Abstract: The bacterial species belongs to genus Brucella produce infections in humans, farm and wild animals are known as Brucellosis. In normal routine there is rational misuse of drugs especially broad spectrum poses a great concern for the treatment of Brucellosis in cattle. Therefore, this study was designed to evaluate the efficacy of locally available various antibiotics against the Brucella abortus isolated from Lohani and Holstein cattle breeds. Various antibiotics such as kanamicin, chloramphenicol, rifapmicin, gentamycin, enroflaxcin, tertracyline, streptomycin, tobramycin and pencillin were tested against the isolated Brucella abortus. Brucella abortus was found highly sensitive to gentamicin, tobramicin and pencillin G with sensitivity percentage 75, 100 and 100%, respectively. The antibiogram results revealed gentamycin and tobramicin were highly effective antibiotics against the Brucella abortus. The organism was moderately sensitive against tetracycline, chloramphenicol, rifapmicin and enroflaxcin with sensitivity recorded of 65, 60, 60 and 90%, respectively. However, the organism was weakly sensitive against streptomycin and kanamicin 50 and 40%, respectively. The organism confirmed its resistance against the ampicillin. Overall, gentamycin and tobramicin were shown the highest antibiogram activity against the isolated Brucella abortus from the bovine milk and blood samples. While, the isolated organism was not sensitive to ampicillin.

Keywords: Bovine, Brucella abortus, antibiotics,resistance.