Microbiology Methods for ERP Review 3-2020

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c. If typical colonies are observed, confirm by use of appropriate techniques. d. If no typical colonies are observed, the sample is regarded as negative.

FDA/BAM Chapter 5

1) For each 25 g test portion, the instant non-fat dry milk powder was aseptically added into a sterile beaker (250 mL) or other appropriate container. Using sterile glass or a paper funnel (made with tape to withstand autoclaving), a 25 g test portion was poured gently over surface of 225 mL brilliant green water contained in sterile 500 mL Erlenmeyer flask. The brilliant green water was prepared by adding 2 mL of 1% brilliant green dye solution per 1000 mL sterile distilled water. The container was allowed to stand undisturbed for 60 ± 5 min. The container was loosely capped and incubated, without mixing or pH adjustment, for 24 ± 2 hours at 35 ± 2.0  C. 2) A 0.1 mL aliquot was transferred to 10 mL of Rappaport-Vassiliadis (RV) broth and 1.0 mL aliquot was transferred to 10 mL TT broth. Due to low microbial load (<1.0 x 10 4 ), the RV broth was incubated at 42  0.2°C for 24  2 h in a circulating water bath and the TT broth was incubated at 35 ± 2.0  C for 24  2 h. 3) The tubes were mixed by vortex and streaked with a 3 mm loopful (10  L) of RV broth onto BS, XLD and HE agars. A loopful of the TT broth was also streaked to BS, XLD and HE agars. All agars were incubated at 35 ± 2.0  C for 24  2 hours. Follow isolation procedure according to FDA/BAM Chapter 5 reference method. 4) All typical colonies were transferred to TSI, LIA and TSA. All slants or plates were incubated at 35± 2.0  C for 24  2 hours. A typical colony per test portion was confirmed with biochemical/serological procedures prescribed by the FDA/BAM method. The somatic (O) and flagellar (H) tests will also be performed. For final confirmation, either the API20E (AOAC Official Method 978.24 ), VITEK GN (AOAC Official Method 2011.17 ) or Bruker MALDI (AOAC Official Method 2017.09 ) can be performed F. Analysis 1) All results were recorded on the data sheets provided. For each test portion, the results were reported by the Solus One Salmonella along with the confirmation results for both the Solus One Salmonella and reference method. 2) The data was reported on data report form labeled “ Solus One Salmonella Collaborative Study Test Portion Data Report Form” for all test portions. 3) Upon completion of analysis, all results were emailed, or faxed, to Benjamin Bastin at BBastin@QLaboratories.com

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