PROTOZOANS (Gen. Char. & Amoeba) Flashcards
memorization
General characteristics of protozoans:
- Eukaryote
- Unicellular with Ectoplasm and Endoplasm
- Motile
Thread-like, long whip-like structure arising from the surface of the cell
Flagella
SHorter, needle-like/hair-like structures; found all throughout the cell
Cilia
False-feet; temporary cytoplasmic extensions
Pseudopods/ pseudopodia
Flexible sheet material that joins the flagella to the surface of the cell
Undulating membrane
Consist of polar rings, subpellicular tubules, conoid, rhoptries and micronemes; for penetration and invasion of the target cell:
Apical complex
Cyst-to-trophozoite =
Excystation
Trophozoite-to-cyst =
Encystation
Active but not resistant
A. Trophozoite
B. Cyst
A. Trophozoite
Non-vegetative and non-reproductive
A. Trophozoite
B. Cyst
B. Cyst
Which is motile?
A. Trophozoite
B. Cyst
A. Trophozite
The only pathogenic intestinal amoeba:
Entamoeba histolytica
“Small race Entamoeba histolytica”
Entamoeba hartmanni
“Largest Entamoeba”
Entamoeba coli
Entamoeba that is found inside the oral cavity
Entamoeba gingivalis
“Smallest intestinal protozoa”
“Dwarf intestinal slug”
Endolimax nana
Nucleus:
PC: Fine, uniform, beaded appearance
K: Small, central, “Bull’s eye appearance”
Cytoplasm:
Finely granular, ground glass appearance (clean looking)
RBCs ingested
Entamoeba histolytica/dispar
Nucleus:
PC: Fine, uniform, beaded appearance
K: Small, Eccentric
Cytoplasm:
No RBC ingested
Entamoeba hartmanni
Nucleus:
PC: Unevenly distributed PC; Dark, solid ring
K: Large, Eccentric
Cytoplasm:
Coarsely granular vacuolated (Dirty looking)
Entamoeba coli
Nucleus:
PC: Closely packed, finely granular
K: small, well-defined, central
Cytoplasm:
Finely granular vacuolated
Ingested Epithelial cells, WBCs
Entamoeba gingivalis
Nucleus:
PC: None
K: Large, irregular, blot-like, central
Cytoplasm:
granular, vacuolated
Endolimax nana
Nucleus:
PC: None
K: Large, central, surrounded by refractile achromatic granules (Achromatic granules surround the karyosome)
Cytoplasm:
Coarsely granular, heavily vacuolated
Iodamoeba butschlii
Amoeba species that has no cyst stage:
Entamoeba gingivalis
1-8 nucleus
PC: Coarse granular, irregular
K: Large, Eccentric
Cytoplasm:
CB: With pointed ends (Splinter-like, broomstick, jagged ends)
Entamoeba coli
1-4 nucleus
Cytoplasm:
CB: Elongated bar with blunt rounded ends (bar-like, rice grain)
Entamoeba hartmanni
1-4 nucleus
PC: Fine, uniform
K: Small, central
Cytoplasm:
CB: Elongated bars with blunt rounded ends (Cigar-shaped, sausage-shaped, rod-like)
Entamoeba histolytica/Entamoeba dispar
1-4 nucleus (cross-eyed cyst, “button hole”)
PC: None
K: Large, blot-like, central
Cytoplasm:
CB: None
Granules or small oval masses
Endolimax nana
1 nucleus “basket-shaped”, “basket of flowers”
PC: None
K: large, eccentric, with refractile achromatic granules (periendosome)
Cytoplasm;
Glycogen: Compact, well-defined (Dark brown in Iodine prep) Large glycogen vacuole
Iodamoeba butschlii
Swine amoeba, cyst is uninucleated, in pigs and monkeys:
Entamoeba polecki
Amoebas that are uninucleated:
- Iodamoeba butschlii
- Entamoeba polecki
Entamoeba histolytica
Infective stage:
Diagnostic stage:
Entamoeba histolytica
Infective stage: Cyst
Diagnostic stage:
- Stool (watery) = Trophozoite
- Stool (formed) = Cyst
- Extraintestinal = Trophozoite
Ulcer shape of Entamoeba histolytica amoebic dysenteric colitis:
Flask-shaped ulcer
E. histolytica extraintestinal infection
Hepatic amoebiasis abscess:
Anchovy sauce abscess
E. histolytica extraintestinal infection
Pulmonary amoebiasis abscess:
Anchovy sauce-like sputum
Gold standard for the diagnosis of E. histolytica amoebiasis:
Concentration technique
Stains for identification of E. histolytica:
- Lugol’s iodine (Cyst)
- Quensel’s methylene blue (Trophozoite)
Naegleria fowleri
Infective stage;
Diagnostic stage:
Naegleri fowleri
Infective stage: Trophozite
Diagnostic stage: Trophozoite
POE and MOT of Naegleri fowleri:
POE: Nasal mucous membrane
MOT: Swimming through brackish or fresh water
Disease caused by N. fowleri:
Primary amoebic meningoencephalitis (PAM)
Stain used for N. fowleri:
Acridine orange
Culture media used for N. fowleri:
Bacteria-seeded agar (BSA)
(Gram-negative bacilli)
Characteristic effect observed in BSA for the diagnosis of N. fowleri:
TRAILING EFFECT
Non-pathogenic Naegleria:
Naegleria gruberi
Difference of N. gruberi to N. fowleri
Culture in BSA:
N.fowleri = growth inhibited by 0.2% NaCl & KCl
N. gruberi = (+) growth even with NaCL & KCl
Lyophilization for 6 months:
N. fowleri = Non-viable
N. gruberi = Viable
Acanthamoeba species
Infective stage:
Diagnostic stage:
Acanthamoeba species
Infective stage: Trophozoite
Diagnostic stage: Trophozoite & Cyst
Sucker-like structure for phagocytosis present in N. fowleri:
Amoebastomes
POE & MOT of Acanthamoeba species:
POE: Eyes
MOT:
- through traumatic contact
- contaminated contact lens solution
- Swimming in stagnant water
Motility of Acanthamoeba species:
Sluggish, polydirectional movement
Diseases caused by Acanthamoeba species:
Immunocompromised patients:
- Granulomatous amoebic encephalitis (GAE)
Immunocompetent patients:
- Corneal ulcer/keratitis
Diagnosis for Acanthamoeba species infection:
Culture:
- Protease-peptone extract, Yeast, Glucose, Cysteine (PYGC)
- Bacteria-seeded agar (BSA); Escherichia coli
- Corneal scrapings stained with calcofluor white
Indirect immunofluorescent Antibody - TECHNIQUE OF CHOICE
Was formerly classified as yeast; now a protozoan
Blastocystis hominis
Culture media for B. hominis:
Boeck/Drbohlav’s, Nelson & Jones
(Optimal growth: at 37C in the presence of bacteria)
