Rapid method for viable Cryptosporidium parvum oocysts detection

Cryptosporidium parvum is a waterborne coccidian protozoan parasite known to infect humans, resulting in an illness known as cryptosporidiosis. The widely used USEPA method 1622 to detect Cryptosporidium is time consuming, and unable to provide the information on oocysts viability and species. In order to develop a fast detection method for viable C. parvum oocysts, a 0.2 μm pore size hollow fiber membrane and 0.45 μm pore size disc membrane were used to filter tap water. Modified Immunomagnetic separation (IMS) purification was followed, and the IMS condition was optimized to shorten the purification time. Finally, fluorescence in situ hybridization (FISH) and FITC-conjugated monoclonal antibody (FMAb) staining were combined to detect viable oocysts, and results indicated that the viable oocysts detection by FISH/FMAb can be achieved in 20 min. The total viable oocysts detection time can be shortened to less than 1.5 h without affecting oocysts recovery.