Intracellular Parasites: Types, Diagnosis And Treatment

2023 Author: Riley Dean | [email protected]. Last modified: 2023-05-24 12:07

Intracellular parasites - they cannot exist outside the limits of their host's organism - they die in the external environment. Under favorable conditions, parasitic creatures begin to actively reproduce, laying up to a million eggs per day. Facultative parasites are characterized by a free lifestyle, they are not attached to their breadwinner. Intracellular parasites are microorganisms that can inhabit any organs and systems, causing the development of various diseases.

The content of the article:

• 1 Intracellular parasites - Protozoa
• 2 Intracellular parasites - Parasitism
• 3 Intracellular parasites - Flagellate class
• 4 Intracellular parasites - Representatives of Leishmania
• 5 Intracellular parasites - Giardia
• 6 Intracellular parasites - Trichomonas
• 7 Class of sporozoa
• 8 Malaria Plasmodium
• 9 Intracellular parasites - Class of ciliates
• 10 Intracellular parasites - Balantidium
• 11 Intracellular parasites - Class of sarcodes
• 12 Intracellular parasites - Amoeba
• 13 Dysentery amoeba
• 14 These 9 Symptoms Will Help You Know If You Have Parasites In Your Body
• 15 Standard feces tests for eggs of worms and parasites

Intracellular parasites - Protozoa

The type of protozoa (Protozoa) includes over 15,000 species of animals that live in the seas, fresh waters, and soil. In addition to free-living forms, many parasitic forms are known, which sometimes cause serious diseases - protozoanosis.

The body of the simplest consists of only one cell. The body shape of protozoa is diverse. It can be permanent, have radial, bilateral symmetry (flagellates, ciliates), or have no permanent shape at all (amoeba). The body sizes of protozoa are usually small - from 2 - 4 microns to 1.5 mm, although some large individuals reach 5 mm in length, and fossil shell rhizomes had a diameter of 3 cm or more.

The body of the protozoa consists of the cytoplasm and the 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 the movement of protozoa are flagella, cilia, pseudopods; or none 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 to encyst, that is, to form a 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.

Encysting is a device that serves not only for protection, but also for the spread of parasites. Some protozoa (sporozoans) form an oocyst and, in the process of reproduction, a sporocyst.

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

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

Parasitism is widespread. Many types of parasitic protozoa cause severe diseases of humans, domestic and game animals, and plants.

Intracellular parasites - Parasitism

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

The host organism for the parasite is a source of food, habitat, protection from enemies. The host's body creates a favorable microclimate for parasites that is not subject to fluctuations that occur in nature.

The study of parasites is necessary for the prevention and treatment of human diseases. Parasitology studies the biology, ecology of parasites, methods of diagnosis, treatment and prevention of parasites. Medical parasitology is subdivided into: protozoology (protozoa), helminthology (parasitic worms), and arachnoentomology (arachnids and insects).

There are four main classes of protozoa:

1 - flagellates (Flagellata or Mastigophora);

2 - sarcode (Sarcodina or Rhizopoda);

3 - sporozoa (Sporozoa);

4 - ciliates (Infusoria or Ciliata).

Intracellular parasites - Flagellate class

About 1000 species, mainly with an elongated oval or pear-shaped body, make up the flagellate class (Flagellata or Mastigophora). Movement organelles are flagella, of which different representatives of the class may have from 1 to 8 or more. The flagellum is a thin cytoplasmic outgrowth consisting of the finest fibrils. By its base, it is attached to the basal body or kinetoplast. Flagellates move forward like a cord, creating by their movement vortex whirlpools and, as it were, "screwing" the animal into the surrounding liquid medium.

Food method. Flagellates are divided into those with chlorophyll and feeding autotrophically, and into those without chlorophyll and feeding, like other animals, in a heterotrophic way.

Heterotrophs on the front side of the body have a special depression - a cytostome, through which food, when the flagellum moves, is driven into the digestive vacuole. A number of forms of flagellates feed on the osmotic route, absorbing dissolved organic matter from the environment through the entire surface of the body.

Reproduction methods. Reproduction occurs most often by dividing in two: usually one individual gives rise to two daughter ones. Sometimes reproduction occurs very quickly, with the formation of countless individuals (night-light).

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

Intracellular Parasites - Representatives of Leishmania

Leishmania is found in the tropics. 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). Leishmaniasis is carried by mosquitoes, which become infected by sucking the blood of a sick person or animal. The pathogen enters the human body when bitten by a mosquito.

Cutaneous leishmaniasis (pendino ulcer). Leishmanias penetrate 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, having entered the human body, does not cause visible manifestations of the disease within 2 to 8 months (rarely 3 to 5 years) (incubation period). Then a brownish nodule (leishmanioma) appears at the site of the mosquito bite (most often on the face or hands), gradually increasing.

After 5 - 10 months, a round ulcer with dense edges and purulent discharge develops at the site of the nodule. More often there are 1 - 3 ulcers. The disease lasts 1 to 2 years.

