Prevalence and distribution of Cryptosporidium spp. in dairy cattle in Heilongjiang Province, China.

Few data are available on the molecular characterization of Cryptosporidium spp. in cattle in China. In the present study, a total of 507 fecal specimens from six dairy farms in Heilongjiang Province were examined for Cryptosporidium spp. by light microscopy of concentrates from the formalin-ethyl acetate sedimentation method (for less than 2-month-old calves) or Sheather's floatation method (more than 3-month-old dairy cattle). Twenty-seven post-weaned calves on five farms were positive for Cryptosporidium oocysts. PCR and DNA sequence analysis of the 18S rRNA, actin, and 70 kDa heat shock protein genes identified Cryptosporidium andersoni and Cryptosporidium ryanae, with C. andersoni as the dominant species (26 out of 27). In comparison with other regions of the world, the distribution of Cryptosporidium species in the areas appears to be unique.