Intestinal Amebae

Question 1

Life cycle: Passed in feces. Mature cysts ingested. Excystation occurs, producing trophozoites. Multiplication occurs and cysts exit host
Route of infection: Contaminated food or water
Geography: Worldwide
Specimen source: stool
Morphology: Troph has RBC in cytoplasm. 12-60 mcm. Single nucleus. Cysts are 10-20 mcm. 4 nuclei in mature cyst. Chromatin is finely beaded. No RBC. Chromatoidal bars have smooth rounded ends
Lab tests: Ova and parasite exam, serological test, immunology tests, enzyme immunoassay (EIA) or ELISA. DNA test; polymerase chain reaction (PCR)
Pathology; Amebiasis- bloody diarrhea (dysentery), extra intestinal - liver, lungs, heart, brain - leading to organ failure and death

Answer 1

Entamoeba histolytica/dispar/moshkobskii

Question 2

Life cycle: same as E. histolytica
Route of infection: Contaminated food or water
Geography: worldwide
Specimen source: stool sample
Morphology: Trophs are 15-50 mcm. Single nucleus with coarse clumps on nuclear membrane. Cytoplasm has dirtier appearance. Vacuoles and cellular debris. Cysts are 10-35 mcm. Up to 8 nuclei in mature cysts. Nucleus has coarse clumps on nuclear membrane. Chromatoidal bars have splintered ends.
Lab tests: Ova and parasite exam, serological test, immunology tests, enzyme immunoassay (EIA) or ELISA. DNA test; polymerase chain reaction (PCR)
Pathology: nonpathogenic

Answer 2

Entamoeba coli

Question 3

Life cycle: same as E. histolytica
Route of infection: contaminated food or water
Geography: worldwide
Specimen source: stool sample
Morphology: Looks just like E. histolytica except trophs are 5-12 mcm and have no RBC. Cysts are 5-10 mcm
Lab tests: Ova and parasite exam, serological test, immunology tests, enzyme immunoassay (EIA) or ELISA. DNA test; polymerase chain reaction (PCR)
Pathology: nonpathogenic

Answer 3

Entamoeba hartmanni

Question 4

Life cycle: same as E.histolytica
Route of infection: Contaminated food or water
Geography: worldwide
Specimen source: stool sample
Morphology: Cysts; 5-10 mcm and have 4 nuclei. Large karyosome and the peripheral chromatin ring is not visible. Trophs; 6-12 mcm. Single nucleus. Large karyosome.
Lab tests: Ova and parasite exam, serological test, immunology tests, enzyme immunoassay (EIA) or ELISA. DNA test; polymerase chain reaction (PCR)
Pathology: nonpathogenic

Answer 4

Endolimax nana

Question 5

Life cycle: same as E. histolytica
Route of infection: contaminated food or water.
Geography: worldwide
Specimen source: stool sample
Morphology: Cysts; 5-20 mcm. irregular shape, single nucleus with large karyosome, peripheral chromatin ring not visible. Trophs; 8-20 mcm, single nucleus with large karyosome, many vacuoles.
Lab tests: Ova and parasite exam, serological test, immunology tests, enzyme immunoassay (EIA) or ELISA. DNA test; polymerase chain reaction (PCR)
Pathology: nonpathogenic

Answer 5

Iodamoeba butchlii

Question 6

Life cycle: same as E. histolytica
Route of infection: contaminated food or water
Geography: worldwide
Specimen source: stool sample
Morphology: Central body (vacuole), numbers nuclei (2-4)
Lab tests: Ova and parasite exam, serological test, immunology tests, enzyme immunoassay (EIA) or ELISA. DNA test; polymerase chain reaction (PCR)
Pathology: when present in large numbers in the absence of other parasites, bacteria, or viruses, it may be the cause of diarrhea, cramps, nausea, fever, vomiting, and abdominal pain and require therapy

Answer 6

Blastocystis hominis