KM0161 – Slanetz & Bartley

//KM0161 – Slanetz & Bartley

KM0161 – Slanetz & Bartley

This medium was originally described by Slanetz and Bartley(1) for the enumeration of enterococci from water samples using membrane filtration. The medium has also become useful as a direct plating medium.
Tryptose and yeast extract provide the required carbon, nitrogen and vitamins. Glucose is a fermentable carbohydrate. The di-potassium hydrogen phosphate acts as a buffer. Selectivity is achieved through the addition of sodium azide which is used to suppress the growth of Gram-negative organisms. The medium contains tetrazolium chloride, which is reduced by enterococci to the insoluble red dye formazan resulting in dark red colonies of enterococci on the agar. It should be noted that this reaction is not exclusive to enterococci and colonies should be confirmed by additional testing e.g. aesculin hydrolysis.

SKU: KM0085 Category:

Additional Information

Shelf Life (days)

Storage Temp (°C)

Dehydrated Medium Appearance

Prepared Medium Appearance

Dehydrated Medium Colour

Prepared Medium Colour

Dehydrated PH

Prepared PH

Product Description

Organisms Ref. No Result
Enterococcus faecalis NCTC 12697 Growth, maroon colonies
Escherichia coli NCTC 12241 Inhibited

 

Formula*

g/L
Tryptose 20.0
Yeast extract 5.0
Glucose 2.0
Di-potassium hydrogen phosphate 4.0
Sodium azide 0.4
Tetrazolium chloride 0.1
Agar 12.0
Total 43.5
*Adjusted/supplemented as required to meet performance requirements

Preparation

Suspend 43.5g of the medium in one litre of deionised / purified water. Allow the medium to soak whilst mixing for 10 minutes. Sterilise by boiling for 1 minute with frequent stirring to completely dissolve the medium. Cool to 45-50°C and dispense into appropriate sterile containers.