PROTOZOA • Cutaneous Amebiasis
• Genital Amebiasis
AMOEBAE
General Characteristics:
B. Virulence factors of Entamoeba
histolytica:
• All amoebae are protozoans • Gal. Gal NAc lectin:
characterized by the presence of Cytoadherence
HYALINE FOOT – foot like extrusions • Ameba Pores: pore formers
from the ectoplasm called pseudopodia. • Cysteine proteinase: tissue
• All amoebae are intestinal dwellers invasion; most virulent factor
(colon) EXCEPT Entamoeba gingivalis
(oral cavity) C. Laboratory diagnosis of Entamoeba
• All amoebae are commensal organism histolytica:
EXCEPT Entamoeba histolytica which is 1. Direct Fecal Smear
pathologic, pathogenic, tissue invader 2. Liver aspiration biopsy –
• All amoebae undergo encystation extraintestinal
EXCEPT Entamoeba gingivalis 3. Culture
Four Stages in the Life Cycle: • Rice and egg saline method
• Chick Embryo Culture – live
• Trophozoites cells
• Pre-cystic Form 4. Serological Test: SREHP (Serine Rich
• Cystic Form E. histolytica Protein)
• Metacystic Form
Difference Between a Cyst and a Trophozoites
D. Concentration Method
• FECT (Formalin Ether
Trophozoite Cyst – Bilog Concentration Technique)
Feeding form Non-Feeding Form • MIFCT (Merthiolate Iodine
Formalin Concentration Method)
Motile Non-motile
Vegetative – feeding Infective Form E. Radiographic non-invasive
Liquid/Diarrhea/Watery Formed Stool techniques: X-ray, MRI, CT scan
Destroyed by Iodine Yellow-brown (Iodine)
A. INTESTINAL AMEBAE – Entamoeba
histolytica
1. Intestinal Amoebiasis
• Character ulcer: “Flask Shaped
Ulcer”
2. Extraintestinal Amoebiasis
• Hepatic Amebiasis
• Pulmonary Amebiasis
• Cerebral Amebiasis
• Amebic Pericarditis
DIAGNOSTIC STAGE: TROPHOZOITE • can be distinguish from E. histolytica by
cyst nucleus (1 only)
Entamoeba Entamoeba coli
histolytica
4. Entamoeba gingivalis: No cyst stage
Movements Unidirectional Sluggish, non- 5. Endolimax nana
progressive • TROPHOZOITE: sluggish, mononuclear
Shape of Finger-like Blunt • CYST: 4 nuclei, “cross eyed” appearance
pseudopodia
Release of Explosive or one Slow manner, 6. Iodamoeba butschlii
pseudopodia at a time several at a time • TROPHOZOITE: mononuclear; large
vesicular nucleus with a large endosome
surrounded by achromatic granules.
Nucleus 1; central 1, eccentric
• CYST: large glycogen vacuole which
karyosome karyosome
stains with IODINE
Cytoplasm Clean- looking Dirty-looking
Inclusions RBCsCaus Cell Debris; Food C. FREE-LIVING PATHOGENIC AMEBAE:
Debris; Bacteria Acanthamoeba, Naegleria fowleri
1. Naegleria fowleri
• Causative agent Primary Amebic
Meningoencephalitis (PAM) –
DIAGNOSTIC STAGE: CYST neurological manifestations
Entamoeba Entamoeba coli • Cultivated in NON-NUTRIENT
histolytica MEDIUM SEEDED WITH LIVING
Escherichia coli (bacteria)
• TROPHOZOITES: can assume
Number of 4 4-8
endolimax form or ameboflageliate
nuclei
o Flagellated: unidirectional
Chromatoidal Cigar, sausage, Splintered, needle motility
bars coffin lid like o Amoeboid: single pseudopod
• CYST: single nucleus, rounded
chromatoidal bars
• Mode of Transmission: ingestion and
B. COMMENSAL AMEBAE: Entamoeba, inhalation while swimming in
Endolimax, Iodamoeba contaminated pools, lakes, rivers.
