Module 6: Protozoans (Intro-Entamoeba histolytica)

Are single-celled organisms which exhibit considerable variation in size, shape, locomotory organelles and methods of reproduction

This is where food synthesis takes place; food is stored in the form of glycogen or protein called chromatoidal bodies

envelopes the cell; functions as the locomotor apparatus for the procurement and ingestion of food, in respiration, discharge of metabolic wastes and protection of the organism

false feet; in Amoeba (crawling movement)

in flagellates; hair-like projections

in Ciliates; numerous short threads distributed over the surface of the body

Other protozoans have specialized cell mouth called __________ usually located in anterior end of the body.

Ciliates have in addition a cell anus or _________ at the posterior end of the body and through which particulate food wastes are discharged.

(Reproduction) division into 2 equal parts

(Reproduction) where 2 or more products of division result; nucleus of the parent cell first undergo repeated division and then the cytoplasm collects around them

2 types of asexual reproduction

(Reproduction) sexually differentiated cells unite permanently and complete fusion of the nuclear materials takes place

(Reproduction) Two Paramecia (Ciliates) unite along their oral surfaces, the macronuclei disintegrate and the micronuclei in each organism divide twice. All the daughter nuclei disintegrate except one.

2 types of sexual reproduction

2 basic events in the life cycle of protozoans

(life cycle) cyst stage becomes trophozoite

(life cycle) formation of cyst from trophozoite

Amoeba comes from a Greek word meaning ________.

Amoeba is any of several tiny, one-celled protozoa in the phylum __________.

The only species of the different intestinal amoebae which has the potential for tissue invasion

__________ (1875) in Saint Petersburg, Russia found amoebae in fecal samples but only regarded them as responsible for maintaining the inflammatory process, not as a cause of dysentery.

_____________ (1903) established the differentiation between Entamoeba histolytica and Endamoeba coli, he decided to call it E. histolytica because of its ability to cause tissue lysis.

(Amoebiasis) There seems to be a seasoned trend in transmission associated with months of great _________.

Is the causative agent of amoebiasis and is globally considered a leading parasitic cause of human mortality

(Entamoeba histolytica) vegetative form

(Entamoeba histolytica) Theoretically, the ingestion of ___________ can cause an infection.

Habitat of Entamoeba histolytica

Infective stage of Entamoeba histolytica

(Entamoeba histolytica) Mode of infection

In viewing Entamoeba histolytica under a microscope, _________are sometimes visible.

Entamoeba histolytica move by means of ______________.

movement of Entamoeba histolytica

Entamoeba histolytica are ___________; change shape constantly

(Entamoeba histolytica) nonivasive forms represent separate species, __________, which is morphologically indistinguishable to E. histolytica.

(Entamoeba histolytica) incubation period

The term __________ is used to denote all those condition which are produced in the human host by infection with Entamoeba histolytica.

A condition in which the infection is confined to the intestinal canal and is characterised by the passage of blood and mucus in stool accompanied by tenesmus

a feeling of incomplete defecation; it is experienced as an inability or difficulty to empty the bowel at defecation

Flask shaped ulcer with narrow neck due to lytic action of trophozoites and broad necrotic bed seen

inflammatory thickening of wall of large bowel resembling carcinoma colon

trophozoites invade the intestinal mucosa

This can develop in the following ways: rupture of amoebic hepatic abscess through diaphragm, lymphatic spread from liver through diaphragm, haematogenous spread

through the bloodstream, extraintestinal sites such as the liver, brain, and lungs, with resultant pathologic manifestations

_________ is non-fibrotic an contains granulation tissue with lymphocytes, plasma cells, eosinophils and giant cells. There is remarkably little inflamation and most of the swelling is due to oedema.

The pus in ___________ appear as red anchovy sauce like appearance; the material aspirated is likely to contain trophozoites and may be detected by direct microscopic examination

_____________________ also occurs which is hematogeneous in origin but usually arises from or is concomitant with amoebiasis of the liver or lungs.

involves extension of lesions on the skin of the abdominal cavity & that of the perianal area

____________ is rarely a recognized entity because this is not the usual site of presentation for amebiasis. Homosexual men have a higher risk of acquiring the lesion.

_______________ is rare but is the most serious complication of hepatic amebiasis. It is usually caused by a rupture of a left-liver lobe abscess and occurs in 3% of patients with hepatic amebiasis. It presents with chest pain and the features of congestive heart failure.

If amoebic pericarditis is not treated early, it could result in __________________and subsequent death.

_______________ is a serious medical condition in which blood or fluids fill the space between the sac that encases the heart and the heart muscle. This places extreme pressure on your heart. The pressure prevents the heart's ventricles from expanding fully and keeps your heart from functioning properly.

(Entamoeba histolytica) __________, __________, and ____________ are the keys to diagnosis.

Invasive amebiasis is treated with a nitroimidazole such as __________ or ________________ or _____________ and then a luminal amebicide such as __________.

In treating invasive amebiasis, _____________ can also be used in children >2 yr of age.

penetrates deeper tissues and destroys amoeba present in liver, brain, lungs, etc.; the organism's metabolism converts the drug into its lethal form

A second drug is used to eradicate the amoeba present in the intestinal lumen (____________)

Entamoeba histolytica
Etiologic agent of:
Infective stage:
Definitive Host:
Portal of Entry:
Mode of Transmission:
Habitat:
Pathogenic Stage:
Locomotive apparatus:
Motility:

(Entamoeba histolytica) nucleus

(Entamoeba histolytica) Mode of reproduction

(Entamoeba histolytica) Pathogenesis

(Entamoeba histolytica) type of encystment

(Entamoeba histolytica) Lab Diagnosis

(Entamoeba histolytica) Treatment