Amoebas Flashcards
What is pathogenicity?
Ability of an organism to cause disease
What is encystment?
Process of forming or becoming enclosed in a cyst or capsule
What is four major groups of protozoans?
Amoeba, flagellate, ciliate, apicomplexan
How did Sarcodina moves?
Using pseudopodia
How did Mastigophora moves?
By using flagella
What stage is attained by an amoeba after excystation?
Trophozoite
Name the only amoeba that is a true pathogen
Entamoeba histolytica
What organism is distinguishable from E. histolytica?
Entamoeba dispar
The small race version of E. histolytica
Entamoeba hartmanni
True or false? E.despair is pathogenic
False
Name the soul determinant that distinguishes E. histolytica from E. dispar under the microscope
Presence of ingested RBCs
True or false? E. histolytica is seen worldwide in all ages sexes and races
True
Types of E.histolytica infections
a) hepatitis
b) asymptomatic colonisation
c) asthma
d) extra intestinal amebiasis
e) invasive intestinal amebiasis/amoebic dysentery
f) conjunctivitis
Bde
What is the shape of the ulceration that characterise an infection with E. histolytica?
Flask-shaped
Extraintestinal amebiasis can affect
a) lungs
b) liver
c) intestine
d) brain
e) all but c are correct
True or false? Trophozoites of E. histolytica are commonly found in solid or formed stool
False
True or false? the diagnostic and infective stage of E. histolytica is when infective cysts pass in feces (trophozoites may be I.D.ed in soft/liquid feces)
True
Where does excystation occur for E. histolytica?
Small intestine specifically the ileum
Where do trophozoites of E. histolytica undergo asexual division or binary fission?
Large intestine
Method of infection for E. histolytica
Ingestion
What is trophozoites?
the active, motile, feeding stage of a protozoan parasite (vegetative stage - reproduction or propagation achieved by asexual mean)
What is cyst?
stage in parasite’s life cycle (outside a host or in tissues) that resistance to unfavorable conditions (dormant or resting stage)
What is reservoir host?
An animal host that makes the parasite available for the transmission to another host (human)
What is the mode of transmission of E. histolytica?
Feco-oral (ingestion of food or water contaminated with faeces)
How did hepatic amebiasis happen?
The trophozoites will travel to the liver via hepatoportal system to form abscess
What is necrosis?
Premature death of cell and living tissues
What is granuloma?
It is an inflammation that may contain collected immune cells which is macrophages
What is the lead symptom of hepatic amoebiasis?
Right upper quadrant pain and fever
What are the symptoms of amoebiasis?
pain in the entire abdomen
• fulminating (occur suddenly with great intensity) diarrhea
• dehydration
• loss of blood
intermittent diarrhea
cramps
vomiting
general malaise
What are the symptoms of acute amoebic dysentery?
headache, fever, severe abdominal cramps and
prolonged ineffective straining at stool
What are the diagnosis for amoebiasis?
• Trophozoites or cysts in stool examination:
• 4 nuclei vs. 8 nuclei for Entamoeba coli
• Direct smear examination:
• Wet mount technique & Fixed and stained (Trichrome)
• Nested PCR and monoclonal antibody.
• E. dispar vs. E. histolytica
• X-ray examination/ scanning liver (ultrasound).
• ELISA assays for amebic lectin antigen (in saliva).
• Serology:
• Secondary amebiasis & extraintestinal amebiasis
• Other specimens:
• Liver abscess (a collection of pus (dead neutrophils) aspirates
What is the treatment for E. histolytica?
Metronidazole and Tetracycline (antibiotic) combination with diiodohydroxyquin
