228 / 596
14
0.00 with 95% confidence intervals of (-0.03, 0.03) was obtained between the candidate and
1
reference method, indicating no statistically significant difference between the two methods.
2
A dLPOD
CP
value of 0.00 with 95% confidence intervals of (-0.03, 0.03) was obtained between
3
presumptive and confirmed results indicating no statistically significant difference between the
4
presumptive and confirmed results.
5
For the un-inoculated controls, 0 out of 132 samples (POD
CP
of 0.00) produced a presumptive
6
positive result by the 3M MDA 2 -
Listeria monocytogenes
method with 0out of 132 test portions
7
(POD
CC
of 0.00) confirming positive. For samples that produced presumptive positive results on
8
the 3M MDA 2 –
Listeria monocytogenes
method, 0out of 132 samples confirmed positive
9
(POD
C
of 0.00). For test portions evaluated by the USDA/FSIS MLG reference method, 0 out of
10
132 test portions produced positive results. A dLPOD
C
value of 0.00 with 95% confidence
11
intervals of (-0.03, 0.03) was obtained between the candidate and reference method, indicating
12
no statistically significant difference between the two methods. A dLPOD
CP
value of 0.00 with
13
95% confidence intervals of (-0.03, 0.00) was obtained between presumptive and confirmed
14
results indicating no statistically significant difference between the presumptive and confirmed
15
results.
16
17
Detailed results of the POD statistical analysis are presented in Table 2016.2A and Figures 1A-
18
1B.
19
20
Raw Chicken Breast Fillet (25 g Test Portions)
21
22
Raw chicken breast fillet test portions were inoculated at a low and high inoculum level and were
23
analyzed for the detection of
Listeria monocytogenes
. Un-inoculated controls were included in
24
each analysis. Laboratory 11 did not participate in the evaluation of this matrix. Laboratory 10
25
submitted data that indicated cross contamination of the inoculating organism in the un-
26
inoculated control samples. Further analysis at the coordinating laboratory confirmed the cross
27
contamination of the un-inoculated controls. Due to this issue, the data submitted from
28
Laboratory 10 was not used in the statistical analysis. All other laboratories submitted data for
29
both methods evaluated. The MPN levels obtained for this matrix, with 95% confidence
30
intervals, were 0.66 CFU/test portion (0.51, 0.83) for the low level and 6.24 CFU/test portion
31
(3.58, 10.88) for the high level.
32
For the low inoculum level, 86 out of 132 test portions (POD
CP
of 0.65) were reported as
33
presumptive positive by the 3M MDA 2 –
Listeria monocytogenes
method with 86out of 132 test
34
portions (POD
CC
of 0.65) confirming positive. For samples that produced presumptive positive
35
results on the 3M MDA 2 –
Listeria monocytogenes
method, 85out of 132 test portions confirmed
36
positive (POD
C
of 0.64). For test portions evaluated by the USDA/FSIS MLGreference method,
37
64 out of 132 test portions produced positive results. A dLPOD
C
value of 0.16 with 95%
38
confidence intervals of (0.04, 0.28) was obtained between the candidate and reference method,
39
indicating a statistically significant difference between the two methods, with a positive
40
correlation in data indicating more recovery of the target analyte by the candidate method. A
41
dLPOD
CP
value of 0.00 with 95% confidence intervals of (-0.12, 0.12) was obtained between
42
AOAC Research Institute
Expert Review Panel Use Only
OMAMAN-30 A/ Collaborative Study Manuscript
OMA ERP June 2016
ERP Use Only