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818
B
ird
et al
.
:
J
ournal of
AOAC I
nternational
V
ol
. 96, N
o
. 4, 2013
between presumptive and confirmed VIDAS SPT results.
The confidence intervals obtained for dLPOD
CP
indicated no
significant difference between the presumptive and confirmed
results using either confirmation process.
For the high-level inoculum, dLPOD
C
values of –0.02 (–0.05,
+0.02) were obtained between the USDA/FSIS-MLG method
and the VIDAS SPT method. The confidence intervals obtained
for dLPOD
C
indicated no significant difference between the two
methods. dLPOD
CP
values of 0.00 (–0.04, +0.04) were obtained
between presumptive and confirmed VIDAS SPT results.
The confidence intervals obtained for dLPOD
CP
indicated no
significant difference between the presumptive and confirmed
results. Detailed results of the POD statistical analysis are
presented in Table
2013.01B
and in appended Table D and
Figure 2A and B.
Traditional Confirmation with IBISA and ASAP
For the high level, 130 of the 132 test portions were reported as
positive by the VIDAS SPT method, with all portions confirming
positive. For the low level, 58 of 131 test portions were reported as
positive by the VIDAS SPT method, with 59 confirming positive.
For the uninoculated controls, none of the 132 samples produced
a presumptive positive result by the VIDAS SPT method and all
Table 4. Individual collaborator results for raw ground beef (375 g test portions) using traditional confirmation
a
High-level test portions
Low-level test portions
Uninoculated test portions
Lab 1 2 3 4 5 6 7 8 9 10 11 12 1 2 3 4 5 6 7 8 9 10 11 12 1 2 3 4 5 6 7 8 9 10 11 12
VIDAS SPT (traditional confirmation)
1 + + + + + + + + + + + + + + + + + – – – + – – – – – – – – – – – – – – –
2
b
+ + + + + + + + + + – + + + + – – – + + – + – – – – – – – – – – + – – –
3 – + + + + + + + + + + + + + + + – – – – – + – – – – – – – – – – – – – –
4 + + + + + + + + + + + + + + – + –
c
– – – – – – NA – – – – – – – – – – – –
5
b
+ + + + + + + + + + + + + – + – – – – – + – + + – – – – – – – – – + – +
6 + + + + + + + + + + + + + – + + – + + – + – – – – – – – – – – – – – – –
7
+ + + + + + + + + + + + + + + – – – + – – + – – – – – – – – – – – – – –
8
b
NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NANANA
9 + + + + + + + + + + + + + + + – + + – + + – – – – – – – – – – – – – – –
10 + + + + + + + + + + + + + + + – + – – + + – – – – – – – – – – – – – – –
11 + + + + + + + + + + + + – – – – – – – – – – – – – – – – – – – – – – – –
12 + + + + + + + + + – + + + + + – – – – – + + + + – – – – – – – – – – – –
13 + + + + + + + + + + + + + + + – – + + + + – – – – – – – – – – – – – – –
14 NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NANANA
15 + + + + + + + + + + + + + + + – – – – – + + – + – – – – – – – – – – – –
USDA/FSIS-MLG
1 + + + + + + + + + + + + + + – – + + + – – – – – – – – – – – – – – – – –
2
b
+ + + + + + + + + + + – – + + – – – – – – – – – – – – – – – – – – – – –
3
+ + + + + + + + + + + + – – + – + + – – – – – – – – – – – – – – – – – –
4 + + + + + + + + + + + + + + – + + + + + + + – – – – – – – – – – – – – –
5
b
+ + + + + + + + + + + + – – + – – – – – – – – – – – + – – – – – – – – –
6 + + + + + + + + + + + + – + – + + + + – – – – – – – – – – – – – – – – –
7 + + + + + + + + + + + + + – – + + + + + – – – – – – – – – – – – – – – –
8
b
NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NANANA
9
+ + + + + + + + + + + + – – – – + + + + – – – – – – – – – – – – – – – –
10 + + + + + + + + + + + + + + – – – + – + – + – – – – – – – – – – – – – –
11 + + + + + + + + + + + + – – – + + + + + + – – – – – – – – – – – – – – –
12 + + + + + + + + + + + + – – + + + + – + – – – – – – – – – – – – – – – –
13 + + + + + + + + + + + + – + + – + – – – + + – – – – – – – – – – – – – –
14 NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NANANA
15 + + + + + + + + + + + + + – – – – + – + + – – – – – – – – – – – – – – –
a
+ = Salmonella spp. were detected in samples; – =Salmonella spp. were not detected in sample; NA = laboratory did not participate in this matrix or
results were not received.
b
Results were not used in statistical analysis due to laboratory error.
c
Sample was confirmed negative using the reference method agars XLT4 and BGS, but confirmed positive on ASAP agar.
14