Catalase test

• Used to differentiate a number of bacteria:
  • Staphylococcus species (positive) from Streptococcus species and Enterococcus species (negative)
  • Bacillus species (positive) from aerotolerant strains of Clostridium species (negative)
  • Members of the Enterobacteriaceae family (positive) from other Gram-negative bacilli
• Detects the presence of catalase, which catalyzes the conversion of hydrogen peroxide into water and oxygen
• Mix a small sample of bacteria with 3% hydrogen peroxide
  • Positive if bubbles appears within 10 seconds
  • Negative if no or only a few bubbles
• Bacteria that are catalase positive: staphylococci, Micrococcus, Listeria, Corynebacterium diphtheriae, Burkholderia cepacia, Nocardia, the family Enterobacteriaceae (Citrobacter, E. coli, Enterobacter, Klebsiella, Shigella, Yersinia, Proteus, Salmonella, Serratia), Pseudomonas, Mycobacterium tuberculosis, Aspergillus, Cryptococcus, and Rhodococcus equi
• Bacteria that are catalase negative: Streptococcus, Enterococcus, Pediococcus, Leuconostoc, Aerococcus, Gemella