Thermo Scientific™ Oxoid™ Muller-Kauffmann Tetrathionate Broth Base (Dehydrated)

The Thermo Scientific™ Oxoid™ Muller-Kauffmann Tetrathionate Broth Base (Dehydrated) is a selective enrichment medium designed to enhance the isolation of salmonellae while suppressing competing commensal organisms and Proteus species. It incorporates brilliant green and ox bile for selectivity, improving the isolation of Salmonella species from contaminated samples, including food, water, and clinical specimens.

This medium is not recommended for use if Salmonella typhi is suspected.

Key Features

1. Highly Selective

• Brilliant green and ox bile inhibit commensal organisms, enhancing the isolation of Salmonella species.

2. Proteus Suppression

• The addition of novobiocin (40 mg/L) selectively suppresses the growth of Proteus species, which can otherwise mask Salmonella colonies.

3. Historical Provenance

• Developed by Muller (1923) and later refined by Kauffmann with the inclusion of selective agents to optimize Salmonella recovery.

4. Proven Efficacy

• Validated in a large-scale, multi-laboratory study involving nine laboratories across eight countries, confirming its reliability in Salmonella isolation.

5. Easy Preparation

• Provided in a dehydrated format for quick and consistent preparation.

Composition (Typical Formula)

Applications

1. Food Safety Testing

• Detect Salmonella species in poultry, meat, eggs, dairy products, and seafood.

2. Clinical Microbiology

• Isolate Salmonella from stool and other clinical samples.

3. Environmental Testing

• Used in water and sewage samples for the detection of Salmonella contamination.

4. Veterinary Diagnostics

• Identify Salmonella in animal feeds and specimens.

Usage Notes

1. Brilliant Green Handling:
   • Use Chroma or BDH brands as recommended to maintain selectivity.
   • Do not heat or pre-incorporate the dye into the basal medium, as this impairs selectivity.
2. Novobiocin Addition:
   • Add novobiocin at 40 mg/L to enhance the suppression of Proteus species.
3. Limitations:
   • Avoid use if Salmonella typhi is suspected, as it may not be effectively enriched.

Storage and Preparation

1. Storage Conditions:
   • Store dehydrated medium at 10–30°C in a tightly sealed container.
   • Prepared broth should be stored at 2–8°C and used within the recommended time.
2. Preparation:
   • Dissolve the specified amount of dehydrated medium in distilled water.
   • Heat gently to ensure complete dissolution.
   • Autoclave at 121°C for 15 minutes and cool before adding novobiocin or other supplements.

Advantages

1. Enhanced Selectivity:
   • Effectively suppresses competing organisms, including Proteus species.
2. Proven Reliability:
   • Widely validated and used in global studies for Salmonella detection.
3. Ease of Use:
   • Dehydrated format simplifies preparation and ensures consistent results.
4. High Sensitivity:
   • Optimized for isolating Salmonella even from heavily contaminated samples.

Why Choose Thermo Scientific™ Oxoid™ Muller-Kauffmann Tetrathionate Broth Base?

This medium provides a selective, reliable solution for isolating Salmonella species from a variety of sample types, with built-in suppression of commensals and Proteus species. Its historical validation and international use underscore its value in diagnostic microbiology, food safety, and environmental testing.