Dysenteric amoeba is the simplest unicellular organism. However, despite its harmless size, it poses a serious threat to humans. You will learn about the features of the structure and life of an amoeba of this species from our article.
General characteristics of the subkingdom Protozoa
Representatives of this systematic unit are distinguished by their primitive structure. The dysenteric amoeba is no exception. The body of the simplest animals consists of one cell. Its surface apparatus, unlike similar algae and fungi, is devoid of a dense shell.
A single cell is capable of carrying out all life processes. So, the movement is carried out with the help of specialized organelles: flagella, cilia or pseudopodia (pseudopodia). The breakdown of organic matter occurs due to the work of digestive vacuoles, and the excretion of metabolic products is due to contractile ones. Gas exchange occurs across the surface of the cell. Reproduction can be either sexual or asexual.
Type Amoeba-like
The representative of the protozoan group, which is discussed in our article, moves with the help ofpseudopods. So called non-permanent outgrowths of the cytoplasm.
Dysenteric amoeba is a parasite belonging to the type of amoebozoa. It lives in the large intestine of animals and humans. Although among the representatives of this type there are free-living species and saprophytes. The dysentery amoeba is a heterotrophic organism that feeds on red blood cells and intestinal epithelial cells.
Life cycle of the dysenteric amoeba
During life, this organism goes through several stages. Each of them has its own morphological and physiological features. But at each stage, the dysenteric amoeba is a unicellular structure of a non-permanent shape. In the course of movement, it forms specialized organelles. They are called pseudopods, or pseudopodia. These are outgrowths of the cytoplasm that form and then disappear. But the number of nuclei and the structure of the cytoplasm can vary significantly depending on the stage of development.
At the resting stage, the dysenteric amoeba is a cyst - a cell covered with a dense membrane. While in the environment, it does not show signs of life. But when it enters the body, the active phase begins. The amoeba successively passes through the following forms: intermediate, luminal, tissue, vegetative.
The process of dissolving the dense shell of the cyst is facilitated by enzymes that are located in the lower part of the small intestine. As a result, an intermediate form with four cores is formed. It begins to divide by mitosis until 8new cells. Each of them contains one core. This is already a translucent form of dysenteric amoeba. It descends into the large intestine, where it continues to divide. This is the next period of development of the protozoa, which is called the vegetative form.
Slowly amoeba penetrate the intestinal mucosa, causing ulcers and colic in the host. This stage of the life cycle is called tissue. Some of these individuals again enter the intestinal cavity. Here, the protozoa absorb red blood cells - erythrocytes. At the same time, the size of amoebas increases significantly. This determines the name of this stage - a large vegetative stage. For the host organism, it is the most dangerous. The development of this form of dysenteric amoeba is the most dangerous, because it causes damage to blood vessels. This is the way they penetrate into other organs and causes a further abscess. This is especially true of the liver.
The amoeba enters the environment with feces. If this happens at the vegetative stage, then the amoebas die very quickly. In the case of the formation of cysts, the viability of amoebas increases significantly. They are also excreted in the feces of the host and remain there until they are re-introduced.
Routes of infection and prevention
The dysenteric amoeba is an extremely prolific organism. Just imagine: within a day, about 300 million individuals develop from one cell. How can these parasites enter the body? There are severalways. This is the use of insufficiently thermally processed foods, unboiled water, unwashed vegetables and fruits. Swimming in a natural or natural reservoir, a person is also exposed to the threat of infection in case of accidental ingestion of liquid into the body.
Carriers of the parasite are many insects, such as flies or cockroaches. Therefore, food contaminated with them is also a source of infection. But the main danger is an infected person. If he does not follow elementary hygiene rules, then the parasite can get on any surface with which he came into contact. It can be bed linen, dishes, clothes, towels, pet hair. You can get infected with a dysenteric amoeba even through a handshake. Moreover, parasites can survive on any surface for about 7 days.
