In this article we will discuss about the stool examination of different intestinal parasites.
For this exercise usually the faecal matter of foul and or cattle is used as a short samples for study of the intestinal parasites. The following techniques are used according to the objective of the experiment.
1. Smear Preparation:
Put a small quantity of fresh droppings (fowl)/dung of cattle in a watch glass. Put a few drops of normal saline solution (0.9%) and mix thoroughly with a narrow sterilized stick.
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(a) Put one drop of the mixture on a glass slide and spread over to form a smear with the help of another slide.
(b) Add a drop of Lugol’s iodine over the smear and cover with a cover slip.
(c) Examine under a microscope.
2. Concentration Method for Less Infected Stool Samples:
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(a) Mix about 1 gm. of faecal matter with 25 ml saturated NaCl solution in a measuring cylinder.
(b) Fill a test tube up to the lirion with the mixture.
(c) Put a Mayer’s albumen coated square cover slip on the mouth of the test tube taking care that no air bubbles are locked between the albumen coated cover slip and the mixture. Wait for 30 minutes.
(d) Remove the cover slip with a forceps, put it face down (abominated surface on the slide) on a glass slide.
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(e) Examine immediately under a microscope.
3. Centrifugal Floatation Method:
(a) Mix about 5 gm. of focal matter with 50 ml distilled water in a measuring cylinder.
(b) Strain the faecal suspension through 1 mm diameter pore sieve to remove coarse material.
(c) Centrifuge the mixture at 2000 rpm for 2-3 minutes. Most of the contents settle at the bottom of the centrifuge tube, but encysted protozoa and helminth eggs float on the supernatant being lighter and discarded.
(d) Decant the supernatant from centrifuge tubes, fill a test tube up to the brain with the fluid.
(e) Put a Mayar’s albumen coated square coverslip on the mouth of the test tube, taking care that no air bubble is locked between the cover slip & the fluid.
(f) Remove the cover slip, put it face down on a glass slide and examine immediately under a microscope.
Intestinal & rectal parasites present in the stool.
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i. Foul:
Egg or cysts.
Protozoa: Emeria sp., Trichomonas sp.
Nematoda: Ascaridia sp, Heterakis sp., Gongylonema sp., etc.
Cestoda: Reillietina sp., Davianea sp., Amoebotaenia sp., etc.
ii. Cattle:
Protozoa: Emeria sp.,
Cestoda: Avitellina sp., Moniezia sp., etc.
Trematoda: Cotylophoron sp., Paramphistimum sp., etc.
Nematodes: Capillaria sp., Toxocara sp., Haemonchus sp., Gongylonema sp., Nematodinus sp., Chaberia sp., etc.