NAEGLERIA FOWLERI

Question 1

Common associated disease or condition name:

Answer 1

Primary amebic meningoencephalitis (PAM)

Question 2

is the only ameba with three
known morphologic forms—ameboid trophozoites, flagellate (pertains to Protozoa that move by
means of flagella) forms, and cysts

Answer 2

Naegleria fowleri

Question 3

The typical motility that is seen is accomplished by jerky movements or spinning.

Answer 3

Naegleria fowleri flagellate

Question 4

Microscopic examination of ______________________(CSF) is the method of choice for the recovery of N. fowleri ameboid trophozoites

Answer 4

cerebrospinal fluid

Question 5

Clinical specimens may be cultured. N. fowleri ameboid trophozoites show a characteristic trailing effect when placed on agar plates that have been previously inoculated with _____________________.

Answer 5

gram-negative bacilli

Question 6

The ameboid trophozoites transform into flagellate trophozoites _______ after
being transferred to water from a tissue or
culture.

Answer 6

in vitro

Question 7

The flagellate trophozoites do not divide
but rather lose their __________ and convert back into the ameboid form, in which reproduction resumes.

Answer 7

flagella

Question 8

defined as a diagnostic sign for meningitis, where the patient is unable to fully straighten his or her leg when the hip is flexed at 90 degrees because of hamstring stiffness

Answer 8

Kernig’s sign

Question 9

___________________ damage the cell wall of Naegleria, inhibiting the biosynthesis of ergosterol and resulting in increased membrane permeability, which causes nutrients to leak out of the cells.

Answer 9

Amphotericin B and miconazole

Question 10

__________ inhibits RNA synthesis in
the amoeba by binding to beta subunits of DNA-dependent RNA polymerase, which in turn blocks RNA transcription. A

Answer 10

Rifampicin

Question 11

The first case of PAM was reported by

Answer 11

Carter and Fowleri

Question 12

One noteworthy species of Naegleria that
could possibly infect humans in the future is
known as

Answer 12

N. australiensis

Question 13

method designed to aid in taxonomic classification

Answer 13

DNA restriction fragment length polymorphism (RFLP)

Question 14

Transformation from the ______________ to _____________ form may facilitate more rapid movement toward food sources.

Answer 14

trophozoite to the flagellate

Question 15

There are two forms of trophozoites of
Naegleria fowleri: _____________ & _____________, only the former of which is found in humans

Answer 15

ameboid and ameboflagellate

Question 16

_____________ are thermophilic organisms
which thrive best in hot springs and other warm aquatic environments.

Answer 16

Naegleria spp.

Question 17

The trophozoites replicate by ____________
(nuclear membrane remains intact) and can turn into temporary non-feeding flagellated forms, which usually revert back to the trophozoite stage.

Answer 17

promitosis

Question 18

Trophozoites infect humans or animals
by penetrating the nasal mucosa and migrating to the brain via the _____________ nerves.

Answer 18

olfactory

Question 19

Therefore, in contrast to Acanthamoeba which is largely an ____________ organism, N. fowleri is considered a true pathogen.

Answer 19

opportunistic

Question 20

The ______________ of the
olfactory neuroepithelium are thought to
phagocytose the amebae and transport these through the cribriform plate and into the brain.

Answer 20

sustentacular cells

Question 21

Characteristic cerebrospinal fluid
findings include _____________________________________________

Answer 21

elevated white blood cell count with neutrophilic predominance, high protein, and low glucose

Question 22

Post-mortem examination of infected brain
shows _________________, particularly of
the olfactory bulbs, congestion and edema of
neural tissue.

Answer 22

hemorrhagic necrosis

Question 23

Death usually occurs as a result of ______________________ as a result of increased intracranial pressure

Answer 23

cerebral or cerebellar herniation

Question 24

____________ produces deleterious changes in the nucleus and mitochondria of the ameba, decreases the number of food vacuoles, and increases the formation of autophagic vacuoles. Ameba exposed to _______________ exhibit decreased pseudopod formation and form blebs on the plasma membrane

Answer 24

Amphotericin B