mTSB Broth with Novobiocin

Modified Tryptic Soy Broth (mTSB with Novobiocin)

EMD Cat. No. 1.09205.0500

500 g

For the selective enrichment of enterohemorrhagic E. coli (EHEC) in foods.

The culture medium complies with the requirements of the ISO Standard 16654 for the detection of Escherichia coli (E. coli) serotype 0157:H7 in foods as well as with the methods of FDA-BAM for the isolation of enterohemorrhagic E. coli (EHEC).

Additives

EMD Cat. No.	Product	Pack Size
1.04036.0100	Fluorocult^® E.coli 0157:H7 Agar	100 g
1.04036.0500	Fluorocult^® E. coli 0157:H7 Agar	500 g
1.09202.0001	CT-Supplement	1 x 16 vials
1.09207.0500	Sorbitol-MacConkey Agar	500 g

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

Mode of Action
The nutrient substrates contained in mTSB broth provide favourable growth conditions. The mixture of bile salts No. 3 and Novobiocin suppresses the growth of the Gram-positive microbial flora.

Preparation
Suspend 33 g in 1 liter of purified water; autoclave (15 min at

121 °C).
pH: 7.3 ± 0.2 at 25 °C.
The prepared broth is clear and yellowish. The broth is stable for up to 6 month when stored at +2 - +8 °C.

Experimental Procedure and Evaluation

Inoculate mTSB Broth with the sample material (usually add
25 g test portion of the sample to 225 ml of broth).

Incubation: 18 to 24 h at 37 °C or 41.5 °C. Incubation temperature depends on standard used.

Afterwards about 0.1 ml of the broth is streaked on the dry surface of a E. coli 0157:H7 Selective Agar, e.g. Fluorocult^® E.xcoli 0157:H7 Agar, SMAC Agar or CT-SMAC Agar in a way, that single colonies can be well isolated.

Quality control

Test strains	Growth
E. coli 0157:H7 ATCC 35150	good
E. coli ATCC 11775	fair
Pseudomonas aeruginosa ATCC 27853	fair

Typical Composition (g/liter)
Peptone from caseine 17.0; peptone from soymeal 3.0; sodium chloride 5.0; bile salts No. 3 1.5; D(+)-glucose 2.5; di-potassium hydrogen phosphate 4.0; novobiocin 0.02.

Literature

DIN Deutsches Institut für Normung e.V.: Nachweis von Escherichia coli 0157 in Lebensmitteln. DIN 10167.
FDA Bacteriological Analytical Manual, 8th Edition/1995, Chapter 4. Escherichia coli and the Coliform Bacteria, page 4.20: Ioslation Methods for Enterohemorrhagic E. coli (EHEC).
WEAGANT, S.D., BRYANT, J.L., a. JINNEMAN, K.G.: An improved rapid technique for isolation of Escherichia coli 0157:H7 from foods. J. Food Prot., 58; 7-12 (1995).