner with water. Reception scheme:
    • 1-2 days, 1 capsule;
    • 3 day 2 capsules;
    • From 4 to 7 days, add 1 capsule daily.
    • From 8 to 14 days, 7 capsules daily.
  • For infusion, you need to take 2 teaspoons of dry wormwood leaves and pour 200 ml of boiling water. After 20 minutes, the infusion must be filtered. Take ¼ cup 3 times a day 30 minutes before meals. When using a pharmacy tincture, take 30 drops 3 times a day.
  • Wormwood juice with honey is also used in a ratio of 3: 1. Take 1 teaspoon 3 times a day and at night. To prepare the syrup, you need 50 g of wormwood herb, soak it in water. Then add 0.5 kg of sugar to 0.5 liters of water. Then you need to cook the resulting mixture over low heat for 40 minutes.

You can also use:

  • Tansy flowers , should be taken with caution, as there are contraindications. To prepare the product, you will need 250 grams of tansy flowers, which must be filled with 400 ml of vodka and infused for 7 days. Take 25-30 drops after meals. The course is 10 days.
  • Troichetka has the greatest effect. It is necessary to take in equal parts wormwood, tansy and cloves. Grind the mixture well. Prepare capsules of 0.3 g each, for this you can use bread. Reception scheme:
    • 1-2 days, one capsule in the morning.
    • Day 3: 1 capsule in the morning and in the evening half an hour before meals.
    • From 4 to 10, 1 capsule 3 times a day.

Take with caution in people with a history of stomach ulcers and hypertension.

  • Prepare an infusion of ginger. You will need grated ginger root. Pour 1 liter of cold water and place in the refrigerator. After 2-3 hours, take 1 glass per day.
  • Grated ginger root combine with 2 tablespoons of honey and 10 ml of water. Take the resulting mixture 1 tablespoon on an empty stomach. The effect will appear in 3-4 weeks.
  • It helps well garlic against parasites and worms. It is enough to eat 4 g of garlic per day.
  • Pumpkin seeds help destroy parasites. To do this, you need to consume them in an amount of 32 g per day.
  • Fresh pineapple , due to the presence of bromelain, an enzyme that destroys the shell of the worm, after which it is broken down by gastric juice.

Complications

With an untimely visit to a doctor and, accordingly, delayed treatment, complications are possible in the form of:

  • intestinal obstruction, when a large number of parasites accumulate in its lumen;
  • penetration of nematodes into the gallbladder and its ducts;
  • intoxication of the body, by the waste products of parasites;
  • appendicitis, when nematodes enter the appendix;
  • entry of worms into the respiratory tract, as a result of which mechanical asphyxia is possible;
  • peritonitis arising from liver abscesses and purulent cholangitis;
  • helminthic invasion, which leads to various pathological processes in the body.

Prophylaxis

In order to avoid infection with nematodes, it is necessary to adhere to some prevention rules:

  • compliance with the rules of personal hygiene. Use only personal hygiene items;
  • it is good to wash your hands after the street, toilet and before eating;
  • thoroughly wash vegetables and fruits, even those that are grown on their own;
  • give food to proper heat treatment;
  • use boiled or bottled water for drinking. Do not swim in polluted waters;
  • do not walk barefoot in nature, as some types of parasites can penetrate the skin, for example, a whipworm;
  • while cutting nails and changing underwear.

After a vacation outside the city or in other cities or countries, it is necessary to take an analysis for worm eggs. This will help to identify the disease in time and start timely treatment.

Nematodes are an integral part of nature. By following simple rules, a person can avoid becoming infected with these parasites.

Forecast

If symptoms appeared and treatment was followed in a timely manner, then the prognosis is positive. With timely detection of the disease and the correct treatment tactics, getting rid of parasites is not difficult. The main thing is to consult a doctor on time and follow all the recommendations.

Do not self-medicate, as this very often leads to serious complications. Before using any product, you need to consult a specialist. And if all preventive measures are followed, it is very easy to avoid infection and, accordingly, problems.

