One of the major sections of protozoology is devoted to unicellular microorganisms, and considers human parasitic protozoa as one of the forms of existence of organisms.
From the point of view of medical parasitology, which studies the forms and causes of diseases, their symptoms (one of the individual signs, the frequent manifestation of a disease, pathological condition or disturbance of any vital process) and methods of treatment, protozoa occupy a leadership position. They are followed by helminthology aimed at getting rid of helminthic invasions and arachnoentomology - systemic methods in medicine that get rid of arthropod parasites.
The animal world is represented in abundance by single-celled microorganisms that live everywhere - from the seafloor to the upper atmosphere. They all belong to the sub-kingdom of protozoa, or protozoa, which has more than 15, 000 representatives of single-celled creatures.
Among free-living single-celled species, there are parasitic forms classified as a separate category that cause several serious diseases - protozoonoses and their corresponding symptoms, says a senior researcher at the medical center.
The simplest ones have several dozen species of parasites that live at the expense of the human body. Amoebas are located in the intestinal tract, causing symptoms (one of the individual signs, a frequent manifestation of any disease, pathological condition or disturbance of any life process) amoebiasis. If this is a dysenteric form of the parasite, it causes dysentery to develop, as does Giardia, which causes giardiasis. The soft tissues of internal organs can be affected by Plasmodium and Toxoplasma, causing unpleasant symptoms of toxoplasmosis, requiring specific treatment.
The structure of unicellular organisms
The body of a microorganism is just one cell, which includes the nucleus and cytoplasm. It is lined by a cytoplasmic membrane containing organelles - the endoplasmic reticulum, ribosomes, Golgi apparatus and mitochondria. They all provide the processes of nutrition, breathing, movement, metabolic processes and excretion.
The body of a unicellular organism has a constant and changing shape (it can mean: the shape of an object - the relative position of the boundaries (outlines) of the object, the object, as well as the relative position of the points on the line). Some representatives of protozoa have symmetrical bodies, and some have an asymmetrical body shape. Representatives of flagellated parasites in appearance resemble a spindle. The rhizomes of the form (can mean: the form of the object - the mutual arrangement of the boundaries (outlines) of the object, the object, as well as the relative position of the points on the line) do not have a body at all.
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 the simplest organisms are heterotrophs, but among them there are autotrophic species of single-celled parasites.
Motor function is produced in the amoeba due to the pseudopods, it seems to overflow, expelling the pseudopods. The ciliates move due to the often shortened cilia that cover their body in abundance. The movement of the scourges is due to the movement of the scourges themselves, from which they got their unpretentious name.
The amoeba feeding process is also associated with pseudopods, enveloping food with pseudopods and absorbing them. Some forms feed using a cellular mouth. Digestion is carried out by phagocytosis - an internal process, as well as pinocytosis - the process of external absorption of food across the entire surface of the body.
The main characteristic of protozoa in the appearance of adverse conditions is the formation of cysts. The process of cyst formation for the dysenteric amoeba is especially characteristic. Allows the parasite (\one of the types of coexisting organisms) to maintain its vital abilities during a period of prolonged anabiosis.
The main classes of protozoan parasites (one of the types of coexisting organisms)
Representatives of unicellular organisms (a living body that has a set of properties that distinguish it from inanimate matter, including metabolism, self-maintenance of its structure and organization and the ability to reproduce them) are assigned to four main classes:
Sarcode class
The sarcode class includes one of the most common and dangerous single-celled parasites for humans - the dysenteric amoeba, which exists in 4 different forms:
- The vegetative form is the largest, reaching 20 microns in size. Finding a parasite in freshly passed stool confirms a disappointing diagnosis, the symptoms of which speak for themselves.
- Tissue, or pathogenic form of the parasite, leading a parasitic lifestyle in the lumen of the colon. Defeat of the amoeba of the intestinal mucosa is produced in a specific way.
- Translucent, or the main form of the dysenteric amoeba that lives in the lumen of the large intestine. This form causes characteristic symptoms for this disease. They are observed in the patient's remission process or in the transport stage. In faeces of any nature, the presence of the parasite has not been established.
- 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 permanent sharp pains in the lower abdomen, frequent evacuations of brown stools due to blood content and streaks of mucus. Body temperature remains within normal limits. A similar picture can periodically accompany the patient for several years and lead to exhaustion, as well as the development of anemia. With complications caused by the tissue form of the amoeba, and without proper treatment, the patient can die.
Class flagellates, or flagellates
A feature is the equipment of the body with the simplest organs of movement - one or more flagella. The pathogenic microorganisms of this class are:
- trypanosomes, which cause African sleeping sickness;
- leshmania causing urban or rural leishmaniasis;
- trichomonas - causative agents of trichomoniasis, mainly in the vaginal form;
- Giardia is a protozoan that causes giardiasis.
sporozoan class
Typical representatives of sporozoans are malarial plasmodium, which causes symptoms of varia and toxoplasma, causing noxoplasmosis.
ciliated class
For microorganisms of this class, a characteristic is the presence of cilia throughout the organism's body. They perform a motor function, thanks to which ciliates have the ability to move quickly. The representative of the class is balantidia - the largest human parasite of the protozoan family. It causes a serious and severe disease balantidiasis at the bottom of the ulcerative process. The disease proceeds in an acute subclinical manner and can be fatal.