Main species of Cryptosporidium: (4)
- Cryptosporidium parvum
- Cryptosporidium muris
- Cryptosporidium baylei
- Cryptosporidium meleagridis
Is Cryptosporidium host specific:
No host specificity
Morphology of Oocyst of Cryptosporidium:
- Contains free 4 Sporozoites, without Sporocyst
- Wall can be thick (80%) or thin (20%)
Describe the lifecycle of Cryptosporidium:
In environment
1. A thick walled Oocyst is ingested by host from contaminated water or food
In Host
1. Once ingested the Sporozoites are released and infect enterocytes in epithelium of small intestine, forming a parasitophorous vacuole
2. First forming a Trophozoite and then first generation Meront with Merozoites that re-infect cells to repeat the cycle or forming a second generation Meront with Merozoites
3. The 2nd gen. Mereozoites re-infect cells forming a undifferentiated Gamont that become either male (microgamont) or female (Macrogamont)
4. Microgamont (unflagellated) enter Macrogament forming a Zygote
5. Unsporulated Oocyst is sporulated within the host cell- without forming sporocysts
6. Oocyst (either thick 80% or thin 20% walled) is released into the GIT to be excreted with feces
7. Thin walled Oocyst cause Auto-infection
What are the Life cycle phases of Cryptosporidium and where do they occur:
- Sporogony = Endogenous
- Merogony = Enogenous
- Gamogony = Endogenous
What type of parasite is Cryptosporidium: (location)
Intracellular
What are the diagnostic methods for Cryptosporidium:
- Direct fecal smear (glycerine, water)
- Stained fecal smear (carbo-rosaniline stain, kinyoun stain..)
- Detection of coproantigen (rapid test)
- PCR
