Entamoeba Flashcards
Entamoeba spp. where only the trophozoite is found.
Entamoeba gingivalis
T/F: All intestinal amoeba are non-pathogenic except for E. histolytica
True
T/F: All free-living amoeba are opportunistic pathogen
True
T/F: E. histolytica is morphologically distinct from three other intestinal amoeba (E. dispar, E. bangladeshi, E. moshkovskii)
False. E. histolytica is indistinguishable.
Which of the pathogens listed here causes non-invasive diarrhea:
A. E. bangladeshi
B. E. dispar
C. E. moshkovskii
C. E. moshkovskii
Who discovered E. histolytica?
Losch in 1875
St. Petersburg, Russia
Most patients seen with E. histolytica have?
With dysentery
T/F: Majority of E. histolytica patients are symptomatic
False. Most are asymptomatic 80-99%
What is the form of E. histolytica present in tissues?
Trophozoites
T/F: E. histolytica is small and motile
False. E. histolytica is LARGE and motile
T/F: E. histolytica’s outer ectoplasm is clear, transparent, and refractile
True
T/F: E. histolytica’s inner endoplasm is finely granular and with ground glass appearance
True
T/F: Pseudopodia of E. histolytica is inhibited at high temperatures
False. It is inhibited by low temperatures
T/F: E. histolytica’s motility is a free swimming one
False. Crawling or gliding motility
Cartwheeling appearance of nucleus is present in:
E. histolytica
How does E. histolytica divide?
By binary fission every 8H.
How does E. histolytica divide?
By binary fission every 8H.
T/F: Live trophozoites passed in stool can initiate infection when re-ingested.
False. Even ingested, trophozoites are killed rapidly in the stomach.
Where does the encystment of E. histolytica trophozoites occur?
In intestinal lumen.
T/F: E. histolytica encystment occurs in tissues and in feces
False. Encystment do not occur in tissues outside the body. It only occurs in intestinal lumen.
T/F: Pre-cystic stage of E. histolytica has glycogen vacuole and 2 chromatid bodies.
True.
T/F: Cystic stage of E. histolytica is spherical in shape
True. It is also 10-20um in size.
Mode of transmission of E. histolytica.
Swallowing of contaminated food and water.
T/F: Mature cyst of E. coli has 6 nuclei
False. It has eight.
T/F: Life cycle of Entamoeba coli is the same as E. histolytica
True. But it remains as luminal commensal without tissue invasion.
Cyst of this Entamoeba closely resembles Endolimax nana
Entamoeba hartmanni
Luminal agents for E. histolytica
Diloxanide, Iodoquinol, Paromomycin, Tetracycline
Tissue amoebicides for E. histolytica
Emetine, chloroquine.
Chloroquine: 1gm x 2 days then 5gm x 3 weeks
T/F: Asymptomatic E. histolytica do not need treatment
False. It also needs treatment.
The chromatid bodies of this Entamoeba are splinter-like and irregular
Entamoeba coli
Description of chromatid bodies of Entamoeba histolytica
Cigar-shaped with rounded ends
Amoeboma closely resembles what cancer?
Adenocarcinoma of colon
T/F: Mature cyst of E. histolytica is octonucleated
False. Quadrinucleated
T/F: Excystation occurs because of the acid environment of stomach
False. It occurs because of the alkaline environment of intestine and is damaged by TRYPSIN
Life stages of E. histolytica
Trophozoite –> precyst –> cyst –> excystation –> metacyst
Incubation period of E. histolytica
4 days to 5 months
How to differentiate pathogenic vs non-pathogenic E. histolytica strains?
Complement-mediated analysis Phagocytic activity Zymodeme activity Genetic markers Monoclonal antibodies
Metacystic trophozoites penetrate what cell layer of GIT?
Columnar epithelial cells of crypts of Liberkuhn in colon
Penetration of E. histolytica is due to what virulence factor?
Histolysin
Adherence of E. histolytica is due to what virulence factor?
Amoebic lectin
T/F: Stool consistency of E. histolytica is characterized by adherence to container
False. It do not adhere to container
Description of intestinal ulcer lesion of E. histolytica amoebiasis
Pin-head center and raised edges
In cross-section, what is the description of typical amoebic ulcer?
Flask-shaped. Narrow neck and rounded base
Perforation and peritonitis is due to what pathophysiology:
Affectation of muscular and serous coats of colon respectively
Amoeboma is a result of Acute or Chronic ulcer?
Chronic ulcer.
Where can we see multiple lesions most?
- In cecum
2. Rectosigmoid, next most area
Vague abdominal symptoms of E. histolytica is termed as
Growling abdomen
Uncomfortable belly
Most common extraintestinal complication of amoebiasis
Hepatic amoebiasis
T/F: In amoebic liver abscess, center of abscess if full of bacteria and amoeba
False. It is bacteriologically sterile and free of amoeba.
Characteristic smell of ALA pus:
Anchovy sauce pus or bagoong like odor
In smear, where can we see the invading amoeba?
In periphery.
Central is free of amoeba and bacteriologically sterilly
How does jaundice occur?
When there is multiple lesions
T/F: Pulmonary amoebiasis occur via lymphatic spread.
False. It occurs via direct hematogenous spread
T/F: Hepatobronchial fistula has non-productive cough as symptoms
False. With productive cough. Expectoration of brown sputum.
T/F: Amoebic empyema has productive cough
False. It has non-productive cough
How does metastatic amoebiasis spread?
Through lymphatics and direct hematogenous spread
Cutaneous amoebiasis is commonly mistaken for what disease entities?
Condylomata and epithelioma
T/F: E. histolytica do not ingest RBCs
False. It phagocytize RBCs.
Entamoeba coli and Entamoeba hartmanni are those that do not ingest RBCs
How many stool samples should be examined to test for excretion of stools?
3x
T/F: Serological tests for E. histolytica becomes positive in non-invasive forms
False. It becomes positive in invasive forms only
Indirect hemagluttin test/assay titer to diagnose with E. histolytica amoebic hepatitis/hepatitis amoebiasis
1:256 or above
T/F: ELISA is of great value to E. histolytica diagnosis
True. Due to its greater sensitivity
T/F: Stool samples are of great use in amoebic hepatitis
False. Because only about 15% of cases become positive.
What part of lobe is usually affected in hepatic amoebiasis?
Right lobe
Are lesions of amoebic liver abscess often solitary or multiple?
Solitary.
In pyogenic abscess is where we can appreciate more the multiple lesions.
What is the drug of choice in treating amoebiasis?
Metronidazole.
750mg 3x/day for 5-10 days.
T/F: Movement of E. coli is active/rapid.
False. It is sluggish.
T/F: Visibility of nucleus in unstained film is a characteristic of E. hartmanni
False. It is characteristic description of Entamoeba coli.
The karyosome of this Entamoeba is large and eccentric?
Entamoeba coli.
E. histolytica and E. hartmanni - small and central
This pathogen can be found whenever E. histolytica is found.
E. hartmanni