Parasites Of Human Ciliates: Description Of Representatives

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Parasites Of Human Ciliates: Description Of Representatives
Parasites Of Human Ciliates: Description Of Representatives

Video: Parasites Of Human Ciliates: Description Of Representatives

Video: Parasites Of Human Ciliates: Description Of Representatives
Video: Microbiology of Parasites 2024, March
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  • Ichthyophthirius life cycle
  • Where does the ciliate shoe live?
  • Ciliates parasites
  • Infusoria for fry
  • Parasitic ciliates
  • You can defeat parasites!

The unicellular ciliate Ichthyophthirius or Ichthyophthirius multifiliis is perhaps the causative agent of a common aquarium disease: ichthyophthiriosis.

It is an ectoparasite (lives on the skin of a parasitized organism), although to be more precise, it lives in the skin, not on the skin, while not affecting the subcutaneous tissue. In addition to the skin, the objects of his attack are the gills, the cornea of the eyes, and the oral cavity.

What to do in such a situation? To get started, we recommend reading this article. This article details the methods of dealing with parasites. We also recommend contacting a specialist. Read the article >>>

The parasite has a rounded or ovoid body 0.5-1.0 mm in diameter, covered with numerous cilia, with which it moves. At the anterior, narrowed end, there is a small mouth opening surrounded by cilia.

During its life, ciliates lead both a free and a parasitic lifestyle. The optimum temperature for development is 25-27 degrees.

It multiplies by dividing in two outside the fish's body (the tropical version of the parasite reproduces, most likely, on the fish itself) - where it forms the form of a reproduction cyst, in which the ciliate cell divides. The cyst is usually large: up to 1 mm. in diameter.

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Ichthyophthirius life cycle

  • the parasite leaves the fish
  • fission cyst formation with a protective capsule of mucus
  • the exit of vagrants from the cyst
  • finding and attaching a young parasite to fish
  • dead fish
  • mating of two ciliates after they have left the body of a dead fish
  • the formation of a special cyst that can survive without fish for many weeks
  • cyst division
  • out of the tramps

In such a cyst, palintomy, or multiple division of the mother, occurs, which leads to the formation of a huge number of small cells, or ichthyophthirius tomites. The number of such cells can reach 2000. It is believed that division lasts 6-8 or even up to 24 hours. In cold water (5-6 ° C) this process can take 6 days or more.

Tomites or vagrants come out, grow for some time in water, find their owner and actively penetrate into the upper layers of the skin, gills and fins. On the body of its host, the parasite capsules grow rapidly under the protection of the epithelial layer of the skin that covers them. In 6-7 days after introduction at a temperature of 16-22 degrees, they reach the size of an adult. Then the capsule surrounding the parasite bursts, and the infusoria comes out. When the ciliates come out of the capsule, a wound forms on the body of the fish, which contributes to the appearance of secondary infections.

The difference between the tropical and domestic ichthyophthyrus is that the tropical variant of the parasite reproduces, most likely, directly on the fish: cysts are formed directly on the epithelium of the fish. The parasites leave their pustules and, probably, immediately penetrate the epithelium of the fish. So there are many small dermoid tubercles located very close to each other. They also share in free swimming.

Tropical ichthyophthirii reproduce very quickly, since they divide at all stages of the life cycle! And it is useless to fight with them with salt (destroying cysts at the bottom), and they tolerate high temperatures quite well. Moreover, increasing the temperature in a biotope with tropical ichthyophthiri can even be harmful: in warm water, its development proceeds even faster.

There is reason to believe that tropical forms of ichthyophthirii are represented by at least one more species. And the famous Russian ichthyopathologist O. N. Yunchis distinguishes this species (Neoichthyophtirius shlotfeldi) even as a separate genus. These ciliates are the most dangerous, it is most difficult to rid the fish of them, although in terms of their external manifestations, both variants of ichthyophthyriosis are similar.

Ichthyophthirii, regardless of the stage of their development, leave the dead fish.

The parasite is resistant to temperature extremes, and easily passes from cold-water fish to warm-water ones.

Without fish, "tramps" die in 2-3 days.

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Where does the ciliate shoe live?

Infusoria slipper lives in fresh stagnant bodies of water. The value of the ciliate shoe in nature is only positive, because where the ciliate shoe lives, the water is always clean and transparent, and it is no coincidence that bacteria and microalgae as pollutants of water bodies serve as food for ciliates and are largely eaten by them.

