Parasitology MTAP Flashcards
Artifacts found in a stool specimen that can be confused with ova or cysts are:
a partially digested meat fibers
b degenerated cells from the gastrointestinal mucosa
c dried chemical crystals
d pollen grains
d pollen grains
Polyvinyl alcohol used in the preparation of permanently stained smears of fecal material:
a concentrates eggs
b dissolves artifacts
c serves as an adhesive
d enhances stain penetration
c serves as an adhesive
Amethod to culture Acanthamoeba sp from corneal ulcer scrapings is to inoculate
a McCoy cells
b Novy, MacNeal and Nicolle (NNN) medium
c an agar plate overlaid with Escherichia coli
d Regan-Lowe medium
c an agar plate overlaid with Escherichia coli
Primary amoebic encephalitis is caused by:
a Entamoeba coli
b Dientamoeba fragilis
c Endolimax nana
d Naegleria fowleri
d Naegleria fowleri
Aformed stool is received in the laboratory at 10:30 pm for ova and parasite exam. The night shift technologist is certain that the workload will prevent examination of the specimen until 7 am when the next shift arrives. The technologist should:
a request that a new specimen be collected after 7 am
b hold the specimen at room temperature
c examine a direct prep for trophozoites and freeze the remaining specimen
d preserve the specimen in formalin until it can be examined
d preserve the specimen in formalin until it can be examined
The advantage of thick blood smears for malarial parasites is to:
a improve staining of the organisms
b improve detection of the organisms
c remove RBC artifacts
d remove platelets
b improve detection of the organisms
Multifocal brain lesions in AIDS patients are commonly caused by:
a Toxoplasma gondii.
b Pneumocystis jiroveci
c Cryptosporidium parvum
d Taenia solium
a Toxoplasma gondii.
A 44-year-old man was admitted to the hospital following a 2-week history of low grade fever, malaise and anorexia. Examination of a Giemsa stain revealed many intra erythrocytic parasites. Further history revealed frequent camping trips near Martha’s Vineyard and Nantucket Island but no travel outside the continental United States. This parasite could easily be confused with:
a Trypanosoma cruzi
b Trypanosoma rhodesiense/gambiense
c Plasmodium falciparum
d Leishmania donovani
c Plasmodium falciparum
A patient is suspected of having amebic dysentry. Upon microscopic examination of a fresh fecal specimen for ova and parasites, the following data were obtained: a trophozoite of 25 pm progressive, unidirectional crawl, evenly distributed peripheral chromatin finely granular cytoplasm. This information indicates:
a Entamoeba coli
b Entamoeba histolytica
c Endolimax nana
d lodamoeba biitschlii
b Entamoeba histolytica
A liquid stool specimen is collected at 10:00 pm and brought to the laboratory for culture and ova and parasite examination. It is refrigerated until 10:10 am the next day, when the physician requests that the technologist look for amoebic trophozoites. The best course action of would be to:
a request a fresh specimen
b perform a concentration on the original specimen
c perform a trichrome stain on the original specimen
d perform a saline wet mount on the original specimen
a request a fresh specimen
Small protozoan cysts are found in a wet mount of sediment from ethyl-acetate concentrated material. Each cyst has 4 nuclei that do not have peripheral chromatin, and fb each nucleus has a large karyosome, which appears as a refractive dot. These oval cysts are most likely:
a Endolimax nana
b Chilomastix mesnili
c Entamoeba histolytica
d Entamoeba hartmanni
a Endolimax nana
The term “internal autoinfection” is generally used in referring to infections with?
