AOAC-RI ERP Book MICRO Sept 2016.pdf

Document 2 of 2 – 3M Petrifilm Salmonella Express PTM Study Report

Table 20. 3M Petrifilm SALX Method Comparison POD Results for Raw Ground Chicken (Internal Data) 1

Reference Method

3M Petrifilm SALX Method

x c

Strain MPN a /25g

N b

95% CI g

e

d

dPOD C f

95% CI

95% CI

x

Matrix Time Point

POD C

POD R

18 Hr Primary Enrichment –

Raw Ground Chicken

0

5

0

0.00 - 0.43

0

0

0.00 - 0.43

0

0 -0.43 – 0.43

Salmonella

8 Hr 2 0 RV-R10 Enrichment Heidelberg

Vs. USDA/FSIS- MLG

1.15 (0.70- 2.07)

20

14

0.7 0.48 - 0.85 14

0.7 0.48 - 0.85

0 -0.27 – 0.27

18 Hr Primary Enrichment – 24 Hr 2 0 RV-R10 Enrichment 24 Hr Primary Enrichment – 8 Hr 2 0 RV-R10 Enrichment 24 Hr Primary Enrichment – 24 Hr 2 0 RV-R10 Enrichment

0

5

0

0

0.00 - 0.43

0

0

0.00 - 0.43

0 -0.43 – 0.43

NCTC

1.15 (0.70- 2.07)

20

14

0.7 0.48 - 0.85 14

0.7 0.48 - 0.85

0 -0.27 – 0.27

5717

0

5

0

0

0.00 - 0.43

0

0

0.00 - 0.43

0 -0.43 – 0.43

1.15 (0.70- 2.07)

20

14

0.7 0.48 - 0.85 14

0.7 0.48 - 0.85

0 -0.27 – 0.27

0

5

0

0

0.00 - 0.43

0

0

0.00 - 0.43

0 -0.43 – 0.43

1.15 (0.70- 2.07)

20

14

0.7 0.48 - 0.85 14

0.7 0.48 - 0.85

0 -0.27 – 0.27

a MPN = Most Probable Number is based on the POD of reference method test portions across labs using the AOAC MPN calculator with 95% confidence interval b N = Number of test potions c x = Number of positive test portions d POD C = Candidate method confirmed positive outcomes divided by the total number of trials e POD R = Reference method confirmed positive outcomes divided by the total number of trials f dPOD C = Difference between the candidate method confirmed results and candidate method confirmed result POD values

g 95% CI = If the confidence interval of a dPOD does not contain zero, then the difference is statistically significant at the 5% level

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