Difference between Staphylococcus and Streptococcus

Staphylococcus in Gram Stain

Staphylococcus and Streptococcus are two most common pathogenic gram positive cocci of medical importance.  They share some of the important properties.

Common characteristics shared by of these gram positive cocci are:

Streptococcus spp (S. pyogenes and S. pneumoniae)





Characteristic Staphyloccus Streptococcus
Shape Gram positive cocci in clusters (grape-like) becausecell division occurs in various directions on multiple axes. Gram positive cocci in pairs, tetrads, short chains also seen. Gram Positive cocci in pairs or short chains (Cell division occurs in single axis)
Catalase Test (Most Important test to differentiate Staph from Strep) Positive (Presence of catalase enzyme) Negative
Growth Requirement Not fastidious (Does not need enriched media) Fastidious (needs enriched media).
Hemolysis No hemolysis or beta hemolysis Either alpha, or beta or gamma hemolysis (Hemolysis can be helpful to differentiate species of Streptococcus)
Common habitat Mostly skin, anterior nares Mainly mouth and respiratory tract
Common Diseases Pneumonia, Meningitis, osteomyelitis, acute endocarditis, septic arthritis, Surgical Site Infection, Wound infection etc. Pneumonia, Sore throat, Wound Infection, Necrotizing fascitis,  Scarlet fever, Rheumatic fever, Acute post-streptococcal glomerulonephritis
Most Pathogenic species Staphylococcus aureus
Staphyloccus saprophyticus (in female)
Streptoccus pneumoniae
Streptoccus pyogens
Streptococcus agalactiae
Useful diagnostic tests Catalase Test
Coagulase Test
Novobiocin sensitivity test
Catalase TestBacitracin Sensitivity Test (S. pyogens)
Optochin Sensitivity Test (S. pneumoniae)
Bile solubility Test (S. pneumoniae)
CAMPT Test (S. agalactiae)