LEVINE EMB Agar (Eosin Methylene-blue Lactose Agar acc. to LEVINE)

EMB Agar LEVINE

EMD Cat. No. 1.01342.0500

500 g

For the isolation and differentiation of Escherichia coli and Enterobacter and for the rapid identification of Candida albicans according to LEVINE
(1918, 1921).

The culture medium complies with the recommendations of the APHA Standard Methods for the Examination of Water and Wastewater (1998) and the United States Pharmacopeia XXIII (1995).


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

Mode of Action
The dyes contained in this medium inhibit the growth of many accompanying Gram-positive microorganisms. According to WELD (1952, 1953) and VOGEL and MOSES (1957), LEVINE EMB Agar can be used to identify Candida albicans in clinical specimens, if chlorotetracycline hydrochloride is added to inhibit the entire accompanying bacterial flora. LEVINE EMB Agar can also be utilized for the identification of coagulase-positive staphylococci which grow characteristically as colorless "pin-point" colonies and which show good agreement with the results of the coagulase test (MENOLASINO et al. 1960).

Typical Composition (g/liter)
Peptone 10.0; lactose 10.0; di-potassium hydrogen phosphate 2.0; eosin, yellowish 0.4; methylene blue 0.065; agar-agar 13.5.

Preparation
Suspend 36 g in 1 liter of purified water. Autoclave (15 min at 121°C), and pour plates.
pH: 7.0 ± 0.2 at 25°C.
The plates are clear and red-brown.
If cultivating Candida, add 100 mg tetracycline hydrochloride/liter after autoclaving and mix homogeneously. The culture medium then is blue.

Experimental Procedure and Evaluation
Inoculate by thinly spreading the sample material on the surface of the culture medium.
Incubation: 1-2 days at 35°C aerobically.

To obtain a primary culture of Candida, incubate the plates containing chlorotetracycline in a 10 % carbon dioxide atmosphere (e.g. with Anaerocult^® C or C mini).

Appearance of Colonies	Microorganisms
Diameter 2-3 mm, greenish metallic sheen in reflected light, dark or even black centre in transmitted light	Escherichia coli
Diameter 4-6 mm, graybrown centre in transmitted light, no metallic sheen	Enterobacter
Transparent, amber-colored	Salmonella and Shigella
colorless, "pin-point" colonies	Coagulase-positive staphylococci
"Spidery" - or "feathery"	Candida albicans
Yeast-like, round, smooth	Other Candida species. Sometimes Nocardia

Quality control

Test strains	Growth	Colonies
		Blue	Metallic sheen
Escherichia coli ATCC 25922	good / very good	+	+
Escherichia coli ATCC 11775	good / very good	+	+
Escherichia coli 194	good / very good	+	+
Enterobacter cloacae ATCC 13047	good / very good	pale blue	-
Shigella sonnei ATCC 11060	good / very good	-	-
Salmonella typhimurium ATCC 14028	good / very good	-	-
Proteus mirabilis ATCC 14273	good / very good	-	-
Staphylococcus aureus ATCC 25923	none / poor	-	-

Additives

EMD Cat. No.	Product	Pack Size
13674	Plate basket	1ea
1.08189.0010	Tetracycline hydrochloride
13699	Anaerocult^® C mini	1 x 25
14255	Anaeroclip^®	1 x 25
13678	Anaerocult^®C	1 x 10
13681	Anaerobic jar	1 ea

Literature

American Public Health Association, American Water Works Association and Water Pollution Control Federation: Standard Methods for the Examination of Water and Wastewater, 20th ed., Washington 1998.
LEVINE, M.: Differentation of E. coli and A. aerogenes on a simplified eosin-methylene blue agar. - J. Infect. Dis., 23; 43-47 (1918).
LEVINE, M.: Bacteria fermenting lactose and the significance in water analysis. - Bull., 62; Iowa State College Engr. Exp. Station (1921).
MENOLASINO, N.I., GRIEVES, B., a PAYNE, P.: Isolation and Identification of coagulase-positive staphylococci on Levine's eosin-methylene blue agar. - J. Lab. Clin. Med., 56 (6); 908-910 (1960).
VOGEL, R.A., a. MOSES, M.R.: Welds method for the rapid identification of Candida albicans in clinical materials. - Am. J. Clin. Path., 28 (1); 10³-106 (1957).
WELD, J.T.: Candida albicans. Rapid identification in pure cultures with carbon dioxyde on modified eosin-methylene blue medium. - Arch. Dermat. Syph., 66; 691-694 (1952).
WELD, J.T.: Candida albicans. Rapid identification in cultures made directly from human materials. - Arch. Dermat. Syph., 67 (5); 473-478 (1953). United States Pharmacopeia XXI, Chapter "Microbial Limit Tests", 1985.