Unit 1: 5.2 Parasitic Helminths Flashcards
Explain why we include the study of parasitic worms in microbiology
Helminth parasites are in microbio because they are identified by looking at microscopic eggs/larvae
What are the two major groups of parasitic helminths?
- Nematoda (roundworms)
2. Platyhelminthes (flatworms)
Nematoda (roundworm) characteristics?
- unsegmented
- full digestive system
Platyhelminthes (flatworms) characteristics?
- flatworms
- flukes
- tapeworms
- tubellarians
Enterobius vermicularis (pinworm)
- Nematoda
- itching around anus
- caused by worm EGGS
Toxocara canis & T.cati
- nematodes found in dogs and cats
- caused by worm LARVAE
Necator americanus (hookworm)
-nematode
Trichinella spiralis
- nematoda
- causes Trichinellosis
- undercooked meat releases LARVAE
Fluke (trematode) characteristics?
- in platyhelminthes group
- non segmented flatworms with an oral sucker
Examples of trematodes?
- Clonchiris
- Opisthorchis
What parasites cause schistosomiasis?
- trematodes
- Schistosoma mansoni
- S. haematobium
- S.japoncium
- fresh water snails
Cestodes (tapeworms) characteristics?
- in platyhelminthes group
- segmented flat worms
- have suckers/hooks at scolex
- proglottids
Scolex
Head region of cestodes/tapeworms that have hooks that attach to wall of small intestine
Proglottids
Segments of cestodes that have reproductive structures
-when gametes are fertilized they release eggs
What group is Taenia saginata in? (Beef tapeworm)
Cestodes
Oncosphere
-tapeworm larval form
Primary cause of infection due to nematodes?
- intestinal parasites transmitted through undercooked foods through larvae
- eggs in feces/anus of cats/dogs/humans
Primary cause of infection due to trematodes
-fresh water snails
Primary cause of infection due to cestodes?
-undercooked/contaminated meat like beef and pork
What group of medically important flatworms is segmented and what group is unsegmented?
- segmented: cestodes/tapeworms
- unsegmented: flukes/trematodes
