Which of the following genera are oxidase positive?

The correct answer indicates that all the listed genera—Moraxella, Aeromonas, and Neisseria—are oxidase positive. The oxidase test is a crucial biochemical test used to identify bacteria based on the presence of cytochrome c oxidase, an enzyme involved in the electron transport chain.

Moraxella species, particularly Moraxella catarrhalis, are known to exhibit oxidase positivity, which aids in differentiating them from other similar organisms. Similarly, Neisseria species, including Neisseria gonorrhoeae and Neisseria meningitidis, are also oxidase positive, which is a key trait utilized during their identification in clinical microbiology.

Aeromonas, which is often found in aquatic environments, has also been noted to have oxidase-positive strains. This feature is significant for understanding their metabolic processes and ecological roles.

The confirmation that all three genera are oxidase positive reinforces the importance of the oxidase test in the identification and characterization of these bacteria, assisting bacteriologists in diagnosing infections they may cause.