Bile Esculin Hydrolysis Test

These flashcards cover key concepts related to the bile esculin hydrolysis test and its significance in microbiology.

Bile Esculin Hydrolysis Test

A presumptive test used to identify group D streptococci and enterococci.

Group D Streptococci and Enterococci

Bacteria that include normal human microflora and opportunistic pathogens, characterized by being Gram + and causing alpha hemolysis.

Esculin

A compound that can be broken down by certain bacteria in the presence of bile, resulting in the release of esculetin.

Esculetin

A compound released from the breakdown of esculin by bacteria, which reacts with agar reagents to produce a dark color.

Positive Test Result

Indicated by 50% or more of the bile esculin slant turning black, suggesting the presence of group D streptococci and enterococci.

Negative Test Result

Indicated by no color change or less than 50% of the slant turning black, suggesting the absence of group D streptococci.

Bile Esculin Hydrolysis Test

A presumptive test used to identify group D streptococci and enterococci.

Group D Streptococci and Enterococci

Bacteria that include normal human microflora and opportunistic pathogens, characterized by being Gram + and causing alpha hemolysis. Examples include Enterococcus faecalis, Enterococcus faecium, and Streptococcus gallolyticus subsp. gallolyticus.

Esculin

A compound that can be broken down by certain bacteria in the presence of bile, resulting in the release of esculetin.

Esculetin

A compound released from the breakdown of esculin by bacteria, which reacts with agar reagents to produce a dark color.

Positive Test Result

Indicated by 50% or more of the bile esculin slant turning black, suggesting the presence of group D streptococci and enterococci.

Negative Test Result

Indicated by no color change or less than 50% of the slant turning black, suggesting the absence of group D streptococci.

Procedure

• Using a loop transfer an alpha hemolytic colony from the BAP inoculated during the last lab to a bile esculin slant.

Incubate the slant at 37°C for 72 h.