Free-living Amoeba

Question 1

These parasites, classified under free-living amoeba, can cause disease
among humans thus, more appropriately called opportunists.

Answer 1

Naegleria fowleri
Acanthamoeba culbertsoni
Acanthamoeba castellani
Acanthamoeba astronyxis
Acanthamoeba polyphaga

Question 2

Opportunist amoeba may be classified under 2 genera,

Answer 2

(1) Naegleria
(2) Acanthamoeba

Question 3

Species of genus Naegleria are classified as

Answer 3

ameboflagellate

Question 4

True or False:

Answer 4

Acanthamoeba species do not have flagellate forms.

Question 5

In general, Naegleria fowleri causes primary

Answer 5

amoebic meningoencephalitis
(PAM)

Question 6

Also known as the brain-eating amoeba. It the causative parasite of a rare and fatal infection of the brain called primary amoebic meningoencephalitis .

Answer 6

Naegleria fowleri

Question 7

People usually get infected when contaminated water enters the body
through the

Answer 7

nose

Question 8

This stage has amoeboid and flagellate forms, colonizes water and moist soil, and is the only stage demonstrated in the tissues of man.

Answer 8

trophozoite

Question 9

The second stage is the ______________ which
is the non-motile resistant form.

Answer 9

cyst

Question 10

has an elongated anterior and distinctly tapered posterior end forming a single clear pseudopod at the forward end and a knoblike structure called uroid process.

Answer 10

Amoeboid form

Question 11

Trophozoite
It measures 7 X 20 μm
when active and 10-5 μm (diameter) when rounded.

Answer 11

Amoeboid form

Question 12

Trophozoite
pear-shaped with two flagella at the broader end. It may move forward rapidly or spin.

Answer 12

Flagellate form

Question 13

stage that forms in agar culture media and the one found in nature. It is spherical with a single nucleus, measuring 7-10 μm in diameter, with a smooth, heavy, and thick cyst wall.

Answer 13

cyst

Question 14

(PAM) is acquired through instillation of trophozoite into

Answer 14

The nose when the person swims
in infected bodies of water.

Question 15

The trophozoites can go into the brain via

Answer 15

Olfactory nerve epithelium

Question 16

Meningeal irritation leads to

Answer 16

Neck stiffness or generalized
seizure or convulsion.

Question 17

The recommended treatment for Naegleria infection is

Answer 17

Combination of Amphotericin B and Miltefosine.

Question 18

an antifungal drug that is usually given intravenously or into the space around the spinal cord.

Answer 18

Amphotericin B

Question 19

An investigational drug used in breast cancer and leishmaniasis. It shows effective in killing Naegleria amoeba in vitro and animal studies.

Answer 19

Miltefosine

Question 20

The organism may be recovered from the CSF obtained through _____ puncture

Answer 20

Lumbar puncture wound

Question 21

staining methods preffered in Naegleria infection

Answer 21

Iron-Hematoxylin or Wright’s staining methods
-Immuno fluorescence and/or immunoperoxidase methods may also be used

Question 22

can be found in the soil, fresh, brackish and sea water, and dust in air. They are also obtained from Jacuzzis, air-conditioning and
ventilating units, dialysis machines, and even contact lens.

Answer 22

Acanthamoeba species

Question 23

Is the active stage in Acanthamoeba

Answer 23

The trophozoite

Question 24

Species of Acanthamoeba produce

Answer 24

granulomatous amoebic
meningoencephalitis (GAE)

Question 25

The resistant stage in Acanthamoeba

Answer 25

the cyst

Question 26

Known portals of entry with Acanthamoeba

Answer 26

ulcerated or broken skin, the eyes, genitourinary tract, and probably the lungs.

Question 27

were found in cases of eye infections only

Answer 27

A. polyphaga and A. hatchetti

Question 28

Most cases of GAE with eye infection were due to

Answer 28

A. castellani.

Question 29

Treatment for Acanthanmoeba

Answer 29

Anti-infective drugs are used in the early stages, and surgical procedure are done for
later stages to remove infected tissues.

Question 30

Acanthamoeba eye infections are effectively
treated with

Answer 30

topical miconazole, metronidazole, and neomycin. Oral ketoconazole can also be given.

Question 31

Laboratory diagnosis is through identification of trophozoites in the CSF
through

Answer 31

hanging-drop preparation or recovery of cysts and trophozoites in brain
tissues.

Question 32

Differentiation in Acanthamoeba is easier with the use of

Answer 32

immunoperoxidase and
immunofluorescent staining procedures.