Microbiology Methods for ERP Review 3-2020

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Salt or Normal Saline prior to the lysis step. If inhibition persists, proceed with an additional 1:3 dilution as described above.

I. Confirmation of Positive Results

All positive results must be confirmed according to the BAM, MLG, or ISO (11) reference methods or according to the following bioMérieux GENE‑UP ® confirmation protocol. Confirmation should be performed using the enrichment broth stored at 2–8°C and should be initiated within 72 h following the end of the incubation period. If using an enriched sample, mix thoroughly by hand. Note: For short protocols, the confirmation can be made at the end of the incubation time (8 h or 10 h). (a) Isolate the enrichment broth on a SALSA ™ agar plate, CHROMID Salmonella or on ASAP and XLD agar plates; incubate at 35°C ± 1°C for 24 ± 3 h. (b) If a typical colony is obtained, test an isolated colony directly using a Salmonella spp. latex or API ® 20E, VITEK GN or VITEK MS.. In the event of discordant results (positive with the alternative method, not confirmed by one of the options described above), the laboratory must take the necessary steps to ensure that the results obtained are accurate. It is recommended, for example, to perform the following procedure:

(a) Transfer 100 μL from the enrichment to 10 mL SX2 for a second enrichment. Incubate at 42°C ± 1°C for 24 ± 3 h.

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