Related Videos

The class of nematodes (from the Greek nema - thread, and eidos - similarity), also called in another way - actually roundworms. The class of nematodes is represented not only by parasitic forms, but also by free-living individuals living in sea and fresh water bodies, soil, where their concentration can exceed 1 million per 1m 3... Many parasitic forms of this class are of medical importance.

Diseases that cause roundworms are called nematodes. Various parasites affect the liver, kidneys, lungs, gastrointestinal tract, muscles. At the present stage of development of society, the therapy of most nematodes has been successfully developed and they are easily treatable.

Determination of the pathotype of nematodes is a very important point in breeding work to create cultivars of plants that are resistant to nematodes. The creation of a variety that is resistant to only one pathotype of the parasite is futile, since it can be attacked by another, more aggressive pathotype.
Ascaris
  • a brief description of
  • The body of the roundworm is not segmented, pointed at both ends, covered with a dense shiny cuticle, which serves as an external skeleton and serves as protection from mechanical influences, poisons and digestive enzymes. The presence of only one layer of the longitudinal musculature is characteristic.

    Females (up to 30 cm in length) are larger than males (up to 20 cm). In males, the posterior end of the body is bent, on it there are cuticular needles - spicules, which serve to hold the female during copulation (Latin copulatio - connection) - the connection of two individuals during intercourse. In one day, a female roundworm is capable of laying up to 240 thousand eggs in the human intestine.

    The mutual evolution of parasitic nematodes and their host plants over millions of years resembles an arms race: plants develop more and more perfect defense mechanisms (for example, thicken integumentary tissues or increase the synthesis of "antibiotics" phytoalexins), while the nematode, respectively, a system of attack (strong stylet or body covers impervious to phytoncides).
  • Life cycle
  • Ascaris, like many other parasites from the nematode class, is a geohelminth - it does not need an intermediate host, the eggs ripen right in the soil, once in favorable conditions.

    Adults live in the human intestine, releasing up to 240 thousand eggs daily. Together with feces, eggs enter the external environment. At this moment, they cannot infect anyone. For an egg to become invasive - capable of infection, 2-3 weeks must pass at a temperature of 20-25 ° C and sufficient air humidity.

    If all the conditions are met, the egg becomes invasive and can infect a person. Once in the intestine, a larva emerges from the egg, which migrates. It perforates the intestinal wall, enters the bloodstream and through the liver, the right atrium and right ventricle reaches the lungs. Here, the larva enters the alveolar cavity (pulmonary vesicle), and then crawls upward, passing through the bronchi, trachea, and pharynx.

    The world of these amazing creatures is very complex and interesting in itself, while studying the secrets of the extraordinary evolutionary success of phytoparasitic nematodes is important not only for fundamental science, but also for practical purposes - preserving the world harvest of agricultural crops.

    During such massive migrations of larvae, pneumonia is possible. Having reached the pharynx, the larva is swallowed a second time by a person and only after that, entering the intestines, it turns into a sexually mature individual. The cycle is closed.

    The publication uses photos of the author
  • Method of infection and prevention
  • A person becomes infected by eating an invasive roundworm egg (by the fecal-oral route) with unwashed fruits and vegetables. Ascariasis is a disease of dirty hands, children often get sick with it. Prevention consists in sanitary and educational work with the population, improvement of settlements adjacent to water bodies, adherence to the rules of personal hygiene (washing hands, fruits, vegetables).

Pinworm
  • a brief description of
  • Geohelminth that lives in the human intestine. Causes the disease - enterobiasis. The female is up to 12 mm long, the male is 5 mm. Outbreaks of pinworm disease occur in children's groups - this parasite, thanks to its life cycle, reproduces well among children, let's see - what is the trick of pinworms?

    Pinworm
  • Life cycle
  • In the human intestine, adults reproduce sexually. After breeding, the male dies, and the female descends into the rectum. At night, the female crawls out of the anus and spreads eggs in the perianal region. Soon after such a sortie, the female also perishes.