A large number of ciliates in water bodies is always associated with an abundance of food and vice versa. In natural reservoirs of ciliates, a shoe can serve as the first starter food for fry.

Ciliates parasites

Along with harmless ciliates, there are also parasites ciliates and they can harm the health of various invertebrates and vertebrates. In aquarism, ciliates parasitizing the body of fish bring significant harm. These pathogenic ciliates can cause a number of serious diseases, often accompanied by the death of fish.

Parasites of ciliates include:

  • Equal ciliates (disease - Ichthyophthiriasis),
  • ciliates Cryptocarion (disease - Cryptokaryonosis),
  • Equal ciliates Chilodonella spp. (disease - Chilodonellosis or breast disease),
  • ciliates Brooklynella sp. (disease - Brooklynellosis),
  • The ciliated ciliate Trichodina sp. (disease - Trichodiniosis),
  • ciliates Tetrahymena sp. (disease - Tetrachimena),
  • ciliates Carchesium. Sp Epistylis sp. Vorticella sp. (disease - False mold).

A large number of different parasitic ciliates may be present in a home aquarium, but they primarily affect only fish with a weakened immune system.

Infusoria for fry

In the hobby, when it comes to raising ciliate fry, a shoe can be invaluable. Infusoria slipper is the smallest live food, its size is 0.1-0.3 mm and it is perfect as a starter food for fry of small fish species, as well as fry of finicky fish, which, apart from ciliates, do not want to see anything else. To provide the fry with starter food, many aquarists breed ciliates at home.

Parasitic ciliates

Among the parasitic ciliates, balantidium, which lives in the intestines of humans and pigs, is of particular interest. As a result of his vital activity, the mucous membrane ulcerates, blood vessels are destroyed. The disease is manifested by bloody diarrhea. Under unfavorable conditions, parasites turn into cysts, which a person becomes infected with if the rules of personal hygiene are not followed.

Balantidium (Balantidium coli)

Localization. Colon.

Geographic distribution. Everywhere.

Morphophysiological characteristics. The body is irregularly oval or ovoid. Dimensions are 30-200 microns in length, 20-70 microns in width. In size, it is the largest human parasite among the protozoa. At the anterior narrowed end of the body there is a peristome, which passes into the cytostom and the funnel-shaped pharynx, located in the form of a slit perpendicular to the surface. At the posterior end of the body is the anal pore. It feeds on the remains of undigested food (especially starch grains), erythrocytes.

There are two contractile vacuoles. The macronucleus is bean or rod-shaped. A rounded micronucleus lies near its concave surface (Fig. 2). Propagated by transverse division and by conjugation. Cysts are oval or spherical (50-60 microns in diameter).

Life cycle. It parasitizes in the large intestine and especially often in the cecum.

Infection occurs by ingestion of cysts. In the digestive tract, vegetative forms are formed from cysts. Reproducing, balantidia sometimes live for a long time in the intestine, without causing any pathological changes. But in some cases, under the influence of some not entirely clear conditions (for example, migratory ascariasis), they begin to invade the intestinal wall and destroy it, causing the formation of deep ulcers. Obviously, tissue destruction occurs in the same way as in amoebiasis, with the help of the lytic enzymes of the parasites. In the lower parts of the intestine, vegetative forms are encystated and carried out.

Domestic and wild pigs are considered the main reservoir of balantidiasis. In some farms, the infection rate reaches 100%.

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In the intestines of animals, balantidia are easily encystated, while in the human body, cysts are formed in relatively small quantities. Animals excrete cysts with faeces and pollute the environment. Pig farm workers can become infected when caring for animals, cleaning livestock premises, etc. The infection of workers in this category is much higher than in other specialties. Cysts in pig feces persist for several weeks. Vegetative forms live for 2-3 days at room temperature.

Infection occurs through contaminated vegetables, fruits, dirty hands, unboiled water.

Pathogenic action. Formation of bleeding ulcers in the intestinal wall, bloody diarrhea. Without treatment, the death rate reaches 30%.

Laboratory diagnostics. Detection in feces of vegetative forms or cysts.

Prevention: personal hygiene is essential; public - the fight against pollution of the environment with feces of pigs, as well as people, the appropriate organization of working conditions on pig farms, the timely identification and treatment of patients.

Free-living and parasitic protozoa were studied by V. A. Dogel and his students, who made a great contribution to the study of the structure, reproduction, life cycles and phylogeny of unicellular animals.

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