<；p>；To evolve epidemiology of brucellosis in both human and animal population in the country, a common ELISA kit for screening multiple species of livestock and humans would be desirable. In the present disclosure indirect ELISA has been standardized using smooth lipopolysaccahride antigen from a standard strain of Brucella abortus S99. Antigen dilution of 1:300 was taken as the optimum dilution by checker board titration. Anti-Brucella sLPS hyperimmune sera raised in two brucellosis-negative adult male pigs and sheep and pre-immune serum from same pigs and sheep were used as the positive and negative controls along with convalescent bovine sera respectively. The moderate positive control was prepared by diluting strong positive sera with Brucella negative sera at 1:500 dilutions. ELISA protocol has been standardized using 1:300 diluted smooth lipopolysaccahride antigen from a standard strain of Brucella abortus S99 and protein-G conjugated with horseraddish peroxidase. Sera samples showing percentage positive values of 55 and above were considered Brucella positive. In the protein-G based ELISA test, the sensitivity with respect to detection percentage of positives varied from 100% in pigs and humans followed by 98% in cattle, 96% in goat and sheep and least in buffaloes (92%). Whereas, sensitivity of detection percentage of negatives ranged from 100% in humans followed by 98% in pig and buffaloes, 95% in cattle and least in goat and sheep (92%). The sensitivity of the test was found more than 90% with respect to both positives and negatives in all livestock species and humans. Use of protein-G conjugate (common conjugate) as single reaction agent is advantageous than the use of 4 different conjugates. Also it is easy to maintain the quality of the kit and easy to perform than the use of multiple kits and protocols for different species. The wider application of this protocol will help to obtain the seroepidemiology of brucellosis in both animals and humans. T
