Tehran University of Medical Sciences Iranian Journal of Parasitology 1735-7020 4 3 2009 09 15 15 24 P Shahbazi P Shayan E Ebrahimzadeh S Rahbari 2015 10 03 Background: Cryptosporidium parvum is a parasitic protozoan that functions as important causa­tive agent of diarrhea in human and animals. The host's immune response to surface anti­gens of C. parvum has been previously demonstrated. In this respect, the role of humoral immu­nity in the development of host protective immunity against this protozoon has been well demon­strated. Methods: The effect of specific chicken egg yolk antibody (IgY) against recombinant C. parvum P23 was examined. IgY sample was prepared from eggs of chickens immunized with recombi­nant C. parvum protein p23 and analyzed with C. parvum lysate and recombinant P23. Results: The anti P23 specific IgY was recognized a protein band with approximately 23 kDa in lys­ates prepared from the C. parvum oocysts. Also dot blot analysis of recombinant P23 showed that it could be recognized by the anti P23 specific IgY up to 1/1000 dilution of antibody. But the best antibody dilution for immunological studies was determined as 1:200. Conclusion: Since P23 is an immunodominant surface glycoprotein expressed in the early phase of infection, specific IgY against recombinant p23 could be recommended as a favorable candi­date for passive immunization against C. parvum infection in human and animals. https://ijpa.tums.ac.ir/index.php/ijpa/article/view/104 https://ijpa.tums.ac.ir/index.php/ijpa/article/download/104/103