Cestodes Midterm Parasitology Lab 2nd Semester PDF

PRELIMS TOPIC Professor: Josephine Cuajotor, RMT Subject: Parasitology – Laboratory SECOND SEMESTER CESTODES PHYLUM PLATYHELMINTHES...

PRELIMS TOPIC Professor: Josephine Cuajotor, RMT Subject: Parasitology – Laboratory SECOND SEMESTER CESTODES PHYLUM PLATYHELMINTHES BINOMIAL NAME COMMON NAME Taenia saginata Beef tapeworm Collectively called the flatworms Taenia solium Pork tapeworm Taenia multiceps Coenurus tapeworm Dorsoventrally flattened Echinococcus granulosus Hydatid tapeworm Bilaterally symmetrical Echinococcus The Multiloculate or Alveolar They are covered by a membrane called tegument multilocularis Hydatid tapeworm They are hermaphrodite except for Schistosoma Hymenolepis nana Dwarf tapeworm species. Hymenolepis diminuta Rat tapeworm Dipylidium caninum Double-pored tapeworm Diphyllobothrium latum Broad Fish tapeworm CESTODES TREMATODES Common name Tapeworms Flukes Morphology Segmented; Unsegmented; Ribbon-like Leaf-like appearance appearance Digestive Tract None Incomplete Circulatory None None System Reproduction Mostly Hermaphroditic hermaphroditic Location in the Mostly found in Found in blood, Definite Host the intestines liver, lung, intestines Intermediate Some require 2 Requires 2 IHS to Hosts (IH) IHS to complete complete its life its life cycle cycle THREE TYPES OF PROGLOTTID 1. Immature – undeveloped sexual organ, nearest to CHARACTERISTICS OF CLASS CESTODA the neck. Taenia species (example) 2. Mature – fully mature sexual organ Adult worms are seen in the intestine 3. Gravid – contains fertilized egg, undergoes apolysis Proglottids contain male and female parts Eggs have 6 hooked embryos PSEUDOPHYLLIDEAN vs. CYCLOPHYLLIDEAN World-wide distribution nO digestive tract, no circulatory system PSEUDOPHYLLIDEAN CYCLOPHYLLIDEAN Ribbon-like body, flat Scolex Scolex - Spatulated with - Globular with four Middle (intermediate host is required) bothria muscular suckers A. PSEUDOPHYLLIDEA Diphyllobothrium latum Spirometra: ▪ S. erinacei ▪ S. mansoni ▪ S. ranarum B. CYCLOPHYLLIDEA Taenia solium and Taenia saginata Hymenolepis nana and Hymenolepis diminuta Segments Segments Dipylidium caninum - Genital pores + - No uterine pore but Raillietina garrisoni uterine pores undergoes apolysis. Echinococcus granulosus Order Order Pseudophyllidea Cyclophylllidea Scolex Spatulate scolex Globular scolex with sucking grooves with 4 muscular suckers Pores Genital + Uterine Genital pores pores Eggs Operculated and Non-operculated immature, require and readily passed aquatic development out containing the of embryo hexacanth embryo Intermediate Require 2 IHs Require only 1 IH Host Mode of Consumption of Consumption of transmission infected infected host; also, intermediate host infection via consumption of larval and cystic stages. Carlos, Mayrel Jedh H. // BSMLS – 2C PRELIMS TOPIC Professor: Josephine Cuajotor, RMT Subject: Parasitology – Laboratory SECOND SEMESTER PSEUDOPHYLLIDEAN CYCLOPHYLLIDEAN SPECIES OF CLASS CESTODA Eggs Eggs Species which require a vertebrate intermediate - Operculated, - Passed out readily host: immature, requires with hexacanth aquatic vegetation embryo. o Taenia solium (pork tapeworm) to develop. o Taenia saginata (beef tapeworm) o Echinococcus granulosus (dogs, carnivores) Species which require an invertebrate intermediate host: o Dipylidium caninum (dog tapeworm, double- pored tapeworm) o Hymenolepis diminuta (rat tapeworm) o Raillietina garrisoni (Tribolium confusum) Species which may or may not require intermediate host: Host Host o Hymenolepis nana (dwarf tapeworm) - 1st IH procercoid - One IH depending larva on species. Taenia: cysticercus Hymenolepis, Dipylidium, Raillietina: cysticercoid type Echinococcus: hydatid - 2nd IH plerocercoid cyst Species which infect man in their larval stages o Echinococcus granulosus (hydatid worm) o Echinococcus multilocus o Taenia solium o Diphyllobothrium latum DIPHYLLOBOTRIUM LATUM