SIM Medium

SIM Medium

Cat. No. 1.05470.0500
(500 g)

Test culture medium used to detect sulfide formation, indole production and motility for the identification of Enterobacteriaceae.

The medium complies with the recommendations of APHA (1992) for food examination.

Typical Composition (g/liter)	Additives/Reagents
Preparation	Picture/Image
Experimental Procedure and Evaluation	Literature
Quality Control

Typical Composition (g/liter)
Peptone from casein 20.0; peptone from meat 6.6; ammonium iron(II)citrate 0.2; sodium thiosulfate 0.2; agar-agar 3.0.

Preparation

Suspend 30 g/liter, dispense into tubes to give a depth of about
4 cm, autoclave (15 min at 121°C), allow to solidify in a vertical position.
pH: 7.3 ± 0.2 at 25°C.
The prepared medium is clear and yellowish-brown.

Experimental Procedure and Evaluation
Introduce a pure culture of the microorganism to be tested into the butt by puncture.
Incubation: 18-24 hours at 35°C aerobically.

Motility is indicated by a diffuse turbidity of the culture medium surrounding the puncture line. In case of immotility, growth takes place solely along the puncture line. H₂S formation is shown by a blackening in those areas of the medium in which microbial growth has occured.
After checking the tubes for motility and H₂S production, the indole test is performed. The medium is covered with a layer of KOV�?CS Indole Reagent. Production of indole causes the reagent layer to become purple in color.

Microorganisms	H₂S	Indole	Motility
Escherichia	-	+	+ / -
Enterobacter	-	-	+
Citrobacter	+	-	+
Klebsiella	-	-	-
Salmonella	+	-	+
Shigella	-	+ / -	-
Prot. vulgaris	+	+	+
Prot. mirabilis	+	-	+
Morganella	-	+	+
Rettgerella	-	+	+
Arizona	+	-	+
Hafnia	-	-	+
Serratia	-	-	+
Providencia	-	+	+
Edwardsiella	+	+	+
Yers. enterocolitica	-	- (+)	-

Quality control

Test strains	Growth	H₂S-formation	Indole formation	Motility
Escherichia coli ATCC 25922	good / very good	-	+	+
Escherichia coli ATCC 4351	good / very good	-	+	+
Klebsiella pneumoniae ATCC 13883	good / very good	-	-	-
Enterobacter cloacae ATCC 13047	good / very good	-	-	+
Salmonella typhimurium ATCC 14028	good / very good	+	-	+
Proteus vulgaris ATCC 13315	good / very good	+	+	+

Additives

EMD Cat. No.	Product	Pack Size
1.09293.0100	KOVACS Indole Reagent	100 ml
1.11350.0001	Bactident^® Indole (dropper bottle)	1 x 30 ml

Proteus vularis, Salmonella gallinarum, E.coli, Klebsiella pneumoniae

Literature

American Public Health Association: Compendium of methods for the microbiological examination of foods. - 3^rd ed. (1992).
COSTIN, I.D.: Die biochemische Identifizierung der Enterobacteriaceae. Kritische Bemerkungen zur Prinzipien und Methoden. - Zbl. Bakt. I. Ref., 219; 81-151 (1961).
COSTIN, I.D.: Orientierende Identifizierung obligat- und fakultativ-aerober, anspruchsloser, gramnegativer Stäbchen von medizinischem Interesse. - Med. Labor., 30; 197-217 (1977).