Microbiology Methods for ERP Review 3-2020

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GENE ‐ UP ® SLM 2 Collaborative Study

July 2019

Note * One isolate should be confirmed from each set of alternative confirmation plates as well

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as traditional confirmation plates.

2. MLG 4.10

2.1. Add 25g into 75 mL mTSB. Homogenize each test portion for approximately two minutes. 6 2.2. After incubation, an aliquot of the primary enrichment is transferred to secondary enrichments 7 Tetrathionate Hajna broth (TT) and Rappaport ‐ Vassiliadis medium (mRV). Transfer 0.5 mL of 8 sample into TT and 0.1 mL into mRV. Incubate at 42 ± 0.5 o C for 22 ‐ 24 h in an incubator or for 9 18 ‐ 24 h in a circulating water bath. 10 2.3. After incubation, secondary enrichments are struck to selective agars, BGS and DMLIA. 11 Incubate agar plates at 35 ± 2°C for 18  ‐ 24 h. Examine plates for typical colonies to be used for 12 confirmation procedures. Regardless of the presence of typical colonies all plates should be 13 reincubated for an additional 18 ‐ 24 h and reexamined for typical colonies. 14 2.4. From each test portion, pick one typical colony inoculate triple sugar iron (TSI) agar and lysine 15 iron agar (LIA). Keep remaining agar plates incase additional confirmation is required. Incubate 16 at 35 ± 2°C for 24 ± 2 h. 17 2.5. For presumptive positive Salmonella isolates streak to tryptic soy agar with 5% sheep blood 18 (TSAB) and Incubate at 35 ± 2°C for 16 ‐ 24 h. Perform the following tests from TSAB: Somatic O 19 and Polyvalent Flagellar H serology tests, biochemical confirmation using API20E (Official 20 Method 978.24) or VITEK GN (Official Method 2011.17). 23 24 All results are to be recorded on the data sheets provided. For each test portion, record the results 25 reported by the candidate method, presumptive and confirmed (traditional and alternative) as well as 26 the reference method. Upon completion, the data sheet should be emailed to the co ‐ Study Directors. 27 Incubate at 42  1  C for 15 ‐ 24 h. 21 22 Final Results

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