In case of rural cutaneous leishmaniasis, infection occurs from great and midday gerbils, fine-toed ground squirrels, etc. The incubation period for rural cutaneous leishmaniasis is from 1 week to 2 months. The disease begins acutely. On the skin (face, hands, often legs), leishmaniomas appear, resembling an abscess (furuncle). Ulcers form in the first weeks of the disease: irregular in shape, with dense edges, a yellow bottom and with a purulent discharge.

Healing begins in 2 to 4 months, followed by scarring. The duration of the disease is 3 to 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 enlarge. 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.

Intracellular parasites - Giardia

Giardiasis causes a disease called giardiasis. They parasitize in the small intestine, sometimes in the gallbladder; exist in two forms: mobile (vegetative) and motionless (cyst form). The mobile form of lamblia has four pairs of flagella and a suction disc, with its help it is attached to the mucous membrane of the small intestine. Infection occurs through the use of food and water contaminated with cysts, as well as through hands and household items. Once in the gastrointestinal tract in persons with low acidity of gastric juice and even in a healthy person, lamblia multiply in the small intestine, sometimes in large quantities, causing irritation of the mucous membrane. Pains appear in the upper abdomen or in the navel area, bloating, rumbling, and nausea are noted. There may be constipation followed by diarrhea (mixed with mucus). Most often, children are sick.

Treatment: diet is recommended.

Prevention: Personal hygiene, food protection from contamination, fly control.

Intracellular parasites - Trichomonas

Trichomonas vaginal cysts does not form, feeds on bacteria and erythrocytes. Causes inflammation of the genitourinary system - trichomoniasis. The causative agent of the disease is sexually transmitted. Extra-sex infection (through shared toilet items, bed, etc.) is less common. Can be transmitted to a newborn girl from a sick mother. The transition of the disease to a chronic form is possible. When spread 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 sensation in the vagina is felt. In men, the symptom is inflammation of the urethra (urethritis), accompanied by only minor mucous secretions.

Treatment: personal hygiene, follow-up visit to the doctor.

Prevention: personal and sexual hygiene.

Sporozoa class

Representatives of this class (Sporozoa) are characterized by the fact that in the cycle of their development they form a stage of spores. All sporozoans are parasites of humans and animals. They parasitize in various tissues and cells. Fever, anemia, jaundice are typical signs of spore disease. Piroplasmas, babesia belong to the order of blood sporozoans, affecting the erythrocytes of mammals (cows, horses, dogs, and other domestic animals).

Disease carriers are ticks. In addition to blood, there are two more orders of sporozoans - coccidia and gregarines.

Coccidia parasitize both invertebrates and vertebrates - mammals, fish, birds. Coccidia toxoplasmosis causes human disease toxoplasmosis. It can be contracted from any member of the feline family.

Gregarins are parasites only of invertebrates, mainly insects and, as a rule, settle in the intestines. Adult gregarines look like worms. They are both small (10 microns) and very large, visible to the naked eye - up to 1.6 mm.

Malaria plasmodium

Plasmodium malaria causes malaria, which occurs with attacks of fever, changes in the blood, enlargement of the liver and spleen. There are four forms of malaria: three-day, four-day, tropical, and ovalemalaria. The source of the disease is a person with malaria, and the carrier is a female malaria mosquito. The female mosquito, becoming infected while sucking the patient's blood, becomes capable of transmitting plasmodium. A healthy person becomes infected with the bite of a mosquito infected with plasmodia, with whose saliva pathogens enter the body.

With the blood flow, plasmodia enter the liver, where they undergo the first (tissue) development cycle, then pass into the blood and penetrate into erythrocytes.

Here they complete the second (erythrocyte) cycle of development, ending with the breakdown of erythrocytes and the release of pathogens into the patient's blood, which is accompanied by an attack of fever.

Treatment: medication; the patient needs rest and care.

Prevention: control of mosquito-carriers of malaria, gauze or metal nets on windows and doors, repellents are used to protect against mosquitoes.

Intracellular parasites - Class of ciliates

Representatives of the class of ciliates (Infusoria or Ciliata) have organelles of movement - cilia, usually in large numbers. For example, a shoe (Paramecium caudatum) has more than 2000 cilia. Cilia (like flagella) are special complex cytoplasmic outgrowths. The body of the ciliates is covered with a shell permeated with the smallest pores through which the cilia exit.

The most highly organized protozoa are combined into the type of ciliates. They are the pinnacle of the achievements accomplished by evolution in this sub-kingdom. Ciliates are free-floating or attached. They live in both fresh and salt waters. Among the ciliates there are many symbionites and few parasitic forms.

Enough among ciliates and parasites of invertebrates and vertebrates (including humans). There are a lot of parasitic in a special part of the stomach of ruminant ungulates - in the rumen.

All ciliates have at least two nuclei. The big core regulates all life processes. The small nucleus plays a major role in the sexual process.

Ciliates multiply by division (across the body axis). In addition, they periodically have a sexual process - conjugation. Infusoria - "shoe" is divided daily, some others - several times a day, and "trumpeter" - once every few days.

