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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Reference Method Confirmation

1.8

1.8.1 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) 1.8.2 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. 1.8.3 Transfer typical colonies to TSI/LIA slants. Incubate 35 ± 1 ° C for 24 ± 2h. 1.8.4 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 negative plates and pick colonies as above.

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

USDA-FSIS MLG Ch. 4.06 – Ground beef

2.0

2.1 To each 25g test portion, add 225 mL buffered peptone water. Stomach each sample for

approximately two minutes. Incubate at 35 ± 1 ° C for 22 ± 2h.

2.2 Transfer 0.5 ± 0.05 mL enriched sample into 10 mL tetrathionate (TT-Hajna) broth and 0.1 ± 0.02 mL into 10 mL modified Rappaport-Vassiliadis (mRV) broth. Incubate at 42 ± 2.3 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 negative plates and pick colonies as Transfer typical colonies to TSI/LIA slants. Incubate 35 ± 1 ° C for 24 ± 2h. 2.5 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 somatic (O) and flagellar (H) tests will also be 3.0 Dry dog food - 3M Petrifilm SALX: Aseptically add the 375g test portion to 3375 mL pre-warmed 36 (41.5°C) 3M Salmonella Enrichment Base with supplement. 37 3.1 Mix in a Stomacher® bag with filter for 2 min. 38 3.2 Incubate 18-24 hr at 41.5 ± 1°C. 39 3.3 Prior to analysis, hydrate the 3M Petrifilm SALX Plates using 2.0 mL of sterile distilled 40 water. After hydration, the liquid was spread across of the surface of the plate using a 41 plastic spreader to evenly distribute the diluent. The plates were left undisturbed and 42 protected from light for a minimum of 1 hour prior to use. 43 3.4 Streak each enriched test portion onto 3M Petrifilm SALX plate and incubate at 41.5° ± 44 1°C for 24 ± 2 hours. 45 3.5 After incubation, record presumptive positive or negative result. 46 3.5.1 Positive – red to brown with yellow zone or gas bubble 47 performed. 0.5 ° C for 22-24 h. above. 2.4

AOAC Research Institute Expert Review Panel Use Only

DRAFT DOCUMENT

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