PARAGONIMUS FLUKES Objectives and requirements 1. To study the life cycles of P. westermani, to learn more about the life history of trematodes 2. To study the main parasitized sites and major pathogenisis 3. To study the laboratory diagnosis of these flukes Observation and Experiment 1.P A. See the preserved specimen(Demonstration) B. Study the internal structures of stained specimen(Manipulation) Note the position of the suckers. Are they equal in size? The branched testes situated in posterior of the body, side by side, and posterior to uterus and ovary lobulated ovary is in the opposite side of uterus(fully filled with ova). Are these two female reproductive organs situated anterior or posterior to the worms? C. See the SEM photographs of Paragonimus spines (2)Larva and intermediate hosts(Demonstration) A. See the first and second intermediate hosts- Melania snail and crayfish. B. See the stained cercaria C. See the live cysts D Isolation of the encysted metacercaria from infected crabs(Students work in groups) Crushed a crab in a mortar. Add some 0.45% Nacl solution or tap water into motar and filter. Allow the filtrate stand and settle, examine sediments for encysted metacercaria under microscop (3)Egg A Morphology of egg(Manipulation) Measures 80118 W mX48-60 u m. Note its ellipsoidal shape, uneven thickness of eggshell, slightly oblique operculum and yellowish brown in color. A germinal cell with more than ten yolk cells inside the egg Materials examined; sputum, feces Examining methods: direct sputum smear, sputum concentration and direct fecal smear B. See the SEM photograph of egg (4)Pathology A. See the preserved infected lungs(Demonstration)6 PARAGONIMUS FLUKES Objectives and Requirements 1. To study the life cycles of P. westermani, to learn more about the life history of trematodes. 2. To study the main parasitized sites and major pathogenisis. 3. To study the laboratory diagnosis of these flukes. Observation and Experiment 1. P. westermani (1) Adult worm A. See the preserved specimen (Demonstration). B. Study the internal structures of stained specimen (Manipulation). Note the position of the suckers. Are they equal in size? The branched testes are situated in posterior of the body, side by side, and posterior to uterus and ovary. The lobulated ovary is in the opposite side of uterus (fully filled with ova). Are these two female reproductive organs situated anterior or posterior to the worms? C. See the SEM photographs of Paragonimus spines. (2) Larva and intermediate hosts (Demonstration) A. See the first and second intermediate hosts-Melania snail and crayfish. B. See the stained cercaria. C. See the live cysts. D. Isolation of the encysted metacercaria from infected crabs (Students work in groups). Crushed a crab in a mortar. Add some 0.45% NaCl solution or tap water into motar and filter. Allow the filtrate stand and settle, examine sediments for encysted metacercaria under microscope. (3) Egg A. Morphology of egg (Manipulation). Measures 80～118μm×48～60μm. Note its ellipsoidal shape, uneven thickness of eggshell, slightly oblique operculum and yellowish brown in color. A germinal cell with more than ten yolk cells inside the egg. Materials examined: sputum, feces. Examining methods: direct sputum smear, sputum concentration and direct fecal smear. B. See the SEM photograph of egg. (4) Pathology A. See the preserved infected lungs (Demonstration)