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

STAINING CHARACTERS AND CULTURAL CHARACTERS

Staining characters

• A small amount of pus is placed in a Petridish and washed to expose the granules associated with the disease.
• A granule is transferred to a slide, and a drop of 10% sodium hydroxide is added.
• A coverslip is placed on the granule, and it is crushed by gentle pressure.
• Small, Gram-negative rods are demonstrable within granules.
• The granules in actinobacillosis are small (< 1 mm), grey, and white under low power microscopy.

Cultural Characters

• For primary isolation 10% serum or blood agar at 10% CO₂ tension, gives satisfactory growth.
• Small, glistening colonies develop in 24 hours.
• They are sticky on primary isolation but lose this characteristic on subculture and are non haemolytic.
• The organism grows well on MacConkey agar, the colonies are at first pale but become pinkish as it is late lactose fermenter.

Bio chemical properties

Motility	-
Catalase	+
Oxidase	+
CAMP	-
Urease	+
H2S	+

• Ferment carbohydrates without gas production

Sucrose	+
Maltose	+
Mannitol	+
Lactose	(+)