Evaluation of Specific Anti-ESAT-6 Antibody in Diagnosis of Bovine Tuberculosis

Bovine tuberculosis (BTB) is a zoonotic disease that caused by Mycobacterium bovis (M. bovis). The most widely used methods to detect BTB are the skin test and in vitro gamma interferon assay which do not detect anergic animals, but serological tests such as ELISA have been found promising in ancillary tuberculosis diagnosis. The overall aim was to study M. tuberculosis ESAT-6 recombinant protein as a target for serological assays in the detection of antibodies to BTB. Serum samples were collected from suspected animals where M. tuberculosis was confirmed at postmortem examination by clinicians and positive skin test. Also, control samples were collected from BTB free bovines. Circulating specific antibody levels were measured by an enzyme-linked immunosorbent assay using purified recombinant proteins of ESAT-6. The results show a mild satisfactory agreement with the skin test reflecting in 95.23 sensitivity and 81.81 Specificityin serum diluted to 1/100. This study demonstrated that ELISA with the use of the esat-6 antigens is simple and sensitive and can be used to analyze large numbers of samples for the serodiagnosis of BTB.