J Clin Pathol Qual Control.  1998 Jun;20(1):219-223.

Evaluation of 5% NaCI-Esculin Hydrolysis Test for the Rapid Identification of Enterococci

• Uh Y
• Jang IH
• Sin SH
• Yoon KJ

Abstract

BACKGROUND: The ability of enterococci to cause severs disease in humans and their relative resistance to commonly used antimicrobial agents make it desirable to rapidly differentiate these organisms from other streptococci. We evaluated a test that distinguishes within a 2 hour period enterococci from other catalase negative gram-positive cocci in a buffered solution containing 0.2% esculin and 5% sodium chloride.
METHODS
A total of 303 enterococci from clinical specimens at Wonju Christian Hospital were tested. The 5% NaCl-esculin hydrolysis test medium contained 2.0 g of esculin (Sigma), 0.5 g of ferric ammonium citrate, 50.0 g of Nacl, 0.4 g of KH2PO4, and 0.1 g of KH2PO4 in one liter of distilled water. The pH was adjusted to 5.6+/-0.2 Six to ten colonies from subculture media were inoculated in 0.5 ml of the buffered esculin solution and incubated at 35degrees C for up to 4 hours.
RESULTS
99.7% ( 302/303) of enterococci tested gave a positive reaction in the buffered esculin solution within 2 hours.
CONCLUSION
A combined sodium chloride-esculin hydrolysis test is simple, rapid and cost-saving for the presumptive identification of enterococci.

MeSH Terms

Ammonium Compounds
Anti-Infective Agents
Catalase
Citric Acid
Esculin
Gangwon-do
Gram-Positive Cocci
Humans
Hydrogen-Ion Concentration
Hydrolysis*
Sodium
Sodium Chloride
Water
Anti-Infective Agents
Catalase
Citric Acid
Esculin
Sodium
Sodium Chloride
Water