Serum based polymerase chain reaction and enzyme linked immunosorbent assays for diagnosis of bovine brucellosis

Brucellosis is one of the economically important diseases in India and diagnosis of brucellosis using single test is cumbersome due to variation in sensitivity and specificity among the different test. The present study was aimed to assess the suitability of serum as clinical specimen in molecular diagnosis and evaluate the serology and molecular assays as in diagnosis of bovine brucellosis. A total of 821 bovine sera samples were subjected to indirect Enzyme Linked Immunosorbent Assay (i-ELISA) and serum based Polymerase Chain Reaction (PCR) assay. On serology 6.70 per cent positivity of brucellosis were reported and on PCR assay, 47 and 29 sera samples were positive for bcsp 31 genus specific and IS711 species specific PCR assay respectively with per cent positivity of 5.72 and 3.53. In comparison between serology and molecular test, 44 samples were positive for both assays and 11 and 3 samples were positive for serology and molecular assays individually. This study suggests that serum sample can be utilised as the choice of clinical specimen for both PCR assay and i-ELISA will be a future choice for the diagnosis of bovine brucellosis.