Cystoisospora

Question 1

What is the morphology of Oocyst of Cystoisospora:

Answer 1

Have 2 Sporocysts each with 4 Sporozoites

Question 2

What are the 3 life cycle stages of Cystoisospora and where:

Answer 2

• Sporogony = External (exogenous)
• Mergony = Endogenous (asexual reproduction in intestine)
• Gametogomy = Endogenour ( sexual reproduction in Final host)

Question 3

Describe the Life cycle of Cystoisospora: (Direct)

Answer 3

In environment
1. Oocyst of Cystoisospora undergose sporulation, Oocyst>Immature Oocyst with Sporoblasts>Immature Oocyst with sporocysts (2)>Mature Oocyst with Sporozoites (8)

In host
1. Mature Oocyst ingested and Sporozoites are released and enter cells of small intestine where they undergo replication (Asexual)
2. Forming Merozoites that re-infect cells forming either Micro or Macrogamete
3. Microgamete fertilize Macrogamet forming a Zygote
4. Unsporulated Oocyst is then eliminated with feces entering the environment

Question 4

Describe Life cycle of Cystoisospora: (facultative indirect)

Answer 4

In environment
1. Oocyst undergo Sporogony

In Paratentic host (mice, rats..)
1. Ingest sporulated Oocyst
2. Sporozoites infect cells of Peyer’s patches or lymph nodes
3. They persist intracellularly in a vacuole without dividing, this stage is called Dormozoites (sleeping stage) and can remain infectious for 2 years
4. Only continue development once ingested by final host (cat eats infected mouse)

In Host
-same as direct

Question 5

What are the species of Cryptoisospora of Pigs : (3)

Answer 5

• Cystoisospora suis
• Cystoisospora almaataenis
• Cystoisospora neyrai

Question 6

What is special for the life cycle of Cystoisospora suis and cause what:

Answer 6

Life cycle
* 3 generations of meronts within the epithelium of small intestines (3-5 days after infection)
* Sporogony takes up to 16 hours compared to 1-3 days with Eimeria

Cause
-Enteric syndrome (diarrhea: yellowish-grey, acidic odour, watery and without blood ending in death)

Question 7

What does Cystoisospora cause in pigs:

Answer 7

Cystoisosporosis
-Neonatal enteritis = chatacterized by destruction of villi of small intestine epithelium, widespread disease of piglets (8-15 days old)
-Enteric syndrome (C. Suis)

Question 8

What are the main species of Cystoisospora in Cats (2) and Dogs (4):

Answer 8

Cat
* Cystoisospora felis = Location: small intestine
* Cystoisospora rivolta (cati) = Location: small intestine

Dog
* Cystoisospora canis = Location: caudal part of small intestine
* Cystoisospora ohioensis complex = Location: small intestine, cecum, colon
* Cystoisospora (?) neorivolta = Location: caudal part of small intestine
* Cystoisospora (?) burrowski = Location: caudal part of small intestine

Question 9

What is different in life cycle of Cystoisospora in dogs/cats and what they cause:

Answer 9

Life cycle
-rarely have Paratenic host (rodents)
-resistan Oocyst for more than 1 year

Cause
-Cystoisosporosis = enteritis, polyuria, anorexia, apathy diarrhea with mucus and blood, then eventually death