Brucella Broth

This medium is widely used to isolate Brucella from diverse specimens contaminated with microflora, whether saprophytes or commensals, as in foods. It can also be used in the development of many anaerobes, of human and animal origin, and in blood culture.

Brucella species are level 3 pathogens and cause brucellosis, a zoonotic disease. It is usually transmitted through milk, dairy products, meat and direct contact with infected animals.

Meat peptone and casein peptone provide nitrogen, vitamins, minerals and amino acids essential for growth. Yeast extract is a source of vitamins, particularly of the B-group. Sodium bisulfite is the reducing agent. Sodium chloride supplies essential electrolytes for transport and osmotic balance. Dextrose is the fermentable carbohydrate providing carbon and energy.

Typical formula in g/L, adjusted and/or supplemented as required to meet performance criteria.

Preparation

Suspend 28.1 grams of the medium in one liter of distilled water. Mix well and dissolve by heating with frequent agitation. Boil for one minute until complete dissolution. Dispense into tubes and sterilize in autoclave at 121 °C for 15 minutes.

Instructions for use

1. Inoculate the sample in the broth tubes with a sterile loop.
2. Incubate the tubes for up to 7 days at a temperature of 35 ± 2 °C in aerobic or 5-10% CO₂ atmospheres.
3. Growth in the tubes is indicated by the presence of turbidity.
4. Confirm by Gram stain and subcultivation in other media.

The microbiological test should be carried out by the end-user laboratory.

• Isenberg, H.D. (ed.) 1992. Clinical microbiology procedures handbook. American Society for Microbiology, Washington, D.C.
• Hausler, W.J. (ed.). 1976. Standard methods for the examination of dairy products, 14th ed. American Public Health Association, Washington, D.C.