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Medical Parasitology Lab. Concentration techniques. Flotation Method. Concentration Methods. Sedimentation method Modified Formal- Ether sedimentation technique Acid- Ether sedimentation technique Flotation method Saturated Salt Solution technique
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Medical Parasitology Lab. Concentrationtechniques Flotation Method
Concentration Methods • Sedimentation method • Modified Formal- Ether sedimentation technique • Acid- Ether sedimentation technique • Flotation method • Saturated Salt Solution technique • Sheather’s Sugar Centrifugal Flotation technique • Zinc Sulphate Centrifugal Flotation technique Raed Z. Ahmed, Medical Parasitology Lab.,2012
Flotation technique • These method use the high specific gravity of a solution to float the lighter ova and cyst. They can be improved by centrifugation. • Advantage: • Easy to perform . • Disadvantage: • Delay in examination can result in distortion. • Larvae and some fluke eggs do not concentrate. • Frequent checking of specific gravity. Raed Z. Ahmed, Medical Parasitology Lab.,2012
Flotation Methods Saturated salt solution Raed Z. Ahmed, Medical Parasitology Lab.,2012
Materials and Method • Boil granular sodium chloride in excess in water to produce a saturated solution which when cooled has a specific gravity of 1.18 - 1.2. • Half fill a wide- mounted flat bottomed container with the saturated salt solution. • Emulsify 1gm of feces in the solution and strain it to remove the debris from the surface. • Pour the filtrate into meniscus and fill it to the top with saturated salt solution. • Lay a glass slide or large coverslip over the top, avoiding any bubbles being trapped. • Leave for 20 min before quickly inverting the slide. • Scan for ova using the 10x objectives. Raed Z. Ahmed, Medical Parasitology Lab.,2012
Saturated Salt solution technique • Advantages: • It is cheap preparation using simple apparatus. • It concentrates nematode ova well. • Disadvantages: • It doesn’t concentrate cysts. Raed Z. Ahmed, Medical Parasitology Lab.,2012
Flotation Methods Sheather’s sugar centrifugal flotation technique Raed Z. Ahmed, Medical Parasitology Lab.,2012
Materials and Method • Sheather’s sugar solution: • Table sugar -------------------------------------- 500gm • Distilled water ---------------------------------- 320ml • Phenol crystal ( melt in hot water bath) ----- 6.5gm Raed Z. Ahmed, Medical Parasitology Lab.,2012
Procedures • Soften 1gm of feces with water to a soft. • Strain the aqueous suspension through a wire sieve. • Mix 1 part aqueous suspension with 2 part of Sheather's sugar solution. • Pour into a centrifuge tube, centrifugation 1500 rpm for 10 minutes. • Pour the supernatant into a meniscus and add a sufficient solution to bring the meniscus to the top. • Place a coverslip and wait for 10 minutes. • Examine under microscope. Raed Z. Ahmed, Medical Parasitology Lab.,2012
Sheather’s Sugar solution technique • Advantages: • Reveals most nematode eggs and protozoan cyst. • Disadvantages: • Flukes eggs and tape worm eggs are not demonstrate well. • Also most nematode larvae are not demonstrate well. Raed Z. Ahmed, Medical Parasitology Lab.,2012
Intestinal Protozoa Balantidium coli Raed Z. Ahmed, Medical Parasitology Lab.,2012
Balantidium coli • Is a parasitic species of ciliate protozoa that cause balantidiasis or Balantidium dysentery. • Balantidium coli has two developmental stages, a trophozoite stage and a cyst stage. • The cystis the infective stage measures about 50 to 70 µm in diameter, characterized by the presence of a large kidney-shaped macronucleus. • The trophozoite is oval with 2 nuclei and measures approximately 50 to 100 µm long and 40 to 70 µm wide. Raed Z. Ahmed, Medical Parasitology Lab.,2012
B.coliCyst Raed Z. Ahmed, Medical Parasitology Lab.,2012
B. coli Trophozoite Raed Z. Ahmed, Medical Parasitology Lab.,2012
Intestinal Protozoa Cryptosporidium parvum Raed Z. Ahmed, Medical Parasitology Lab.,2012
Cryptosporidium parvum • Infect human and most mammals. • The infective stage is oocyst containing sporozoites measuring 5u in diameter. • The diagnostics stage is sporocyst containing 4 sporozoites. • Diagnosis: • Detecting oocyst in stool. • Acid-fast stain. Raed Z. Ahmed, Medical Parasitology Lab.,2012
Cryptosporidium parvum oocyst Raed Z. Ahmed, Medical Parasitology Lab.,2012
Tissue Protozoa Toxoplasma gondii Raed Z. Ahmed, Medical Parasitology Lab.,2012
Toxoplasma gondii • Habitat: reticulo-endothelial system, monocyte, and muscle fiber and cause toxoplasmosis. • Humans can acquire Toxoplasma gondii infection by ingestion cyst or sporylated oocyst • Cyst: precipitated in flesh of cow. • Sporulated oocyst: cat feces. • Intermediate host: Human. • Definitive host: Cat. • The tachyzoites are crescent-shaped and measure about 5 µm in length. • Diagnostic stages: • Diagnosis also can be done by detection antibody IgG, IgM, IgE and IgA. Raed Z. Ahmed, Medical Parasitology Lab.,2012
Tachyzoites Raed Z. Ahmed, Medical Parasitology Lab.,2012
Urogenital Protozoa Trichomonas vaginalis Raed Z. Ahmed, Medical Parasitology Lab.,2012
Trichomonas vaginalis • Is the most common cause of vaginitis, inhabit the urogenital system • There is no cyst stage but only have trophozoite stage. • The trophozoite measures about 15 x 10 µm. The trophozoite has a single nucleus and four flagella and undulating membrane. • Diagnosis: • Male: finding trophozoite in urethral prostatic discharge • Female: finding trophozoite in vaginal discharge. Raed Z. Ahmed, Medical Parasitology Lab.,2012
T. vaginalis Trophozoite Raed Z. Ahmed, Medical Parasitology Lab.,2012
Intestinal Cestodes Hymenolepis nana Raed Z. Ahmed, Medical Parasitology Lab.,2012
Hymenolepis nana • This is one of the most common cestodes of humans, especially children. And it’s the smallest tape worm in man, also called dwarf tape worm. • Eggs measures 30-37u, and have double membrane and contain six hooked oncosphere. • The scolex of H. nana has four suckers and a short rostellum with hooks. • Infective stage: Eggs. • Diagnosis: • Stool examination to detect the eggs. Raed Z. Ahmed, Medical Parasitology Lab.,2012
H. nana egg Raed Z. Ahmed, Medical Parasitology Lab.,2012
H. nana adult worm Raed Z. Ahmed, Medical Parasitology Lab.,2012
H. nana scolex Raed Z. Ahmed, Medical Parasitology Lab.,2012