    When oxygen is available, eggs become invasive after 4-6 hours. The child develops itching in the perianal region and, of course, the child begins to itch - the eggs fall on his hands. If the hygiene rules are not followed, the child often infects himself (autoinvasion). The eggs enter the intestines, where they develop into adults.

    You can imagine a kindergarten and (just one) sick child who takes toys with "these" hands. All children can get sick with enterobiasis in one day, the kindergarten is closed for quarantine and thorough disinfection is carried out - unfortunately, I assure you, this is a very true scenario.

    Literature
  • Method of infection and prevention
  • A person becomes infected by the fecal-oral route: most often, an invasive egg enters the gastrointestinal tract with unwashed hands. Prevention consists in sanitary and educational work, regular preventive measures in children's groups, strict adherence to hygiene rules - washing hands, caring for nails.

Guinea worm
  • a brief description of
  • Rishta (Tajik, literally - thread) is a parasitic round worm that lives in the subcutaneous fat of humans and animals. The female is up to 120 cm long, the male is up to 30 cm long. The spicules and papillae are located at the posterior end of the body. The final owner for a rishta is a man, a dog, a monkey. The intermediate host is the freshwater crustacean Cyclops. Dracunculiasis causes the disease.

    Guinea worm
  • Life cycle
  • Pridannikov M.V., Shumilina D.V., Kromina K.A. conf. parasitologists of Siberia and the Far East. Novosibirsk, 2009. 226-228.

    Once in the reservoir, the larvae of the rishta are introduced into the organism of the freshwater crustacean Cyclops, an intermediate host. After 14 days, the larva becomes invasive, and can be swallowed by the final host together with water from the reservoir. In the intestine, the larvae migrate through the intestinal wall into tissues, where they reach sexual maturity, after which they mate.

    After mating, the male dies, and the female migrates to the host's subcutaneous tissue. After about a year, on the body of an infected person, the head end of the female forms a bubble, which burns strongly, extremely painful. Instinctively, you want to cool it with water - this is just what the rishta is waiting for.

    Upon contact with water in a reservoir, the bubble bursts and thousands of larvae of rishta go out into the water, infecting cyclops crustaceans. The cycle is closed. Looking at the picture below, try to retell the rishta cycle in your own words.

    Pridannikov M.V., Shumilina D.V., Kromina K.A. conf. parasitologists of Siberia and the Far East. Novosibirsk, 2009. 226-228.
  • Method of infection and prevention
  • A person becomes infected by drinking a cyclops crustacean with water, in whose body there are viable larvae. Prevention consists in sanitary and educational work among the population, the protection of drinking water from pollution, the destruction of freshwater crustaceans - cyclops, the inadmissibility of drinking raw water, its obligatory boiling.

Trichinella
  • a brief description of
  • The length of the female is up to 3-4 mm, the length of the male is 1.4-1.6 mm. The hosts of Trichinella are most often carnivores. It is noteworthy that one and the same species serves first as the final and then as the intermediate host of Trichinella. Thus, Trichinella was able to achieve a unique life cycle - without the larvae entering the external environment at all. Causes disease trichinosis.

    Trichinella
  • Life cycle
  • Trichinella larvae swallowed with meat become sexually mature in the human intestine. As a result of sexual reproduction, females give birth to larvae, which pierce the intestinal wall and enter the bloodstream, spreading throughout the body. Encapsulated larvae form in organs and tissues.

    Think about it - the smallest larvae, which are visible only under a microscope, settle in muscles throughout the body! It becomes painful for a person to move, chew (chewing muscles are affected) and even breathe due to damage to the diaphragm, respiratory muscle. Five larvae in the muscles per 1 kg of body - a lethal concentration, leading to death.

    In the animal kingdom, the parasite is transmitted along the food chain - the predator eats the prey, in the muscles of which there are Trichinella, and infects itself: adults develop from the larvae in the intestines. The cycle is closed. In this sense, for Trichinella, a person is a dead-end owner, since no one eats him.

