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AOAC INTERNATIONAL
Screen prompts were followed to load samples into the cycler/detector and run a full process with
282
the “Real Time Salmonella” target. At the completion of the PCR and detection process, the screen
283
prompts were followed to remove samples and display results.
284
BAX® System results were displayed as follows:
285
Green (-)
Negative for
Salmonella
Yellow (?)
Indeterminate
result
Red (+)
Positive for
Salmonella
Yellow (?) with
red slash
Signal error
286
Reference Methods
287
For ground beef, 10 µL of each secondary enrichment for test and reference method samples was
288
streaked onto XLT-4 and BGS agars (for the USDA-MLG method) or BS and BGS agars (for the HC
289
Compendium method). All agars were incubated at 35°C for 18-24 hours, after which plates were
290
examined for colonies with typical characteristics of
Salmonella
. If typical colonies were not present on
291
BS plates after 18-24 hours, they were incubated for an additional 22-26 hours and reexamined.
292
Suspect colonies were confirmed using the biochemical and serological methods described in the
293
appropriate corresponding reference methods (biochemical, serological) [3,4].
294
For cream cheese, 10 µL of each TT and RV broth enrichment was streaked onto BS agar, XLD
295
agar and HE agar. All agars were incubated at 35°C for 22-26 hours, after which plates were
296
examined for colonies with typical characteristics of
Salmonella
. Suspect colonies were confirmed
297
using the biochemical and serological methods described in the FDA-BAM [2].
298
For dry pet food, 10 µL of each RVS and TBG broth was streaked onto Bismuth Sulfite (BS) and
299
Brilliant Green Sulfa (BGS) agars. Plates were incubated at 35°C for 22-26 hours. If colonies
300
suggestive of
Salmonella
had not developed on BS plates, then these plates were incubated for an
301
additional 22-26 hours. Suspect colonies were confirmed using the biochemical and serological
302
methods described in the Health Canada Compendium of Microbiological Methods [3].
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Statistical Analysis
304
Statistical analysis was conducted for this study using the Probability of Detection (POD)
305
statistical treatment of data as described in the current AOAC validation guidelines [5].
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Dupont BAX Salmonella PTM Report
Modification Approved 2012 / PTM Certification No. 081201
For Expert Review Panel Use Only
Do Not Distribute