They do not grow on MacConkey agar. They are usually oxidase positive and also positive for nitrate reduction, phosphatase, β-galactosidase and acid production from D - Glucose fermentation. They are negative for catalase, indole, urease, Voges-Proskauer and methyl red tests.

What gram-negative rods do not grow on MacConkey agar?

Long, thin, slowly growing, oxidase-positive, catalase-positive gram-negative rods that do not grow on MacConkey agar should suggest DF-2. Although testing of antimicrobial susceptibility is problematic, DF-2 has been found to be resistant to aminoglycosides.

Does Pasteurella ferment lactose?

It was observed that vaccinal strain of Pasteurella multocida fermented glucose, Sucrose ,Maltose, Galactose , Mannose and Fructose but did not ferment lactose and salacin. It did not liquefy gelatin. the investigation, various types of the colonies of the organism were also observed on blood agar.