To the other tube, add 2 drops of sterile distilled water and
Leave both tubes for 10-15 minutes.
Look for a clearing of turbidity in the tube containing the
Results Clearing of turbidity -------------- Probably S.pneumoniae
No clearing of turbidity -----------organism is probably Not S.pneumoniae
There should be no clearing of turbidity in the tube to which distilled water was added. If there is, repeat the test. Note: Some strains of S.pneumoniae are not dissolved by bile salts, and very occasionally some strains of viridans streptococci give a positive tests.
Bile solubility positive control: Streptococcus pneumoniae. Bile solubility negative control: Streptococcus faecalis.
This test is used to differentiate those bacteria that produce the enzyme catalase, such as staphylococci, from non-catalase producing bacteria such as streptococci.