Pseudophyllidean Common name: fish tapeworm, broad tapeworm GENERAL ANATOMY OF TAPEWORMS Scolex is SPOON-SHAPED or SPATULATE Scolex bears 2 slit-like grooves called bothria o 1 on the dorsal surface o 1 on the ventral surface Scolex has NO ROSTELLUM and NO HOOKLETS Neck is thin and unsegmented and is much longer than the head. Carlos, Mayrel Jedh H. // BSMLS – 2C PRELIMS TOPIC Professor: Josephine Cuajotor, RMT Subject: Parasitology – Laboratory SECOND SEMESTER Definitive host: LARVAE o Man, dog, cat Passed first in water and then in the perspective o Small intestine intermediate hosts. Three stages: First Intermediate Host: o First stage larva o Cyclops or Diaptomus - Coracidium - Ciliated oncosphere that develops from egg Second Intermediate Host: in water. o Fresh water fish, pike, trout, salmon, perch o Second stage larva - Procercoid Mode of Infection: - Spindle-like solid body with cephalic o Ingestion of imperfectly cooked infected fish or invagination. roe containing plerocercoid larvae. - Found inside the cyclops (the first IH) o Third stage larva - Plerocercoid MORPHOLOGY - Head is invaginated in the neck 3,000 to 4,000 proglottids - Found in the fresh water fish, the second IH A mature segment is filled with male and female reproductive organs. Terminal segments shrink and becomes empty as eggs are constantly discharged. Dried up segments break off from the body in chains and are passed out in the host’s feces. Uterus at the center of the segment appears in the form of a rosette. OVA DIAGNOSIS 66 x 44 um with 58 – 76 um length and 40 – 51 um Microscopic examination of feces for the width. characteristic operculated eggs. Oval Bile stained Contains abundant granules and unsegmented ovum. Inconspicuous operculum at one end and a small knob at the other end. Does not float in saturated solutions of common salt. A single egg gives rise to a single larva. Not infective to man About 1 million released every day. Carlos, Mayrel Jedh H. // BSMLS – 2C PRELIMS TOPIC Professor: Josephine Cuajotor, RMT Subject: Parasitology – Laboratory SECOND SEMESTER TAENIA SOLIUM vs. TAENIA SAGINATA Taenia solium Taenia saginata Diagnosis Cysticercosis Taeniasis Taenia solium Taenia saginata Biopsy Anal swab: Common Pork tapeworm Beef tapeworm (subcutaneous To find egg at name nodule) perianal region. Length Whitish, creamy White and semi- white, measures 3- transparent, X-ray/ CT/ MRI: Fecal exam: 5 meters. measures 5-10 Cerebral To find segment meters. cysticercosis (species identification) Opthalmoscopy: Ophthalmic cysticercosis Number of 800 – 1000 1000 – 2000 Segments Scolex Proglottids With accessory None ovary Proglottids (Gravid) 8-12 lateral 15-30 lateral branches branches HYMENOLEPIC NANA vs. HYMENOLEPIS DIMINUTA Hymenolepis nana Hymenolepis diminuta Common Dwarf tapeworm Rat tapeworm name Length 25 to 45 mm 60 mm Apolysis In chains Singly Scolex Subglobular in Club-shaped with Number of 30,000 to 50,000 80,000 eggs shape with 4 4 cuplike sucker, eggs/gravid eggs cuplike suckers, rostellum proglottid has a retractable unarmed or Egg 31 – 56 micra in diameter with oncosphere rostellum armed devoid of hooks. embryo, radially striated. with single row of 20 – 30 Y-shaped hooklets. Long and slender neck. Intermediate Pig Cow Proglottids Segment is Segment is broad Host (Mature) narrow Bilobed ovary Infective Cysticercus Cysticercus bovis One ovary more 3 globular, widely stage cellulosae or less straight separated pattern across unilateral genital 3 ovoid testes pores Carlos, Mayrel Jedh H. // BSMLS – 2C PRELIMS TOPIC Professor: Josephine Cuajotor, RMT Subject: Parasitology – Laboratory SECOND SEMESTER Hymenolepis Hymenolepis DIPYLIDIUM CANINUM vs. RAILLIETINA GARRISONI nana diminuta Proglottids Dipylidium Raillietina (Gravid Narrow, uterus Sac-like filled Caninum garrisoni segment) is sac-like with eggs. Length 10 – 70 cm >60 cm in length irregular Disintegrate, Scolex Small with 4 Subglobular and Testes and release