What is a positive bile esculin test?

For this test, esculin is incorporated into a medium containing 4% bile salts. Bacteria that are bile-esculin positive are, first of all, able to grow in the presence of bile salts. Hydrolysis of the esculin in the medium results in the formation of glucose and a compound called esculetin.Click to see full answer. Also to know is, what is a positive result for the bile esculin test?Positive: Blackening of more than half of the agar slant, if the medium containing ferric ammonium citrate is used. NOTE: In case of esculin broth without iron citrate, positive test means blackening of the broth after addition of the ferric reagent or by the loss of fluorescence of the medium.Similarly, is Listeria bile esculin positive? Some strains of Staphylococcus, Aerococcus, and Listeria monocytogenes may grow in the presence of bile and hydrolyze esculin. There are a few streptococci that do not hydrolyze esculin but will grow in the presence of bile. Growth without blackening of this medium does not constitute a positive test. Also question is, what does the bile esculin test for? Bile esculin agar (we do not use bile esculin azide agar, as sodium azide is extremely hazardous) is a selective and differential medium which is used to presumptively identify enterococci and group D streptococci based on the ability of an organism to hydrolyze esculin.What is Esculin hydrolysis?Esculin Hydrolysis Test. This is a nutrient agar-based medium containing 0.1% esculin and 10% bile salts, and allowed to solidify at a slant. The bile salts inhibit some bacteria, and so the ability to grow in the presence of bile salts represents a second test use for the medium.