General

• The oxidase test is used to identify bacteria that produce cytochrome c oxidase, an enzyme of the bacterial electron transport chain.
  
  When present, the cytochrome c oxidase oxidizes the reagent (teramethyl-p-phenylenediamine) to (indophenols) purple color end product.
  When the ezymes is not present, the reagent remains reduced and is colorless.
  
  Expected results of oxidase test
  1. Positive: Development of dark purple clor (indophenols) within 10 seconds.
  2. Negative: Absence of color.
  
  Strains may be either oxidase-positive (OX+) or oxidase-negative (OX-).
  
  OX+
  OX+ normally means the bacterium contains cytochrome c oxidase and can therefore use oxygen for energy production by converting O₂ to H₂O₂ or H₂O with an electron transfer chain. 
  - Pseudomonadaceae are typically OX+
  - Gram negative diplococci Neisseria and Moraxella are OX+
  - Many Gram-negative, spiral curved rods which includes Helicobacter pylori, Vibrio cholerae and Campylobacter jejuni are OX+
  
  Oxidase Variable
  - Legionella pneumophila may be OX+
  
  OX−
  OX− normally means the bacterium does not contain cytochrome c oxidase and, therefore, either cannot use oxygen for energy production with an electyron transfer chain or employs a different cytochrome for transferring electrons to oxygen.
  - Enterobacteriaceae are typically OX−

History

Related

• Pseudomonas aeruginosa

References

• Microbe Online
  http://microbeonline.com/oxidase-test-principle-procedure-and-oxidase-positive-organisms/
  
  Wikipedia