ABSTRACT
Most rodents are supplied as Cryptosporidium-free animals and can be maintained easily in strict isolation. The three best laboratory hosts for propagating large numbers of Cryptosporidium parvum oocysts are suckling calves, goats, and lambs that are less than 3 d of age at the time of inoculation. Obtaining and maintaining calves, goats, and lambs completely free of contaminating isolates of C. parvum is sometimes difficult and requires special isolation facilities. Concentration techniques are used routinely in the research laboratory, whereas staining techniques, before or after concentration of oocysts, are used more in the clinical microbiology laboratory. Oocysts are similar in size and shape to some yeast cells, considerable experience is required to obtain accurate results with concentration and/or staining techniques. The most widely used staining techniques for demonstrating Cryptosporidium spp. Suckling mice or rats are suitable hosts for maintaining pure isolates of C. parvum in the laboratory.
