[In vitro cultivation model of Cryptosporidium parvum in MDCK cells and its development].
OBJECTIVE
To develop an in vitro culture system for Cryptosporidium parvum in Madin-Darby canine kidney (MDCK) cell and observe its life cycle (from desquamate to oocyst).


METHODS
Oocysts of C. parvum were co-cultured with MDCK cells in vitro. Culture condition was optimized and the life cycle of C.parvum investigated.


RESULTS
The optimal culture conditions for C. parvum in MDCK cells were 2.0 x 10(5) cells cultured for 12 h, and infected by 1.0 x 10(5) oocysts in the Dulbecco's Modified Eagle Medium with 5% FBS. Following 72 h co-culture, desquamate, sporozoites, trophozoites, meronts, microgametocytes, macrogametocytes, zygote, thin-wall oocyst, and thick-wall oocyst appeared orderly. Between the 60th and 72nd hour, many oocysts emerged. Inoculated by the C. parvum-infected cell culture supernatant at the 48th hour, the immunosuppressed mice became infected.


CONCLUSIONS
The culture system provides a model for propagation of the parasites and demonstrates a complete in vitro life cycle of C. parvum.
College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China.
Fu
F
Chen
Ke-He
KH
Huang
D000818:Animals; D002460:Cell Line; D018920:Coculture Techniques / Q000379:methods; D016785:Cryptosporidium parvum / Q000254:growth & development*; D004285:Dogs; D005260:Female; D007668:Kidney / Q000166:cytology* / Q000469:parasitology*; D051379:Mice; D008807:Mice, Inbred BALB C