Catalase test

• Used to differentiate a number of bacteria:
  • Staphylococcus (positive) from Streptococcus and Enterococcus (negative)
  • Bacillus (positive) from aerotolerant strains of Clostridium (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

Catalase Positive Organisms

	Stain	Shape	Catalase
Achromobacter	Gram-negative	bacillus	positive
Aeromonas	Gram-negative	bacillus	positive
Alcaligenes faecalis	Gram-negative	bacillus	positive
Bacillus	Gram-positive	bacillus	positive
Brevibacillus	Gram-positive	bacillus	positive
Brucella melitensis	Gram-negative	coccobacillus	positive
Campylobacter	Gram-negative	bacillus	positive
Coagulase-negative staphylococci	Gram-positive	coccus	positive
Cronobacter sakazakii	Gram-negative	bacillus	positive
Dermabacter hominis		bacillus	positive
Listeria monocytogenes	Gram-variable Gram-positive	bacillus pleomorphic	positive
Neisseria	Gram-negative	diplococcus	positive
Nocardia	Gram-positive partially acid-fast	bacillus	positive
Ochrobactrum	Gram-negative	bacillus	positive
Raoultella	Gram-negative	bacillus	positive
Raoultella ornithinolytica	Gram-negative	bacillus	positive
Staphylococcus aureus	Gram-positive	coccus	positive
Stenotrophomonas maltophilia	Gram-negative	bacillus	positive
Vibrio	Gram-negative	bacillus	positive

Catalase Negative Organisms

	Stain	Shape	Catalase
Enterococcus	Gram-positive	coccus	negative
Erysipelothrix rhusiopathiae	Gram-positive	bacillus	negative
Leuconostoc	Gram-positive	coccus	negative
Neisseria elongata	Gram-negative	bacillus	negative
Pediococcus	Gram-positive	coccus	negative
Streptococcus	Gram-positive	coccus	negative
Streptococcus anginosus group	Gram-positive	coccus	negative
Streptococcus mitis	Gram-positive	coccus	negative
Streptococcus pneumoniae	Gram-positive	coccus	negative
Streptococcus pyogenes	Gram-positive	coccus	negative