Food enters the animal's body through the cellular "mouth", where it is driven by the movement of the cilia; at the bottom of the pharynx, digestive vacuoles are formed. Undigested residues are discharged outside.

Many ciliates feed only on bacteria, while others are predators. For example, the most dangerous enemies of “shoes” are ciliates of Didinia. They are smaller than her, but attacking in two or four, surround the “shoe” from all sides and kill it, throwing a special “stick” out of the throat like a spear. Some didinia eat up to 12 “shoes” a day.

The excretory organelles of ciliates are two contractile vacuoles; in 30 minutes, they remove an amount of water from the ciliate equal to the volume of its entire body.

In addition to living freely, there are also parasitic ciliates.

Intracellular parasites - Balantidium

The parasite of the human colon is a large ciliate balantidium (Balantidium coli). Distributed everywhere. Forms a cyst. Infection occurs when the cyst is swallowed. The main source of human infection is the pig, for which this ciliate is harmless. Often, apparently, balantidium is harmless to humans. The length of the organism is from 30 to 200 microns, the width is 20 - 70 microns; ciliates cause the formation of ulcers on the intestinal wall, which is accompanied by symptoms that are also characteristic of amoebic dysentery (bloody diarrhea).

The disease caused by balantidium is called balantidiasis.

Intracellular parasites - Class of sarcodes

Representatives of the class of sarcodes, or rhizopods (Sarcodina or Rhizopoda), move with the help of false legs - pseudo-similarities.

The class includes a variety of aquatic unicellular organisms: amoebas, sunflowers, ray beetles. Among amoebas, in addition to forms that do not have a skeleton or shell, there are species that have a house.

Most of the sarcodes are inhabitants of the seas, there are also freshwater ones living in the soil.

Sarcodes are characterized by a fickle body shape. Breathing is carried out by its entire surface. Nutrition is heterotrophic. Reproduction is asexual, there is also a sexual process.

Intracellular parasites - Amoeba

Amoeba lives in fresh waters. Body shape is inconsistent. Performs very slow (13 mm / h) movements. It moves with the help of pseudopods, the body flows from one part to another: either shrinking into a round lump, or spreading the “tongues-legs” to the sides.

Pseudopods also serve to capture food. In the process of feeding, the body of the amoeba flows around food particles from all sides, and they end up inside the cytoplasm. A digestive vacuole appears. This way of eating is called fabitosis. Food is made up of bacteria, unicellular algae, small protozoa. Dissolved substances from the environment are absorbed by pinocytosis.

The body of the amoeba has a contractile or pulsating vacuole. Its function is to regulate osmotic pressure inside the protozoan body.

Reproduction is asexual, by mitosis, followed by the division of the amoeba body into two.

The most important in medicine are the amoeba of the genus Entamoeba, which lives in the human digestive tract.

These include the amoeba dysentery or histolytic.

Dysentery amoeba

Dysentery amoeba is a persistent human parasite that excites amoebiasis. Can form cysts in the human colon. Their diameter is 8 - 15 microns. It causes ulcers in the large intestine. This amoeba causes a disease similar to dysentery. In unfavorable conditions - amoebacistitis.

These 9 symptoms will help you know if you have parasites in your body

Parasites are organisms that live and feed on another organism. Anyone can become infected with parasites. This is more common than you might think.

According to the WHO (World Health Organization), 3.5 billion people worldwide suffer from various types of parasitic infections.

Parasites live in our body and feed on nutrients in our tissues, which can seriously harm our health.

Here are 9 main symptoms that indicate that you are suffering from a parasitic infection:

1. Anemia is an iron deficiency.
2. Weight loss or inability to gain weight.
3. Sleep problems such as bruxism and insomnia.
4. Anxiety, anxiety, nervousness, mood swings, and depression.
5. Skin problems such as dry and itchy skin, eczema, sores and lesions.
6. Fatigue and apathy.
7. Fertility problems, PMS symptoms, menstrual problems, cysts, fibroids, and fluid retention.
8. Muscle and joint problems, cramps, numbness and tingling in the limbs.
9. Digestive problems such as diarrhea and irritable bowel syndrome.

Irritable bowel syndrome is a common symptom of intestinal parasitic infection that occurs due to inflammation caused by parasites in the intestinal lining.

Standard feces tests for eggs of worms and parasites

Routine stool tests can detect parasites or their eggs, but these tests are largely limited. The problem with these analyzes is that they are only marginally effective. They require three separate stool samples that are sent to the laboratory, where the pathologist examines them under a microscope. The life cycle of parasites is unique - it allows them to be in an intermediate state between hibernation and functioning.

To detect parasites in routine tests, a stool sample must contain a living parasite, the parasite must remain alive while the sample is delivered to the laboratory, and then the pathologist must see the living parasite through a microscope.

While this type of test may be important to some, it does not detect dormant parasites, and for this reason, this type of stool test often gives an erroneous negative result.

Find out more:

• Plasmodium malaria: stages, types, development scheme
• Intestinal amoeba: symptoms, diagnosis, treatment
• Giardia in the liver: how to remove giardia from the liver