Streptococcal IdentificationLaboratory testing algorithm for groups A, B, D, and pneumococci. Hover over the animation to start / stop rotationGram Stain Catalase Test Streptococci Beta-hemolysis on Blood Agar Group A Streptococcus (S. pyogenes) Beta Hemolysis on Blood Agar Group B Streptococcus (S. agalactiae) Alpha Hemolysis on Blood Agar Streptococcus pneumoniae (pneumococcus) Alpha Hemolysis on Blood Agar 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 |