Microbiology Methods for ERP Review 3-2020

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GENE ‐ UP ® SLM 2 Collaborative Study

July 2019

(1) Five enriched samples can also be wet pooled. After incubation, mix the contents of each sample bag and combine 1 mL from each sample into a prelabeled tube. e) Pasteurized liquid egg and powdered egg (100 g). ― Add 900 mL of pre ‐ warmed (42 ± 1°C) BPW. Homogenize and incubate at 42 ± 1°C for 22–26 h. f) Whey protein powder & instant non ‐ fat dried milk (375 g). ― Add 1125 mL of pre ‐ warmed (42 ± 1°C) BPW. Homogenize and incubate at 42 ± 1°C for 22–26 h. g) Garlic powder (375 g). ― Add 3375 mL of pre ‐ warmed (42 ± 1°C) BPW + K2SO3. Homogenize and incubate at 42 ± 1°C for 22–26 h. h) Creamy peanut bu Ʃ er (375 g). ― Add 3375 mL of pre ‐ warmed (42 ± 1°C) BPW. Homogenize and incubate at 42 ± 1°C for 20–24 h. i) Dark chocolate (375 g). ― Add 3375 mL of pre ‐ warmed (42 ± 1°C) BPW. Homogenize and incubate at 42 ± 1°C for 10–24 h. j) Dry pet food (375 g). ― Add 3375 mL of pre ‐ warmed (42 ± 1°C) BPW. Homogenize and incubate at 42 ± 1°C for 22–26 h. k) Environmental samples. ― Add enough BPW to cover the sampling device (ex. 10 mL for a swab and 100 mL for a sponge). Homogenize and incubate at 42 ± 1°C for 18–24 h. Note: For environmental samples, the collection device should first be dampened with a sterile diluent (e.g., buffered peptone water) containing, if necessary, a suitable neutralizing agent (e.g., Lecithin - Polysorbate - L ‐ Histidine - Sodium thiosulfate mixture or Dey Engley). Note: Incubation conditions may have repercussions on short detection procedures. The temperatures indicated must be scrupulously respected. In particular, it is advisable to ensure that the conditions for preheating the enrichment broth enable the indicated temperature to be reached. The sample preparation time (time between the end of the enrichment broth pre - heating phase and the start of the food sample incubation phase), must not exceed 45 minutes. It is recommended to use a ventilated incubator for the incubation phase. Note: Extending the enrichment time to 24 hours allows for performance improvement of the alternative method only for large portions of raw meat products. a) Following incubation, manually mix the contents of the blender bag. Optionally, a sterile technique can be used to remove 1 mL of enriched sample; place it in a pre ‐ labeled microcentrifuge tube. Note: Do not discard the individual enriched samples until the analysis is complete and it has been confirmed that no further testing is required. Enriched samples can be stored at 2– 8°C for up to 72 h before performing analysis. b) Use the plate map created in the GENE ‐ UP® Routine software to determine the number of lysis tubes required from the GENE ‐ UP® Lysis Kit and place the correct number of lysis tubes in the GENE ‐ UP® Lysis Tube Holder. If less than 8 tubes in a strip are required, the strips can be cut apart. Note: Never open the lysis tubes. If a lysis tube opens or leaks, this should be considered a contamination event.

i) Sample Lysis

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