Serological, bacteriological, and molecular detection of brucellosis in pigs of Tamil Nadu, India

Brucellosis caused by the facultative intracellular bacteria of the genus Brucella is associated with huge economic and zoonotic implications worldwide. The disease is among the top priority zoonosis for integrated “one health” approach and has gained wide attention in developed countries. Epidemiological data on brucellosis in ruminants is readily available; however, reports on swine brucellosis remain scanty. Hence, the present study has been undertaken to assess the endemicity of brucellosis in the swine population of Tamil Nadu, India and to identify the infecting Brucella species using conventional bacteriological and molecular techniques. The apparent seroprevalence of brucellosis in pig farms were assessed by RBPT and indirect ELISA (i-ELISA) as 5.2 per cent and 10.1 per cent respectively. There was a moderate agreement between the RBPT and i-ELISA results (Cohen’s kappa coefficient (κ) = 0.512, percent agreement = 93 per cent) Six Brucella isolates could be obtained from various samples; biovar typing by biochemical and molecular methods revealed B. suis biovar 1 as the most prevalent type among swine population in Tamil Nadu. Thus, the determination of Brucella biovar in swine is an important step for epidemiologic characterization of the disease to design the control and eradication strategies.