Biochemical Tests Staphylococcus aureus ests 5 Staphylococcus saprophyticus ests 6 Growth on Bile + + Esculin Hydrolysis--2) Which of the following bacteria would be most likely to encounter bile salts in their normal habitat? It is a low cost, rapid test … is used by clicking on the “T” icon and reading up on those tests. It tests the ability of organisms to hydrolyze esculin in the presence of bile. above mentioned tests are used for confirmation of the Staphylococcus aureus. From the initial isolation plate, how many more agar plates would you need to inoculate in order to determine the circled items on this flowchart? If using plates instead of slants, any darkening of color is considered positive. However, the usefulness of a medium containing azide must be weighed against its safety concerns. Demonstration of the group D antigen may assist the identification of enterococci; however, it is not a particularly sensitive test because it is present in about 80% of enterococcal strains. Moral of the story: If you see yellow, it’s probably S. Aureus. Bile Esculin Test. They are facultative anaerobes that grow optimally at 35° C in broth containing 6.5% NaCl and hydrolyze esculin in the presence of 40% bile salts (bile-esculin medium). It is commonly used to identify members of the genus Enterococcus (E faecalis and E. faecium). Which image depicts the way in which Streptococcus agalactiae would appear on blood agar? Table of Contents hide Biochemical Test of Staphylococcus aureus Fermentation of Enzymatic Reactions Biochemical Test of Staphylococcus aureus Biochemical Test of Staphylococcus aureus ­Basic Characteristics Properties (Staphylococcus aureus) Capsule Non-Capsulated Catalase Positive (+ve) Citrate Positive (+ve) Coagulase Positive (+ve) Gas Negative (-ve) Gelatin Hydrolysis … Two. Bile-esculin test is widely used to differentiate Enterococci and Non-enterococcus group D streptococci, which are bile tolerant and can hydrolyze esculin to esculetin, from non-group D viridans group streptococci, which grow poorly on bile. Bacitracin test. For this reason, Bile Esculin Azide agar is even more helpful in identifying Enterococcus faecalis, Enterococcus faecium, and Streptococcus bovis because its sodium azide inhibits most Gram negatives. This is a medium that is both selective and differential. In this medium there is bile and esculin. - Bile esculin test - Bacitracin test - Catalase test. 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