The bile-solubility test can be performed either with a broth culture of the organism or with colonies growing on agar media. The shelf life of the solution is usually 270 days. If the direct plate is difficult to interpret, the test should be repeated using the tube or slide method. Bile solubility test should only be used to differentiate. The addition of bile salts (sodium deoxycholate) activates the autolytic enzyme and the organisms rapidly autolyse. Save my name, email, and website in this browser for the next time I comment. This site uses Akismet to reduce spam. The plate is kept right side up and is incubated at 35°C for 15-30 minutes or until the drop has evaporated. Citrate Utilization Test: Principle, Procedure and Results, Optochin Sensitivity Test: Principle, Procedure, Results and Quality Control, Streptococcus pyogenes is the leading cause of uncomplicated bacterial pharyngitis and tonsillitis commonly referred to as strep throat. Bile salts, specifically sodium deoxycholate and sodium taurocholate, have the capability to lyse Streptococcus pneumoniae selectively when added to actively growing bacteria in agar or broth media. A negative result is demonstrated when there is no change in the integrity of the colony within 30 min. Continue to incubate the tubes for up to 2 hours at 35-37°C in CO2 if negative after 10 minutes. © 2020 Microbe Notes. S. pneumoniae possesses an autolytic enzyme, an amidase, which lyses the cell’s own wall during division. When performing the spot test, keep the plate level to prevent reagent from running, which may cause some nonpneumococcal colonies to be washed away and result in a false-negative test. 6% – https://microbiologynotes.com/bile-solubility-test-principle-procedure-result-interpretation-examples-and-limitation/, 4% – http://www.apsi.it/public/ufiles/smi/tp5_3_en_141111.pdf, 2% – https://catalog.hardydiagnostics.com/cp_prod/content/hugo/BileSpotRgnt.htm, 2% – http://www.nature.com/articles/s41598-017-07772-x, 1% – https://www.sciencedirect.com/topics/immunology-and-microbiology/optochin, 1% – https://www.onlinebiologynotes.com/bile-solubility-test-principle-procedure-and-result/, 1% – https://assets.thermofisher.com/TFS-Assets/LSG/manuals/IFU21206.pdf, 1% – http://www.keydiagnostics.com.au/clinical-testing-2/products-by-organism/bile-spot-reagent-detail, <1% – https://www.sciencedirect.com/topics/neuroscience/lysis, <1% – https://www.researchgate.net/publication/274261127_Current_methods_for_capsular_typing_of_Streptococcus_pneumoniae, <1% – https://www.researchgate.net/publication/14534749_Identification_classification_and_clinical_relevance_of_catalase-negative_Gram-positive_cocci_excluding_the_Streptococci_and_Enterococci, <1% – https://www.justanswer.com/medical/bcstf-blood-infection-gram-positive-cocci-pairs.html, <1% – https://microbeonline.com/bile-solubility-test-principle-procedure-expected-result-and-quality-control/, Bile Esculin Test- Principle, procedure, results, uses, limitations, CAMP Test- Principle, Procedure, Types, Results, Uses, Limitations, Catalase Test- Principle, Procedure, Types, Results, Uses, Indole Test- Principle, Media, Procedure, Types, Results, Uses, Solubility Tests of Proteins- Definition, Principle, Procedure, Result, Uses, Widal Test- Objective, Principle, Procedure, Types, Results, Advantages and Limitations, Acetate Utilization Test- Principle, Procedure, Results, Uses, Acetamide Utilization Test- Principle, Procedure, Results, Uses, Bacitracin Susceptibility Test- Principle, Procedure, Results, Uses, Butyrate Disk Test- Principle, Procedure, Results, Uses, Limitations, Citrate Utilization Test- Principle, Procedure, Results, Uses, Decarboxylase Test- Principle, Procedure, Results, Uses, Esculin Hydrolysis Test- Principle, Procedure, Results, Uses, Methyl Red (MR) Test- Principle, Procedure, Results, Uses, Novobiocin Susceptibility Test- Principle, Procedure, Results, Uses, Coagulase Test- Principle, Procedure, Types, Result, Uses, Gelatin Hydrolysis Test- Principle, Procedure, Types, Result, Uses, Cetrimide Agar Test- Principle, Procedures, Results, Uses, Lipase Test- Objectives, Principle, Procedures, Results, Uses, Microdase (Modified Oxidase) Test- Principle, Procedure and Results, Lecithinase Test- Objectives, Principle, Procedure and Results, Lipid Hydrolysis Test- Objectives, Principle, Procedure and Results, Malonate Test- Objectives, Principle, Procedure and Results, Nitrate Reduction Test- Objectives, Principle, Procedure and Results, Optochin Susceptibility Test- Principle, Procedure and Results, Motility Test- Principle, Procedure and Results, MRS Broth Test- Principle, Procedure and Results, Oxidase Test- Principle, Procedure and Results, Starch Hydrolysis Test- Objectives, Principle, Procedure and Results, Spot Indole Test- Objective, Principle, Procedure, Results and Limitations, https://doi.org/10.1038/s41598-017-07772-x. Only 85% of pneumococcal strains will lyse completely in bile solubility test. The bile solubility test is not reliable with old cultures that have autolyzed. When testing using the plate method, care must be taken not to dislodge the colony being tested, therefore leading to false positive results. The bile (sodium deoxycholate) solubility test distinguishes Streptococcus pneumoniae from all other alpha-hemolytic streptococci. There are more than one method or procedure variations for the catalase test. Gently roll the drop over several representative colonies by tilting the plate. This test is a qualitative test for the differentiation of bile-soluble and bile-insoluble organisms. When performing the spot test, keep the plate level to prevent reagent from running, which may cause some nonpneumococcal colonies to be washed away and result in a false-negative test. Negative test: Test and Control suspensions remain turbid after 3 hours. There are more than one method or procedure variations for the catalase test. Professor and Microbiologist at Department of Microbiology and Immunology, Patan Academy of Health Sciences, Nepal. The Control suspension remains turbid. The bile solubility test is employed to distinguish Streptococcus pneumoniae from alpha-haemolytic Streptococcus spp. possesses an autolytic enzyme, an amidase, which lyses the cell’s own wall during division. Published 9 March 2014 Last updated 13 August 2018 — see all updates. The test may be performed using a cell suspension on a slide or in a tube or by adding the reagent directly to the colony. Lysis indicates S. Pneumoniae while no lysis does not. Bile solubility is demonstrated as disintegration or flattening of the colony within 30 min, leaving an area of alpha-.