Background
- Identifies cytochrome C oxidase by testing for the ability to oxidize tetramethyl-p-phenylenediamine to indophenols, which are purple
- The test is positive when it turns purple within 10 seconds
- Must be done from plain 5% SBA
Interpretation
- All oxidase-positive bacteria are aerobic
- P: Pseudomonas
- V: Vibrio cholerae
- N: Neisseria
- C: Campylobacter
- H: Helicobacter and Haemophilus
- Aeromonas
Oxidase-Positive Organisms
| Stain | Shape | Oxidase | |
|---|---|---|---|
| Achromobacter | Gram-negative | bacillus | positive |
| Aeromonas | Gram-negative | bacillus | positive |
| Alcaligenes faecalis | Gram-negative | bacillus | positive |
| Brucella melitensis | Gram-negative | coccobacillus | positive |
| Burkholderia pseudomallei | Gram-negative | bacillus | positive |
| Campylobacter | Gram-negative | bacillus | positive |
| Francisella tularensis | Gram-negative | coccobacillus | positive negative |
| Helicobacter pylori | Gram-negative | bacillus | positive |
| Herbaspirillum | Gram-negative | bacillus | positive |
| Micrococcus | Gram-positive | coccus | positive |
| Moraxella catarrhalis | Gram-negative | diplococcus | positive |
| Neisseria | Gram-negative | diplococcus | positive |
| Ochrobactrum anthropi | Gram-negative | bacillus | positive |
| Pasteurella | Gram-negative | bacillus | positive |
| Pseudomonas aeruginosa | Gram-negative | bacillus | positive |
| Vibrio | Gram-negative | bacillus | positive |
| Vibrio cholerae | Gram-negative | bacillus | positive |
| Vibrionaceae | Gram-negative | bacillus | positive |
Oxidase-Negative Organisms
| Stain | Shape | Oxidase | |
|---|---|---|---|
| Acinetobacter ursingii | Gram-negative | coccobacillus | negative |
| Cronobacter sakazakii | Gram-negative | bacillus | negative |
| Erysipelothrix rhusiopathiae | Gram-positive | bacillus | negative |
| Francisella tularensis | Gram-negative | coccobacillus | positive negative |
| Listeria monocytogenes | Gram-variable Gram-positive | bacillus pleomorphic | negative |
| Proteus | Gram-negative | bacillus | negative |
| Raoultella | Gram-negative | bacillus | negative |
| Raoultella ornithinolytica | Gram-negative | bacillus | negative |
| Stenotrophomonas maltophilia | Gram-negative | bacillus | negative |
Further Reading
- Microbe Online. Oxidase Test: Principle, Procedure and Oxidase-Positive Organisms.
