Thermo Scientific™ Oxoid™ Buffered Peptone Water (Dehydrated), 500G

Thermo Scientific™ Oxoid™ Buffered Peptone Water is a non-selective pre-enrichment medium designed for the recovery and growth of injured or low numbers of Salmonella spp. from food and environmental samples. The medium facilitates resuscitation and proliferation of Salmonella cells that may have been sub-lethally injured by food preservation processes, improving the detection success rate before selective enrichment.

Key Features

1. High Growth and Recovery Rates:
   • Nutrient-rich medium supports intense bacterial resuscitation and growth.
   • Ideal for repairing damaged Salmonella spp. cells.
2. Enhanced Buffering System:
   • Prevents detrimental pH changes during incubation, ensuring optimal recovery of sub-lethally injured Salmonella cells.
3. Proven Efficacy:
   • Supported by studies (e.g., Edel and Kampelmacher, 1973; Sadovski, 1977) showing superior recovery results compared to other pre-enrichment media.
4. Applications Across Food Matrices:
   • Effective for a wide range of food samples, including meats, dairy, and frozen vegetables.

Applications

1. Food Microbiology:
   • Pre-enrichment of Salmonella spp. in various food products prior to selective culture.
   • Supports recovery from complex matrices such as meats, vegetables, and dairy.
2. Environmental Monitoring:
   • Detection of Salmonella spp. in environmental samples associated with food production and safety.
3. Laboratory Diagnostics:
   • Enhances the recovery of injured Salmonella cells, enabling downstream testing.

Composition

Preparation

1. Suspend 20 g of the medium in 1 liter of distilled or deionized water.
2. Mix well and heat until fully dissolved.
3. Sterilize in an autoclave at 121°C for 15 minutes.
4. Cool the prepared medium to room temperature before use.

Test Procedure

1. Pre-Enrichment:
   • Add food sample to the prepared Buffered Peptone Water in a ratio of 1:10 or 1:9.
   • Incubate at 37 ± 1°C for 16–20 hours.
2. Subsequent Enrichment:
   • Transfer an aliquot to selective enrichment media, such as Brilliant Green Tetrathionate Bile Broth, for targeted Salmonella spp. recovery.

Performance Characteristics

• Resuscitation of Injured Cells:
  • Effective for repairing sub-lethally injured Salmonella from processes like freezing or preservation.
• pH Stability:
  • Maintains stable pH for up to 24 hours, ensuring optimal conditions for microbial recovery.
• Supports Selective Enrichment:
  • Enhances the efficacy of downstream selective media by increasing the target population.

Quality and Reliability

• Proven Studies:
  • Outperforms lactose broth and other media in recovering freeze-damaged or acid-sensitive Salmonella cells (Edel and Kampelmacher, Sadovski).
• ISO Compliance:
  • Compatible with standard methods for food safety testing.

Physical Characteristics

Storage

• Dehydrated Medium: Store at 10–30°C in a dry, tightly sealed container.
• Prepared Medium: Use immediately after sterilization or store refrigerated (if applicable).

Limitations

1. Non-Selective:
   • Buffered Peptone Water does not inhibit competing microflora; additional selective enrichment is required.
2. Dependent on Sample Quality:
   • Low-quality or improperly stored samples may yield inaccurate results.

Key Advantages

• High recovery rates for injured cells from food preservation processes.
• Proven efficacy across a wide range of food and environmental matrices.
• Easy preparation with reproducible results.

Specifications

Thermo Scientific™ Oxoid™ Buffered Peptone Water is a robust, non-selective pre-enrichment medium essential for the recovery of Salmonella spp. from food and environmental samples. Its nutrient-rich and highly buffered formulation ensures optimal recovery of sub-lethally injured cells, making it a reliable choice for food safety and microbiological testing laboratories.

General References

1. Edel W., Kampelmacher E.H. (1973) Bulletin of WHO, 48:167–174.
2. Sadovski A.Y. (1977) Journal of Food Technology, 12:85–91.
3. Angelotti R. (1963) Microbiological Quality of Foods, Academic Press.