Parasitology: Eimeria tenella Study

Parasitology

• Parasitology is the study of parasites and their interactions with hosts.
• Protozoa are single-celled eukaryotic organisms. There are various phylum and class classifications within the Protozoa kingdom.
• Eimeria tenella is a protozoan parasite.
• Eimeria tenella is an intracellular endoparasite found in the epithelium of intestinal caeca of chickens and small ducks.
• The definitive host is only chickens.
• The infective stage is the sporulated oocyst.
• Infection occurs by ingesting sporulated oocysts in contaminated food or water.
• The diagnostic stage is the unsporulated oocyst.
• The disease caused by Eimeria tenella is coccidiosis.
• The life cycle involves sporulation, excystation, sporocysts, sporozoites, merozoites, and formation of gametes. It occurs outside the host, requiring oxygen.

Eimeria tenella Classification

• Kingdom: Protozoa
• Subkingdom: Bacillata
• Infrakingdom: Alveolata
• Phylum: Apicomplexa
• Class: Conoidasida
• Order: Eucoccidiorida

Toxoplasma gondii

• Kingdom: Protozoa
• Subkingdom: Bacillata
• Infrakingdom: Alveolata
• Phylum: Apicomplexa
• Class: Conoidasida
• Order: Eucoccidiorida
• Toxoplasma gondii is an endoparasite found in tissues (skeletal muscle, myocardium, brain, and eyes).
• The definitive host is a cat.
• Intermediate hosts include man, birds, rodents (mice, rats and rabbits), and sheep.
• The infective stage for humans include sporulated oocysts and tissue cysts for cats.
• The diagnostic stage are tachyzoites in blood or bradyzoites in muscle tissues.
• The disease caused by Toxoplasma gondii is Toxoplasmosis.
• Infection for humans: eating undercooked meat, contaminated food/water with cat feces/contaminated soil, blood transfusion or organ transplant, transplacentally from mother to fetus.

Toxoplasma gondii Life Cycle

• The life cycle involves sporulated oocysts, sporozoites, tachyzoites, tissue cysts, and bradyzoites.
• Sporulated oocysts are expelled in cat feces and become infective in the environment.
• Intermediate hosts ingest sporulated oocysts leading to infection.
• In the definitive host (cat), the parasite undergoes sexual reproduction.
• Formation of gametes and fertilization leads to oocyst development, then the oocysts are expelled.

Flotation

• A method used for parasite identification in stool samples.
• Zinc sulphate flotation is a commonly used method for separating parasites.
• The method involves layering the sample in a solution of increasing density, so that parasitic components are floated to the surface enabling easier visualization.