RAMBACH^® Agar

EMD Cat. No. 1.07500.0001

Differential-diagnostic culture medium for identifying non-typhi Salmonella in foodstuffs and clinical samples.

Mode of Action	Preparation
Experimental Procedure and Evaluation	Quality Control
Typical Composition (g/liter)	Literature
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Mode of Action
The nutritive substrates in the RAMBACH^® Agar enable Enterobacteriaceae to multiply readily. Sodium desoxycholate inhibits the accompanying Gram-positive flora. RAMBACH^® Agar enables species of Salmonella to be differentiated unambiguously from other bacteria by means of a new procedure, for which a patent application has been submitted. This is made possible by adding propylene glycol to the culture medium. Salmonellae form acid with propylene glycol, so that, in combination with a pH indicator, the colonies have a characteristic red color. In order to differentiate coliforms from Salmonellae, the medium contains a chromogene indicating the presence of -galactosidase splitting, a characteristic for coliforms. Coliform microorganisms grow as blue-green or blue-violet colonies. Other Enterobacteriaceae and Gram-negative bacteria, such as Proteus, Pseudomonas, Shigella, S. typhi and S. parathyphi A grow as colorless-yellow colonies.

Preparation

1.	Add 1 vial of liquid-mix to 250, 1000 or 50.000 ml distilled water and mix by swirling until completely dissolved (the water quantity is dependent on the respective pack-size).
2.	Add 1 vial of nutrient-powder and mix by swirling until completely suspended.

3.	Heat in a boiling water-batch or in a current of steam, while carefully shaking from time to time. The medium is totally suspended, if no visual particles stick to the glass-wall. The medium should not be heat-treated further! Standard time for complete dissolution (shaking in 5-minute sequence): 250 ml: 20-25 minutes 1000 ml: 35-40 minutes. Do not autoclave, do not overheat!
4.	Cool the medium as fast as possible in a water-bath (45-50 °C). During this procedure (max. 30 minutes) gently shake the medium from the time to time. Pour into plates.
5.	In order to prevent any precipitate or clotting of the chromogenic-mix in the plates, we advice to place Petri dishes during pouring procedure on a cool (max. 25 °C) surface.
6.	The ready-plates are opaque and pink. Before inoculation, the plates should be dry. pH: 7.3 ± 0.2 at 25 °C.
7.	Shelf-life and storage conditions of fresh prepared plates: room-temperature: 12 hours. in the fridge (not below 6 °C) unsealed. 3 weeks in the fridge (not below 6 °C) sealed in plastic-pouch or with tape: 3 months.

Experimental Procedure and Evaluation
Specimen enriched in appropriate Salmonella Selective Broth. Afterwards inoculate ¼ of the agar surface. In order to achieve individual colonies, the inoculation shall be continued with the same loop over the rest of the plate
Incubation: Aerobically at 35-37 °C for 24-28 hours.

Quality control

Test strains	Growth
Salmonella enteritidis ATCC 13076	red
Salmonella typhimurium ATCC 14028	red
Escherichia coli ATCC 25922	blue-green
Klebsiella pneumoniae ATCC 13883	blue-green
Shigella flexneri ATCC 29903	yellowish
Proteus mirabilis ATCC 14153	yellowish
Staphylococcus aureus ATCC 25923	inhibited
Bacillus cereus ATCC 11778	inhibited

Typical Composition (g/liter)
Peptone 8.0; sodium chloride 5.0; sodium deoxycholate 1.0; chromogenic mix 1.5; proplylene glycol 10.5; agar-agar 15.0.

Literature

RAMBACH, A.: "New Plate Medium for Facilitated Differentiation of Salmonella spp. from Proteus spp. and Other Enteric Bacteria". Appl. Enrionm. Microbiol., 56; 301-303 (1990).
GRUENEWALD, R., et al.: "Use of Rambach Propylene Glycol containing Agar for identification of Salmonella spp." J. Clin. Microbiol.: 2354-2356 (1991).
BARTOLOME, R.M., et al.: Nuevo media de cultivo para el aislamiento de salmonella sp. V Congreso de la Sociedad espanola de Immunologia clinica, Barcelona; November 1992.
LAUDAT, P., et al.: Rambach Agar: New Plate Medium for Rapid and Faciliated Identification of Salmonella spp. 5th European Congress of Clinical Microbiology and Infectious Diseases. Oslo, Norway, p. 177; September 9-11, 1991.
OSSMER, R.: Salmosyst and Rambach-Agar. A Rapid Alternative for the Detection of Salmonella. Congress-Poster Salmonella and Salmonellosis Ploufragen/Sant-Brieux France, September 1992.
BENETT, A.R., et al.: Evaluation of Rambach Agar and Salmosyst Enrichment for the isolation of Salmonella from foods. Congress-Poster RAMI, London; September 1993.
CANTONI, C., et at.: Comparazione tra vari terreni selettivi per l'isolamento di salmonella spp da funghi biologici e da alimenti. Ingegneria Alimentare, 3/93; p. 35-43.
CASERIO, G., et al.: Performances del terreno di Rambach nell'isolamento di Salmonella da prodotti alimentari. Ingegneria Alimentare, 5/95; p. 42-43.
DIEHL, T., et al.: Salmonella enterica: Aktuelles aus der bakteriologischen Diagnostik. Tierärztl. Umschau, 48; 703-706 (1993).
GIACCONE, V. et al.: Confronto de terreni selettivi per la ricerca di Salmonella spp. in prodotti carnei. Ingegneria Alimentare, 3/93; p. 31-35.
MALASPINA, P.M., et al.: Impiego di un nuovo terreno solido selettivo per la ricerca di Salmonella spp. in prodotti lattiero-caseari. II latte, 7/93; p. 770-775.

Salmonella Enteritidis, E.coli, Proteus