Amebiasis Flashcards
(25 cards)
Which parasite causes Amebiasis?
Entamoeba histolytica
What is the non-invasive form of Entameoba?
Entamoeba dispar
What regions are affected by Amebiasis?
Mexico, Central and South America, Africa, South Asia
What are the modes of infection of Amebiasis?
Water, food, sex, person-to-person contacts
What is the main reservoir for E. histolytica?
Humans
How is the disease transmitted?
Fecal-oral transmission
What is the life cycle of Entamoeba?
Mature cysts are ingested
Cysts become trophozoites and infect the intestines, the liver, the lungs and the brain
The cysts are passed in feces
True or false: The cysts can survive for weeks at appropriate temperature and humidity
True
What lines the inner surface membrane of the nucleus in the Entamoeba trophozoite?
Peripheral chromatin
Where is the endosome of the trophozoite located?
In the center of the nucleus
What is the function of the vacuoles in the trophozoite?
Feeding
True or false: Amoeba cells invade the mucous layer and can live in the crypt
True
What initiates tissue invasion of the large intestine?
Hydrolyzation of the mucosal cells and absorption of the pre-digested products
True or false: At the stage of tissue invasion, the amoeba cells still need to feed on bacteria
False, they no longer need to feed on bacteria
Which structure of the trophozoites has the functions of endocytosis, attachment to substrate, penetration of the tissue, release of cytotoxic materials and cytolysis of cells?
Filopodia
True or false: Most affected people are symptomatic
False, they are asymptomatic
What are the symptoms of Amebiasis?
Diarrhea to dysentery with blood and mucous, fever, abdominal pain
How can Amebiasis be diagnosed?
Amoeba in stool, patchy inflammation in colonoscopy, serology, stool PCR, antigen capture
What is the pathology of Amebiasis in the intestine?
Lesions in the cecum, appendix or colon and amoeboma (granuloma obstructing the bowel)
What is the pathology of Amebiasis in the liver?
Hepatic amebiasis and formation of abscesses
What treatment is used for Amebiasis?
Metronidazole or tinidazole, followed by iodoquinol or paromomycin
Which of the following are mechanisms of cytotoxicity?
a. Direct contacts with the host tissues
b. Release of soluble toxic metabolites
c. High enzymatic activities of the amoeba
d. Interfering with the immune response of the host
e. All of the above
f. None of the above
e
Which key immune players are important in killing amoeba?
Macrophages, CD8 lymphocytes
True or false: Antibodies, ADCC and Th2 responses are not necessary for killing ameoba
True
