AOAC-RI ERP Book MICRO Sept 2016.pdf

OMAMAN-08/Collaborative Study Protocol March 2014 Expert Review Panel Use Only

3M Petrifilm SALX Collaborative Study

July 2013

OMA-2013-July-XXX

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3.5.2 Negative – no typical colonies present

Alternative 3M SALX Confirmation Method

3.6

3.6.1 Using a fine tip marker, circle presumptive positive colonies (red to brown colonies with discrete yellow zones and/or gas bubbles) on the plate top film. 3.6.2 Lift the top film and place a 3M Petrifilm Salmonella Express Confirmation Disk onto the gel. Close the film using a gloved hand (while practicing good laboratory technique) and remove air bubbles by gently applying a sweeping motion with even pressure onto the top of the film with the analyst’s fingers. 3.6.3 Incubate the plates with confirmation disks at 41.5° ± 1°C for 4 to 5 hours. 3.6.4 Observe circled colonies for color change - red/brown to green blue, blue, dark blue or black confirm the colony as Salmonella species. No color change, colony

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is negative.

3.6.5 Transfer typical colonies from SALX plate to TSI/LIA slants. Incubate 35 ± 1 ° C for

24 ± 2h.

3.6.6 Confirm a minimum of one typical colony per test portion with

biochemical/serological procedures prescribed by the USDA/FSIS method. Either the API20E (Official Method 978.24) or the VITEK GN (Official Method 2011.17) will be used as an alternative to the conventional biochemical tests. The

somatic (O) and flagellar (H) tests will also be performed.

Reference Method Confirmation

3.7

3.7.1 Transfer 0.5 ± 0.05 mL 3M SALX enriched sample into 10 mL tetrathionate (TT- Hajna) broth and 0.1 ± 0.02 mL into 10 mL modified Rappaport-Vassiliadis (mRV) 3.7.2 Streak both secondary enrichments onto double modified lysine iron agar (DMLIA) or xylose lysine Tergitol (XLT4) agar and brilliant green sulfa (BGS) agar. Use one loopful of inoculum for each plate. Incubate 35 ± 2 ° C for 18-24h. Select colonies. Re-incubate all plates for an additional 18-24 h. Reexamine initially broth. Incubate at 42 ± 0.5 ° C for 22-24 h.

negative plates and pick colonies as above.

3.7.3 Transfer typical colonies to TSI/LIA slants. Incubate 35 ± 1 ° C for 24 ± 2h. 3.7.4 Confirm a minimum of one typical colony per sample with

biochemical/serological procedures prescribed by the USDA/FSIS method. Either the API20E (Official Method 978.24) or the VITEK GN (Official Method 2011.17) will be used as an alternative to the conventional biochemical tests. The AOAC Research Institute Expert Review Panel Use Only somatic (O) and flagellar (H) tests will also be performed.

FDA-BAM Chapter 5 – Dry dog food

4.0

1.1.1. Add twenty 25g contaminated test portions and five 25g uncontaminated test portions to 225ml lactose broth. Blend 2 min. Let stand 60±5 min at room temperature. Mix 1.1.2. Transfer 0.1 mL to 10 mL RV broth (prepared from individual ingredients) and 1 mL to 10 mL TT broth. Incubate the RV at 42 ± 0.2°C for 24 ± 2 h. Incubate the TT broth at 35 ± 1.1.3. Mix and streak 3 mm loopful (10 µ L) RV broth onto BS, XLD and HE agars. Repeat from TT broth. Incubate at 35 ° C for 24 ± 2 h. Follow isolation procedure according to FDA- and adjust pH to 6.8±0.2 if necessary. Incubate 24 ± 2h at 35°C. 2.0 ° C for 24 ± 2 h in a forced air incubator.

BAM.

DRAFT DOCUMENT

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