eggs into deeply cupped is provided with ovary disappear the feces. suckers and a 4 cuplike Uterus hollows protrusible suckers with out and filled rostellum which refractile with eggs. is armed with 1- rostellum 7 rows of rose- armed with 2 thorn hooklets. alternating circular rows of 90 – 140 hammer shaped hooks. Ova 30 – 47 um Has an inner diameter polar membrane around filaments the oncosphere originating from which has 2 polar polar knobs at knobs but no either end of the polar filament. embryo pore. Fan-like Proglottids Segment is With bilobed Polar filaments hooklets. (Mature) narrow ovary and 30 – are 4 – 8 in Circular 60 – 80 Double set of 50 ovoid testes. number. um diameter. reproductive Genital pore organs and a opens on one Bile stained. genital pore at side near the each lateral anterior lateral margin. border of the segment. Intermediate Flea Flea host Beetle Beetle Proglottids Pumpkin seed- 2 mm in length Cockroaches Cockroaches (Gravid) shaped filled with 200 – 400 Mealworms with capsules or eggs containing Earwigs pockets of 8-15 1-4 spindle - DOES NOT eggs enclosed in shaped eggs. NECESSARILY - REQUIRES AN IH embryonic Enclosed in REQUIRE AN membrane. two IH membranes: Arthropod 1. Outer – IH Rat flea Xenopsylla spp. elongated Dog flea Ctenophalides 2. Inner – Human Flea canis spherical Flour flee Pulex irritans Tribolium spp. Segments – motile, white, Diagnosis Demonstration of eggs in stool “rice grain” Light infection: concentration of stool on alternate days. Stool exam repeated after 2 weeks. Note: Hymenolepis nana: Proglottids are not recovered --- undergo degeneration prior to passage with stools. Hymenolepis diminuta: At time whole worm is expelled. Carlos, Mayrel Jedh H. // BSMLS – 2C PRELIMS TOPIC Professor: Josephine Cuajotor, RMT Subject: Parasitology – Laboratory SECOND SEMESTER Dipylidium Raillietina OVA caninum garrisoni Subspherical with a brown radially striated Diagnosis Recovery of Recovery of embryophore which cannot be differentiated from gravid gravid Taenia eggs. segments. segments. Egg capsules Segment is are rarely glistening with passed-out in rice grain the feces appearance. Intermediate Host Binomial name Common HYDATID CYST name Infective stage of the parasite Dipylidium Ctenocephalides Dog flea caninum canis 20 cm in diameter Ctenocephalides Cat flea Developing membrane is 2 layers: felis 1. Outer laminated layer Trichoedectes Dog louse - Milky opaque canis - Non-nucleated layer Pulex irritans Human flea 2. Inner nucleated germinal layer - Buds or capsules which contain Raillietina Tribolium Flour beetle protoscolices garrisoni confusum - Free brood capsule and free scolices are referred to as “HYDATID SAND” EXTRA INTESTINAL CESTODES Echinococcus granulosus Echinococcus multilocularis Spirometra mansoni Spirometra erinacei Spirometra ranarum ECHINOCOCCUS GRANULOSUS SCOLEX Bears a prominent rostellum with double row of 20 to 40 large and small hooklets. SEGMENTS LIFE CYCLE Three segments: 1. 1 immature Definitive host: dogs and other canines 2. 1 elongated mature Intermediate host: sheep, goasts, swine 3. 1 long gravid Accidental host: man Carlos, Mayrel Jedh H. // BSMLS – 2C PRELIMS TOPIC Professor: Josephine Cuajotor, RMT Subject: Parasitology – Laboratory SECOND SEMESTER PATHOLOGY Affects primarily the liver and the lungs. DIAGNOSIS Unilocular cysts (only after they have grown to a tremendous size) X-Ray Exploratory cyst puncture Immunologic test o Intradermal test o Precipitin test o CF o Hemagglutination o IHA, IFA, EIA ECHINOCOCCUS MULTILOCULARIS MORPHOLOGY Adult similar to E. granulosus 1.2 mm – 3.7 mm Cyst has a thin outer wall that grows and infiltrates into surrounding host tissues. Fluid filled pockets containing protoscolices Break off and metastasize to other parts of the body forming alveolar or multilocular hydatid cysts. DIAGNOSIS Radiological studies alveolar hydatidosis ELISA PREVENTION Deworming of dogs Carlos, Mayrel Jedh H. // BSMLS – 2C