NON-PATHOGENIC

1
NON-PATHOGENICOPPORTUNISTICAMOEBAE
2
NON-PATHOGENIC AMOEBAE

• Entamoeba dispar
• Entamoeba hartmanni
• Entamoeba coli
• Entamoeba gingivalis
• Endolimax nana
• Iodamoeba beutschlii

3
ENTAMOEBA DISPAR

• Non-invasive,nonpathogenic
• Earlier it was considered as a nonpathogenic
  strain of E.histolytica
• E.histolytica E.dispar are morphologically
  identical
• Cysts of E.histolytica E.dispar cannot be
  differentiated microscopically

4
(No Transcript)
5
ENTAMOEBA HARTMANNI

• Earlier considered as small race of E.histolytica
• Morphologically similar to E.histolytica
• But trophozoites cysts are smaller and have a
  diameter of 4-12µm 5-10µm respectively
• Trophozoites never contain ingested red blood
  cells
• LIFE CYCLE-Similar to E.histolytica
• ? is by measurement of size of the trophozoites
  and cysts absence of red blood cells in
  trophozoites

6
(No Transcript)
7
ENTAMOEBA COLI

• World wide parasite
• Nonpathogenic
• Habitat-Lumen of large intestine of man
• It exists in 3 stages-Trophozoite,Precyst and
  Cyst
• Life cycle-Similar to E.histolytica

8
TROPHOZOITES

• Sluggish movement
• Cytoplasm is not differentiated into ectoplasm
  and endoplasm
• They never contain red blood cells
• But bacteria and cellular debris is present
• Karyosome is eccentric
• Nuclear membrane is thick and is lined by coarse
  chromatin granules

9

• CYST
• Spherical,15-20µm
• Nuclei-1to8
• Chromidial bars are filamentous
• PRECYST
• Resembles in shape with that of E.histolytica

10
ENTAMOEBA GINGIVALIS

• First parasitic amoebae to be recognised
• Commensal in the gingival tissue around the teeth
• Described by Gros in 1849 in the soft tartar
  between the teeth
• Also found in the diseased tonsils and in the
  vaginal cervical smears from women using
  intrauterine devices

11
ENTAMOEBA GINGIVALIS

• Only the trophozoite stage has been found
• Encystation probably does not occur
• TROPHOZOITE10-25µm in diameter
• Actively motile by multiple pseudopodia
• CytoplasmDifferentiated into clear ectoplasm and
  granular endoplasm
• Food vacuoles consists of digested leukocytes and
  epithelial cells

12
Cont..

• Bacteria are seen at times
• Red blood cells are seen very rarely
• Nuleus sphericalcentral karyosome
• Chromatin granules are closely packed
• TRANSMISSIONBy close contact like kissing and
  from contaminated drinking utensils

13
ENDOLIMAX NANA

• World wide,nonpathogenic,small amoeba
• HabitatLumen of large intestine of
  humans,primates and pigs
• It has 3 stagesTrophozoite,precyst and cyst
• TROPHOZOITES are small in size and cytoplasm is
  demarcated into ectoplasm and endoplasm

14

• Motility Sluggish
• Cytoplasmic inclusionsBacteria, small vegetable
  cells and crystals
• No red blood cells
• NUCLEUS Large irregular karyosome , arranged
  eccentrically with Achromatic strands
• Chromidial bars and glycogen vacuole are absent

15
IODAMOEBA BUETSCHLII

• Nonpathogenic luminal parasite of large
  intestine
• TROPHOZOITESActive in freshly evacuated unformed
  stools sluggish in older stools
• Ectoplasm is not well differentiated from
  endoplasm
• NULEUS relatively largekaryosome surrounded by
  refractile globules
• Cytoplasmic inclusionsBacteria and yeast cells
• CYSTUninucleate,Chromidial bars absent.

16
(No Transcript)
17
NAEGLERIA FOWLERI

• MORPHOLOGY
• 2 stagesMotile trophozoites and non-motile cysts
• TROPHOZOITE2 forms?Amoeboid Flagellate
• AMOEBOID Amoebostomes- Distinctive phagocytic
  structures
• No peripheral chromatin. Reproduction is by
  simple binary fission
• FLAGELLATENon-dividing,non-feeding form
• CYST Uninucleatespherical
• mucoid-plugged pores or ostioles in cyst wall

18
PATHOGENICITY

• Amoeboid form is the invasive stage
• INFECTIONNasal contamination during swimming or
  inhalation of dust containing infective forms
• Flagellate and cyst forms could also enter the
  nose
• Flagellate forms revert to amoeboid forms and the
  amoeboid forms escape from the cysts in the nose

19
Life cycle
20

• Amoeboid forms invade nasal mucosa
• Cribriform plate
• Olfactory nerve
• Olfactory bulbs
• Posterior regions of the brain.,
  leading to
  Primary amoebic meningoencephalitis

21
ACANTHAMOEBA Sp..

• Acanthamoeba culbertosoni
• A.castellani
• A.hatchetti
• A.polyphaga
• A.rhysodes

22
MORPHOLOGY

• Acanthamoeba exists as active trophozoites and
  resistant cysts
• No flagellate form
• TROPHOZOITES24-56µmlarger than that of
  Naegleria
• Irregular in appearance due to acanthopodia-taperi
  ng like pseudopodiaMotility-slow
• CYSTDouble walled and so are quite resistant
• Double wall-Outer wrinkled ectocyst and inner
  endocyst

23
PATHOGENICITY

• INFECTIONBy inhalation of trophozoites and
• by direct invasion through broken or ulcerated
  skin or eye
• Trophozoites reach lower respiratory tract? CNS
  through blood stream
• It causes Granulomatous amoebic encephalitis(GAE)
  in immunosupressed patients
• In healthy persons Acanthamoeba keratitis and
  infection occurs by direct contact of cornea with
  amoebae
• It releases proteases?cytolysis of corneal
  epithelium

24
Keratitis
25

• Diagnosis
• GAE-Demonstration of Trophozoites in CSF or
  trophozoites and cysts in brain tissue
• KeratitisTrophozoites and cysts in corneal
  scrapings(wet mount preparation)
• TREATMENT GAETotal excision of the mass and
  treatment with ketoconazole, penicillin and
  chloramphenicol
• KeratitisDibromopropamidine Propamidine
  isethionate ointment or drops

26

• THANK YOU