    Phytoparasitic nematodes of Russia / ed. S. V. Zinovieva and V. N. Chizhova. M .: Partnership of scientific publications KMK, 2012.
  • Method of infection and prevention
  • Most often, a person becomes infected with trichinosis by eating pig meat with encapsulated larvae (including in the form of lard), which has not passed sanitary control. Prevention consists in sanitary and educational work among the population, sanitary control of fat and pig meat, inadmissibility of eating meat that has not passed control.

    Separately, I note that Trichinella larvae are extremely resistant and can remain viable even with prolonged cooking of meat.

Cobb N. A. Nematodes and their relationships. // Yearbook United States Department of Agriculture. United States Department of Agriculture. 1914. p. 457-490.

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What is a nematode and how to deal with it?

Crop production is an occupation that requires the farmer to pay constant attention to his own plantings in order to protect them in time from the invasion of unwanted guests. Nematoda is one of those enemies that you need to react to especially quickly, otherwise the consequences can be severe.

  • What is it and what happens? These pests are also called roundworms in another way, which well describes their appearance. At the same time, nematodes are not one biological species, but a large group of related species capable of infecting not only plants in the garden or greenhouse, but also animals.
  • For this reason, such parasites are doubly dangerous, but acquaintance with them should begin with an approximate description of the most common varieties. Stem
  • ... The name implies the main danger of such nematodes - they like to penetrate into the stem, blocking the transfer of sap and affecting all parts of the plant above the ground, poisoning them with the toxins produced. The pest is dangerous for vegetable and flower crops, often found on cucumbers and garlic, tomatoes and phlox. Thickening in the form of a spindle on the stems, their deformation with the appearance of cracks, brown corrugation on the leaves, loose tissue in the bulbs - all these are signs of the activity of the described enemy. Sheet

... If the previous species chooses stems as a habitat, then this one, accordingly, lives in foliage. The effects of infection are best seen, again, in the leaves, which turn pale and yellow, thin, dry and eventually die. At the dacha, the consequences of the penetration of intruders are most noticeable for ornamental crops, but strawberries are also at risk.

Root (gallic).

Such worms live in the soil. A soil pest affects the root system, forming specific growths on its surface - galls, which interfere with the normal absorption of moisture from the soil. Lacking water and nutrients, garlic, beet and cucumber bushes begin to dry and wither for no reason.

It is believed that the rootworm nematode is especially interested in greenhouse crops, but it is also dangerous for open ground, where it can get to tomatoes, cabbage, clematis and many other crops.

  • Signs of defeat
  • The most obvious sign that a plant has developed a fierce foe is when you directly see nematodes. The pest looks like a very long, thin, whitish worm. The problem with its detection is that most often it lives in the roots, and can even penetrate into the structure of the plant, while it is practically not found on the leaves.
  • Accordingly, it is usually possible to suspect that an invisible enemy is hitting the garden bed only by the characteristic symptoms:
  • the planted crop shows an unusually low germination rate;
  • growth and development slows down significantly;

on the leaves and other parts of the plant, visible deformations appear in the form of dark brown dead spots surrounded by a beige halo;

flowering and fruiting show a marked decline; adult plants begin to hurt often and for a long time, and young plants are able to die from any negative factor that is not expressed enough to kill greens alone.

Mechanical methods of struggle Nematodes are an enemy that is considered very serious and difficult to remove, but at the same time theoretically allows you to save even those bushes that are already completely affected.

This possibility is provided by the mechanical method. We will fight the enemy in the following way - all the affected plants must be carefully dug up and the rhizomes removed from them, dividing them into several parts. The method is practical only if the cultivated culture allows reproduction by division - then the divided bush can be continued to grow in the form of the cuttings obtained. The worm could hardly affect the entire plant as a whole, especially if the farmer noticed the warning signs in time, because some of the cuttings obtained should be healthy.

