Lab Exam 2 Flashcards
What stage of a protozoan (cyst or troph) is most likely to be seen in a liquid stool?
troph
What are Charcot-Leyden crystals?
artifacts found in stool specimens, spindle shaped structures
How soon after collection should a semi-solid or liquid stool be examined?
within 30 minutes of passage
Diphyllobothrium latum proglottid
Which genera of parasites can be detected and identified by examination of a peripheral blood smear?
Leishmania, Plasmodium, Trypanosoma, Loa, Brugia, and Babesia
What is the principle of the zinc-sulfate procedure commonly used for the concentration of a stool specimen?
floatation
Why is it useful to perform the direct examination of a stool specimen using iodine?
used to observe cyst of protozoa. Darkens nuclei of cyst of protozoa
Ascaris lumbricoides decorticated egg
Schistosoma japonicum
Taenia saginata proglottid
Trichuris trichiura
Entamoeba coli troph
Balantidium coli troph
Entamoeba histolytica cyst
Why is it useful to perform the direct examination of a stool specimen using saline?
used to view anything motil, especially helminth eggs
Diphyllobothrium latum egg
Hymenolepsis dimunata
How soon after collection should a formed stool be examined?
macro and microscopic must be done same day, time permitting
Diphyllobothrium latum scolex
Fasciola/Fasciolopsis
Name several specimens other than stools that might be examined for ova and parasites.
Duodenal aspirates, perianal swabs, sputum, urine, blood, tissue biopsy
Giardia lamblia cyst
Enterobius vermicularis
What stage of a protozoan (cyst or troph) is most likely to be seen in a formed stool?
cyst
If a formed stool cannot be examined on the day of collection, what steps should be taken?
put specimen in preservative within 30 minutes and refrigerate
Trichinella spiralis encysted larva
Chilomastix mesnili troph
Entamoeba coli cyst
Trichomonas
Paragonimus westermanii
What does PVA stand for?
poly vinyl alcohol
Endolimax nana troph
What type of container is best to use for the collection and transporting of a stool specimen?
Clean and dry, does not need to be sterile
What is the significance of Charcot-Leyden crystals?
indicates inflammation, parasitic infections, or allergic reactions
Iodamoeba bütschlii troph
Name several species of protozoa that have “emerged” as significant pathogens in recent years due to the spread of AIDS.
Pneumocystis carinii, Cryptosporidium, Toxoplasma gondii
What are Charcot-Leyden crystals thought to be composed of?
ruptured eosinophil granules
Dientamoeba fragilis
Necator americanus (hookworm) rhabditiform larva
What organism is the scotch tape preparation used for?
Enterobius vermicularis (pinworms)
Trypanosoma
Schistosoma mansoni
Iodamoeba bütschlii cyst
Clonorchis sinensis
Ascaris lumbricoides unfertilized egg
Strongyloides stercoralis rhabditiform larva
Taenia solium scolex
Name several artifacts that can be found in ova and parasite preparations.
plant fibers, pollen grains, meat fibers, epithelial cells, Charcot-Leyden crystals, and WBCs
Name the two procedures commonly used for the concentration of a stool specimen?
Formalin-ethyl acetate and zinc-sulfate
Ascaris lumbricoides fertilized egg
What is the principle of the formalin-ethyl acetate procedure commonly used for teh concentration of a stool specimen?
sedimentation
Taenia solium proglottid
Hymenolepsis nana
Balantidium coli cyst
Hymenolepsis dimunata
Chilomastix mesnili cyst
Taenia saginata scolex
Necator americanus (hookworm) egg
Schistosoma haematobium
Giardia lamblia troph
Hymenolepsis nana
Hymenolepsis dimunata
Entamoeba histolytica troph
What fixative should be used with a liquid stool?
PVA
Taenia saginata egg
What fixative should be used with a formed stool?
10% formalin
What are teh four components of the procedure for the laboratory examination of a stool specimen for ova and parasites?
Macroscopic exam, direct microscopic exam, concentration, permanent stain smear
Endolimax nana cyst
