AOAC-RI ERP Book MICRO Sept 2016.pdf

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

Table 24. 3M Petrifilm SALX Method Comparison POD Results for Raw Ground Pork (Internal Data) 1

3M Petrifilm SALX Method

Reference 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 R

POD C

18 Hr Primary Enrichment –

Raw Ground Pork

0

5

0

0

0.00 - 0.43

0

0

0.00 - 0.43

0 -0.43 – 0.43

Salmonella

8 Hr 2 0 RV-R10 Enrichmnet Montevideo

Vs. USDA/FSIS- MLG

0.66 (0.38- 1.16)

20

9

0.45 0.26 – 0.66

9

0.45 0.26 – 0.66

0 -0.28 – 0.28

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

0

5

0

0

0.00 - 0.43

0

0

0.00 - 0.43

0 -0.43 – 0.43

ATCC 8387

0.66 (0.38- 1.16)

20

9

0.45 0.26 – 0.66

9

0.45 0.26 – 0.66

0 -0.28 – 0.28

0

5

0

0

0.00 - 0.43

0

0

0.00 - 0.43

0 -0.43 – 0.43

0.66 (0.38- 1.16)

20

9

0.45 0.26 – 0.66

9

0.45 0.26 – 0.66

0 -0.28 – 0.28

0

5

0

0

0.00 - 0.43

0

0

0.00 - 0.43

0 -0.43 – 0.43

0.66 (0.38- 1.16)

20

9

0.45 0.26 – 0.66

9

0.45 0.26 – 0.66

0 -0.28 – 0.28

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

2