The more cuttings made from a bush, the more likely it is that the percentage of healthy bushes will be high.

At the same time, in order not to contribute to the spread of the infection, each stalk must be cultivated under quarantine conditions. This means that they cannot be grown in the same pot or in close proximity to each other. At the same time, staying in quarantine is relevant for perennial plants, because its recommended period is at least a year.

Heat treatment You can also get rid of pests with the help of an increased temperature, after all, there are practically no biological species on earth that can withstand uncomfortable heat for a long time. In a sense, humans are lucky with nematodes - they are "burned" at a temperature that is still incapable of harming a cultivated plant. It is assumed that heat treatment will be safer for plants that are not currently in the stage of active growth, therefore, it is usually carried out during a dormant period. As a forced measure, it is allowed to use the technique when transplanting plants (which is already stressful).

The bottom line is to treat affected areas of the plant with warm water: +50 degrees will be enough, such a temperature threshold should not be exceeded in order to avoid the possible appearance of burns already on the culture itself. The thermal method is most convenient for fighting rootworm nematode - the roots are simply dipped in warm water. It is enough to hold them in such a liquid for 5-15 minutes, after which a cooling session is required, when the roots are already dipped into cool water.

The simplicity of the technique would surely attract a lot of followers, but there is a problem:

it is not potent enough to fight serious infection. Summer residents resort to heat treatment usually as a kind of prophylaxis - if the nematode has just penetrated into the plant, without having time to noticeably manifest itself and multiply, this effect may be enough to defeat it. The method is good for quickly processing a large number of plants, but it is not suitable for saving a sick specimen.

What means to use?

All known types of nematodes are considered terrible and dangerous enemies of the summer resident, not only because of their gluttony and omnivorousness, but also because it is quite difficult to destroy them on the site - many "traditional" pest control drugs do not really work on them. However, humanity has not yet died out of hunger, which means that farmers have still found effective methods of combating the infection, allowing them to prevail over it. Chemical If the easiest way to fight you consider the need to treat the bed with "chemistry", pay attention for specific drugs

specifically aimed at combating nematodes. They are called nematicides. The peculiarity of such substances is the ability to effectively kill worms without disturbing either the chemical composition of the soil or the balance of bacteria and fungi. Good examples of such drugs are "Aktofit" and "Fitoverm" ... In both cases, it is a powder that must be scattered over the soil surface a few days before planting seedlings and "drown" in the ground using a cultivator. The preparations show good results in cleaning the soil from the most common root nematodes, but, alas, they will not help in any way in the case of plants that are already infected.

It is still possible to save a plant that has entered the growing season and shows clear signs of nematode infection, but this will require an order of magnitude more "heavy artillery". Knowledgeable summer residents are advised to use systemic drugs, such as

Aldoxycarb, Alanicarb, Marshal and Karbofuran

... Another thing is that all these substances are characterized by increased toxicity not only for nematodes, but also for humans or domestic animals, therefore, they can be used in everyday life with great care.

According to the instructions, they resort to their help mainly in open areas, while the use in greenhouses or even more so in a residential building is highly undesirable. Farms operating on an industrial scale must ventilate greenhouses before using such "chemicals", and also provide forced ventilation.

After all of the above, it is hardly necessary to specify separately that processing is carried out only with strict adherence to the rules of chemical safety - the farmer should at least protect his hands, eyes and nose. Biological The enemy of my enemy is my friend, and this rule works not only in relations between people, but also in the fight against pests in the beds. In nature, there are practically no living organisms that do not have natural enemies, which means that the human task is to help ensure that such enemies of nematodes, harmless to agricultural crops, are present in the garden and have good conditions for reproduction. A number of organisms are capable of parasitizing the larvae of worms, preventing them from developing normally. This includes certain types of carnivorous (not "vegetarian") nematodes, as well as ticks and fungi. Such organisms can be purchased in the form of a biological preparation in stores for summer residents.

