Quiz #1

* Each question is worth one point 1.)This insect is known as the kissing bug and is the vector/intermediate host for what parasite? 4.) Name the structure the arrows are pointing to in the picture of T. vaginalis. 2.) What is the genus of this organism? 5.) What are the benefits of performing a thick blood smear over a thin blood smear in malaria detection? 3.) What phylum does Toxoplasma gondii belong to? * Each question is worth one point

Cestodes! Parasitic in the intestines of vertebrates Typically have bodies divided into three major sections 1.) Scolex (head) 2.) Neck (zone of proliferation) Metabolic activity 3.) Strobila (body) They have no digestive tract and strictly rely on their surface area to volume ratio and tegument for nutrient acquisition

Scolex Acetabula (suckers) Bothria (grooves or slits) Rostellum (anterior projections and might be armed with hooks!) Phyllidea (leaf-life flaps)

Phylum Platyhelminthes Class Cestoidea Order Pseudophyllidea ANIMALIA CESTODA Kingdom Animalia Phylum Platyhelminthes Class Cestoidea Order Pseudophyllidea Family Diphyllobothriidae Genus Diphyllobothrium Species latum (coracidium)  oncosphere  procercoid  pleurocercoid  adult   Oncosphere  bladder larvae (cysticercoid, cysticerus, coenurus, hydatid)  adult

Diphyllobothrium latum Occasionally, humans are infected with the plerocercoid stage of cestodes. Such infections are referred to sparganosis. BEAR feces(eggs)  swimming coracidium in the environment  oncosphere (6 hooked hexacanth)  proceroid (copepod)  pleurocercoid (fish)  adult (mammalian host)

Diphyllobothrium latum This species produced shelled eggs that are released via a uterine pore rather than detachment of the proglottid (apolysis) and can release over 1 million eggs per day!!!!!!!!!!!!! The enclosed embryo will develop into a coracidium, a ciliated, free-swimming larva which must be eaten by a copepod, such as Diaptomus or Cyclops in order to continue the life cycle.  From: http://workforce.cup.edu/buckelew/ 400x From: http://www.ksu.edu/parasitology abopercular knob

Diphyllobothrium latum Proglottids, note rosette-like uterus which is filled with eggs Scolex. This is a pseudophyllidean tapeworm and has "sucking slits" called bothria rather than suckers or acetabula as in the cyclophyllideans. The scolex is also unarmed or without a hooked rostellum.  100x From: http://www.ksu.edu/parasitology Bothria From: http://workforce.cup.edu/buckelew/

Diphyllobothrium latum Examine slides: 57 for EGGS, 58 for SCOLEX, 59 for SEGMENTS

Phylum Platyhelminthes Class Cestoidea Order Cyclophyllidea ANIMALIA CESTODA Kingdom Animalia Phylum Platyhelminthes Class Cestoidea Order Cyclophyllidea Family Taeniidae Genus Taenia Species saginata, solium Feces (gravid proglottids)  cattle, pig,  oncosphere  cysticercusus (fluid filled bladder with an invaginated scolex)  dog, human (scolex evaginates and attches to gut of definitive host)  young adult tapeworm

Taeniidae Egg 400x T. solium Scolex (pork tapeworm) T. saginata Scolex The capsular wall is lost by this point in development and the outer embryophore is pitted with radiating pores which give it the striated appearance.  400x T. solium Scolex (pork tapeworm) T. saginata Scolex From: Web Attlas of Parasitology

Taenia saginata gravid proglotid Taenia solium gravid proglotid Note the lateral arms of the central uterine stem

0.5 mm vas deferens cirrus sac genital pore excretory canal vagina uterus ovary 0.5 mm vitelline glands testes

Taenia saginata Examine slides: 60 for EGGS, 62 for CYSTICERCUS, 65 for GRAVID PROGLOTID.

Taenia solium Examine slides: 63 for SCOLEX.

T.saginata T.solium Size 4-8 m 2-4 m Scolex 4 suckers 4 suckers, rostellum & hooklets Mature proglottid Ovary 2 lobes 3 lobes Testes 300-400 150-200 Gravid proglottid: Uterine branches 15-30 7-12

Phylum Platyhelminths Class Cestoda Subclass Eucestoda ANIMALIA CESTODA Kingdom Animalia Phylum Platyhelminths Class Cestoda Subclass Eucestoda Order Cyclophyllidea Genus Echinococcus Species granulosus

Echinococcus granulosus Feces (gravid proglottid)  oncosphere (vegetarian mammal)  hydatid cyst  hydatid sand  wolf, dog

Echinococcus granulosus total length = 3-6 mm

Echinococcus granulosus Hydatid cysts cysts the size of golf balls are not Uncommon The interior of a hydatid cyst is filled with "protoscolices" each of which has the ability to grow into an adult worm when ingested by a canine host http://www.youtube.com/watch?v=3s1Aeky8OME

Echinococcus granulosus Examine slides: 68 for CYST, 69 for ADULT.

Hymenolepis diminuta Cyclophyllidean cestode Adults can be found in birds by the thousands! HOWEVER, it uses rats as definitive hosts and is a great model Scolex= 4 suckers and unarmed rostellum Unsegmented neck(zone of preliferaiton) Osmoregulatory canals that run though the rest of the strobila Feces (gravid proglottid)  oncosphere (beetle)  cysticerci/cysticercoid human/rodent

a b f 100 mm 100 mm 50 mm c c d d e e 200 mm 500 mm 1 mm 7.13

Diplyidium caninum Reports of infecting humans (ingesting a flea with a cysticercoid); however, definitive host is a dog or cat 4 sucksers with a retractable rostellum with armed rows of hooks Two complete sets of male and female reproductive structures Progottids are very distinctive Feces (gravid proglottid)  oncopshere (fea)  cystiercoid  human or dog

a b c d e 200 mm 100 mm 200 mm 500 mm 1 mm 7.15