Membrane-filter Enterococcus Selective Agar Base acc. to SLANETZ und BARTLEY

m-Enterococcus Agar Base

EMD Cat. No. 1.05289.0500

500 g

For the enumeration of enterococci in water and other liquids by the membrane filtration technique according to SLANETZ und BARTLEY (1957).

Additives

EMD Cat. No.	Product	Pack Size
TX1510-3	2,3,5-Triphenyltetrazolium chloride	10 g

Mode of Action	Preparation
Experimental Procedure and Evaluation	Quality Control
Typical Composition (g/liter)	Literature

Mode of Action
The growth of the entire accompanying Gram-negative microbial flora is inhibited by sodium azide. Enterococci reduce TTC to give a red formazan, their colonies are thus red in color. According to LACHICA and HARTMAN (1968), the selectivity for enterococci can be improved by adding carbonate and Tween 80^®.

Preparation
Suspend 41.5 g/liter, sterilize by heating for 20 minutes in a current of steam (e.g. autoclave without excess pressure). Afterwards cool rapidly!

Do not autoclave.
When using Cat. No. 1.05289.0500, add 10 ml of a filtersterilized 1 % 2,3,5-triphenyltetrazolium chloride solution/liter to the base medium at a temperature of approximately 50 °C. Pour plates.
pH: 7.2 ± 0.2 at 25 °C.
The plates are clear and yellowish-brown. A reddish color with Cat. No. 1.05262.500 might occur.

Experimental Procedure and Evaluation
Place the inoculated membrane filters on the surface of the plates.
Incubation: up to 48 hours at 35 °C aerobically.

Pink to brown colonies with a diameter of 0.5 to 2 mm are usually enterococci.

Quality control

Test strains	Growth	Red colonies
Streptococcus pyogenes ATCC 12344	poor / fair	-
Streptococcus agalactiae ATCC 13813	none / poor	-
Enterococcus faecalis ATCC 11700	good / very good	+
Enterococcus faecalis ATCC 19433	good / very good	+
Enterococcus hirae ATCC 8043	good / very good	+ (poor)
Staphylococcus aureus ATCC 25923	none
Escherichia coli ATCC 25922	none
Pseudomonas aeruginosa ATCC 27853	none

Typical Composition (g/liter)
Tryptose 20.0; yeast extract 5.0; D(+)glucose 2.0; di-potassium hydrogen phosphate 4.0; sodium azide 0.4; 2,3,5-triphenyltetrazolium chloride (not present in Cat. No. 1.05289.0500) 0.1; agar-agar 10.0.

Literature

LACHICA, R.V.F., a. HARTMAN, P.A.: Two improved media for isolating and enumerating enterococci in certain frozen foods. J. Appl. Bact., 31; 151-156 (1968).
SLANETZ, L.W., a. BARTLEY, C.H.: Numbers of enterococci in water, sewage, and faeces determined by the membrane filter technique with an improved medium J. Bact., 74; 591-595 (1957).