You do not need to spend money on the drug, stimulating the natural appearance of the necessary organisms in the soil. The easiest ways are to add organic fertilizers or even ordinary sugar dissolved in water to the soil. ... Thanks to such additives, the number of saprophytes in the soil will grow many times over, and the necessary species will come after them. Here, however, it is important to understand that the presence of living creatures parasitizing on nematode larvae is only a deterrent for their reproduction and further spread, but it will not work to heal already diseased plants in this way. Biological control methods can include breeding not only predators, but also plants that can demonstrate phytoncidal properties, that is, scare off pests.

Calendula and marigolds are some of the most popular phytoncides

whose presence in the garden means that pests (and nematodes among them) will bypass the side of the garden. However, the landing of such assistants is not needed somewhere in the corner and not around the perimeter of the garden - for full protection, they must grow between every two adjacent rows of the main crop.

Prevention measures

  • All the described measures taken together are usually still unable to give a result of the level when the nematodes completely disappear from the site.
  • The task is more realistic: if the enemy cannot be completely destroyed, it is necessary at least to keep its numbers under control. Naturally, it is more reasonable to spend energy not on fighting a stronger enemy, but on counteracting the fact that it becomes too much.
  • The following are considered effective measures:
  • regular and timely removal of weeds, which can also become a haven for breeding nematodes and additionally weaken cultivated plants;

obligatory laying of manure in the soil;

Lambert K., Bekal S. Introduction to Plant-Parasitic Nematodes. // The Plant Health Instructor. DOI: 10.1094 / PHI-I-2002-1218-01.

diligent spilling of the soil mixture and its subsequent drying, which repeatedly alternate with each other;

planting on "alien" beds of legumes, as well as watercress - these plants are considered capable of resisting the spread of the most dangerous root nematode, controlling its population on the site.

The use of preventive measures alone does not guarantee that the nematodes will never reach the crops, but together with the other methods described above, this will allow the farmer to collect an acceptable yield and maintain a positive balance of his farm.

: 29 Sep 2014,

My NSU

, volume 57/58, no. 3/4

Phytopathogenic nematodes: the crop is threatened

Nematodes, or roundworms, are one of the most numerous and widespread multicellular animals. Representatives of about half of the species live in soil or in the aquatic environment, and the rest parasitize on animals, including humans, and plants. Phytoparasitic nematodes are among the most dangerous and economically significant pests of agricultural crops: global crop losses from them are estimated at 77 billion dollars a year!

In Russia, phytoparasitic nematodes are studied at the Center for Parasitology of the Institute of Ecology and Evolution. A.N. Severtsov RAS (Moscow) and at the All-Russian Scientific Research Institute of Phytopathology of the Russian Agricultural Academy. Here, diagnostic kits are being developed for the molecular genetic identification of the most significant phytoparasitic nematodes, promising and environmentally friendly biological products for plant protection are being developed, as well as transgenic varieties of potatoes, sugar beets and rapeseed that are resistant to root cyst nematodes.

Nematodes, or roundworms, are one of the most numerous and widespread multicellular animals on our planet: they account for about 4/5 of the biodiversity of the entire animal world! Representatives of about half of the nematode species live in the soil or in the aquatic environment, however, the rest lead a parasitic lifestyle, presenting a big problem for agriculture and medicine

Back in 1914, the famous biologist, the “father” of American nematology N. Cobb wrote: “... if all matter in the universe, except nematodes, disappeared in an instant, our world would still be vaguely recognizable: we could assume where there were mountains, hills, valleys, rivers, lakes and oceans only on a thin film of nematodes. It would be possible to determine the location of cities, since each community of people would correspond to an accumulation of certain nematodes. Along the non-existent streets and alleys, trees would still stand in ghostly shadows. Plants and animals would remain distinguishable, and if we had enough knowledge, we could in many cases even pinpoint their species by studying the parasitic nematodes that once inhabited them ”(Cobb, 1914, p. 472).

