PROTOZOA
Usual Developmental stages of some protozoa:
o PRE-CYST → CYST → METACYSTIC TROPHOZOITE → TROPHOZOITE
Common characteristic
1. Unicellular/Single celled eukaryotic microorganism; non-helminth
2. Classified under Kingdom Protista
3. A single cell performs all the unctions: Reproduction, digestion, excretion etc.
4. They appear like cells because they have nucleus & cyctoplasm; Cytoplasm: with ectoplasm &
endoplasm
TYPES:
o Ciliate Cilia
o Flagellates Flagellate / undulating membrane; Protozoa that moves by means of flagella
o Amoeba Pseudopodia
o Sporozoa Protozoa that are not provided with organs for locomotion
o Microsporidia/Microspora Protozoa that are not provided with organs for locomotion
Cyst & Trophozoite = 2 most important stages because they are usually the infective and diagnostic stages
When Cyst becomes trophozoite = Excystation
When Trophozoite becomes cyst = Encystation / Encystment
CYST TROPHOZOITE
Non-motile form Motile form
Usually found in FORMED fece Usually found in LIQUID/DIARRHEIC/WATERY feces
Usually, INFECTIVE Usually NOT INFECTIVE
Usually SMALLER than trophozoite Usually LARGER than cyst
Usually MULTINUCLEATED (more than 1 nucleus) Usually, UNINUCLEATED
Usually RESISTANT to damage (does not easily Usually SUSCEPTIBLE to damage
disintegrate) Best demonstrated using PERMANENT STAINS
Best demonstrated using IODINE Ex. Iron hematoxylin & Gomori’s technique
Iodine is good only for cysts.
Consistency of stool is determined to know which stage the parasite is at the moment.
If stool is water, examine it ASAP because it may contain trophozoites and trhophozoites easily
disintegrate
Non-pathogenic aka commensal
CILIATE: Cilia / Pseudopodia is the organ for locomotion
Species: o Can cause BALANTIDIAL DYSENTERY / Balantidiasis
Balantidum coli which may be acquired through ingestion of food
o Only ciliate important to man: B. coli or water contaminated with fecal material with B.
o A common parasite of PIGS (occupational coli cyst, so pag meron ka nito, yung stool mo ay
hazard) & a tissue invader may BLOOD
o Parasitize the LARGE INTESTINE & regarded as o Exam of
the LARGEST 1. DIRECT FECAL SMEAR
, INTESTINAL PROTOZOA 2. CONCENTRATION TECHNIQUE
o Can develop cyst & trophozoite stage 3. RECTAL BIOPSY
o Infective stage: Cyst o Are the usual means of detection in the laboratory
o MOT: Ingestion o Cyst can be identified under LPO because it is large
MORPHOLOGY OF CYST OF CILIA MORPHOLOGY OF TROPHOZOITE OF CILIA
Measures 45x 64u Measures 50x70u
Spherical or oval w/ thick wall (which makes it Surrounded w/ hairlike cilia, exhibits directional
difficult to stain) tumbling motility
Cytoplasm w/ kidney or bean shaped macronucleus, W/ macronucleus & spherical micronucleus
contractile vacuoles and cilia Equipped with cytostome & cytopyge
Has macronucleus & micronucleus Provided with 2 contractile vacuoles
FUNCTIONS:
Micronucleus For reproduction
Macronucleus For vegetation
Cytostome Cell mouth for food ingestion
Cytopyge Cell anus for waste excretion
Balantidum coli
Usual Developmental stages of some protozoa:
o PRE-CYST → CYST → METACYSTIC TROPHOZOITE → TROPHOZOITE
Common characteristic
1. Unicellular/Single celled eukaryotic microorganism; non-helminth
2. Classified under Kingdom Protista
3. A single cell performs all the unctions: Reproduction, digestion, excretion etc.
4. They appear like cells because they have nucleus & cyctoplasm; Cytoplasm: with ectoplasm &
endoplasm
TYPES:
o Ciliate Cilia
o Flagellates Flagellate / undulating membrane; Protozoa that moves by means of flagella
o Amoeba Pseudopodia
o Sporozoa Protozoa that are not provided with organs for locomotion
o Microsporidia/Microspora Protozoa that are not provided with organs for locomotion
Cyst & Trophozoite = 2 most important stages because they are usually the infective and diagnostic stages
When Cyst becomes trophozoite = Excystation
When Trophozoite becomes cyst = Encystation / Encystment
CYST TROPHOZOITE
Non-motile form Motile form
Usually found in FORMED fece Usually found in LIQUID/DIARRHEIC/WATERY feces
Usually, INFECTIVE Usually NOT INFECTIVE
Usually SMALLER than trophozoite Usually LARGER than cyst
Usually MULTINUCLEATED (more than 1 nucleus) Usually, UNINUCLEATED
Usually RESISTANT to damage (does not easily Usually SUSCEPTIBLE to damage
disintegrate) Best demonstrated using PERMANENT STAINS
Best demonstrated using IODINE Ex. Iron hematoxylin & Gomori’s technique
Iodine is good only for cysts.
Consistency of stool is determined to know which stage the parasite is at the moment.
If stool is water, examine it ASAP because it may contain trophozoites and trhophozoites easily
disintegrate
Non-pathogenic aka commensal
CILIATE: Cilia / Pseudopodia is the organ for locomotion
Species: o Can cause BALANTIDIAL DYSENTERY / Balantidiasis
Balantidum coli which may be acquired through ingestion of food
o Only ciliate important to man: B. coli or water contaminated with fecal material with B.
o A common parasite of PIGS (occupational coli cyst, so pag meron ka nito, yung stool mo ay
hazard) & a tissue invader may BLOOD
o Parasitize the LARGE INTESTINE & regarded as o Exam of
the LARGEST 1. DIRECT FECAL SMEAR
, INTESTINAL PROTOZOA 2. CONCENTRATION TECHNIQUE
o Can develop cyst & trophozoite stage 3. RECTAL BIOPSY
o Infective stage: Cyst o Are the usual means of detection in the laboratory
o MOT: Ingestion o Cyst can be identified under LPO because it is large
MORPHOLOGY OF CYST OF CILIA MORPHOLOGY OF TROPHOZOITE OF CILIA
Measures 45x 64u Measures 50x70u
Spherical or oval w/ thick wall (which makes it Surrounded w/ hairlike cilia, exhibits directional
difficult to stain) tumbling motility
Cytoplasm w/ kidney or bean shaped macronucleus, W/ macronucleus & spherical micronucleus
contractile vacuoles and cilia Equipped with cytostome & cytopyge
Has macronucleus & micronucleus Provided with 2 contractile vacuoles
FUNCTIONS:
Micronucleus For reproduction
Macronucleus For vegetation
Cytostome Cell mouth for food ingestion
Cytopyge Cell anus for waste excretion
Balantidum coli
