PARA 410 Lecture Notes - Lecture 8: Fasciola Hepatica, Fascioloides Magna, Fasciolopsis
12 Jun 2018
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Parasitology – lecture 08 (January 23rd, 2018)
Review
- How many testes and ovaries do cestodes have?
o Testes – Several – can be 3-4 or can be several 100s
o Ovaries – 2
- How many testes and ovaries do trematodes have?
o Testes – 2 (some have a few more but not the ones we are looking at)
▪ What is important is the shape and position
o Ovaries – 1
- What animal is usually the 1st IH in trematodes
o Snail
- Bottle jaw?
o Ruminants – liver flukes
- What
o Fascioloides magna
- Which trematode has a terrestrial life cycle
o D. dendriticum
▪ 2nd IH is ant
- Which is with the commercial fish?
o Chlonorchis sinensis
Slide 1 – Trematodes
- Intestinal flukes
o Large intestinal fluke (Fasciolopsis buski)
o Small intestinal fluke (Heterophyes, Metagonimus, and Echinostoma spp.)
Slide 2 – Intestinal flukes/Digestive tract flukes
- Fasciolopsis buski
- Heterophyes heterophyes
- Metagonimus yokogowi
find more resources at oneclass.com
find more resources at oneclass.com
Slide 3 – Large intestinal fluke – Fasciolopsis buski
- Fasciolopsis buski is the principal intestinal fluke infecting humans and the largest intestinal fluke of humans
- Common parasite of the intestine in Asia and the Indian subcontinent, especially in areas where humans raise
pigs and consume freshwater plants
- It is estimated that over 10 million people are infected with this parasite
Slide 4 – Fasciolopsis buski
- Common name: giant intestinal fluke
- Definitive host: humans, dogs, pigs, rabbits
- First intermediate host: water snail
- Second intermediate host: aquatic vegetation
- Infective stage: encysted metacercariae
- Diagnostic stage: eggs in feces
- Size: length 20-75mm long and 20mm wide
- Adult is somewhat similar to Fasciola hepatica
Slide 5 – Life cycle: Fasciolopsis buski
- Life cycle is similar to that of Fasciola hepatica except that adults inhabit the intestinal tract (not the liver)
- Dogs and pigs are common reservoir hosts
find more resources at oneclass.com
find more resources at oneclass.com
Slide 6 – Life cycle: Fasciolopsis buski
- After ingestion, the metacercariae excyst in the duodenum and attach to the intestinal wall. There they develop
into adult flukes (20-75mm by 8-20mm) in approx.. 3 months, attached to the intestinal wall of the mammalian
hosts (humans and pigs). The adults have a life span of about 1 year.
1- Unembryonated eggs passed in feces
2- Embryonated eggs in water (embryonate in water)
3- Miracidia hatch, penetrate snail
4- Snail
a. Sporocyst
b. Rediae
c. Cercariae (shed from the snail into the environment)
5- Free-swimming cercariae
6- Metacercariae on water plant ingested by humans or pigs causing infection
7- Excyst in the duodenum
8- Adults in the small intestine
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
How many testes and ovaries do cestodes have: testes several can be 3-4 or can be several 100s, ovaries 2. How many testes and ovaries do trematodes have: testes 2 (some have a few more but not the ones we are looking at, what is important is the shape and position, ovaries 1. What animal is usually the 1st ih in trematodes: snail. Bottle jaw: ruminants liver flukes. Which trematode has a terrestrial life cycle: d. dendriticum, 2nd ih is ant. Which is with the commercial fish: chlonorchis sinensis. Intestinal flukes: large intestinal fluke (fasciolopsis buski, small intestinal fluke (heterophyes, metagonimus, and echinostoma spp. ) Slide 3 large intestinal fluke fasciolopsis buski. Fasciolopsis buski is the principal intestinal fluke infecting humans and the largest intestinal fluke of humans. Common parasite of the intestine in asia and the indian subcontinent, especially in areas where humans raise pigs and consume freshwater plants.