Indeed, the biodiversity of nematodes is simply amazing: in this sense, among all animals, only insects are superior to them. With their small size, nematodes have occupied almost all ecological niches where there is at least a small amount of water: from the mountain slopes of the Himalayas to the bottom sediments of the Mariana Trench; from hot African deserts to cold soils of the Arctic and Antarctic; from the integuments of small insects to the insides of sperm whales. Of the more than 24 thousand described species of nematodes, about 40% lead a free lifestyle and feed on bacteria, fungi, protozoa or even other nematodes. However, about 44% of nematodes parasitize animals, including humans, and the rest are to some extent associated with plants. Almost all higher plants known to us can host one or more parasitic nematode species (Lambert & Bekal, 2002). Target - plant Parasitic plant nematodes (so-called phytoparasitic

or

phytopathogenic

) are among the most dangerous and economically significant crop pathogens in the world. The host plants of these nematodes include many important food and forage crops, including cereals, vegetables and legumes, as well as ornamental and flower crops. According to some estimates, global crop yield losses from nematode parasitism on plants are estimated at over $ 77 billion per year (Sasser & Freckman, 1987)!

Sasser J. N., Freckman D. W. A world perspective on nematology: the role of the society. // Vistas on nematology: A commemoration of the twenty-fifth anniversary of the Society of Nematologists / eds. Veech J.A., Dickson D.W. Hyattsville, MD: Society of Nematologists, 1987. p. 7-14.

In Russia, there are about 150 species of parasitic nematodes that affect the vegetative (shoot and root) and generative (seeds and fruits) organs of plants from different families. In addition, some of these nematodes are simultaneously carriers of fungal, bacterial and viral diseases, which enhance their negative effect on infected plants.

Nematodes are the second most species-rich group of the animal kingdom after insects. Parasitic plant nematodes morphologically differ little from each other, except perhaps in size (from 0.5 to 5.0 mm). The worm-like body of nematode larvae is specially adapted to move along soil capillaries or the intercellular space of plant tissue. The main differences relate to the manifestation of changes in plant organs (symptoms of damage), visible to the naked eye. Gall nematodes cause the formation of nodules (galls); leaf nematodes often form a mosaic on the leaves, caused by the death of some of the cells between the leaf veins; migrating root parasites can stimulate root "beardiness", that is, the formation of a large number of small lateral root branches; virus-carrying nematodes infect plants with specific viruses, which, in turn, cause chlorosis of the leaves, which manifests itself in the form of their bizarre yellowing

Unfortunately, the methods for controlling the number and harmfulness of phytoparasitic nematodes are currently not diverse. Highly effective chemical preparations-nematicides, due to their toxicity, have a harmful effect on the environment, including on human health, therefore, their use in agriculture is limited. The use of biological preparations based on bacteria and fungi pathogenic for nematodes, as well as specialized predators, is not always economically justified.

The most accessible method today is still the prevention of phytohelminthiasis through the application of measures to limit the spread of nematodes from the focus of infection (quarantine measures), as well as such agrotechnical methods as the cultivation of resistant varieties and science-based crop rotation systems.

Know the enemy by sight!

One of the important points in protecting plants from harmful nematodes is their correct and timely diagnosis. Only by accurately determining the representative of nematodes in each specific case, it is possible to recommend certain protective measures that will reduce crop losses.

Nematodosis

Today, there are three main methods for diagnosing nematodes. The first (classical) identification method uses a number of morphological features and morphometric parameters. By their appearance, representatives of different families, genera or groups of nematodes can be distinguished. To identify nematodes at the species level, quantitative characteristics such as body length and width, length of the stylet, esophagus, reproductive system, etc. are used. The main tools of the classical method for identifying nematodes are microscopes and special reference books (diagnostic keys). The modern molecular method for the identification of nematodes is based on the study of the structure of individual sections of their genome. It should be noted that it was the free-living nematode Caenorhabditis elegans that turned out to be the first multicellular animal whose genome was completely “read” (Genome sequence of the nematode C. elegans…, 1998).

