Parasitology Flashcards
Lab identification of Ancyclostoma duodenale and Necator americanus is made by observing ____ in fresh stool. On occasion, _____ worms may be seen attached to intestinal lining.
eggs; adult worms
A. duodenale adult worms can be differntiated from N. americanus by _____
A. duodenale has a pair of teeth; N.americanus has a pair of cutting plates
What is the diagnosis of choice for E. histolytica
EIA
This amoeba creates “flask-like lesions” in biopsies
E. histolytica
This amoeba has a “cigar-shaped” cromatoid body
E. histolytica
This amoeba contains up to 4 nuclei in its cyst form
E. histolytica
What is the cyst size and troph size of E. histolytica
Cyst: 12-15 um
Trop: 15-20 um
The nucleolous inside the nucleus = what (amoeba)
Karyosome
This amoeba looks like E.histolytica but is half the size
E. hartmanni
E. dispar is identical to E.histolytica and must be distinguished using DNA sequencing
True
What is the infective form of Ancanthamoeba
Cyst AND troph
This amoeba has a double walled cyst and has a “bulls-eye” nucleus in the troph
Acanthamoeba
Cryptosporidium, cyclospora, and cystoisospora are all groups of GI ______
Sporozoa/Coccidia
What GI sporozoa caused the waterborne outbreak in Milwaukee, 1994?
Cryptosporidium
What is the infectious form of sporozoa – cryptosporidium, cyclospora?
Oocyst
What is the test of choice for Cryptosporidium?
EIA
What stain is used to diagnose Cryptosporidium?
What secondary test used to diagnose Cryptosporidium?
Acid-fast; DFA
What is the test of choice for Giardia?
What is a secondary test used?
EIA; String test
What is the size of the Cryptosporidium oocysts> What is distinguishing features?
4-6um & crescent-shaped sporozoites
How big is Cyclospora oocysts?
8-10um
Can cryptosporidium or cyclospora be transmitted human to human?
Cryptosporidium NOT cyclospora
What stains can be used to ID Cyclospora?
MAF or Modified Safrinin
MS is usually better; less “ghosts” compare to MAF
What sporozoa/coccidia autofluoresce?
Cyclospora; Cystoisospora belli
What vector is associated with Babesia microti?
Ticks - mostly deer ticks here
What vector is associated with Babesia on Nantucket island (will be on exam)
Black lake tick
Ixodes scapularis is associated with what infection?
Babesia
A merozoite showing a “maltese cross” is associated with what infection?
Babesia
This organism can show ring forms inside AND outside of RBC AND contain multiple rings and merozoites per RBC. This is unique to this organism.
Babesia spp.
Where is Plasmodium ovale found? (Will be on exam)
Sub-Saharan Africa aka WESTERN Africa
What Plasmodium species can remain dormant in the liver?
P. ovale
P. vivax
HINT: It’s not OVer – Ovale; Vivax
What Plasmodium species have Schuffner’s dots?
Vivax and ovale
What Plasmodium species infects larger RBD, has Schuffners dots, and infected cells are round or oval. Also may have fimbrations
P. ovale
Best way to diagnose Toxo. gondii?
Serology– IFA, EIA
Trachyzoites are detected in some specimens; bradyzoites are detected in _____ specimens
tissue
Trachyzoites are seen extracellularly as banana-shaped whereas bradayzoites are seen ____ in cysts
intracellularly
What is the infectious form of Leishmania?
Promastigotes
What is the diagnostic form of Leishmania
Amastigotes
Leishman-Donovan (L-D) bodies is an old term for
Amastigotes
What tapeworm (cestode) has double genital pores in one proglottid?
Dipylidium canium
What is the vector for African Sleeping Sickness
Tsetse fly
What is the vector for Chagas disease?
Kissing/Reduuvid bug
What is the organism that causes African Sleeping Sickness?
Trypanosoma brucei
What is the organism that causes WEST African Sleeping Sickness?
T. brucei gambiense
West Africa: gambling out west in Vegas
What is the organism that causes EAST African Sleeping Sickness?
T. brucei rhodesiense
What is the infectious form of Trypanosomiasis
Trypomastigotes
T. cruzi has _____ (large/small) kinetoplasts whereas T. brucei has _____ (large/small) kinetoplasts
Large; Small
This type of worm is associated with anemia and iron deficiency
Hookworm
What GI helminth is associated with B12 deficiency
Diphyllobothrium latum (AKA Dibothriocephalus latus)
Largest trematode with VERY prominent opperculum
F. hepatica/F. buski
What cestode has a striated outer membrane and contains six hooklets within its oncosphere
H. diminuta
What cestode has a THICK outer membrane and contains polar thickenings/filaments
H. nana
The hooklets of Echinococcus stain ______ and look like bottle openers
Acid-fast
What is one important factor when collecting blood for filarial parasites?
TIME of collection
What filariae require tissue snips for diagnosis? (2)
O. volvulus; M. streptocera
What microfilariae are nocturnal? (2)
W. bancrofti & Brugia spp.
What microfilariae are dinural? (2)
Loa Loa, M. ozzardi
Which Mansonella sp has no sheath and a BLUNT ended tail
M. perstans
Which Mansonella sp has no sheath and a tapered tail with a small hook shaped terminus
M. ozzardi
Which Mansonella sp has no sheath and a tapered tail with a very obvious hook shaped tail
M. streptocerca