RESULTS & INTERPRETATION
Enterococci produce red or maroon colonies. All red, maroon or pink colonies as presumptive enterococci. Not all species reduce the
triphenyltetrazolium chloride therefore pale colonies should not be ignored.

QUALITY CONTROL
Enterococcus faecalis ATCC 29212: good growth; deep red coloured colonies.
Escherichia coli ATCC 25922: no growth.

REFERENCES
1. ISO 7899-2:2000: Water quality -- Detection and enumeration of intestinal enterococci -- Part 2: Membrane filtration method.
2. Slanetz and Bartley Agar. Biokar diagnostics - product leaflet.
3. CM0377 Slanetz and Bartley Medium (Enterococcus Agar). Oxoid - product leaflet.
COMPOSITION
Tryptose 20.0 g, yeast extract 5.0 g, glucose 2.0 g, Di-potassium hydrogen phosphate
4.0 g, sodium azide 0.4 g, 2,3,5-triphenyltetrazolium chloride 0.1 g, agar 10.0 g.
Distilled water ad 1000 ml, pH 7.2 ± 0.2.
Bring to the boil to dissolve the agar completely. Do not autoclave! Dispense into Petri
dishes.

PRINCIPLE
The reduction of triphenyltetrazolium chloride to an insoluble formazan is seen by the
formation of red to maroon colonies. Sodium azide inhibits the growth of
Gram-negative bacteria.
DESCRIPTION
The medium is used for the enumeration of enterococci in foods and water by membrane filtration technique, but  also can be used as
a direct plating medium.
Slanetz & Bartley Agar
(c) Costin Stoica
Antibiogram
Encyclopedia
Culture media
Biochemical tests
Stainings
Images
Movies
Articles
Identification
Software
R E G N U M
PROKARYOTAE
Previous page
Back
Slanetz & Bartley Agar
Enterococcus faecium colonies on S & B agar
PROCEDURE
Water: use the membrane filtration technique. Add the membrane on medium
surface and incubate at 36°C ± 2°C for 48 hours. After incubation all red, maroon or
pink colonies as presumptive enterococci. Presumptive colonies are confirmed by
transferring the membrane on a Bile-Esculin Agar plate and incubating at 44°C ±
0.5°C for 2 hours. Black-brown colonies are confirmed.

Food: samples are homogenised and diluted with physiological saline.
Homogenates or dilutions are spread evenly over the agar surface with a glass rod
and allowed to soak in. Plates are incubated at 35°C for 48 hours, after which typical
colonies are counted.

Besides the water and food applications, the medium may be used by direct plating
for other purposes.