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Document 2 of 2 – 3M Petrifilm Salmonella Express PTM Study Report
Table 28. Statistical Analysis (Chi Square) of 3M Salmonella Petrifilm Method Compared to the USDA/FSIS Method for Detection of
1
Salmonella in Raw Ground Chicken and Pasteurized Liquid Eggs (Independent Laboratory Data)
2
Matrix
Level of
Target
Organism MPN/25g
a
Total
Samples
b
Presumptive
Positive
Confirmed
Positive
c
Reference
Positive
d
X
2e
Relative
Sensitivity
Rate
f
False
Positive
Rate
g
Raw Ground
Chicken Control
NA
5
0
0
0
-
-
Low
0.8
20
12
12
11
0.1
100
0.0
Pasteurized
Liquid Eggs
Control
NA
5
0
0
0
-
-
Low
0.2
20
7
7
8
0.1
100
0.0
a
Most probable number of colony forming units (cfu)/g food
b
Number of test assay positive samples not considering subsequent confirmations
c
Number of test assay positive samples subsequently confirmed
d
Number of samples positive by reference method
eMantel-Hansezel chi square
g
Test false positive rate is 100 – test specificity rate. Not calculated where the number of samples negative by both methods is 0.
3M Salmonella Petrifilm Method
results, expressed as a percentage.
positive reference results
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4
5
6
7
8
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