Determination of Antibody Responses to MPB83 Antigen in BCG-vaccinated Rusa Deer (Rusa timorensis)

Abstract

Bovine tuberculosis (BTB) is a contagious zoonotic disease that causes serious public health concerns. Cervidae are highly susceptible to BTB and it has been diagnosed in various deer species. In order to develop BTB eradication and control program, Mycobacterium bovis Bacille Calmette Guerin (BCG) vaccination has been studied in cervids. In this study 15 rusa deer were tested for responsiveness to mycobacterial reaction using a comparative cervical skin test (CCT). The rusa deer were divided into 2 groups; BCG vaccination group, which were inoculated with a single dose of 2x10⁶ cfu M. bovis BCG Tokyo subcutaneously (n=8) and control group (n=7). The MPB83 protein was constructed and used as a specific antigen for an indirect ELISA to determine antibody levels against BCG vaccination in rusa deer. Sera were collected pre-vaccination and 4, 10, 15, 20 and 25 weeks post-vaccination. The antibody levels at each time point were determined by indirect ELISA using the MPB83 antigen. In the vaccination group, mean difference in optical density (ODs) increased significantly (p<0.05) 4 weeks after vaccination. Thereafter, the antibody level continuously declined until the final measurement at 25 weeks. The antibody levels against the MPB83 protein in the vaccination group were higher than in the control group at 4, 10, 15 and 20 weeks post-vaccination and were not different between the positive and negative CCT animals. In the control group, the mean difference in ODs were not significantly different at any measured time point. In conclusion, the immunity response to BCG-vaccination in the rusa deer could be monitored by indirect ELISA using the specific antigen MPB83. Therefore, further studies to determine protective level of antibody against BCG and cell-mediated immune responses should be implemented.