Evaluation of Performance and Workflow Efficiency of MilliporeSigma Readybag Buffered Peptone Water Acc. ISO 6579, ISO 21528, ISO 22964, FDA-BAM and EP for Salmonella Detection in Food

Introduction: Nutrient rich Buffered Peptone Water (BPW) for Salmonelladetection according to ISO 6579, ISO 21528, ISO 22964, FDA-BAM and EP supports high resuscitation rates and intensive growth. A phosphate buffer system prevents bacterial damage from media pH changes. This composition has been incorporated into a pouch system of pre-weighed, gamma-irradiated dehydrated media for adding directly to weighed food samples and hydrating with sterile water, reducing sample preparation time by up to 50%.

Purpose: To evaluate performance and workflow efficiency of the Buffered Peptone Water ready-to-use pouch system.

Methods: Four foods were inoculated with 4 Salmonella strains at ~1.0 CFU/ml, 10 replicates and enriched according to ISO 6579. Competitor comparison studies evaluated growth rate and buffering capacity by inoculating 4 Salmonellastrains into the pouch system and 4 competitor BPW. Bioscreen C equipment measured growth rate by automating turbidity measurements at 36.5°C over 18 h. Buffering capacity was measured by recording pH of BPW media from t=0 and after addition of 200 µl 1N HCL until acidity target (pH 2.0 – 3.0) was reached at 18.0 ml. Workflow efficiency was evaluated in an independent study comparing the pouch system to high efficiency and traditional sterilizing methods for 375 g food samples.

Results: The pouch system growth rate was stronger than all 4 competitor BPW by 30% - 633%, pH decreased at the slowest rate from pH 7.0 to pH 4.0 whereas all 4 competitors decreased further to pH 2.0 – 3.0, food testing results were equivalent to ISO 6579 reference and workflow total costs were up to $210.45 cheaper and up to 3.2 h faster.

Significance: Readybag Buffered Peptone Water acc. ISO 6579, ISO 21528, ISO 22964, FDA-BAM and EP demonstrates a stronger growth rate and superior buffering capacity compared to all 4 competitors, is equivalent to ISO 6579 reference method and improves lab efficiency by reducing labor time and cost.