To avoid infection with dysenteric amoeba, you should follow basic hygiene rules. So, it is necessary to eat only well-washed or thermally processed foods, as well as boiled or bottled water.
Translucent shape
This stage is the first in the active phase of development of the dysenteric amoeba. It develops from a cyst. The size of its cells during this period is 20 microns, and the place of dislocation is the upper part of the large intestine. An amoeba cell of translucent form has one spherical nucleus, actively moves with the help of pseudopods, and feeds on bacteria.
Fabric shape
When the luminal stage amoeba penetratesthe mucous membrane of the large intestine, it passes to the next stage. At the same time, its dimensions increase to 60 microns. The tissue form of the amoeba is characterized by a change in the composition of the cytoplasm. It contains no inclusions. This is what is called non-permanent cellular structures. The tissue form of the amoeba is constantly dividing. This causes the development of ulcers, the appearance of mucus, purulent and bloody secretions.
Large vegetative form
Part of the cells of the dysenteric amoeba from the mucous membrane return to the intestinal lumen. Here they acquire the ability to absorb red blood cells, so the amoeba of this stage is also called erythrophages. It is they who cause the acute phase of the disease, since they can move through the vessels to other organs. Here they cause extraintestinal amoebiasis, or secondary inflammation.
Cyst stage
The structure of the dysenteric amoeba of this form is characterized by the formation of a dense membrane around the cell of the translucent form. Its size is 12 microns, and the cytoplasm contains a vacuole rich in carbohydrate glycogen. Cysts form when undigested food accumulates in the large intestine.
Once in the environment with faeces, in the presence of moisture, they can remain alive for a whole month. If an infection occurs, the cysts divide and turn back into translucent forms.
Signs of illness
Dysentery amoeba causes serious disruption of many organ systems. Amoebiasis, a disease that causesthis organism, manifests itself in the form of intoxication. A person experiences nausea, vomiting, cramping abdominal pain, diarrhea, dizziness. Body temperature rises frequently.
Initially, these symptoms are very similar to typical dysentery. But they are only manifestations of the incubation period of the disease. After a maximum of a month, real symptoms appear. These include frequent urge to defecate - from 4 to 20 times a day. In this case, blood clots appear in the stool. This process is accompanied by an increase in body temperature above 38 degrees, sometimes fever. Pain increases during bowel movements.
These are manifestations of the acute form of the disease. If you do not take any measures within a month, it develops into a chronic one. And initially there is an improvement in well-being and unpleasant symptoms disappear. This is the remission stage, which lasts for several months.
Next, manifestations of the chronic form of amoebiasis begin, which can last for years. Its symptoms are somewhat different from acute. These include a decrease or complete lack of appetite, which leads to weakness, fatigue and further exhaustion. Physiological manifestations of amoebiasis also include the appearance of an unpleasant aftertaste in the oral cavity, an increase in the size of the liver, rapid heartbeat, a violation of the rhythm of the pulse, and pallor of the skin. The latter is a manifestation of anemia - a decrease in hemoglobin levels. This disease is a consequence of the defeat of red blood cells by parasite cells.
Diagnosis andamoebiasis treatment
Because the symptoms of this disease are similar to other infections, it is necessary to pass a series of tests. First of all, this is a microbiological study of feces. Patients usually have a large vegetative form or cysts of the parasite.
Treatment of amoebiasis is medical. Depending on the form of the disease, there are drugs that affect single-celled, which are in the walls or lumen of the intestine, as well as the liver. In folk medicine, tinctures from the fruits of sea buckthorn or hawthorn, bird cherry, cumin are used. Decoctions of herbs of plantain, cinquefoil, shepherd's purse, horse sorrel will also be effective.
So, dysenteric amoeba is a unicellular parasite that causes a dangerous disease - amoebiasis. Infection occurs by contact through contaminated surfaces. If symptoms of amoebiasis appear, you should consult a doctor and undergo a series of necessary studies.
