Protozoa Flashcards
How many species of amebae occur in humans?
Seven
Name the amebae species that occur in humans.
E. histolytica
Commensals
E. dispar
E. moshkovskii
E. hartmanni
E. coli
Endolimax nana
Iodamoeba bustchlii
Refers to an intestinal ameba of pigs and monkeys that has been occasionally detected in humans, and is a probably cause of diarrhea.
Entamoeba polecki
T or F. Amoeba & commensals belong to the Subphylum Sarcodina (pseudopodia) classification.
True
T or F. Parasitic Protozoa perform asexual but not sexual reproduction in different hosts.
False. It performs both asexual and sexual reproduction.
These are intestinal dwellers that has pseudopodium (false feet/hyaline foot-like protrusion for locomotion)
amoeba
Entamoebas are all intestinal dwellers except for ________ which is found in the mouth
E. gingivalis
He first described E. histolytica in 1873 and transferred amoebae to a dog by rectal injection which later on became ill and showed ulceration of colon.
Fedor Alexandrewitch Losch
Habitat of E. histolytica
mucosa & submucosa of the large intestine in man
Refers to a pseudopod-forming non-flagellated protozoan parasite that is the most invasice of the Entamoeba parasites and the only member o the family to cause COLITIS and LIVER ABSCESS.
E. histolytica
Infective stage of E. histolytica
cyst
MOT of E. histolytica
Drinking water contaminated with feces containing cyst
Name the three types of amebiasis tha can result from infection with Entamoeba
- Luminal amebiasis
- Invasive amebic dysentery
- Invasive extraintestinal amebiasis
T or F. Maintaining clean water is not a form of Entamoeba infection prevention.
False.
Excystation occurs in the small or large bowel, where a cyst undergoes nuclear followed by cytoplasmic division to form ____ trophozoites
A. 4
B. 8
C. 12
D. 16
E. NOTA
B. 8 trophozoites
Phoretic vectors of E. histolytica
Cockroach
Flies
Treatment for E. histolytica
Metronidazole
Why are trophozoites motile whereas cysts are non-motile?
Trophozoites have pseudopods
The most common form of diseas associated with amoebae.
Colitis
This clinically presents as gradual onset of abdominal pain and diarrhea with or without blood and mucus in the stools where fever is uncommon yet there are formation of ulcers.
Amebic colitis
This would develop in children with severe bloody diarrhea, fever, and abdominal pain.
fulminant colitis
It clinically presents as a mass-like lesion with abdominal pain and a history of dysentery
Ameboma
It is the most common extra-intestinal form of amebiasis. Its cardinal manifestations are fever and right upper quadrant (RUQ) pain.
Amebic liver abscess (ALA)
The most serious complication of amebic colitis.
Perforation and secondary bacterial peritonitis
Should amebix colitis be ruled out BEFORE or AFTER steroid therapy for inflammatory bowel disease
BEFORE steroid therapy is started bc of the risk of developing toxic megacolon
LAB Dx for Amoebiasis:
Stool Examination
Blood Examination
Serological Tests
Culture: Boeck and Drbohlav’s diphasic medium
Diagnostic Aspiration
Liver Biopsy
Molecular Methods
For the diagnosis of Amoebiasis, what is the ideal number of stool specimens to be collected on different days for examination?
a minimum of 3
For the dection of trophs, fresh stool specimens should be examined within ___________ from defacation
A. 1 hr
B. 30 mins.
C. 15 mins.
B. 30 mins.
The detection of E. histolytica trophs with ingested RBCs is diagnostic of __________.
Amebiasis
The differentiation between E. histolytica and E. dispar can only be done by the following, except:
A. Microscopy
B. PCR
C. ELISA
D. Isoenzyme analysis
E. NOTA
A. microscopy
Its detection in the serum is the key in the diagnosis of Amebic Liver Abscess (ALA)
antibodies
Other than metronidazole, the ff. are also effective treatment for Amoebiasis, except:
A. Tinidazole
B. Secnidazole
C. Diloxanide
D. NOTA
D. NOTA
This genus has a spherical nucleus with a distinct nuclear membrane lined with chromatin granules and a small karyosome found near the center of the nucleus.
Entamoeba
This genus has a spherical nucleus with a distinct nuclear membrane lined with chromatin granules and a small karyosome found near the center of the nucleus.
