Protozoans

Motility: Pseudopods

Nucleus: Peripheral chromatin - usually evenly distributed and uniform in size

Karyosome - chromatin small, discrete; usually centrally located

Cytoplasm: Finely granular

Inclusions: RBCs occasionally

Pathogenic: YES: Invasive - usually causes Amoebic dysintary

Shape: Usually spherical, round to oval, with thick cell wall

Nucleus: Four mature cyst, peripheral chromatin present

 Karyosome - small, discrete, usually centrally located

Cytoplasm: Chromatid bodies - present; elongate bars with bluntly rounded ends, cigar-shaped

Motility: Non-progressive, sluggish

Nucleus: Peripheral chromatin - irregular in size and distribution

 Karyosome - chromatin is large, discrete, usually eccentrically located

Cytoplasm: Coarse; often vacuolated

Inclusions: May include bacteria, yeasts

Pathogenic: NO

Shape: Usually spherical

Nucleus: 8 nuclei in mature cyst

Karyosome - large, discrete; usually eccentrically located

Cytoplasm: Chromatid bodies less frequently present; usually splinter-like pointed ends

Motility: Sluggish

Nucleus: No peripheral chromatin - reddish purple when stained

 Karyosome - Large, usually centrally located

Cytoplasm: Vacuolated

Inclusions: Bacteria and yeasts

Pathogenic: NO

Shape: Ovoid or egg-shaped

Nucleus: No peripheral chromatin

 Karyosome - large, usually eccentrically located

Cytoplasm: Glycogen compact, well-defined mass. Glycogen stains dark with iodine

Shape: Ameboid shape

Motility: Sluggish

Nucleus: 1 or 2.4% of D. fragilis only have one nucleus, but this is usually fragmented

Karyosome usually in form of cluster of 4-8 granules

Cytoplasm: Finely granular

Pathogenic: YES

Shape: Pear-shaped

Motility: Rapid, jerking

Nucleus: 1 nuclei

Flagella: 3-5 anterior, 1 posterior

Undulating membrane extends half length of body; seen in vaginal smears and urethral charges

Pathogenic: YES

Shape: Pear-shaped

Motility: "Falling Leaf"

Nucleus: 2 nuclei

Axostyle: Structure down the middle

Flagella: 4 lateral, 2 ventral, and 2 caudal

Sucking disk occupies 50-75% of body

Pathogenic: YES

Shape: Oval or Ellipsoid

Nucleus: Usually 4, located at one end

Fibrils & Flagella: Oriented longitudinally in cyst

Pathogenic: YES

Characteristics: Parasite will not take up iodine

  Uses a traunt stain - red to pink

  Mostly found in daycares with small children

Size: Very small

Pathogenic: YES

Motility: Rotary, boring

Shape: Ovoid with tapered anterior end

Nuclei: 1 large, kidney shaped macronucleus

Characteristics: Body surfaces covered by spiral, longitudinal rows of cilia

  Monkey or primate parasite

Pathogenic: YES

Shape: Ovoid with tapered anterior end

Nuclei: 1 large, kidney shaped macronucleus