564-565 / 1195
Table 2013.2A(cont’d.)
: Comparative Results for the Detection of
Listeria
spp. in Queso Fresco (25 g) by the VIDAS LPTMethod vs. AOAC 993.12 in a
1
Collaborative Study (Low Level)
2
Statistic
MPN/
Test Portion Laboratory
Candidate
presumptive (CP)
Candidate confirmed
(CC)
Candidate result (C)
Reference method
(R)
C vs. R
N
x
POD(CP)
N
x
POD(CC)
N
X
POD(C) N
X POD(R) dLPOD
(C,R)
dLPOD
(CP,CC)
0.63
0.49
0.79
1
12
6
0.50
12
6
0.50
12
6
0.50
12
5
0.42
0.08
0.00
2
12
4
0.33
12
4
0.33
12
4
0.33
12
5
0.42
-0.09
0.00
3
12
4
0.33
12
4
0.33
12
4
0.33
12
6
0.50
-0.17
0.00
4
12
7
0.58
12
7
0.58
12
7
0.58
12
7
0.58
0.00
0.00
5
12
5
0.42
12
5
0.42
12
5
0.42
12
4
0.33
0.09
0.00
6
12
6
0.50
12
6
0.50
12
6
0.50
12
6
0.50
0.00
0.00
7
12
6
0.50
12
6
0.50
12
6
0.50
12
7
0.58
-0.08
0.00
8
12
8
0.66
12
8
0.66
12
8
0.66
12
6
0.50
0.16
0.00
9
12
7
0.58
12
7
0.58
12
7
0.58
12
7
0.58
0.00
0.00
10
12
6
0.50
12
6
0.50
12
6
0.50
12
6
0.50
0.00
0.00
11
a
12
6
0.50
12
6
0.50
12
6
0.50
12
8
0.66
-0.16
0.00
12
12
7
0.58
12
7
0.58
12
7
0.58
12
6
0.50
0.08
0.00
13
12
7
0.58
12
7
0.58
12
7
0.58
12
5
0.42
0.16
0.00
14
12
7
0.58
12
5
0.42
12
5
0.42
12
6
0.50
-0.08
0.16
Estimate
All
156 80
0.51
156 78
0.50
156 78
0.50
156 76
0.49
0.01
0.01
LCL
0.43
0.42
0.42
0.41
-0.10
-0.10
UCL
0.59
0.58
0.58
0.57
0.13
0.13
s
r
b
0.51
0.51
0.51
0.52
LCL
0.46
0.46
0.46
0.46
UCL
0.52
0.52
0.52
0.52
s
L
c
0.00
0.00
0.00
0.00
LCL
0.00
0.00
0.00
0.00
UCL
0.13
0.14
0.14
0.10
s
R
d
0.51
0.51
0.51
0.52
UCL
0.46
0.46
0.46
0.47
LCL
0.52
0.52
0.52
0.52
P
T
e
0.9210
0.9161
0.9161
0.9937
a
Results were not used in statistical analysis due to laboratory error.
3
b
Repeatability Standard Deviation,
c
Among-Laboratory Standard Deviation,
d
Reproducibility Standard Deviation,
e
P Value=Homogeneity test of laboratory PODs
4
LCL – Lower Confidence Limit; UCL – Upper Confidence Limit
5
6
22