Week 5 Flashcards
What are the technical terms for the head, neck, and body of cestodes?
What are the different names of tapeworms in prey vs. predator?
What are the two stages of cestodes?
* Adult in definitive host (DH) (intestine; mostly non-pathogenic)
* Larva (metacestode) in IH (Tissues; pathogenic in vertebrates)
What are the two orders of eucestoda?
Pseudophyllidea (aquatic LC; 2 IHs)
Cyclophyllidea (terrestrial LC; usually 1 IH)
What are the two groups of Cyclophyllideans?
* Non-taeniids (herbivorous, omnivorous or carnivorous DH)
* Taeniids (always carnivorous DH; major socioeconomic importance)
General life cycle of cestodes
Egg passed in faeces–> ingested by IH
**metacestode (larval stage) that causes the infection
What are the genera of Pseudophyllidea (aquatic LC; 2 IHs) that are important?
Diphyllobothrium latum
Spirometra erinacei
** humans, cats and dogs
What are the genera of Cyclophyllideans, Non-taeniids that are important?
* Dipylidium caninum (humans, cats, dogs)
* Anoplocephala perfoliata (horse)
* Moniezia expanza, M. benedeni (cow, sheep)
* Hymenolepis (rodent, chicken, human)
* Choanotaenia, Amoebotaenia, Raillietina, Davainea (chicken)
What are the genera of Cyclophyllideans taeniids that are important?
Taenia and Echinococcus (cats and dogs)
Life cycle patterns via ingestion of Pseudophyllidea (aquatic) vs. Cyclophyllidea (terrestrial)?
Which tapeworm (cestodes) are of human significance?
Anoplocephala perfoliata (horse)
Raillietina, Davainea (chicken)
Morphology of cestodes
* 2-4 suckers +/- armed (aka hooks)
* Rostellum (permanent or retractable)– may contain hooks (aka armed)
Anoplocephala perfoliata (horse) (cestode)
What does an osmoregulatory system have?
What is osmoregulation?
Flame cells
Osmoregulators maintain a more or less stable internal osmolarity by physiological means. Terrestrial animals must osmoregulate because they unavoidably lose water by evaporation and excretion, and replacement water is not always immediately available.
What is the most unique thing about the organ systems in cestodes? What are proglottids?
No gut!!
proglottids- segments
What does the tegument and subtegument of a tapeworm do?
Protection, traction, nutrient absorption, digestion
Reproductive systems of Cyclophyllidea vs. Pseudophyllidea
Cyclophyllidea: proglottids can be filled with eggs, they are alive- pooped out of the host. Dries out, ruptures, and that is how eggs are released. 1 can give rise to 50,000 metacestodes.
Pseudophyllideans: uterine pore- where the eggs pops out. So if you’re doing a faecal float, the chances of finding this egg is close to zero.
Pseudophyllidean tapeworm
Raillietina (chickens)
Which egg is which?
** some of the thick shelled terrestrial can survive for a couple of years in the environment
How likely are you to see Hymenolepis, Taenia, Echinococcus, Anoplocephala, Dipylidium, and Moneizia in faeces?
Uncommon to see in faeces because they are Cyclophyllidea therefore they release segments (proglottids) in faeces, not single eggs. The proglottids have to dry first for the eggs to rupture.
What is the metacestode of Pseudophyllideads?
plerocercoid (infectious stage)- 2nd IH
procercoid- 1st IH metacestode
What are the metacestodes called from Taenia spp., Taenia multiceps, Echinococcus, Taenia taeniaformis, Dipyliidium/ Hymenolepis?
How many adult worms per hydatid cyst? What is a problem oversea with one Echinococcus species?
Hundreds of protoscolex per cyst (bud internally- asexually- each protoscolex will produce 1 adult worm)
(There is one Echinococcus species that is cancerous- like a neoplastic growth- organ dysfunction)
Metacestode
Metacestode
Metacestode
Metacestode- this one not present in AUS
Metacestode
Metacestode- kangaroo lung with hytadid cysts
Life cycles of Pseudophyllidea vs. Cyclophyllidea
Pseudophyllidian vs. Cyclophyllidian
Characteristics of Pseudophyllideans
operculated= lid
** eggs are shed in faeces through uterine pore
What is unique about Spirometra’s life cycle?
Many paratenic hosts (facilitator hosts)
Life cycle of Diphyllobothrium
Will you see this in Australia?
Potentially due to trade if just chilled instead of frozen could potentially infect people globally
Clinical signs of Diphyllobothrium, treatment, where, how long can it grow, how to prevent?
What is the life cycle of Spirometra spp.?
Spirometra- species, clinical signs, and treatment?
Diagnosis and Treatment of Spirometra
Biggest thing is usually asymptomatic and no big deal
Spirometra
Proliferative Disease: Spirometra spp.- dog ingested procercoid– doesn’t develop into a pleurocercoid just keeps multiplying as procercoids– proliferative. Usually occurs in the lungs, but one case in the abdominal cavity has occurred.
Proliferative Disease: Spirometra spp.- dog ingested procercoid– doesn’t develop into a pleurocercoid just keeps multiplying as procercoids– proliferative. Usually occurs in the lungs, but one case in the abdominal cavity has occurred.
