VMC 311: Systematic Veterinary Bacteriology and Mycology (2+1)

Staining charatcter and cultural characters

STAINING CHARACTER AND CULTURAL CHARACTERS

Staining charatcter

• They are Gram negative, non sporulating and non motile cocco bacilli.
• They readily stain pink by modified acid fast staining.

Cultural characters

• The organisms grow well on media enriched with blood or serum (Albimi medium).
• Serum dextrose agar. Dextrose starch agar, Tryptose agar and liver infusion agar give satisfactory growth.
• The medium should have a slightly acidic pH (6.8).
• For the initial isolation of Brucella abortus, 5 to 10% CO₂ tension is required.
• Colonies are small, delicate and semitransparent. They may be mucoid, smooth or rough.

Bio-chemical properties of Brucella abortus

Oxidase	+
Catalse	+
H2S	+
Urease	+
MR	-
VP	-
Indole	-
Nitrate	+