This diagnostic procedure differentiates bacterial species based on their cytochrome c oxidase enzyme activity. Specifically, it assesses the presence of this enzyme, which plays a critical role in the electron transport chain during aerobic respiration. A positive result, indicated by a color change upon reagent addition, suggests the organism possesses the enzyme. Conversely, the absence of color change signifies its absence. The test aids in distinguishing certain bacterial genera, for instance, helping to rule out Pseudomonas species (oxidase-positive) from Staphylococcus aureus (oxidase-negative).
The determination of oxidase activity is a valuable tool in bacterial identification, streamlining the process of microbiological diagnosis and contributing to appropriate treatment strategies. Its simplicity and relatively rapid results make it an advantageous preliminary step in laboratory workflows. Historically, this test provided a crucial initial step in characterizing unknown bacterial isolates, particularly before the advent of more automated and molecular methods, and continues to play a role in settings with limited resources.
