BILE ESCULIN AZIDE BROTH

Rochaix first demonstrated the value of esculin hydrolysis in the identification of enterococci. Meyer et al found that 61 of 62 strains of enterococci hydrolyzed esculin in a medium containing bile, Swan determined that positive results obtained on esculin agar incorporated with 40% bile correlated well with serologically confirmed group D streptococci. Using Swan?s formula, Facklam and Moody tested over 700 strains of streptococci and enterococci representing all known serological groups. All strains of group D streptococci and enterococci were found to be bile-resistant and esculin-positive. Isenberg et al. modified the formulation of Swan by reducing the concentration of bile and adding the selective agent, sodium azide. The lower concentration of bile is less inhibitory to non-group D streptococci.

for selective isolation and presumptive identi?cation of faecal Enterococci