| S.N. | Characteristics | S. pneumoniae | Viridans Streptococci |
|---|---|---|---|
| 1. | Morphology | Lanceolate diplococci | Oval or round cells in chain |
| 2. | Capsule | Capsulated | Non-capsulated |
| 3. | Quellung Test | Positive | Negative |
| 4. | Bile solubility | Bile soluble | Bile insoluble |
| 5. | Inulin fermentation | Positive | Negative |
| 6. | Optochin sensitivity | Sensitive | Resistant |
| 7. | Pathogenicity in mice | Pathogenic | Non-pathogenic |
| 8. | Hemolysis | Alpha-hemolytic (under aerobic conditions) or Beta-hemolytic (under anaerobic conditions) | Alpha hemolytic or non-hemolytic |
| 9. | Pathogenesis | Causes pneumonia | Causes mainly oral infections |
