• Home |
• Contacts |
• Quality Standards |
• Instructions for Use |
• Careers

 MULLER-KAUFFMANN TETRATHIONATE BROTH BASE

Code: CM0343

An improved enrichment medium for the isolation of salmonellae and the suppression of Proteus species.

Directions
Suspend 82g in 1 litre of distilled water and bring to the boil. Cool below 45°C and add, just prior to use, 19ml of iodine solution and 9.5ml of a 0.1% brilliant green solution. Mix well and fill out into sterile tubes or flasks.

Dissolve the potassium iodide in approximately 5ml of distilled water, add the iodide and gently warm the solution to completely dissolve it. Make up the volume to 100ml with distilled water.

Add the brilliant green to the distilled water and shake to dissolve the dye. Heat the solution to 100°C for 30 minutes and shake from time to time whilst cooling, to ensure that the dye has completely dissolved. Store in a brown glass bottle or away from light.

Description
Muller¹ developed this medium in 1923. It was later modified by Kauffmann^2,3 with the addition of brilliant green and ox bile to suppress commensal organisms and thus improve the isolation of salmonellae.

The brilliant green dye used in the medium has been shown to be critical and Chroma or BDH brands should be used. It is essential that the dye is added as directed because heating the brilliant green or attempting to incorporate it in the basal medium seriously impairs its selective action.
The addition of novobiocin at 40mg per litre of broth was described by Jeffries⁴ to suppress the growth of Proteus species.

Muller-Kauffmann Tetrathionate Broth should not be used if Salmonella typhi is suspected.

Muller-Kauffmann Tetrathionate Broth was used in a large-scale investigation between nine laboratories in eight different countries⁵.

Incubation of Muller-Kauffmann Broth at 43°C was shown to be essential in this trial and the technique used for enrichment of the salmonellae is as follows:
Add approximately 10g of sample to 100ml of Muller-Kauffmann Broth. Shake vigorously and immediately place the flasks of medium in a 45°C water-bath for 15 minutes. Remove the flasks from the water-bath, without drying them, and place in an incubator or another water-bath at 43°C.
Sub-culture the broth after 18-24 hours and again after 48 hours. Take one loopful of broth from the edge of the surface of the fluid and inoculate either two Oxoid Brilliant Green Agar (Modified) CM0329 plates (9cm diameter) without recharging the loop between plates, or one large plate (14cm diameter).

Incubate the plates at 35°C for 18-24 hours.

Storage conditions and Shelf life
Store the dehydrated medium at 10-30°C and use before the expiry date on the label.
Store the prepared medium at 2-8°C.

Appearance
Dehydrated medium: Off-white, free-flowing powder
Prepared medium: Off-white opaque suspension

Quality control

* This organism is available as a Culti-Loop®

Precautions
Do not autoclave the base broth.
Add the iodine solution and brilliant green just prior to use.
The medium is not suitable for the growth of Salmonella typhi, Salmonella sendai, Salmonella pullorum and Salmonella gallinarum.

References
1. Muller L. (1923) C. R. Soc. Biol. (Paris) 89. 434-443.
2. Kauffmann F. (1930) Z. f. Hyg. 113. 148-157.
3. Kauffmann F. (1935) Z. f. Hyg. 117. 26-32.
4. Jeffries L. (1959) J. Clin. Path. 12. 568-570.
5. Edel W. and Kampelmacher E. H. (1969) Bull. Wld Hlth Org. 41. 297-306.