a Ascaris lumbricoides
b Necator americanus
c Trichuris trichiura
d Strongyloides stercoralis
d Strongyloides stercoralis
Proper collection of a sample for recovery of Enterobius vemqlculafls includes a
a 24-hour urine collection
b a first morning stool collection with proper preservative
c ascotch tape preparation from the perianal region
d peripheral blood from a finger
c ascotch tape preparation from the perianal region
A fibrous skin nodule is removed from the back of a patient from Central America. A microfilaria seen upon microscopic exam of the nodule is most likely:
a Wuchereria bancrofti
b Brugia malayi
c Onchocerca volvulus
d Loa loa
c Onchocerca volvulus
Human feces is not a recommended specimen in the detection of:
a Strongyloides stercoralis
b Entamoeba histolytica
c Echinococcus granulosus
d Ancylostoma duodenale
c Echinococcus granulosus
The causative agent of cysticercosis is:
a Taenia solium
b Taenia saginata
c Ascaris lumbricoides
d Trichuris trichiura
a Taenia solium
Organisms that can be easily identified to the species level from the ova in fecal specimens include:
a Metagonimus yokogawai, Heterophyes heterophys
b Taenia solium, Taenia saginata
c Necator americanus, Ancylostoma duodenale
d Paragonimus westermani, Hymenolepis nana
d Paragonimus westermani, Hymenolepis nana
The preferred specimen for the diagnosis of paragonimiasis is:
a bile drainage
b blood smear
c skin snips
d sputum
d sputum
A stool specimen for ova and parasite examination contained numerous rhabditiform larvae. Which factor(s) aid in the identification of larvae?
a larva tail nuclei and presence of sheath
b length of the buccal cavity and appearance of the genital primordium
c presence of hydatid cysts
d prominent kinetoplasts in trypomastigote
b length of the buccal cavity and appearance of the genital primordium
Which one of the following routine tests for Entamoeba histolytica has the highest sensitivity and specificity?
a colonic ulcer biopsy
b stool microscopy
c stool EIA
d urine PCR
c stool EIA
What is the principal means of distinguishing Entamoeba histolytica from Entamoeba hartmanni by light microscopy?
a size of trophozoite
b appearance of karyosome
c appearance of nuclear chromatin
d number of nuclei in cyst form
a size of trophozoite
Which characteristic will identify lodamoeba butschlii ?
a nuclei in mature cyst
b small (5-10 um) size
c prominent vacuole in the cyst form
d presence of up to 8 nuclei in the cyst form
c prominent vacuole in the cyst form
The only medically significant ciliate organism is:
a Acanthamoeba
b Balantidium coli
c Cryptosporidium parvum
d Chilomastix mesnili
b Balantidium coli
Where do Plasmodium sporozoites proliferate?
a bone marrow
b liver
c red blood cells
d nucleated erythrocyte precursors
b liver
Individuals who lack the Duffy antigen on the surface of their red blood cells are protected against which species of Plasmodium?
a P vivax
b P falciparum
c P malariae
d P ovale
a P vivax
Which nematode produces eggs with characteristic hyaline polar
a Ascaris lumbricoides
b Necator americanus
c Strongyloides stercoralis
d Trichuris trichiura
d Trichuris trichiura
Which nematode has a characteristic mammillated bile staine
a Ascaris
b Necator
c Strongyloides
d Trichuris
a Ascaris
Which organism is predominantly responsible for visceral larva migrans
a Ancylostoma braziliensis
b Onchocerca volvulus
c Toxocara canis
d Trypanosoma brucei
c Toxocara canis
Which organism has the largest egg?
a Clonorchis
b Diphyllobothrium
c Fasciola
d Paragonimus
c Fasciola
The eggs of which species of Schistosoma can be isolated from urine
a S haematobium
b S japonicum
c S mansoni
d S stercoralis
a S haematobium
Which one of the following features of Taenia saginata helps distinguish it from T. Solium
a egg with a radially striated wall
b pork tapeworm
c proglottid with <13 uterine branches
d unarmed rostellum
d unarmed rostellum
Infection by this organism can cause of B12 deficiency:
a Diphyllobothrium latum
b Echinococcus granulosus
c Taenia solium
d Schistosoma mansoni
a Diphyllobothrium latum
This organism is responsible for hydatid cysts of the liver:
a Diphyllobothrium
b Echinococcus
c Hymenolepis
d Trichomonas
b Echinococcus
How is Trichomonas vaginalis transmitted?
a ingestion of cyst stage
b ingestion of trophozoite stage
c larval stage burrows through the skin
d sexual transmission
d sexual transmission
This parasite has the following characteristics: banana shaped gametocytes in RBCs multiple ring forms in RBCs all RBCs are infected. The identification of the parasite is:
a Plasmodium falciparum
b Plasmodium malariae
c Plasmodium ovale
d Plasmodium vivax
a Plasmodium falciparum
This parasite has the following characteristics: stains red with acid fast stain zoonotic transfer to humans spread by fecal-oral route. The most likely organism is:
a Cryptosporidium
b Giardia
c Naegleria
d Necator
a Cryptosporidium
