Exercise No. 6c-1 PROTOZOA Phylum Sarcomastigophora - Subphylum Mastigophora Flashcards
Trophozoite: 9 to 12 µm long by 5 to l5 µm wide
Giardia lamblia
Trophozoite: average size of 14 x 7 µm
Giardia lamblia
Trophozoite: pyriform, pear-shaped or teardrop shaped
Giardia lamblia
Trophozoite: rounded anterior
Giardia lamblia
Trophozoite: tapering, pointed, attenuated posterior
Giardia lamblia
Trophozoite: resembles the curved portion of a spoon if examined from the side
Giardia lamblia
Trophozoite: dorsoventrally flattened
Giardia lamblia
Trophozoite: dorsal side is convex and the ventral side is flat or concave
Giardia lamblia
Trophozoite: anterior half of the ventral surface bears two sucking discs on each side
Giardia lamblia
Trophozoite: bilaterally symmetrical with a pair of medial lines
Giardia lamblia
Trophozoite: possesses two ovoid to spherical nuclei, located one in each of the sucking disc
Giardia lamblia
Trophozoite: Each nucleus has a large karyosome, usually centrally located
Giardia lamblia
Trophozoite: no peripheral chromatin
Giardia lamblia
Trophozoite: Two slightly curved rodlike structures sit on the axonemes posterior to the nuclei
Giardia lamblia
Trophozoite: four pairs of flagella that arise from the blepharoplasts
Giardia lamblia
Trophozoite: One pair of the flagella projects from the the anterior end, another pair on the posterior end, and 2 pairs on the midportion extending laterally.
Giardia lamblia
Trophozoite: propelled into a “falling leat” or “flipflop” motility
Giardia lamblia
Trophozoite: “monkey face”
Giardia lamblia
Trophozoite: “old man with eyeglasses”
Giardia lamblia
used for attachment to the intestinal mucosa
sucking discs
bilaterally symmetrical with a pair of medial lines dividing the trophozoite into 2 halves throughout most of its length
axostyles (or axonemes)
Two slightly curved rodlike structures
parabasal bodies (or median bodies)
Cyst: ovoid or ellipsoidal in shape
Giardia lamblia
Cyst: 8 to 12 µm long by 7 to 10 µm wide
Giardia lamblia
Cyst: surrounded by a tough hyaline cyst wall secreted from cytoplasm
Giardia lamblia
Cyst: cytoplasm may retract from the cyst wall creating a clearing zone and a double wall appearance
Giardia lamblia
Cyst: immature cyst contains two nuclei
Giardia lamblia
Cyst: mature cyst has four
Giardia lamblia
Cyst: axostyles lie diagonally forming a dividing line
Giardia lamblia
Cyst: Remnants of the flagella and parabasal bodies are seen
Giardia lamblia
Trophozoite: 5- 12 µm in diameter
Dientamoeba fragilis
Trophozoite: slightly progressive motility
Dientamoeba fragilis
Trophozoite: does not have flagella
Dientamoeba fragilis
Trophozoite: characterized as having one (20 to 40%) or two (60 to 80%) nuclei
Dientamoeba fragilis
Trophozoite: nuclear chromatin is usually fragmented into three to five granules
Dientamoeba fragilis
Trophozoite: no peripheral chromatin on the nuclear membrane
Dientamoeba fragilis
Trophozoite: has a hyaline ectoplasm
Dientamoeba fragilis
Trophozoite: highly vacuolated endoplasm with ingested bacteria, yeast, and other debri
Dientamoeba fragilis
possess characteristic serrate margins which sometimes give it a stellate appearance
broad hyaline pseudopodia
Giardiasis can be diagnosed by identification of cysts or trophozoites of Giardia lamblia in stool by
direct fecal smears, concentration, or permanent staining
Cysts of G. lamblia are found in
formed stools
Cysts and trophozoites of G. lamblia are found in
diarrheal stools
Often multiple specimens need to be examined and concentration techniques prior to reporting that a patient is free of Giardia.
Direct Microscopy: Stool examination
This is done if the stool exam reveals negative results despite the clinical manifestations of giardiasis.
Examination of duodenal specimen
Obtained by gastroduodenoscopy and examined microscopically as a wet preparation or permanent-stained smear
Duodenal aspirate
another method for obtaining duodenal specimen
Enterotest® (HDC Mountain View, CA) or string test
a gelatin capsule lined with silicone rubber that contains a spool of nylon string and a weight
Enterotest® (HDC Mountain View, CA) or string test
The end of the string is taped to the back of the patient’s [?]
neck or cheek
The patient then swallows the [?]
capsule with water
The patient is not allowed to eat during this time but is allowed to [?]
drink a small amount of water
As the capsule dissolves, the string unwinds and is carried by [?] to the duodenum, and the duodenal mucus adheres to the string.
peristalsis
After about [?], the string is retrieved, and duodenal contents adherent to the string is scraped off and placed in saline on the slide for microscopic examination.
4 to 6 hours
also used for detecting larvae of Strongyloides, eggs of liver flukes and oocysts of lsospora
Enterotest® (HDC Mountain View, CA) or string test
A variety of immunodiagnostic methods, relying on detection of serum antibodies or antigens in feces, are in use.
Immunodiagnosis of Giardia lamblia
have been used to demonstrate parasitic genome in the stool specimen containing Giardia lamblia
Deoxyribonucleic acid (DNA) probes and polymerase chain reaction (PCR)
has only the trophozoite stage; Cysts have not been identified
Dientamoeba fragilis
