Which enzymatic property is true for Acinetobacter baumannii?

Which enzymatic property is true for Acinetobacter baumannii?

• A. Requires cysteine
• B. Is oxidase negative
• C. Ferments glucose
• D. Does not grow on MacConkey agar

Answer: (B)

Oxidase status distinguishes Acinetobacter baumannii from many other Gram-negative bacteria. This organism is oxidase-negative because it lacks cytochrome c oxidase, so applying the oxidase test yields no color change. That negative result is a reliable identifying feature for Acinetobacter. It is also a non-fermenter of glucose, so it does not produce acid from glucose fermentation. It does not require cysteine, and it can grow on MacConkey agar as a non-lactose fermenter, producing colorless colonies. Putting it together, the property that fits Acinetobacter baumannii is the oxidase-negative result.

Oxidase status distinguishes Acinetobacter baumannii from many other Gram-negative bacteria. This organism is oxidase-negative because it lacks cytochrome c oxidase, so applying the oxidase test yields no color change. That negative result is a reliable identifying feature for Acinetobacter. It is also a non-fermenter of glucose, so it does not produce acid from glucose fermentation. It does not require cysteine, and it can grow on MacConkey agar as a non-lactose fermenter, producing colorless colonies. Putting it together, the property that fits Acinetobacter baumannii is the oxidase-negative result.