One of the major sections of protozoology is devoted to unicellular microorganisms and considers protozoan human parasites as one of the forms of existence of organisms.
From the point of view of medical parasitology, which studies the ways and causes of diseases, their symptoms (one of the individual signs, frequent manifestation of a disease, pathological condition or disturbance of any life process) and methods of treatment, protozoa occupy a leading position. They are followed by helminthology that aims to get rid of helminth infestations and arachnoentomology - systemic methods in medicine that get rid of arthropod parasites.
The animal world is abundantly represented by unicellular microorganisms that live everywhere - from the seabed to the upper atmosphere. All of them belong to the sub-kingdom of protozoa, or protozoa, which has more than 15 thousand representatives of unicellular creatures.
Among free-living single-celled species, there are parasitic forms classified as a separate category that cause a range of serious diseases - protozoa and their associated symptoms, says a senior researcher at the medical center.
The simplest have several dozen types of parasites that live at the expense of the human body. Amoebae are localized in the intestinal tract, causing symptoms (one of the individual signs, frequent manifestation of any disease, pathological condition or disturbance of any life process) amoebiasis. If this is a dysenteric form of the parasite, then it provokes the development of dysentery as well as Giardia, which causes giardiasis. The soft tissues of the internal organs can be affected by Plasmodium and Toxoplasma, causing unpleasant symptoms of toxoplasmosis, which require specific treatment.
The structure of unicellular organisms
The body of a microorganism is just a cell, which includes the nucleus and cytoplasm. It is lined with a cytoplasmic membrane containing organelles - the endoplasmic reticulum, ribosomes, the Golgi apparatus and the mitochondria. They all provide the processes of nutrition, respiration, movement, metabolic processes and secretion.
The body of a unicellular organism has a constant and variable shape (can mean: the shape of an object - the relative position of the boundaries (contours) of the object, object, and the relative position of the points. Line). Some representatives of protozoa have symmetrical bodies, and some have an asymmetrical body shape. Representatives of flagellate parasites in appearance resemble a finger. The rhizomes of the shape (can mean: the shape of the object - the mutual adjustment of the boundaries (contours) of the object, the object, as well as the relative position of the line points) have no body. fare.
Cells divide by simple mitosis, but in some species, in the process of reproduction, fertilization occurs sexually with the formation of a zygote. Almost all simple organisms are heterotrophic, but among them there are autotrophic types of unicellular parasites.
Motor function is produced in the amoeba due to pseudopodia, it seems to overflow, throwing out the pseudopodia. The ciliates move because of the often trimmed eyelashes that cover their body profusely. The movement of the flagella is due to the movement of the flagella themselves, from which they got their name unassumingly.
The process of feeding the amoeba is also associated with pseudopods, wrapping food with pseudopods and absorbing it. Some forms are fed using a cellular mouth. Digestion is carried out by phagocytosis - an internal process, as well as by pinocytosis - the process of external absorption of food from the entire surface of the body.
The main feature of protozoa with the onset of adverse conditions is the formation of cysts. Particularly characteristic is the process of cyst formation for dysenteric amoebae. It allows the parasite (\ one of the coexisting types of organisms) to maintain its vital abilities over an extended anabolic period.
Main classes of protozoan parasites (one of the types of coexistence of organisms)
Representatives of unicellular organisms (a living body that has a number of properties that distinguish it from inanimate matter, including metabolism, self-maintenance of structure and organization, and the ability to reproduce them) are assigned to four main classes. :
Sarcode class
The sarcoma class includes one of the most common parasites, dangerous to humans, the unicellular parasite - dysenteric amoeba, which exists in the form of 4 different forms:
- The vegetative form is the largest, reaching a size of 20 microns. Finding a parasite in newly excreted feces confirms a disappointing diagnosis, the symptoms of which speak for themselves.
- India, or the pathogenic form of the parasite, leading a parasitic lifestyle in the lumen of the colon. Loss of amoeba of intestinal mucosa is produced in a specific way.
- Translucent, or the main form of the dysenteric amoeba that lives in the lumen of the colon. This form causes symptoms characteristic of this disease. They are observed in the process of patient forgiveness or in the transport phase. In feces of any nature, the presence of the parasite was not detected.
- The pre-cystic form of the amoeba is fixed in the semi-formed feces of a human carrier of the disease, or in a patient in the recovery phase.
The main symptoms of diseases caused by amoebic forms are manifested by persistent sharp pain in the lower abdomen, frequent bowel movements of brown stool due to the content of blood and mucus lines. Body temperature remains within normal limits. A similar picture can periodically accompany the patient for several years and lead to exhaustion as well as to the development of anemia. With complications caused by the tissue form of the amoeba and without proper treatment, the patient may die.
Class flagellate, or flagellates
A characteristic feature is the equipping of the body with the simplest organs of movement - one or more flagella. The most common pathogenic microorganisms of this class are:
- trypanosomes, which cause African sleep disorders;
- leishmaniasis causing urban or rural leishmaniasis;
- trichomonas - causative agents of trichomoniasis, mainly of the vaginal form;
- Giardia is a protozoan that causes giardiasis.
sporozoa class
Typical representatives of sporozoans are malarial plasmodium, which causes symptoms of valaria and toxoplasmosis, causing noxoplasmosis.
ciliate class
For microorganisms of this class, a characteristic feature is the presence of eyelashes throughout the body of the microorganism. They perform a motor function, thanks to which the ciliates have the ability to move quickly. The representative of the class is balantidia - the largest human parasite from the protozoan family. Causes a serious and severe disease balantidiasis on the background of the ulcerative process. The disease persists in an acute subclinical form and can be fatal.