Brucella are intracellular parasites that cause epizootic abortions in animals and septicemic febrile illness or localized infections of bone, tissue or organ systems in humans (1, 2). Brucella species are highly fastidious and therefore require a nutrient rich medium to be able to grow. Also, Brucellaspecies are highly infective and so extreme care should be taken while handling. Brucella Agar Base is used for the isolation and cultivation of Brucella species. The basal medium (with addition of Campylobacter Supplements) can be also used for the isolation of Campylobacter (3). Brucella Medium is a modified medium formulated to support luxuriant growth of fastidious bacteria like Brucella, streptococci, pneumococci, Listeria, Neisseria meningitides and Haemophilus influenzae (4). Brucella Agar is also recommended by APHA for isolation of Brucella species from foods (5).
Casein enzymic hydrolysate and peptic digest of animal tissue provide organic nitrogen. Yeast extract serves as a source of vitamin B complex, and additionally it also supplies some nitrogenous nutrients. Sodium bisulphite is a reducing agent and sodium chloride helps to maintain the osmotic equilibrium of the medium. Dextrose serves as an energy source. The medium can also be enriched with 5 % v/v sterile defibrinated horse blood. For selective isolation of Brucella species antibiotic mixtures in the form of freeze dried supplements (FD) are incorporated into the base (6, 7, 8).
Swab specimens can be directly streaked on the plate. Liquid specimens can be inoculated by means of an inoculation loop. When non-selective medium is required, Brucella Broth Base may be employed with the addition of serum only (i. e. without antibiotics).
Storage and Shelf-life:
Store below 30°C in tightly closed container and the prepared medium at 2 - 8°C. Use before expiry date on the label.
1. Moyer N. P., and Holcomb L. A., Laboratory Diagnosis and Infectious Diseases: Principles and Practice, Vol. I, Springer-Verlag, New York
2. Smith L. D., and Fient T. A., 1990, Crit. Rev.Microbiol., 17 : 209-230
3. Murray P. R., Baron E. J., Jorgensen J. H., Pfaller M. A., Yolken R. H., (Eds.), 8th Ed., 2003, Manual of Clinical Microbiology, ASM, Washington, D.C.
4. Finegold et al, (Ed.), 1990, Bailey and Scotts Diagnostic Microbiology, 8th Ed., The C.V. Mosby Co., St. Louis
5. Vanderzant C. and Splittstoesser D. F., (Eds.), 1992, Compendium of Methods for the Microbiological Examination of Foods, 3rd Ed., APHA, Washington, D.C.
6. Jones L. M. and Brinley M. W. J., 1958, Bull. Wld. Hlth. Org., 19:200.
7. Kuzdas C. D., and Morse E. V., 1953, J. Bacteriol., 66 (4):502
8. Renoux G., 1954, Ann. Inst. Pasteur, 87 (3):325.