SIMMONS Citrate Agar

SIMMONS Citrate Agar

Cat. No. 1.02501.0500
(500 g)

Synthetic test agar proposed by SIMMONS (1926) for the identification of microorganisms (particularly of Enterobacteriaceae and certain fungi) on the basis of their metabolism of citrate, being the sole carbohydrate source.

This culture medium complies with the recommendations of the APHA for the examination of water (1998) and the recommendations of the APHA for the examination of food (1992).
According to VAN KREGTEN et al. (1984) this culture medium can be used for cultivating Klebsiella by adding inositol.

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

Mode of Action
Metabolism of citrate leads to alkalinization of the medium, which is indicated by a change in the color of the pH indicator bromothymol blue to deep blue.

Typical Composition (g/liter)
Ammonium dihydrogen phosphate 1.0; di-potassium hydrogen phosphate 1.0; sodium chloride 5.0; sodium citrate 2.0; magnesium sulfate 0.2; bromothymol blue 0.08; agar-agar 13.0.

Preparation
Suspend 22.5 g/liter, autoclave (15 min at 121°C), prepare slant agar tubes or pour plates.
pH: 6.6 ± 0.2 at 25°C.
The plates or slants are clear and green.

Preparation of Klebsiella agar: Add 10 g inositol/liter before autoclaving the culture medium.

Experimental Procedure and Evaluation
Streak a pure culture of the microorganism to be tested on the surface of the culture medium.
Incubation: 24 - 48 hours at 35°C aerobically.

Growth	Microorganisms
Positive, culture medium deep blue	Citrate-positive; Citrobacter, Enterobacter, S. paratyphi B., S. enteritidis, S. typhimurium, Arizona, Klebsiella, Serratia and others
Negative or inhibited	Citrate-negative: Escherichia, Shigella, S. typh., S. parathyphi A and others

Quality control

Test strains	Growth	color change to blue
Enterobacter cloacae ATCC 13047	good / very good	+
Salmonella typhimurium ATCC 14028	good / very good	+
Klebsiella pneumoniae ATCC 13883	good / very good	+
Escherichia coli ATCC 25922	none / poor	-
Shigella flexneri ATCC 12022	none / poor	-
Morganella morganii ATCC 25830	none / poor	-

Additives

EMD Cat. No.	Product	Pack Size
	myo-Inositol	100 g

Enterobacter cloacae, E.coli

Literature

American Public Health Association: Compendium methods for the microbiological examination of foods. - 3^rd ed. 1992.
American Public Health Association, American Water Works Association and Water Pollution Control Federation: Standard Methods for the Examination of Water and Wastewater, 20^th ed., Wash., 1998.
SIMMONS, J.S.: A culture medium for differentiating organisms of typhoid-colon aerogenes groups and for isolating of certain fungi. - J. Infect. Dis., 39; 209-241 (1926).
EWING, W.H. a. EDWARDS, P.R.: The principal divisions and groups of Enterobacteriaceae and their differentiation. - Int. Bull. Bact. Nomencl. Taxon., 10; 1-12 (1960).
VAN KREGTEN, E., WESTERDAHL, N.A.C., a. WILLERS, J.M.N.: New, simple medium for selective recovery of Klebsiella pneumoniae and Klebsiella oxytoca from human feces. - J. Clin. Microbiol., 20; 936-941 (1984).