Is Streptococcus mutans bile-esculin tested?

Is Streptococcus mutans bile-esculin tested?

The bile-esculin test is widely used to differentiate enterococci and 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.

Is Streptococcus bile-esculin positive?

Streptococcus pyogenes does not hydrolyze esculin in the presence of bile. No dark brown complex is formed. This is a negative result.

What organisms are bile-esculin positive?

Uses

  • This test is used for the presumptive identification of enterococci and organisms in the Streptococcus bovis group.
  • The test differentiates enterococci and group D streptococci from non–group D viridans streptococci.

Which strep SPP is bile-esculin positive?

All strains of S. bovis and approximately 10% of viridans streptococci are bile-esculin positive.

What two tests are incorporated into the bile esculin test?

Bile esculin medium contains esculin and peptone for nutrition and bile to inhibit Gram-positive bacteria other than Group D streptococci and enterococci. Ferric citrate is added as a color indicator.

What test is used for identification of Streptococcus pneumoniae?

S. pneumoniae can be identified using Gram stain, catalase, and optochin tests simultaneously, with bile solubility as a confirmatory test. If these tests indicate that the isolate is S. pneumoniae, serological tests to identify the serotype can be performed.

Is Streptococcus coagulase positive or negative?

Gram-positive cocci include Staphylococcus (catalase-positive), which grows clusters, and Streptococcus (catalase-negative), which grows in chains. The staphylococci further subdivide into coagulase-positive (S. aureus) and coagulase-negative (S.

How does a bile esculin test work?

The bile esculin test selects organisms first on the basis of their ability to grow in a medium with 4% bile salts followed by the selection based on their ability to hydrolyze esculin. The hydrolysis of esculin results in glucose and a compound called esculetin.

What is the principle of bile esculin test?

Bile esculin test is based on the hydrolysis of esculin into glucose and esculetin (6, 7-dihydroxy-coumarin) by a micro-organism that produce an enzyme esculinase. Esculetin reacts with an iron salt (ferric citrate) in the medium to form a phenolic iron complex which produces a dark brown or black color.

What is bile solubility test?

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.