Protozoa: Amoeba, Intestinal Flagellates and Ciliates

What are the 4 groups of protozoa

What are the 4 groups of protozoa

Amoeba

Ciliates

Flagellates

Sporozoan

Is protozoa an unicellular organism

yes

What are the 3 groups that have motility organelles

pseudopods

flagellae

cilia

What is pseudopods

false feet

Which protozoa group is related to pseudopods

amoebae

What is flagellae

whip-like structures

Which protozoa group is related to flagellae

flagellates

What is cilia

short, hair-like structures

Which protozoa group is related to cilia

ciliates

What are the two stages or forms for protozoa

trophozoite

cyst

What is trophozoite

active, motile, feeding form that reproduces

What does trophozoite indicate

active infection

Where is trophozoite mostly seen in

loose or watery stools

What is cyst

rigid, survival form

What does cyst indicate

inactive infection or carrier state

Where is cyst mostly seen in

formed stools

What is the most common specimen for protozoa

stool

What are some other specimens for protozoa

urogenital

CSF

lung, liver, or brain abscess

corneal scrapings

Are trichrome smear required to identify the amoebae

yes

What does Entamoeba. histolytica cause

amebic dysentery

Dysenteric bowel disease

Is Entamoeba. histolytica pathogenic

yes

What are the symptoms of Entamoeba. histolytica

Bloody diarrhea, sometimes cramping

Lower abdominal pain

Low-grade fever

What are the  Mechanism of invasion for Entamoeba. histolytica

Adherence to mucous layer of intestine

Disruption of the intestinal barrier by enzyme secretion

Invasion of epithelial cells

Lysis of intestinal epithelial cells

Invasion of deeper layers of mucosa

is Entamoeba. histolytica mostly asymptomatic

yes

What is the incubation period for Dysenteric bowel disease cause by E. histolytica

of 1-4 weeks, large bowel lesions, Flask-shaped ulcers

What are the characteristics of Troph (trophozoite) in Entamoeba histolytica/dispar

progressive, directional motility

engulfed RBCs

one nucleus

fine, regular peripheral chromatin

central karyosome

 (15-25um)

What are the characteristics of Cyst in Entamoeba histolytica/dispar

up to 4 nuclei

smooth, rounded chromatoid body-- “cigar body”

 (10-20um)

E. histolytica Cyst

E. histolytica Trichrome (trop)

Entamoeba histolytica  Cyst: trichrome smear

Cyst: Iodine prep    

Is Entamoeba hartmanni Nonpathogenic

yes

Is Entamoeba hartmanni smaller than E. histolytica

yes

What are the characteristics of Cyst in Entamoeba hartmanni

5-10 μm

One to four nuclei (frequently just two nuclei seen)

Cigar-shaped chromatoidal body

Eccentric karyosome

What are the characteristics of Troph (trophozoite) in Entamoeba hartmanni

Single pseudopod

4-12 μm

Eccentric karyosome

Uneven peripheral chromatin

Finely granular cytoplasm

E . hartmanni Trophozoite and Cyst(A)

What are the characteristics of Troph (trophozoite) in Entamoeba coli

 15-50um)

nondirectional motility

engulfs bacteria or yeast

one nucleus

coarse, irregular peripheral chromatin

eccentric karyosome

What are the characteristics of Cyst in Entamoeba coli

 15-25um)

round

up to 8 nuclei

splintered chromatoid body

Is Entamoeba coli Nonpathogenic

yes

Which of the Entamoeba species are Nonpathogenic

E. dispar

E. coli 

E. hartmanni    

Endolimax nana

Iodamoeba butschlii

Blastocystis hominis

Entamoeba coli ( Cyst: Trichrome smear)

Entamoeba coli ( Cyst: iodine prep)

What are the characteristics of Cyst in ENDOLIMAX NANA

(5-12um)
 oval to ellipsoidal
 4 nuclei if mature

What are the characteristics of Troph in ENDOLIMAX NANA

(5-12um): No
peripheral chromatin
& large karyosome

What are the characteristics of Troph in IODAMOEBA BUTSCHLII

(6-
20um)
one nucleus
 no peripheral
chromatin
 large, eccentric
karyosome surrounded
by granules

What are the characteristics of Cyst in IODAMOEBA BUTSCHLII

(6-15um)
one nucleus
large, glycogen-
filled vacuole
 clear on trichrome
 stains rust-brown in
iodine wet prep

What organism are EXTRA-INTESTINAL
AMOEBAE

Naegleria fowleri
Acanthamoeba
spp.

Where do Naegleria fowleri and Acanthamoeba spp. live in

soil and water

How can a person get infected by Naegleria fowleri and Acanthamoeba spp.

Infection acquired by direct contact with
contaminated water---lakes, ponds,
swimming pools

What are the infections for NAEGLERIA FOWLERI

 Primary Amoebic Meningoencephalitis
 mimics bacterial meningitis
 rapidly fatal (within 1 week of symptoms)

How is NAEGLERIA FOWLERI transmission

moeba in water is inhaled
& enters nasal mucosa, then spreads via
olfactory nerve to the brain and CNS
 According to the CDC: “You cannot get infected
from drinking water contaminated
with Naegleria. You can only be infected when
contaminated water goes up into your nose.”

What kinds of infections do ACANTHAMOEBA SPP.

ulcer/keratitis

GAE- Granulomatous Amoebic
Encephalitis

What is GAE- Granulomatous Amoebic
Encephalitis

spreads via blood from skin or lungs to CNS
 occurs in the debilitated/immunosuppressed
 usually slow, chronic (incubation may be months to
years), but often fatal infection

What are the characteristics of Cyst in ACANTHAMOEBAE

15-20 μm
 Spherical, double walled with a wrinkled appearance

What are the characteristics of Troph in ACANTHAMOEBA

10-45 μm
 Spiny pseudopodia
 Single nucleus with central prominent endosome

What organism are INTESTINAL
FLAGELLATES

Giardia
Dientamoeba fragilis
Trichomonas
vaginalis
Chilomastix mesnili
Pentatrichomonas
hominis

How does INTESTINAL FLAGELLATES transmit

most by ingestion of cysts in contaminated food
or water
some may be sexually transmitted
one probably ingested with helminth eggs

Which organisms are Pathogenic flagellates

Giardia lamblia

Which organisms are Nonpathogenic, commensal flagellates

Chilomastix mesnili
 Pentatrichomonas hominis