Pulmonary Pathology

Streptococcal Identification

Laboratory testing algorithm for groups A, B, D, and pneumococci.

Gram Stain
Gram positive Cocci - Chains

Catalase Test
Negative

Streptococci

Beta-hemolysis on Blood Agar
Bacitracin Sensitive

Group A Streptococcus (S. pyogenes)

Beta Hemolysis on Blood Agar
CAMP Test Positive

Group B Streptococcus (S. agalactiae)

Alpha Hemolysis on Blood Agar
Optochin Sensitive

Streptococcus pneumoniae (pneumococcus)

Alpha Hemolysis on Blood Agar
Optochin Negative

Streptococcus, viridans group

Gamma Hemolysis on Blood Agar

Bile Esculin Agar Positive

Growth in BHI Broth with 6.5% NaCl

Group D enterococcus

Gamma Hemolysis on Blood Agar

Bile Esculin Agar Positive

No Growth in BHI Broth with 6.5% NaCl

Group D non-enterococcus