|Cell Wall: Gram Positive||Shape: Cocci|
|Biochemistry: Catalase Positive||Metabolism: Facultative Anaerobe|
- Both Staphylococci and Streptococci are Gram Positive Cocci; therefore, it is important to understand how these organisms are differentiated. Additionally, it is important to appreciate how different strains of staphylococci are differentiated from one another.
- Differentiation from Streptococci
- Gram Stain: Staphylococci appear as grape-like clusters on gram stain while streptococci appear as strings of beads.
- Catalase: All staphylococci are catalase positive, possessing catalase enzyme and thus bubble when exposed to Hydrogen Peroxide (H2O2) while all streptococci are Catalase Negative.
- Differentiation between Staph Strains
- Coagulase: Only Staphylococcus aureus produces coagulase
- Color: Only S. aureus produces a pigment which gives colonies a golden color whereas other strains produce white colonies
- Hemolysis: Only S. aureus can hemolyze RBCs and is thus beta-hemolytic.