Parasites are pathogenic microorganisms: main characteristics, types, clinical presentation and treatment. Definition of the concepts "parasite", "parasitism", "parasitic system" Brief definition of parasites

The real ones that are actually in another organism are excreted in its feces where they can be found (house fly larvae);

False (imaginary), which can accidentally get into the feces, brought, for example, for analysis (flies can lay eggs on them, and larvae quickly hatch from them).

1. Depending on the number of likely hosts:

Evriksenny (from the Greek.ωύρύω - wide) - those that have a wide range of hosts (ixodid ticks, mosquitoes);

heteroxenni (from the Greek.έτερος - different, different) - those that go through complex development cycles due to several owners. Yes, dog tick. passes three stages of development: larva, nymph, imago - and at each stage it has its own host.

Temporary - those that live outside the host's body and attack him only to feed on blood (ticks, fleas, mosquitoes, mosquitoes) lasting from half a minute to several days;

Permanent - live in the host's body or on its covers at all stages of development.

3. Depending on the location:

External - live on the outer covers of the host (lice, fleas, mosquitoes);

Skin - live in the thickness of the skin, and partly on its surface (scabies verbun);

Cavitary - live in cavities that communicate with the external environment - in the external auditory canal, in the nasal cavity (wolfart fly larvae).

Cavitary - live in the body cavities of internal organs (ascaris, gostrik);

Tissue - in muscle, nervous tissues (trichinela);

Internally (sporozoans, flagellates).

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The body of protozoa consists of only one cell. The body shape of protozoa is varied. It can be permanent, have radial, bilateral symmetry (flagellates, ciliates) or not have a permanent shape at all (amoeba). The size of the body of protozoa is usually small - from 2-4 microns to 1.5 mm, although some large individuals reach 5 mm in length, and fossil shell rhizomes were 3 cm or more in diameter.

The body of protozoa consists of cytoplasm and nucleus. The cytoplasm is limited by the outer cytoplasmic membrane, it contains organelles - mitochondria, ribosomes, endoplasmic reticulum, Golgi apparatus. Protozoa have one or more nuclei. The form of nuclear division is mitosis. There is also a sexual process. It consists in the formation of a zygote. The organelles of protozoan movement are flagella, cilia, pseudopods; or they don't exist at all. Most protozoa, like all other representatives of the animal kingdom, are heterotrophic. However, among them there are also autotrophic ones.

The peculiarity of protozoa to endure adverse environmental conditions is the ability incis- tired , i.e. form cyst . With the formation of a cyst, the organelles of movement disappear, the volume of the animal decreases, it acquires a rounded shape, the cell is covered with a dense membrane. The animal goes into a state of rest and, when favorable conditions occur, returns to an active life.

The reproduction of protozoa is very diverse, from simple division (asexual reproduction) to a rather complex sexual process - conjugation and copulation.

The habitat of protozoa is diverse - it is the sea, fresh water, moist soil.

This is a form of interspecific relationship between two organisms, in which the organism uses the other either as a habitat or as a source of food. Parasitic organisms affect all human organs and tissues. They live on the outer covers (fleas, lice), in body cavities - tissues (helminths), in the blood (malarial plasmodium).

1 - flagella (Flagellata, or Mastigophora);

2 – Sarcodidae (Sarcodina, or Rhizopoda);

3 - sporozoans (Sporozoa);

4 - ciliates (Infusoria, or Ciliata).

CLASS FLAGELLATES
About 1000 species, mainly with an elongated or pear-shaped body, make up the flagellate class (Flagellataor
Mastigophora). The organelles of movement are flagella, which various representatives of the class can have from 1 to 8 or more. Flagellum- a thin cytoplasmic outgrowth, consisting of the thinnest fibrils. Its base is attached to basal body or kinetoplast . Flagellates move with a tourniquet forward, creating vortex whirlpools with their movement and, as it were, “screwing” the animal

into the surrounding liquid.

Way nutrition : flagella are divided into those with chlorophyll and feeding autotrophically, and those without chlorophyll and feeding, like other animals, in a heterotrophic way. Heterotrophs on the front side of the body have a special depression - cytostome through which, when the flagellum moves, food is driven into the digestive vacuole. A number of flagellate forms feed by osmosis, absorbing dissolved organic substances from the environment over the entire surface of the body.

Ways breeding : Reproduction occurs most often by dividing in two: usually one individual gives rise to two daughters. Sometimes reproduction occurs very quickly, with the formation of countless individuals (night-lights).

Among the flagellates are found colonial forms ,
consisting of a different number of individuals (from 8 to 10,000 individuals or more) (volvox).

REPRESENTATIVES

Leishmania

Leishmania is found in the tropics. It causes a group of diseases - leishmaniasis, occurring with damage to the skin and mucous membranes (cutaneous leishmaniasis or Pendin ulcer) or internal organs (visceral leishmaniasis or kala-azar). The carrier of leishmaniasis is mos-whales, which become infected by sucking the blood of a sick person or animal. The pathogen enters the human body through the bite of a mosquito.

Cutaneous leishmaniasis (pendinskaya ulcer). Leishmania penetrate the human skin, in the cells of which they multiply; an inflammatory process occurs, followed by tissue necrosis (necrosis) and the formation of ulcers. There are two types of cutaneous leishmaniasis: urban and rural.

