Protozoa (Free-living Amoeba & Ciliates) Flashcards
What are the free-living amoeba?
Acanthamoeba
Naegleria
Causative agent of Primary Amoebic Meningoencephalitis (PAM)
Naegleria fowleri
Small free-living amoeba characterized by an active trophozoite stage and dormant cystic stage.
Acanthamoeba
The causative agent of Granulomatous Amebic Encephalitis (GAE).
Acanthamoeba
Free-living amoebo-flagellates.
Naegleria
What is an amoebo-flagellate?
Trophozoite can transform into nonreproductive flagellate stage or a resistant cyst.
Naegleria that is nonpathogenic.
Naegleria gruberi
Naegleria that is pathogenic that may cause menigoencephalitis in man.
Naegleria fowleri
What are the symptoms in Naegleria fowleri infection?
Headache
Fever
Neck rigidity
Mental confusion
May lead to coma and death
Free-living amoeba that after entering the nose and nasal cavities, the trophozoites will migrate along the olfactory nerves, through the cribriform plate and into the cranium.
N. fowleri
This unique stage transformation allows N. fowleri to move toward food sources more rapidly.
The ability of Naegleria fowleri to transform from an ameba into flagellated organisms.
The trophozoite form of Naegleria.
Ameba
The swimming form of Naegleria.
Flagellate
How many hours or days does the transformation from ameba to flagellate of Naegleria?
2-3 hrs or up to 3-4 days
True or False: The trophozoite stage of Naegleria is readily forms a pair of flagella originating from the tip of a pear-shaped body.
True
Naegleria that is locally isolated in the Philippines in thermally-polluted streams, an artificially-heated swimming pool, and from a brain aspirate of a young patient
Naegleria philippinensis
How does PAM be diagnosed?
Actual appearance of trophozoites in the brain and cerebrospinal fluid.
Deadly free-living amoeba
Naegleria fowleri
A 12 year old female is brought to the emergency room with MENINGITIS and a history of swimming in a warm water spring. Motile amoeba is seen in CSF and are most likely:
a. Iodamoeba butschlii
b. Endolimax nana
c. Dientamoeba fragilis
d. Naegleria fowleri
d. Naegleria fowleri
Free-living amoeba that the trophozoites had a blunt, lobose pseudopodia and directional motility.
N. fowleri
What are the specific test for N. fowleri?
PCR and ELISA
Drug of choice of Primary Amebic Meningoencephalitis
Polytene antibiotic Amphotericin B
True or False: There is no known means of prevention and control of Naegleria infection
True
Treatment that inhibits the growth of N. fowleri when used at high concentration of 25 -50 ug/ml. and also prevents enflagellation and encystment of ameba.
Tetrahydrocannabinol
Lethal to N. fowleri trophozoites
Drying
It can be a successful therapy to PAM
Azithromycin
Epidemiology of Naegleria
Chlorinated swimming poos, freshwater lakes, Thermal springs, domestic water supplies, Thermally polluted water, sewage, soil, air, humidifier systems, cell cultures, and human throat and nasal cavities
Soil
Infective stage of N. fowleri
Trophozoite
Diagnostic stage of N. fowleri
Trophozoite
Since there is no known means of prevention and control of Naegleria infection, could you think of way to avoid the infection?
Anything is acceptable.
To decrease the possibility of infection, one should avoid diving into and swimming in warm and stagnant freshwater pools, water discharge pools, unchlorinated poorly maintained swimming poolsm or mud-lined lake and ponds.