ELEMENTS IN THE EXAMINATION Stool MICROSCOPY 1. Trophozoites and intestinal protozoan cysts 2. Worm eggs and larvae 3. Red blood cells: which indicates other bleeding. 4. White blood cells (neutrophil polymorphonuclear(PMN)) : which indicates inflammation. 5. White blood cells (eosinophils): which usually indicate an immune response (which may be related to parasitic infections) 6. Macrophages: which may be present in bacterial or parasitic infections. 7. Charcot – Leyden crystals: which can be found when disintegration of eosinophils occurs (may or may not be related to parasitic infections). 8. Mushrooms:Candidaspp. and yeast-like fungi (“yeast like fungi”) or yeast. 9. Plant cells, pollen grains, or fungal spores: which can resemble some worm eggs or protozoan cysts. 10. Plant fibers or hair roots or animal hair: which can resemble worm larvae. PMN Entamoeba histolytica(cyst) 1. Average size 14 µm, on permanent preparations that are stained 10 – 12 µm. 1. The average size is 20 µm, the size is smaller in permanent stain preparations. 2. The ratio of nucleus to cytoplasm is 1/1. 2. Ratio of nucleus to cytoplasm 1/10 - 1/12 (troph.), ½ - 1/3 (cyst). 3. Nucleus: 2 - 4 segments connected by short and narrow chromatin threads. The segments may appear as separate nuclei similar to cystsE. histolytica-focus carefully to see the chromatin threads 4. Granular cytoplasm 5.The characteristic features in appearance of trichrome are the same as inE. histolytica 3. Nucleus: round with central karyosome and peripheral chromatin. 4. Cytoplasm is agranular, uniform – can contain red blood cells (HR). 5. Trichrome: green cytoplasm, dark red nucleus. Macrophages Entamoeba histolytica(trophozoites) 1. 30 – 60 µm, maybe 5 – 10 µm (less in permanent stain preparations) 1. 12 – 60 µm ; average 20 µm (smaller in permanent stain preparations) 2. Comparison of nucleus to cytoplasm ¼- 1/6 2. The ratio of nucleus to cytoplasm is 1/10 – 1/12 3. One large nucleus of any possible shapemonocytes) 4. Usuallyeating, PMN and HR 5. May contain round red objects and nuclei may be absent. 6. The characteristic features of trichrome appearance are the same as E. histolytica 3. One nucleus, round with central karyosome and irregular (like the core peripheral chromatin containing debris Which 4. May contain human resources, some debris; without PMN 5. There is always a core 6. Trichrome; Cytoplasm green, nucleus dark red.