In urban cutaneous leishmaniasis, infection occurs through sick people and probably dogs; The pathogen, once in the human body, within 2-8 months (rarely 3-5 years) does not cause visible manifestations of the disease (incubation period). Then, at the site of the mosquito bite (most often on the face or on the hands), a brownish nodule (leishmani-oma) appears, gradually increasing. After 5-10 months, a round ulcer with dense edges and a purulent compartment develops at the site of the nodule. More often there are 1-3 ulcers. The disease lasts 1-2 years.

With rural-type cutaneous leishmaniasis, infection occurs from large and midday gerbils, fine-toed ground squirrel, etc. . Incubation period with rural-type cutaneous leishmaniasis, it ranges from 1 week to 2 months. The disease begins acutely. Leishmaniomas appear on the skin (face, hands, often legs), resembling an abscess (furuncle). Ulcers form in the first weeks of the disease: irregularly shaped,

With dense edges, yellow bottom and purulent discharge. Healing begins in 2-4 months, followed by scarring. The duration of the disease is 3-6 months.

Visceral leishmaniasis (kala-azar). Infection occurs from a sick person, dogs, wild animals (wolves, foxes, etc.). The incubation period lasts from 10-21 days to 1 year and rarely longer, most often - 3-6 months. The disease develops gradually. Weakness, lethargy appear, the temperature rises, the spleen and liver increase. The skin acquires a peculiar color - waxy, pale green or dark ("kala-azar" - black disease). There are changes in the heart, blood, adrenal glands, kidneys.

Treatment leishmaniasis - stationary.

Prevention consists in the destruction of rodent burrows (both rodents and mosquitoes living in these burrows die), catching stray dogs, examining the entire population of dogs in the outbreak and eliminating animals with leishmaniasis, as well as destroying mosquito breeding sites.
Giardia

Prevention : Personal hygiene, food contamination protection, fly control.
Trichomonas vaginalis
Trichomonas vaginalis does not form cysts, feeds on bacteria and red blood cells. Causes inflammation of the urinary system - trichomoniasis. The causative agent of the disease is transmitted sexually. Extra-sexual infection (through common toilet items, bedding, etc.) is less common. It can be transmitted to a newborn girl from a sick mother. The transition of the disease to a chronic form is possible. When spreading to the appendages, it is difficult to treat. With trichomoniasis, the vagina is most often affected, abundant purulent discharge with an unpleasant odor appears; itching and burning in the vagina are felt. In men, the symptom is inflammation of the urethra (urethritis), accompanied by only slight mucous secretions.

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Food, in whatever form, is essential for the survival of living beings. Millions of years have led to multiple foraging strategies, and these various interactions are the glue that holds them together.

Some feeding strategies are more familiar to us, such as carnivores (and plants) that eat other animals, and herbivores that eat plants. However, there are different kinds of symbiotic relationships that involve closer and more complex interactions.

It is a partnership between organisms in which each of the life forms involved benefits the other.

This is when one organism uses another for its own purposes, but without causing obvious harm to it. An example is mosses growing on the bark of a tree.

Gaul

Some galls, such as ink nuts on oak leaves (caused by wasps), support insect communities, which in turn can be food for birds. Look at the canopy of a birch and you will see dense branch structures that look a lot like bird nests. This is the result of infection with fungi of the species - Taphrina betulina.

Extracted tapeworms

General information

Types and routes of transmission

• worm-like (pinworms and helminthic worms, echinococci, roundworms);
• protozoa (toxoplasma, giardia, trichomonas protozoa);
• fungi (known candida that causes thrush in women);
• bacterial flora (all types of staphylococci, streptococci);
• viral agents (chicken pox, rotavirus infection, influenza and SARS, herpes infection).

Ways of infection

Clinical picture

• stool disorder (diarrhea or constipation);
• jaundice secondary (the result of overlapping of the bile ducts);
• persistent flatulence, bloating, gas formation;
• muscle or joint pain;
• allergic reactions (irritation and redness of the skin, hyperemia and swelling of the mucous membranes);
• skin manifestations (rash, itching, redness);
• iron deficiency anemia;
• sudden weight gains for no apparent reason;
• feeling of constant hunger;
• psychoemotional disorders.

Worm inside the human body

Diagnosis of invasions

• examination of the patient, the study of complaints and anamnesis;
• fecal analysis for, smear;
• linked immunosorbent assay;
• x-ray examination:
• ultrasound;
• endoscopy.

Treatment tactics

Medical consultation

The treatment process necessarily includes the prescription of drugs. Modern medicine does not deny the beneficial effects of some folk recipes against parasites (for example, pumpkin seeds). Non-traditional methods can be used only in the absence of serious health disorders, while maintaining the normal function of the liver, kidneys, and cardiac activity. For each type of invasion, certain types of antiparasitic agents are prescribed, Pirantel, Albenazol, Tiabendaloz, Medamin and others. Hepatic trematodes are treated with chemotherapy using Praziquantel, ascariasis is successfully treated with Levamisole. With trichuriasis and similar pathologies, Medamin or Mebendazole is prescribed. Worms are expelled from the body by Pirantel, moreover, a single dose is enough for a complete cure. In severe forms of helminthiasis, glucocorticosteroid therapy will be effective.