Naegleria fowleri - M.Vignesh, Zentronz, G.T.M.College, Thiruvarur

1. - M.VIGNESH
ZENTRONZ
G.T.M.C
Naegleria fowleri

2.  It is a brain eating amoeba
 Causes an acute and fulminating primary
amoebic meningoencephalitis
 Lives in water such as lakes & swimming pools

3. Morphology:
Naegleria fowleri
Stage 1 : Stage 2 :
-Trophozoites -Cyst
-Amoeboid -Flagellate

4. Trophozoite:
- Length : 10-
20m
-Motile by mean
of rounded
psirdopodia
called lobopodia
-Nucleus has
large central
karyosome
-No pheripheral
nuclear
chromatin

5. Trophozoite:
-Pear shaped
-Two flagella
present in
anterior end
-Moves rapidly
forward
. Or
spines slowly in
circle
-This form does
not multiply

6. Cyst:
--Spherical,
--Uninicleate,
--Diameter : 7-10m
--Surround by thin cyst
wall
--Cyst and flagellate
forms have never been
found in tissue and CSF

7. Mode of infection:
Acquire infection by swimming in fresh water lakes
or swimming pools containing infective forms of
N.fowleri
Or acquired by inhaling dust cointaining infective
forms

8. Life cycle:

9. Life cycle:
 Life cycle is completed in external environment
 Amoboid form is multiplies by binary fission
 Amoeboid form is invasive stage of the parasite
 Flagellate form of trophozoite helps in the spread of
N.fowleri to new water bodies

10. Pathogenesis:
Amoeboid form
Enters through nasal mucosa
Invades criform plate
Olfactory nerve to brain
Primary amoebic meningoencephalitis

11. Clinical features:
 Incubation period : 2- 15 days
(Average 5 days)
 Severe fontal headache
 Fever (39-40deg. C)
Meningeal irritaion
Visual distrabance
Confusion
Seizures
Coma

12. Laboratory diagnosis:
Specimen:
-CSF is collected for demonstration of amoebae
Microscopy:
-Staining with Wright or Giemsa stains or
Fluorescent stains
-Appeared as small pink nuclei with sky blue
cytoplasm

13. Contd…
Culture:
-Culture media: Non-nutrient agar
-Inoculated overnight at 37deg.C
-Grown on moist agar surface
Histologic examination:
-Immunoflurescence & immunoperoxidase
methods

14. Treatment:
 Amphotericin B is used for treatment and is clinically
effective