development of an indirect elisa using different fragments of recombinant ncgra7 for detection of neospora caninum infection in cattle and water buffalo.

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.