1. Entamoeba dispar 2. Acanthamoeba
• Morphologically similar to E. Histolytic; • Causative agent Granulomatous
Can be distinguished by Polymerase Amebic Encephalitis (GAE)
Chain Reaction. • Also, an ocular surface pathogen
2. Entamoeba hartmanni
causing amebic keratitis
• Similar to E. histolytica except smaller;
• TROPHOZOITES: with spiny-
Can be distinguish by size filaments for locomotion
3. Entamoeba polecki
• CYST: double-walled (with
• Parasite of pigs and monkeys
ostioles/ pores in between)
• Rarely infect humans
• Mode of Transmission: Giardia Chilomastix Trichomonas
intranasal or skin penetration lamblia mesnili vaginalis
from open wound
Cyst Ovoid, flagella Uninucleate No cyst
CILIATES retracted to with distinct stage
axoneme anterior
1. Balantidium coli (median protuberance
• PATHOLOGY: body); deeply
Balantidiasis/Balantidial stained curved
Dysentery – rounded-base and fibril
wide neck ulcer
• Reservoir host: Pigs
• Tissue invader because of the
lytic enzyme in the cilia called
hyaluronidase
• TROPHOZOITE:
o Ovoidal, bean shape; Trophozoite -Pear-shaped; -4 flagella: 3 -Pear-
prominent cytosome; bilateral anterior and shaped, 4
indented excretory pore symmetry 1 flagellar anterior
o 2 nuclei: -4 pairs of cytostome flagella with
Macronuclei: large flagella. - Curved short
-2 ventral cystosomal undulating
kidney shaped;
sucking discs fibril membrane
vegetative function-
(for - Prominent
feeding attachment) siderophile
Micronuclei: small round - Axostyle is granules in
shaped; reproduction present with cytoplasm
o MOTILITY: thrown ball/ parabasal
rolling motility body
• CYST: ovoid, rounded, well- - 2 nuclei with
defined cystic wall (cilia centrally
enclosed in cystic wall), consists located
of 2 nuclei karyosome
“OLD MAN’s
• Mode of Transmission:
Eyeglasses”
Ingestion
Motility “Falling – leaf “Cork-screw “Tumbling-
motility” motility” jerky
motility”
Mode of Ingestion Ingestion Sexual
Transmission intercourse
Pathology 1.Giardiasis 1. 1. Male – non-specific
2.Malabsorption of Intestinal prostatitis, UTI
fat/starch disorders 2. Female –
nonspecific vaginitis,
itchiness burning
sensation,
COCCIDIANS – vulvovaginitis
inflammation of the
immunosuppressed,
cervix
immunocompromised Laboratory 1.Stool exam 1.Stool 1. Microscopy: stain
individuals diagnosis 2. Duodenal aspirate Exam with Giemsa or
3. Beale Wright – siderophile
1. Isospora beli string test granules
• PATHOLOGY: often 4.Immunochromatography • Male – urine,
asymptomatic; if prostatic
symptomatic cause fluid, seminal
diarrhea fluid
• Sexual multiplication • Female –
takes place in the urine, vaginal
intestinal mucosa discharge,
vaginal
ONLY coccidial parasite scrapings
in which MAN is the 2.Culture
DEFINITIVE HOST • Teinberg-
Wittington
2. Cryptosporidium – AIDS, CM
Immunocompromised • Trypticase
- Causes diarrhea in Liver Serum
travelers, in day-care Medium
centers and in water-
borne outbreaks 2. Biopsy (stained with Giemsa or
• Cryptosporidium parvum – Hematoxylin and Eosin stain)
mainly bovine (cattles) but 3. IgG or IgM studies – serological
can infect humans tests, immunoglobulins,
• Cryptosporidium hominis – antibodies
humans 4. SABIN – FELDMAN DYE TEST
3. Cyclospora - PRINCIPLE: Inhibition Mechanism
• Cyclospora cayetanensis – - Methylene blue
originally called a +Ag and Ab ====> colorless (troph)
cyanobaterium-like body (CLB)
OTHER INTESTINAL PROTOZOANS:
4. Toxoplasma gondii 1. Blastocystis hominis: no exact taxonomic
• PATHOLOGY: SABIN SYNDROME classification
• MOT: Oral-ingestion, - ovoid or spherical, vacuole-like
Transplacental (mother to fetus) structure
• Natural Final Host: Cats - may cause diarrhea to some patients
• Intermediate Host: Rats - NOTE: commonly mistaken as
• Man: 2 types of trophozoite protozoan cyst
1. Bradyzoite: inactive form 2. Dientamoeba fragilis
2. Tachyzoite: actively dividing - No cyst stage, rosette shaped
- Diagnosis: nucleus
1. Serology test - can be transported by pinworm to man