Every year there is more and more information about the nucleotide sequences of various genes of parasitic and free-living nematodes. Today, having carried out a number of rather routine procedures, such as DNA isolation, polymerase chain reaction with visualization of the results in an agarose gel, one can confidently judge the belonging of the studied individual to a particular species.

ON THE DOMESTIC FRONT

Almost half a century ago, the famous Soviet phytohelminthologist A. A. Paramonov (1968 wrote: "The study of the secrets of the extraordinary success of nematodes - these are mostly small animals - one of the important problems of modern zoology and the entire national economy."

It was Paramonov who founded in 1952 the country's first Helminthological Laboratory of the Academy of Sciences of the USSR, the purpose of which was to study various aspects of the life of parasitic plant nematodes. Nowadays, this scientific "baton" was taken by the laboratory of phytohelminthology of the Center for Parasitology of the Institute of Ecology and Evolution. A. N. Severtsov RAS and the laboratory for diagnostics of phytopathogenic organisms of the All-Russian Scientific Research Institute of Phytopathology (VNIIF) of the Russian Agricultural Academy.

Work on the study of plant parasitic nematodes is carried out here in three main areas: study of the biodiversity of nematodes in Russia and monitoring the distribution of the main species of phytoparasitic nematodes; creation of systems for molecular identification of nematodes using genus- and species-specific primers for PCR; study of the biology of nematodes and the mechanisms of plant resistance to nematodes (Pridannikov et al., 2009).

The result of long-term painstaking work was the monograph "Phytoparasitic Nematodes of Russia" edited by Dr. Sc. S. V. Zinovieva, which presents a huge amount of information on the biodiversity of parasitic plant nematodes on the territory of our country, accumulated over the past forty years.

On the basis of VNIIF, a collection of living cultures of phytoparasitic nematodes was created, which is used as a basis for fundamental research on the phylogeny of nematodes and applied research on the resistance of agricultural crops to nematodes.

To unify methods for identifying nematodes, diagnostic kits were developed for molecular genetic determination by PCR of such important agricultural parasite species as potato cyst nematodes (Globodera rostochiensis and G. pallida), cereal cyst nematodes (Heterodera avenae, H. filipjevi, etc. ), root-knot nematodes (Meloidogyne incognita, M. javanica, M. arenaria, etc.) and many other species.

The study of the biology of phytoparasitic nematodes is impossible without studying their hosts - plants, as well as their relationships. A huge amount of material on the mechanisms of plant resistance to nematodes and the use of these mechanisms in plant protection against nematodes made it possible to develop a number of promising biological products for protecting agricultural plants from these parasites, such as immunocytophyte (based on arachidonic acid) and agrochite (based on chitosan).

In addition, transgenic varieties of potatoes, sugar beets, and rapeseed were created, into which the gene responsible for plant resistance to cyst nematodes was inserted (Dzhavakhiya et al., 2007).

The third, the so-called bioindicator method, serves mainly to divide one species of parasitic nematodes into pathotypes, that is, into separate intraspecific groups that differ in different pathogenicity in relation to different species or varieties of plants. For example, the potato nematode Globodera rostochiensis has five pathotypes, while the closely related species Globodera pallida has three. All of these pathotypes are distinguished by their ability to reproduce on different potato genetic lines.

Lambert K., Bekal S. Introduction to Plant-Parasitic Nematodes. // The Plant Health Instructor. DOI: 10.1094 / PHI-I-2002-1218-01.

diligent spilling of the soil mixture and its subsequent drying, which repeatedly alternate with each other;

planting on "alien" beds of legumes, as well as watercress - these plants are considered capable of resisting the spread of the most dangerous root nematode, controlling its population on the site.

The use of preventive measures alone does not guarantee that the nematodes will never reach the crops, but together with the other methods described above, this will allow the farmer to collect an acceptable yield and maintain a positive balance of his farm.

Nematodes in humans: what is it, symptoms and treatment, photo

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