<prompt> Bile esculin test is used to differentiate -Streptococcus agalactaeEnterococcus fecalisStreptococcus bovisStreptococcus pneumoniae  <response>: Ans. is b i.e., Enterococcus fecalis Enterococci grow in the presence of bile and hydrolyze esculine - bile esculin positive.Enterocococci Enterococci were originally classified as streptococcit because organisms of the two genera share many morphologic and phenotypic characteristics. However, DNA hybridization and 16 S rRNA sequencing clearly demonstrated that enterococci should be grouped as a genus distinct from streptococci. Thus, enterococci are not streptococci previously they were classified as group D streptococci, along with non-enterococcal group. Majority of the infections are caused by E. faecalis and E. faecium. Less frequently isolated species are E. gallinarum, E. durans, E. hirae and E. avium. Enterococci are normal inhabitants of the large bowel of human adults, although they usually make up 1 of the culturable intestinal microflora. They are catalase negative as all streptococci. Their characteristic feature is that they can grow in presence of1 40 bile2 6.5 Sodium chloride3 At pH 9.64 At 45degC relative heat resistant surving 60degCfor 30 minutes5 In 0.1 methylene blue milk They hydrolyze esculin. They grow in presence of 40 bile and hydrolyze esculin -- Bile esculin positive. They are PYR Pyrrolidonyl Arylamidase positive. They are usually non hemolytic gamma-hemolytic, but some times may show alpha or beta hemolysis. 