Intestinal & Atrial Amoeba

E. histolytica Habitat

Colon / large intestine

E. histolytica Effect to Host Pathogenesis

Pathogenic

Cyst & Trophozoite

E. histolytica Developmental Stage

E. histolytica Infective Stage

Cyst

E. histolytica Mode of Transmission

Ingestion / fecal-oral route

E. coli Habitat

Colon / large intestine

E. coli Effect to Host Pathogenesis

Non-Pathogenic / commensal

E. coli Developmental Stage

Cyst & Trophozoite

E. coli Infective Stage

Cyst

E. coli Mode of Transmission

Ingestion / fecal-oral route

E. nana Habitat

Colon / large intestine

E. nana Effect to Host Pathogenesis

Non-Pathogenic / commensal

E. nana Developmental Stage

Cyst & Trophozoite

E. nana Infective Stage

Cyst

E. nana Mode of Transmission

Ingestion / fecal-oral route

I. bütschlii Habitat

Colon / large intestine

I. bütschlii Effect to Host Pathogenesis

Non-Pathogenic / commensal

I. bütschlii Developmental Stage

Cyst & Trophozoite

I. bütschlii Infective Stage

Cyst

I. bütschlii Mode of Transmission

Ingestion / fecal-oral route

E. gingivalis Habitat

Buccal cavity / mouth

E. gingivalis Effect to Host Pathogenesis

Non-Pathogenic / commensal

E. gingivalis Developmental Stage

Trophozoite (no cyst stage)

E. gingivalis Infective Stage

Trophozoite

E. gingivalis Mode of Transmission

Oral contact -> kissing / utensils

Encystation / Excystation stages

1. Pre-cyst 2. Cyst 3. Metacystic troph 4. Troph 5. Pre-cyst 6. Cyst

CYST Characteristics

Usually INFECTIVE | Found in formed feces | Resistant to damage | Usually Smaller than trophozoite | Best visualized using Iodine (Lugol's / 0.1% Amato) | > 1 nucleus | non-motile

TROPHOZOITE Characteristics

Usually NOT infective (except E. gingivalis / Trichomonas) | Found in liquid feces | Susceptible to damage; easily disintegrated | Usually larger than cyst | Best seen using permanent stains | tissue-invading | only 1 nucleus | motile

Iodine note

iodine when used in troph -> disappearance of troph

E. histolytica clinical overview

E. histolytica can cause Intestinal and Extraintestinal amebiasis. ↳ pathogenic & tissue-invading -> flask-shaped ulcers

A. INTESTINAL AMEBIASIS -> GIT

1) ACUTE / SYMPTOMATIC - Bloody diarrhea / dysentery, abdominal pain, stool consistency watery / liquid, patient passes out trophozoites in feces. Diagnosis: Examination of Direct Fecal Smear, use of permanent stain -> iron hematoxylin, Gomori's trichrome (+DFS + NSS)

A. INTESTINAL AMEBIASIS -> GIT (Cont.)

2) Chronic / asymptomatic - stool consistency is NORMAL, patients are CARRIERS, patient passes out cyst in feces. Diagnosis: Examination of Direct Fecal Smear. Use of Iodine + NSS and set to + Concentration techniques (acid ether conc. tech. & formalin)

B. EXTRAINTESTINAL -> Trophozoite

Trophozoite -> TISSUE INVADING. E. histolytica can produce: 1) hepatic amebiasis -> liver (Most common form of extraintestinal amebiasis - liver abscess) 2) pulmonary amebiasis -> lungs 3) cerebral amebiasis -> brain - DEADLY 4) flask-shaped ulcers -> lining of intestine 5) peritonitis

Intestinal & Atrial Amoeba - Entamoeba histolytica (CYST)

Size: 10-20 um | Number of Nuclei: 1-4 (4 Cysts) | Chromatodial Bodies: Cigar / bar shaped

Intestinal & Atrial Amoeba - Entamoeba histolytica (TROPHOZOITE)

Size: 12-60 um | Karyosome of Nucleus: Central, small nucleus "Bull's eye" | Cytoplasmic Inclusions: RBCs ingested

Intestinal & Atrial Amoeba - Entamoeba coli (CYST)

Size: 10-35 um | Number of Nuclei: 1-8 | Chromatodial Bodies: Splintered ends with broomstick appearance

Intestinal & Atrial Amoeba - Entamoeba coli (TROPHOZOITE)

Size: 15-50 um | Karyosome of Nucleus: Eccentric / off-center | Cytoplasmic Inclusions: Bacteria / food vacuoles & debris

Intestinal & Atrial Amoeba - Endolimax nana (CYST)

Size: 5-10 um | Number of Nuclei: 4 (Quadrinucleated) | Chromatodial Bodies: Small, spherical

Intestinal & Atrial Amoeba - Endolimax nana (TROPHOZOITE)

Size: 6-12 um | Karyosome of Nucleus: Irregular, blot-like

Intestinal & Atrial Amoeba - Iodamoeba bütschlii (CYST)

Size: 5-20 um | Number of Nuclei: Uninucleate, 1 | Chromatodial Bodies: NO CHROMATODIAL BODIES / NONE (large glycogen vacuole)

Intestinal & Atrial Amoeba - Iodamoeba bütschlii (TROPHOZOITE)

Size: 8-20 um | Karyosome of Nucleus: Surrounded with Achromatic granules / Refractile ring

Intestinal & Atrial Amoeba - Entamoeba gingivalis (CYST)

Unable to produce cyst

Intestinal & Atrial Amoeba - Entamoeba gingivalis (TROPHOZOITE)

Size: 10-20 um | Karyosome of Nucleus: Central & DISTINCT | Cytoplasmic Inclusions: Food vacuoles and WBCs

Amoeba locomotion notes

Active / motile / pseudopodia -> locomotion. Long, finger-like -> E. histo -> progressive, directional motility. E. coli -> sluggish, non-directional motility.

Amoeba move by means of

pseudopodia - organ for locomotion

Considered to be TISSUE INVADING (its trophozoite is)

E. histo

With BULL'S EYE KARYOSOME

E. histo

Smallest intestinal protozoa, CROSS EYED CYST, "DWARF INTERNAL SLUG"

E. nana

"Iodine cyst"

I. bütschlii

With LONG FINGER LIKE PSEUDOPODI

E. histo

With DIRECTIONAL PROGRESSIVE MOTILITY

E. histo

With SLUGGISH NON-DIRECTIONAL MOTILITY

E. coli

Morphologically Indistinguishable Amoebas

E. histolytica, E. dispar, and E. moshkovskii are MORPHOLOGICALLY INDISTINGUISHABLE -> DFS + SERO

Microscopic detection of E. histolytica trophozoite with ingested RBC

report as (+) for E. histolytica

Microscopy shows "E. histolytica-like-forms" in stool plus (+) SERO

report as (+) for E. histolytica

Microscopy shows "E. histolytica-like-forms" in stool plus (-) SERO

report as (+) for E. histolytica / E. dispar

Routine microscopy only with no immunoassay procedures

report (+) E. histolytica / E. dispar