• Amebiasis-10% worldwide,2-3% US
• Malaria-200 million worldwide 1-2 million deaths/year
• Toxoplasmosis-33% worldwide
• Schistosomiasis-200 million worldwide
• Ascarasis-650 million worldwide
• Strongyloides-25 million worldwide

1.  Direct smear

2.   Concentration

3.   Permanent stain smear

Actively motile form

Typically have one nucleus in teh intestional amoeba category

• Early cysts have one nucleus
• As cyst matures nucleus divides. Each individual species of amoeba cyst has a mature state(this is the form usually seen)
• Early cyts have glycogen(trophozoites do not have glycogen)
• As the cyst matures, theglycogen disappears(ex Iodamoeba). Glycogen can be stained with iodine(brownish)

Entamoebe histolytica

      Cyst                   Troph

[image][image]

• Worldwide, invasive infective form in US in the thousands
• 2 stages: trophozoite and cyst
• Lives in intestine, may  become invasive (esp liver )
• Causes tissue damage , lyses host cells
• Pathogenic and nonpathogenic strains
• Symptoms:diarrhea,flatulence and cramping
• Source of infection: CYSTS
• Acquired from contaminated water(sewage) food (handler) and persont to person
• Must differentiate from other nonpathogenic intestional amoeba

Entamoeba histolytica

~ troph~[image]

Size: 12 - 60 μm

Cytoplasm: fine granular,little to no vacuoles,may ingest RBCs

Nucleus:  fine central karyosome,fine beaded peripheral chromatin

[image]

Entamoeba histolytica

~ cyst ~

Size:  10-20 μm

Inclusions: chromatid body is rod-shaped with rounded ends

Nucleus: 1-4 nuclei,fine central karosome,fine beaded peripheral chromatin

Entamoeba coli

[image]

Cyst - wetmount

Trophozoite

Size: 10-35 μm

Cytoplasm: coarsely granular,vacuolated"dirty"

Nucleus: large eccentric karyosome,irregular coarse peripheral chromatin[image]

Entamoeba coli[image]

Cyst

Cyst

Size: 10-35 μm

Inclusions: chromatoidal body is rod shaped with splintered ends

Nucleus: 1-8 nuclei, large eccentric karyosome,irregular coarse peripheral chromatin

Entamoeba species have peripheral chromatin

If peripheral chromatin is not present, then it is not as Entamoeba sp

Usually nonpathogenic

Characteristics of both Entamoeba histolytica and Entamoeba coli

Primarily found in pigs and monkeys

Entamoeba hartmanii

[image]

Trophozoite

Size: 5-12 μm

Cytoplasm: same as E histolytica (except RBC ingestion)

Nucleus: same as E histolytica

Entamoeba hartmanni

[image]

Cyst

Size: 5-10 μm

Inclusions: same as E histolytica

Nucleus: same as E histolytica

Entamoeba gingivalis

• Pathogenic?
• Found in mouth @ ends of gums
• Scavenger of disintigrated cells
• Similar to E histolytica (which could be in sputum from pulmonary abscess)

Trophozoite

Size 5-35 μm

Cytoplasm: similiar to E histolytica(contains WBCs)

Nucleus: similiar to E histolytica

Cyst

!! No cyst stage has been demonstrated!!

Endolimax nana

[image]

troph

Endolimax nana

Troph

Size: 6-15 μm

Cytoplasm: granular and vacuolated

Nucleus: karyosome large and irrregular, no peripheral chromatin

Iodamoeba butschlii[image]

troph

Troph

Size: 8-20 μm

Cytoplasm: coarsly granular,vacuolated,"dirty"(ingests bacteria)

Nucleus: large,central,no peripheral chromatin

Iodamoea butschlii

[image]

cyst

Cyst

Size: 5-20 μm. spherical to oval

Nucleus: 1 nucleus,large eccentric karyosome

Naegleria fowleri

• Primary amoebic meningocephalitits
• Acquired by swimming in contaminated water(ponds,lakes)
• Troph stage reaches brain through nasal cavity
• Course is rapid/brief- 1 day to 2 weeks
• Flagellate form- place in water to see flagellate form

Diagnosis:

Examination of CSF, difficult to detect

Culture on non-nutrient agar plate (7 days)

Naegleri fowleri

Troph

[image]

Trophozoite

Size: 5-20 μm

Motility: rapid and directional

Cytoplasm: multiple blunt pseudopods,contractile vacuole

Nucleus: large,central karysome,no peripheral chromatin

Naegleri fowleri

[image]

Wet mount

Cyst

Size: 9-60 μl

Not found in human tissue

Acanthamoeba sp

• Primary amoebic meningoencephalitis and keratitis
• Free living amoeba found in soil and water
• Trophozoite and cyst stage in human tissue

Transmission

• Enters the body through nasal area from swimming,PAM
• Following contact with contaminated water or contact lens solution(keratitis)
• Encephalitis involved mainly in immulogically compromised individuals
• Karatitis is difficult to treat,may lead to reduced vision or loss of eye
• Diagnosis by wet mount of CSF,corneal scraping,culture on non-nutrient agar.

Acanthamoeba sp.

Troph

[image]

Troph

Size: 10-20 μm

Motility: sluggish

Cytoplasm: filamentous pseudopods,contractile vacoule

Nucleus: large,central karysome,no peripheral chromatin

Acanthamoeba sp

[image]

Troph

Cyst

Size: 15-20 μm

Double wall. Outer wall is slightly wrinckled.Inner wall is polyhedral shaped