Which reagent is used in bile solubility test?

The addition of bile salts (sodium deoxycholate) activates the autolytic enzyme and the organisms rapidly autolyse. Other α-haemolytic streptococci do not possess such an active system and therefore do not dissolve in bile. by applying the Bile solubility Reagent directly to the colony.

Is bile soluble in water?

Typically, bile is concentrated five-fold in the gall bladder by absorption of water and small electrolytes – virtually all of the organic molecules are retained. Free cholesterol is virtually insoluble in aqueous solutions, but in bile, it is made soluble by bile acids and lipids like lecithin.

Is S. pneumoniae bile soluble?

III. pneumoniae from all other alpha- hemolytic streptococci. S. pneumoniae is bile soluble whereas all other alpha-hemolytic streptococci are bile resistant. Sodium deoxycholate (2% in water) will lyse the pneumococcal cell wall.

What is Optochin test?

This test determines whether the bacterium is either sensitive (susceptible) to optochin or resistant to the chemical. The optochin test is widely used in the form of filter paper discs, impregnated with ethylhydrocupreine hydrochloride, which are applied directly to inoculated plates before incubation.

What’s the procedure for the bile solubility test?

Bile Solubility test: Principle, Procedure, expected result and quality control. Divide the cell suspension equally into 2 tubes (0.5 ml per tube). Add 0.5 ml of 2% sodium deoxycholate (bile salts) to one tube. Add 0.5 ml of 0.85% saline to the other tube. Mix each tube well. Incubate the tubes at 35-37°C in CO2.

How does the bile solubility test differentiate Streptococcus pneumoniae?

Last updated: June 14, 2019. Bile Solubility Test is the test which differentiate Streptococcus pneumoniae (positive- soluble) from alpha-hemolytic streptococci (negative- insoluble). Streptococcus pneumoniae is bile soluble whereas all other alpha-hemolytic streptococci are bile resistant.

Which is bile soluble pneumococcal or alpha hemolytic?

Streptococcus pneumoniae is bile soluble whereas all other alpha-hemolytic streptococci are bile resistant. Sodium deoxycholate (2% in water) will lyse the pneumococcal cell wall. Procedure of bile solubility test: Preparation of 2% sodium deoxycholate (bile salt) solution.

Which is soluble in bile and which is insoluble?

This test is used to differentiate Streptococcus pneumoniae, which is soluble in bile and bile salts, from alpha- hemolytic Streptococcus which are insoluble.