Procedure done: Microcospic detection using direct fecal smear on NSS.
3.26.2026
Stool sample: Brown/Soft
Clinically significant findings: Mix amebae
E. coli & E. histolytica cysts
The picture was captured on HPO magnification.
How to identify cysts if only DFS on NSS is used?
Both are usually spherical. Their hyaline cyst wall is highly refractile. Their outline is defined. Like it was drawn by a black pen.
How to differentiate the two?
1. Size. E. coli is bigger than E. histolytica
Remember that you can't see their nucleus much using NSS so, you have to use iodine if you really want to confirm.
2. # of nucleus. E. coli has more nuclei (8). E. histolytica ranges from 1-4.
3. Chromotoidal bodies. E. coli has splinter-like chromotoidal body. E. histolytica has rod-shaped or cigar-shaped chromotoidal bars.
3.27.2026
Stool sample: Light brown/ Mucoid with streaks of blood
Clinically significant findings: E. histolytica trophozoite
The video was recorded on HPO magnification.
E. histolytica trophozoite caharacteristics:
Highly motile, very progressive, and movement is directional unlike E. coli which is more sluggish and has undirected movements(usually stays in place).
Has pseudopodia for locomotion. Unlike e. coli which uses their pseudopodia usually for feeding.
E. histolytica ingests RBCs.
References:
1. The head of our Clinical Microscopy section 😃
2. Medical Parasitology in the Philippines by Belizario
