[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.

CONCLUSION

The culture system provides a model for propagation of the parasites and demonstrates a complete in vitro life cycle of C. parvum.