Popular tips

What is trophozoite and cyst?

What is trophozoite and cyst?

Cysts and trophozoites are passed in feces (1). Cysts are typically found in formed stool, whereas trophozoites are typically found in diarrheal stool. Infection by Entamoeba histolytica occurs by ingestion of mature cysts (2) in fecally contaminated food, water, or hands.

What are trophozoites?

A trophozoite (G. trope, nourishment + zoon, animal) is the activated, feeding stage in the life cycle of certain protozoa such as malaria-causing Plasmodium falciparum and those of the Giardia group. (The complement of the trophozoite state is the thick-walled cyst form).

What is the structure of trophozoite?

The ventral disc is the most distinctive structure of the trophozoite. It has been called the sucker cup, striated disc, and adhesive disc. Its shape is supported by a complex cytoskeleton of microtubules, microfilaments, and associated fibrous structures.

Where is the trophozoite located?

The trophozoite resides in the cecal area and throughout the large intestine. It thrives in an environment rich in starch, such as the small intestine; however, in such an environment, the trophozoite does not invade the intestinal mucosa.

What’s the difference between a cyst and a trophozoite?

The life cycle of a protozoan exhibits two main stages: the trophozoite stage and the cyst stage. The trophozoite stage is the feeding stage of the protozoan whereas the cyst stage is the dormant, resistant and infectious stage of the protozoan. This is the key difference between cyst and trophozoite.

Where does the formation of a trophozoite take place?

The formation of the trophozoite from a cyst is referred to as excystation. The excystation takes place in the large intestine of the host at the subsequent ingestion of the cyst by the host. Trophozoites are not resistant structures. Generally, trophozoites are covered with cilia. Hence, they are motile.

What does trophozoite stand for in medical dictionary?

troph·o·zo·ite. The ameboid, vegetative, asexual form of certain Sporozoea, such as the schizont of the plasmodia of malaria and related parasites. trophozoite. The active growing stage of a protozoan parasite, as distinct from the dormant encysted stage.

How long is the prepatent period for trophozoite?

A cyst is developed to envelop the trophozoite, as it travels caudally in the gut. The prepatent period is short: 4–16 days. The cysts are infective to the new host immediately and the dose required for infection is small.