938-939 / 1195
24
1
Table 11. Heat-stress Injury for GovVal study
2
3
4
5
Analysis of data for all of the Method Comparison Studies
6
7
Fractionally positive data (5-15 positives) by at least one method, the LMX or reference method was required for analysis. The data
8
was analysed according to current AOAC guidelines. Comparison of data for the LMX method and the Reference method using Chi-
9
square test at the 5% level was conducted for unpaired data (Mantel-Haenszel test). The chi-square analysis must show that there was
10
no significant difference between the 2 methods at the 5% level or that the LMX method was significantly better than the Reference
11
method.
12
13
Discussion of results
14
15
PTM Study:
16
17
Processed cheese
18
For processed cheese inoculated with
L.monocytogenes
(unpaired enrichments) there were 5 confirmed positives for both the LMX
19
and AOAC methods. All uninoculated samples were negative with both methods. There were no false positives for the VIDAS
20
method for uninoculated samples. Confirmation using OAA or ChromID Lmono media showed exact agreement with traditional
21
media. There was no significant difference between the LMX method and the reference method using unpaired Chi-square test (Table
22
12)
23
Test Organism
Matrix
CFU/OXA
CFU/BHI
Degree Injury
L. monocytogenes
1/2a
ATCC 49594
Liver paté
2.4 x 10
8
1.1 x 10
9
78 %
L. monocytogenes
1/2b
ATCC BAA-751
Hot dogs
4.4 x 10
8
1.5 x 10
9
71 %
L. monocytogenes
3b
CWD 1591
Fermented
sausage
3.8 x 10
8
1.2 x 10
9
68 %
L. monocytogenes
3c
FSL-J1-049
Sliced deli turkey
6.6 x 10
8
1.5 x 10
9
56 %
L. monocytogenes
4b
ATCC 19115
Sliced deli ham
7.2 x 10
8
1.8 x 10
9
60 %
L. innocua
ATCC 33091
Hot dogs
3.5 x 10
8
9.4 x 10
8
63 %
PTM Certification Report