Evaluation of BCSP 31 kDa and IS711 PCR assays in detection of bovine brucellosis

The efficacy of BCSP 31 kDa and B. abortus specific IS711 PCR assays was evaluated in detection of Brucella spp. from cultures and blood samples of naturally infected animals. The BCSP 31 kDa PCR identified the reference Brucella strains and all the field isolates by generating amplicons of 223 bp. In IS711 PCR, an amplification product of 498 bp was generated by B. abortus 544, B. abortus 8–19 and two field isolates, while, three field isolates identified as B. abortus on the basis ofbiochemical tests did not show amplification. Both the assays were also used to screen 173 blood samples of animals from the herds with history of abortions due to brucellosis with a serological positivity of, over 61%. The BGSP 31 kDa gene PCR could detect greater proportion (76.30%) of positive samples than B. abortus -specific IS711 PCR (16.76%). In 12.71% cases the results of all the three techniques viz. serology, BCSP 31 kDa and 18711 PCR assays were concordant with each other. The overall agreement between BCSP 31 kDa and IS711 PCR assays was 40.46% while that between serology and BCSP 31 kDa PCR was 67.05%. Analysis of data by Win Episcope 2.0 revealed a fair agreement between the BCSP 31 kDa PCR and serology. Greater sensitivity of BCSP 31 kDa PCR suggests that this technique could be of potential value as an adjunct to serology for reliable diagnosis of brucellosis.