AOAC-RI ERP Micro June 2016

Table 15: 3M ™ MDA 2 Listeriamonocytogenes Assay, Presumptive vs. Confirmed – POD Results (INDEPENDENT STUDY)

Analysis Time Point

Presumptive

Confirmed

CFU a / Test Area

N b

95% CI g

dPOD CP f

Matrix

Strain

x c

d

POD CC e

POD CP

95% CI 0.00, 0.43 0.11, 0.47 0.57, 1.00 0.00, 0.43 0.11, 0.47 0.57, 1.00 95% CI 0.00, 0.43 0.53, 0.89 0.57, 1.00 0.00, 0.43 0.58, 0.92 0.57, 1.00 95% CI 0.00, 0.43 0.39, 0.78 0.57, 1.00 0.00, 0.43 0.39, 0.78 0.57, 1.00

X

95% CI 0.00, 0.43 0.11, 0.47 0.57, 1.00 0.00, 0.43 0.11, 0.47 0.57, 1.00 95% CI 0.00, 0.43 0.53, 0.89 0.57, 1.00 0.00, 0.43 0.53, 0.89 0.57, 1.00 95% CI 0.00, 0.43 0.39, 0.78 0.57, 1.00 0.00, 0.43 0.39, 0.78 0.57, 1.00

-

5

0 5 5 0 5 5

0.00 0.25 1.00 0.00 0.25 1.00 0.00 0.75 1.00 0.00 0.80 1.00 0.00 0.60 1.00 0.00 0.60 1.00

0 5 5 0 5 5

0.00 0.25 1.00 0.00 0.25 1.00 0.00 0.75 1.00 0.00 0.75 1.00 0.00 0.60 1.00 0.00 0.60 1.00

0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.05 0.00 0.00 0.00 0.00 0.00 0.00 0.00

-0.43, 0.43 -0.26, 0.26 -0.43, 0.43 -0.43, 0.43 -0.26, 0.26 -0.43, 0.43 -0.43, 0.43 -0.26, 0.26 -0.43, 0.43 -0.43, 0.43 -0.21, 0.30 -0.43, 0.43 -0.43, 0.43 -0.28, 0.28 -0.43, 0.43 -0.43, 0.43 -0.28, 0.28 -0.43, 0.43 95% CI g 95% CI g

L. monocytogenes ATCC 19118 & Enterococcus faecium ATCC 19434

20

42 & 530

24 Hours

Stainless Steel (225 mL)

5 5

400 & 4000

-

20

26 Hours

42 & 530

5

400 & 4000 CFU a / Test Area

Analysis Time Point

Presumptive

Confirmed

N b

dPOD CP f

Matrix

Strain

x c

d

POD CC e

POD CP

X

-

5

0

0

20

15

15

35

24 Hours

Sealed Concrete (100 mL)

5 5

5 0

5 0

360

L. monocytogenes ATCC 19117

-

20

16

15

26 Hours

35

5

5

5

360

Analysis Time Point

Presumptive

Confirmed

CFU a / Test Area

N b

dPOD CP f

Matrix

Strain

x c

d

POD CC e

POD CP

X

-

5

0

0

L. monocytogenes ATCC 51782 & Enterococcus faecalis ATCC 29212

20

12

12

42& 540

24 Hours

5 5

5 0

5 0

590 & 3600

Plastic (10 mL)

-

20

12

12

26 Hours

42 & 540

5

5

5

590 & 3600

a CFU/Test Area = Results of the CFU/Test area were determined by plating the inoculum for each matrix in triplicate b N = Number of test portions c x = Number of positive test portions d POD CP = Candidate method presumptive positive outcomes divided by the total number of trials e POD CC = Candidate method confirmed positive outcomes divided by the total number of trials f dPOD CP = Difference between the candidate method presumptive result and candidate method confirmed result POD values g 95% CI = If the confidence interval of a dPOD does not contain zero, then the diistically significant at the 5% level