Categories: Microbiology

Aesculin hydrolysis test principle, procedure for streptococci

Asculine is a glycoside and it is incorporated with a nutrient base a ferric salt. Aesculin hydrolysis means the breakdown of aesculin. This hydrolysis is indicated by a BROWN coloration.

It occurs due to the reaction of aglycone (6.7 Dihydroxycoumarin) with iron. Sometimes another chemical (SODIUM AZIDE) is added. It acts as a preservative.

The Aesculin hydrolysis test is used to identify the enterococci, anaerobic cocci, streptococci, and others.

Aesculin hydrolysis test principle

Some organism hydrolyse aesculine. It results in the formation of a substance called AGLYCONE. It reacts with iron and forms a compound that is BROWN to BLACK in color.

Aesculin hydrolysis test procedure

Following are the steps in the aesculin test procedure.

First, inoculate the aesculin broth or agar.
Incubate that agar at 37 C temperature.
Examine daily for up to 5 days.
If you notice blackening, the result is positive.

Aesculin hydrolysis test positive bacteria / negative bacteria list

Aesculin hydrolysis Positive bacteria list

Enterococci
Anaerobic cocci
Streptococcus porcinous
S. uberis
S.Suis
S.Sanguis
S.Bovis
S.Eequinus
S.Mutans
S.Salivarius
Listeria

A. hydrolysis Negative bacteria list

All other streptococci

Bile Solubility Test Principle, Procedure, Result

Bile Tolerance test procedure, principle, and Reagents

The Bile Tolerance test is used to differentiate streptococcus agalactia from other gram-positive cocci. Certain streptococci (S.agalactiae) and enterococci are resistant to 10-40% bile and this test is used to differentiate these from other Gram-positive cocci. Anaerobic bacteria also vary in their ability to grow in the presence of 20%…

Routine microscopic urinalysis procedure, Physical, chemical, microscopic

The urinalysis procedure test is important because it provides important information about the patient's health. The Urine test is a valuable index for normal and pathological mechanisms. Many characteristics and components of it are unstable therefore urinalysis should be done within thirty minutes (30) after collection. The delay in testing…

admin