AMOEBA

Question 1

amoeba move through __

Answer 1

pseudopodia

Question 2

•motile
•reproducing
•feeding stage

Answer 2

trophozoite

Question 3

•non-motile
•non-feeding stage
•infective stage to humans

Answer 3

cysts

Question 4

transmission of amoeba is generally by

Answer 4

ingestion of cyst

Question 5

-cause dysentery
-nucleus karyosome or endosome
-mostly with RBC in cytoplasm
-the cyst of this has chromatoid bars (rounded)

Answer 5

entamoeba histolytica

Question 6

• Nonpathogenic
• Size: cyst = < 10um, trophozoite = < 12 um

Answer 6

entamoeba hartmanni

Question 7

•Cysts and trophozoites are morphologically
identical to E. histolytica
•noninvasive
•never ingests RBCs

Answer 7

Entamoeba dispar

Question 8

Transmission (Entamoeba histolytica)
• The infection can be transmitted sexually by homosexual males and is
one cause of the disease known as

Answer 8

gay bowel syndrome

Question 9

• Nonpathogenic
• Commonly confused with E. histolytica

Answer 9

Entamoeba coli

Question 10

• nonpathogenic
• found primarily in pigs and monkeys
• Occasionally in humans
• resembles both E. histolytica and E. coli morphologically

Answer 10

Entamoeba polecki

Question 11

•Nonpathogenic
•found in:
• mouth in soft tartar between teeth or in tonsillar crypts
• Occasionally in sputum
• no cyst stage
• only species to ingest white blood cells.
• (fragments in large vacuole)

Answer 11

Entamoeba gingivalis

Question 12

irregular dump karyosome with no peripheral chromatin

Answer 12

Endolimax nana

Question 13

large irregular karyosome with no peripheral chromatin

Answer 13

lodamoeba bütschlii

Question 14

• strictly anaerobic intestinal protozoa
• Reproduction:
• binary fission or sporulation
• Fecal-oral transmission through contaminated food or water
• Metronidazole -treatment is needed.
• size and shape:
• Round
• from 6 to 40 µm in diameter.
• confused with yeast cells

Answer 14

Blastocystis hominis

Question 15

• May become opportunistic parasites to humans
•found in fresh or salt water, moist soil, and decaying
vegetation.
• In most instances, no disease is produced by these
organisms. In a few cases, however, severe
consequences result.
• The notable potential pathogens are Naegleria fowleri
and, less commonly, Acanthamoeba spp.

Answer 15

free-living amebae

Question 16

• Ameboflagellate (ONLY ameboid phase found in host tissues)
• Entry: through the nasal mucosa (swimming, diving)
• It then migrates along the olfactory nerves and, within several days,
invades the brain.
• highly thermophilic
• survives at water temperatures up to 113ºF.
• tolerates chlorinated water

Answer 16

Naegleria fowler

Question 17

• Atleast 6 species cause granulomatous amebic encephalitis
(GAE)
• isolated from the upper respiratory tract (healthy individual)
• grow best in the upper airways of susceptible patients
• Infections:
• inhalation of contaminated dust or aerosols
• invasion of broken skin or mucous membranes.
• found in the lungs, nasal and sinus passages, eyes, ears, skin
lesions, and vagina

Answer 17

Acanthamoeba spp.

Question 18

•related to poor contact lens care
•Direct examination of a patient’s cornea using a
confocal microscope can aid in diagnosing
• Direct examination and culture of corneal scrapings can
also lead to a correct diagnosis.
•Using contaminated saline cleaning solutions and
wearing lenses while swimming in contaminated
water are the usual causes of these infections.

Answer 18

Acanthamoeba keratitis

Question 19

• another causative agent of GAE
• It has also been found in immunocompetent children.
• This parasite has been found in many primates (e.g., gorillas, gibbons,
monkeys) and sheep and horses.
• One-third of the few cases reported in the United States were in
patients with AIDS

Answer 19

Balamuthia mandrillaris

Question 20

• resistant to chlorination and drying
• trophozoites:
• spinelike pseudopodia but are rarely seen motile
• 30 µm
• have a large central karyosome in the nucleus.
• cysts:
• T10- to 25-µm
• round with a single nucleus and has a double wall;
• the outer cyst wall may be slightly wrinkled with a polyhedral inner
wall.

Answer 20

Acanthamoeba spp.