Background: Dense granules are immunodominant proteins for the standardi-zation of immunodiagnostic procedures to detect neosporosis. In the presented study different fragment of a dense-granule protein was evaluated for serodiagno-sis of Neospora caninum in cattle and water buffalo. Methods:NcGRA7, from N. caninum tachyzoites was amplified. PCR product and pMAL-c2X plasmid were digested with EcoR1 restriction enzyme and ex-pressed in Escherichia coli to evaluate its competence for detection of anti- N. cani-num antibodies with ELISA in comparison with commercial IDEXX ELISA. Fur-thermore, 230 sera of presumably healthy cattle and water buffaloes (108 cattle and 122 water buffaloes) were analyzed by both tests to determine the agreement of these two procedures. Results:Sensitivities and specificities of NcGRA7-based ELISA were 94.64% and 90.38% respectively using sera of cattle, but were 98.57% and 86.54% in the case of buffaloes respectively. A good correlation between the results of IDEXX ELISA and ELISA based on recombinant NcGRA7 for detecting N. caninum an-tibodies was appeared. Analyzing by Mc Nemar´s showed that NcGRA7-based ELISA has acceptable capability to differentiate the positive results in comparison with IDEXX ELISA. Conclusion:NcGRA7-based ELISA considering utilized new fragment of ge-nomic DNA is a good tool for serodiagnosis of anti- N. caninum antibodies for screening and epidemiological purposes on cattle herd and water buffaloes as well. |