Department of Epidemiology and Preventive Veterinary Medicine, College of Veterinary Science, Guru Angad Dev Veterinary and Animal Sciences University, Ludhiana, 141004, (Punjab), India.
Cell mediated immunity (CMI) produced by mycobacterial organisms was tested to find out whether it protects the animal from other similar organism (Brucella). Seven organized dairy farms were screened and 3.02% and 1.83% of the animals were found to be positive for tuberculosis (TB) and paratuberculosis (JD), respectively. To test the production of cell-mediated immunity, dinitro chlorobenzene (DNCB) test was conducted. Mean increase in thickness of the skin 48 hours after application of second dose of DNCB was significantly higher (t-test; P<0.05) both in TB and JD positive animals as compared to control animals, indicating production of CMI. Concurrent to TB and JD testing, all the animals were also screened for brucellosis with RBPT by which 15.61% animals were found to be positive for brucellosis. The prevalence of brucellosis in TB and JD positive animals was significantly lower (ANOVA; P<0.01) than those in TB and JD negative animals. Risk of brucellosis was found to be almost half in TB positive animals as compared to TB negative animals (Odds ratio=0.397, Relative risk=0.405). Similar was the case of JD (Odds ratio=0.445, Relative risk=0.450), indicating that CMI produced by the mycobacterial organisms is nonspecifically protecting the animals against brucellosis, which are also intracellular organisms like mycobacterium organisms.
Cell mediated immunity, brucellosis, paratuberculosis, tuberculosis
