AOAC-RI ERP Book MICRO Sept 2016.pdf

February 20, 2013

Figure 2. 3M Petrifilm Salmonella vs. FDA-BAM – raw shrimp, bunched spinach, dry dog food (375g) 1 2

Screen for Indigenous Salmonella

Estimate total Aerobic Counts

Matrix

3M

BAM

Dry dog food : 375g+3.375L 3M BPW ISO Spinach & shrimp : 25g + 225ml 3M BPW ISO (prewarmed to 42C)

Add 25g + 225ml Lactose broth, Spinach – mix manually, do not blend. Shrimp & dog food : blend 2 min and let stand 60±5 min at room temp Mix and adjust pH to 6.8±0.2 if necessary 24±2h h at 35°C

Homogenize 2 min 18-24h h at 42±1°C

MPN

Dog food

0.1ml sample + 10ml RV, 24±2h at 42±0.2°C

1.0ml sample + 10ml TT, 24±2h at 35±2°C

Shrimp & Spinach 0.1ml sample + 9.9ml RV10 8h at 41.5°C

High Microbial Load Products 1.0ml sample + 10ml TT, 24±2h at 43±0.2°C

Low Microbial Load Products 1.0ml sample + 10ml TT, 24±2h at 35±2°C

0.1ml sample + 10ml RV, 24±2h at 42±0.2°C

• Streak to XLD & HE - 24±2h at 35°C • Streak to BS - incubate at 35°C for 24±2h, read and pick if applicable. Re-incubate another 24 h

Run the 3M Petrifilm Salmonella Express System

• Streak to XLD & HE - 24±2h at 35°C • Streak to BS - incubate at 35°C for 24±2h,

read and pick if applicable. Re-incubate another 24 h

Pick typical colony and transfer to TSI/LIA slants 24±2h at 35°C

Transfer typical colonies to TSI/LIA slants 24±2h at 35°C

Transfer typical colonies to TSI/LIA slants 24±2h at 35°C

Biochemical/serological confirmation on all enrichments according to FDA-BAM

Biochemical/serological confirmation on all enrichments according to FDA-BAM

Biochemical/serological confirmation on all enrichments according to FDA-BAM

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