Diagnosis of bovine cryptosporidiosis by indirect immunofluorescence assay using monoclonal antibody

Two hybridoma cell lines against Cwptosporinium possum oocysts nFRl-CN911 were produced. The isotype of these 2 monoclonal antibodies (mAbs) was IgG2b (lE7.2) and and IgM (C6). Enzyme immuno-transfer blotting analysis showed that 157.2 reacted specifically to 36 kDa protein and C6 reacted to 67 and 70 kDa proteins. C. pcnlum was bound specifically to the surface region of oocysts by these mobs. No cross-reactivity was observed with tachyzoites of ToxopLosma gonnii and oocysts of Eimeria zuernii,5. bouis and E. canadensis of bovine origin. The indirect immunofluorescence assay (IIF) using mAb C6 was successful with counterstain. With the IIF using mob C6, oocysts appeared as 3 to 5 ㎛ spherical objects fluorescing bright apple green against a reddish dark background. The IIF using mAb C6 was agreed in specificity and sensitivity with those of a commercial diagnostic kit. These results demonstrated that the produced mAbs were specific to C. parvum and that the mAb C6 could be used for diagnosis of cryptosporidiosis. Key words: Cryptosporidium ponpum, VRI-CN91, monoclonal antibody, diagnosis, Korea