Entamoeba
This genus has a vesicular nucleus with a relatively large, irregularly-shaped karyosome anchored to the nucleus by achromatic fibrils.
Endolimax
This genus is characterized by a large, chromatin-rich karyosome surrounded by a layer of achromatic globules and anchored to the nuclear membrane by achromatic fibrils.
Iodamoeba
Which among the two statements is true
A. E. gingivalis has no cyst stage and does not inhabit the intestines
B. E. gingivalis has a cyst stage but does not inhabit the intestines
A.
Morphologically similar to E. histolytica but differs in their DNA and rRNA.
Entamoeba dispar
Identify the commensal amoeba being described:
Harmless inhabitant of the colon
E. coli
Identify the commensal amoeba being described:
Similar with E. histolytica but smaller and has no RBC inclusion
E. hartmanni
Identify the commensal amoeba being described:
“small race” of E. histolytica that is non-pathogenic
E. hartmanni
Identify the commensal amoeba being described:
Parasite of pigs and monkeys that rarely infect humans with their cysts consistently uninucleated.
E. polecki
Identify the commensal amoeba being described:
This can be found in the mouth (gum or teeth) that has no cyst stage and transmitted through kissing, droplet spray, and sharing utensils
E. gingivalis
Identify the commensal amoeba being described:
Classified as free-living amoeba (rarely infect humans) that is first detected in sewage, osmotolerant, and able to survive at temperature range of 0-41 degree C.
E. moshkovskii
Identify the commensal amoeba being described:
Smallest protozoa with its sluggish and mononuclear troph form hacing a quadrinucleated cyst form with eccentric karyosome (cross-eyed cyst)
E. nana
Identify the commensal amoeba being described:
Has an iodine cyst, a large glycogen vacuole/body which stains deeply with iodine and is uninucleated
Iodamoeba butschlii
1st parasitic amoeba to be recognized n the soft tartar between the teeth in 1849.
E. gingivalis
Refers to the only amoeba that ingests WBCs
E. gingivalis
Its cyst is a “basket of flowers” in shape
I. butschlii
LAB Dx of Commensals
FECT (Formalin ether/ethyl acetate concentration technique)
Lugol’s Iodine
Treatment for Commensals
None (Not necessary as it doesn’t cause disease)
An ubiquitous, free-living ameba that is commonly found in soil & water where they feed on bacteria as opportunists that may produce serious infection of the CNS and the eye.
Acanthamoeba
It is characterized by an active trophozoite stage with characteristic promininent “thorn-like” appendages and a highly resilient cyst stage into which it transforms when environmental conditions are not favorable.
Acanthamoeba
Associated with the use of improperly disinfected soft contact lenses, particularly those which are rinsed with tap water or contaminated lens solution.
A. keratitis
LAB Dx of A. Keratitis
Epithelial biopsy
Corneal scrapings
Most common Acanthamoeba spp.
A. castellani
Exists as active trophs and resistant cyst; no flagellate form
Acanthamoeba sp.
MOT of Acanthamoeba spp.
Inhalation of aerosol or dust containing trophs and cysts
Direct invasion through cuts, wounds, and eye
Pathology of Acanthamoeba spp.
GAE - Granulomatous Amebic Encephalitis
AK - Amebic Keratitis
What are the two vegetative forms of Naegleria spp.?
- ameba (trophozoite form)
- flagellate (swimming form)
This form of Naegleria fowleri trophozoites are found in humans.
Ameboid trophozoites
T or F. Naegleria spp. are thermophilic organisms which thrive best in hot springs and other warm aquatic envrionments.
True
MOT of N. fowleri
Oral or intranasal routes while swimming in contaminated lakes, pools, and rivers
LAB Dx for N. fowleri
Microscopic identification of living or stained amoeba in CSF
Tissue samples and nasal discharges
Culture of clinical specimens
PCR assay
Monoclonal Ab testing
Flow cytometry
DNA hybridization
ELISA
Refers to a Naegleria spp. that could possibly infect humans in the future that is pathogenic in mice exposed to the parasite by intranasal instillation.
N. australiensis
Kills Naegleria fowleri easily
chlorination of water at 1 ppm or higher
A newly described amoeba that does not have a flagellate stage.
Balamuthis mandrillaris
Causes chronic CNS infection
Balamuthia mandrillaris
This infection generally manifests as intestinal diarrhea
Giardia