Tuyển tập các báo cáo nghiên cứu khoa học quốc tế về bệnh thú y đề tài: Comparative antibody response of five recombinant antigens in related to bacterial shedding levels and development of serological diagnosis based on 35 kDa antigen for Mycobacterium avium subsp. Paratuberculosis | J. Vet. Sci. 2004 5 2 111-117 JOURNAL OF Veterinary Science Comparative antibody response of five recombinant antigens in related to bacterial shedding levels and development of serological diagnosis based on 35 kDa antigen for Mycobacterium avium subsp. paratuberculosis Sung Jae Shin1 2 Han Sang Yoo2 Sean P. McDonough1 Yung-Fu Chang1 College of Veterinary Medicine Cornell University Ithaca NY 14853 USA Department of Infectious Diseases College of Veterinary Medicine and School of Agricultural Biotechnology Seoul National University Seoul 151-742 Korea Eighty-five complex 85A 85B and 85C 35-kDa and superoxide dismutase SOD were cloned expressed and purified as antigens in an enzyme-linked immunosorbent assay ELISA to compare the serological reactivity of cows with different shedding levels of Mycobacterium avium subsp. paratuberculosis MPT . Antibody responses to all recombinant antigens positively increased depending on shedding levels. In particular antibody responses to the 35 kDa were higher than those to the others in all shedder groups. Also the mean of O. D. values among Ag 85 complex 85B showed slightly higher response than others with high sensitivity and specificity in all shedder groups. In receiver operating characteristic ROC curve analysis the result of 35 kDa ELISA yielded an area under the curve value of 95 confidence interval - which indicated that this 35 kDa is more accurate indicator of MPT infection than other antigens. At the cut-off point recommended by the ROC curve analysis the sensitivity and specificity of 35 kDa ELISA were higher than those of other antigens with and respectively. Finally a commercially available ELISA kit was used to clarify 200 positive and 200 negative sera. We then re-tested these serum samples with our ELISA test using the 35-kDa antigens. 35 kDa ELISA and commercial kit showed almost similar results in ROC curve analysis even though two of positive sera in commercial kit were negative in
