Sarcocystis

Question 1

Morphology of Oocyst of Sarcosystis:

Answer 1

Have 2 sporpcyst with 4 sporozoite in each

Question 2

What are the final host of Sarcosystis: (2)

Answer 2

Humans and Carnivores (dog, cat)

Question 3

What are the Intermediate hosts of Sarcocystis: (3)

Answer 3

Herbivores, Omnivores and Birds

Question 4

What are the stages of Sarcocystis and where:

Answer 4

• Gamogony = small intestine of Final host
• Sporogony = small intestine of Final host
• Merogony = small intestine of Intermediate host

Question 5

Describe the Life cycle of Sarcocystis:

Answer 5

In intermediate host
1. Ingest sporocyst, where excystation happens in small intestine
2. Merogony: Sporozoite enter endothelial cells of blood capillaries where they become Meront >repeated until 3rd generation of Meronts are formed
3. The 3rd gen. Merozite infect muscles forming a cyst with Bradyzoit

In Final host
1. Cyst with Bradyzoities are ingested in undercooked meat
2. Bradyzoites released from the ruptured cell enter the intestinal cells forming Microgamete or Macrogamete
3. Microgamete fertilize Macrogamete forming an Immature Oocyst
4. They undergo Sporulation, forming Sporocysts (2) within a thin walled Oocyst
5. The sporulated Oocyst is passed in feces into the environment

ATH! Sporulated Oocyst is not infectious in dogs/cats only in Intermediate hosts

Question 6

What are the main species of Sarcocystis: (15)

Answer 6

• Sarcocystis cruzi (bovicanis)
• S.hirsuta (bovihominis)
• S.ovicanis (tenella)
• S.arieticanis
• S.gigantaea (ovifelis) = Sheep-Oesophagus, cyst: 10mm
• S.medusiformis
• S.capracanis (moulei)
• S.hircicanis
• S.suicanis
• S.porcifelis
• S.suihominis (miescheriana)
• S.equicanis (bertrami)
• S.fayeri
• S.horvathi
• S.cuniculi

Question 7

What are the diagnostic methods: (FH and IH)

Answer 7

Final host
-Flotation method (sporulated cysts in feces) with Faust (dog/cat) or Breza (pig) flotation solution
! Size 14-15x9-10um

Intermediate host
-Serological test
-Biopsy > histology
-Post mortem = Digestive method (microcyst <1mm), Histology, Meat inspection (macrocyst 4-15mm, muscle cysts)

Question 8

Sarcocystis neurona causes what and what are the type of hosts:

Answer 8

Cause
-Myeloencefalitis in horses

Casual host
-Eq

Final host
-Opossum (Didelphis virginiana, Didelphis albiventris)

Intermediate host
-Raccoon, armadillo, skunk, feline….

Question 9

Life cycle according to Phases of Sarcocystis:

Answer 9

Schizogony/Merogony (IH)
* Endothelial cells -2x rapid multiplication = Endopolygony
* Leukocytes - slow multiplication = Endodyogony
* Muscles - slow multiplication = Endodyogony
-Young cysts=Metrocytes
-Mature cysts=Bradyzoites

Gamogony (FH)
* Lamina propria of small intestine

Sporogony (FH)
* Endogenous - small intestine