INTESTINAL AND FREE-LIVING AMOEBA

What are the FREE-LIVING AMOEBAS

• Naegleria Fowleri

• Acanthamobeba spp

This refers to the commensal phase of E. histolytica and often mistaken for E. hismanni

minuta form

Trophozoite of this parasite has a Hyaline Pseudopodium and exhibit ACTIVE, UNIDIRECTIONAL, RAPID PROGRESSIVE, and PURPOSEFUL motility

E. histolytica trophozoites

Highly refractile hyaline cystwall, one to four nuclei and ROD-SHAPED/CIGAR-SHAPED chromatoidal bars

E. histolytica CYST FORM

How manu forms does E. histolytic have?

• Trophozoites Stage

• Precyst Stage

• Cyst Stage

How many host does E. histolytica requires?

Single Host

E. HISTOLYTICA:

• Infective Form =

• Diagnostic Form =

E. HISTOLYTICA:

• Infective Form = Mature Quadrinucleated Cyst

• Diagnostic Form = Mature Quadrinucleated Cyst

How should E. histolytica stool examination be done?

3 stool specimen collected in different days

Trophozoites in fresh stool should be examined within __________

30 minutes

What is the GOLD STANDARD for E. histolytica determination

• STOOL CULTURE → gold standard but not done ROUTINELY

  • Robinson’s & Inoki’s Medium

E. histolytica TREATMENT:

• Invasive Amoebiasis =

• Asymptomatic Cyst Carries =

• Px who don’t respond to Metronidazole =

E. histolytica TREATMENT:

• Invasive Amoebiasis = Metronidazole

• Asymptomatic Cyst Carries = Diloxanide furoate

• Px who don’t respond to Metronidazole = Percutaneous drainage of liver abscess

Similar to E. histolytica:

• But differ in DNA & rRNA = _______________

• But differ biochemically & genetically = _____________

Similar to E. histolytica:

• But differ in DNA & rRNA = E. dispar

• But differ biochemically & genetically = E. moshkovskii

ENTAMOEBA:

• First discovered in sewage

• Surive = 0-41*C

• Grows = RT (25-30*C)

E. moshkovskii

Cyst resembles E. nana

E. hartmanni

• 1-8 nuclei

• Splinter-like chromatoidal body

E. coli

• Slugging and Undirective movement of trophozoites

E. coli

• E.his = rapid progressive and purposeful

• 1-4 nuclei

• cross-eyed cyst

E. nana

• Troph = Bull’s eye appearance

• Cyst = Iodophilic body

Iodamoeba butschilii

• 1st parasitic amoeba discribed in human

• Inhabits mouth

• no cyst stage

E. gingivalis

NO CYTS PARASITES:

“TED has no cyts”

• Trichomonas

• E. gingivalis

• D. fragilis

N. FOWLERI:

• Can resist drying & chlorine up to _____ ppm

• Withstand _________ heat (_________)

• Dies at chlorine at _____ ppm & salinity of _____%

N. FOWLERI:

• Can resist drying & chlorine up to 50 ppm

• Withstand moderate heat (45*C)

• Dies at chlorine at 2 ppm & salinity of 0.7%

What pseudopodia do N.fowleri has?

LOBOPODIA = rounded

What form of N. fowleri can be demonstrated in the CSF

Trophozoites

Jerking/Spinning motility

Naegleria Fowleri

N.fowleri ______ form turns into _______ in exposed to distilled water

N.fowleri trophozoite form turns into Biflagellate in exposed to distilled water

This amoeba feeds on gram (-) bacteria, blue green algae

Acanthamoeba spp.

• Cyst form is Polygonal Double Walled

• Troph has a SPINE-LIKE/THORN-LIKE PSEUDOPODIA

Acanthamoeba spp.

• Acanthapodia

• feeds on gram (-) bacteria

• PRIMARY AMEBIC MENINGOENCEPHALITIS (PAM) = ____________

• GRANULOMATOUS AMEBIC ENCEPHALITIS (GAE) = ________

• PRIMARY AMEBIC MENINGOENCEPHALITIS (PAM) = N. fowleri “PAMeN”

• GRANULOMATOUS AMEBIC ENCEPHALITIS (GAE) = Acanthamoeba “GAE A”

Associated with use of contact lenses leading to Keratitis

Acanthamoeba spp.

N. Fowleri:

• Infective Form =

• Diagnostic Form =

N. Fowleri:

• Infective Form = Trophozoites

• Diagnostic Form = Trophozoites

Acantamoeba spp.

• Infective Form =

• Diagnostic Form =

Acantamoeba spp.

• Infective Form = Cyst and Trophozoites

• Diagnostic Form = Cyst and Trophozoites in tissue (not stool)