311 / 363
B
ird
et al
.:
J
ournal of
AOAC I
nternational
V
ol
.
96, N
o
. 4, 2013
819
samples confirmed negative. For test portions analyzed by the
USDA/FSIS-MLG method, all of the 132 high and 57 of 132 low
inoculum test portions confirmed positive. For the uninoculated
controls, none of the 132 test portions confirmed positive.
For the low-level inoculum, dLPOD
C
values of 0.02 (–0.18,
+0.22) 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 –0.01 (–0.15, +0.14) 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 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
Table 5. Individual collaborator results for raw ground beef (375 g test portions) using alternative 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 (alternate confirmation)
b
1 + + + + + + + + + + + + + + + + + – – – + – – – – – – – – – – – – – – –
2 + + + + + + + + + + – + + + + – – – + + – + – – – – – – – – – – – – – –
3 – + + + + + + + + + + + + + + + – – – – – + – – – – – – – – – – – – – –
4 + + + + + + + + + + + + + + – + –
c
– – – – – – NA – – – – – – – – – – – –
5
d
+ + + + + + + + + + + + + – + – – – – – + – + + – – – – – – – – – + – +
6 + + + + + + + + + + + + + – + + – + + – + – – – – – – – – – – – – – – –
7 + + + + + + + + + + + + + + + – – – + – – + – – – – – – – – – – – – – –
8
d
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 NA NA NA
9 + + + + + + + + + + + + + + + – + + – + + – – – – – – – – – – – – – – –
10 + + + + + + + + + + + + + + + – + – – + + – – – – – – – – – – – – – – –
11 + + + + + + + + + + + + – – – – – – – – – – – – – – – – – – – – – – – –
12
d
+ + + + + + + + + – + + + + + – – – – – + + + + – – – – – – – – – –
c
–
c
–
c
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 NA NA NA
15 + + + + + + + + + + + + + + + – – – – – + + – + – – – – – – – – – – – –
USDA/FSIS-MLG
1 + + + + + + + + + + + + + + – – + + + – – – – – – – – – – – – – – – – –
2 + + + + + + + + + + + – – + + – – – – – – – – – – – – – – – – – – – – –
3 + + + + + + + + + + + + – – + – + + – – – – – – – – – – – – – – – – – –
4 + + + + + + + + + + + + + + – + + + + + + + – – – – – – – – – – – – – –
5
d
+ + + + + + + + + + + + – – + – – – – – – – – – – – + – – – – – – – – –
6 + + + + + + + + + + + + – + – + + + + – – – – – – – – – – – – – – – – –
7 + + + + + + + + + + + + + – – + + + + + – – – – – – – – – – – – – – – –
8
d
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 NA NA NA
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 NA NA NA
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
Alternative confirmation = direct streak of the primary enrichment onto IBISA and ASAP.
c
Sample was confirmed negative using the reference method agars XLT4 and BGS, but confirmed positive on ASAP and IBISA agar.
d
Results were not used in statistical analysis due to laboratory error.
Candidates for 2016 Method of the Year
310