Methodological study on the isolation and purification of Cryptosporidium andersoni oocysts.

Objective To obtain Cryptosporidium andersoni oocysts from feces to culture in vitro.Methods The present study was undertaken to isolate and purify Cryptosporidium andersoni oocysts using different diluted Sheather's solution with distilled water and PBS, in which recovery rates and excystation rates were compared.Results The recovery rate was 83.70% when oocysts were isoalted by 2:1Sherther's sucrose solution diluted with distilled water in three times, and the number of oocysts was 57.53% more than the number isolated by Sheather's sucrose solution.Recovery rate and excystation rate of purified oocysts were 47.52% and 87.87% using solution sucrose diluted with distilled water, respectively, and the excystation rate of purified oocysts was not significantly differen(tP0.05)compared with Sheather's sucrose solution diluted with PBS which excystation rate is 84.71% in the same method.Conclusion Sheather's sucrose solution diluted with distilled water is economic and effective for isolating Cryptosporidium andersoni oocysts from feces and its recovery rate is higher than Sherther's sucrose solution.Sheather's solution sucrose diluted with distilled water does not affect the activity of the oocysts and it can be used as an alternative to PBS for in vitro culture.