Characterization and biotyping of Brucella species isolated from animals

Twelve Brucella species isolated from animals were characterized up to species level. Six PCR assays were carried out using genus specific primers viz, BCSP31 (B4/B5 and 31F/31R) and species specific primers viz: IS711/AB and IS711/BM, DNAJ/AB and DNAJ/BM for identification of Brucella isolates. Based on the combined results of the conventional and molecular method, 8 isolates were identified as B. abortus spp., whereas 4 isolates could not be identified upto species level. Out of 8 B. abortus isolates, 5 were found to be B. abortus biotype 2, while one was either biotype 1 or 4. Biotypes of 2 isolates could not be identified In antibiotic susceptibility test, no difference was found in antibiogram pattern of 12 Brucella isolates indicating nonexistence of drug resistance in Brucella isolates. In PCR assays; BCSP31 proved useful in confirming Brucella isolates at genus level, whereas IS711/AB PCR produced B. abortus specific (biotype 1, 2, 4) amplification of 498 bp product in 8 isolates thereby confirming identity as B. abortus, whereas none of 12 isolates showed B. melitensis specific amplification in IS711/BM PCR.