924-925 / 1195
17
Table 7. Ruggedness – Time of temperature equilibration of reagents
1
2
Trial 1
Trial 2
Strains
Test
Time of temperature equilibration (min.)
Time of temperature equilibration (min.)
0
30
60
120
0
30
60
120
Listeria monocytogenes
ATCC 19115
1
0.81
0.75
0.72
0.73
0.89
0.92
0.87
0.78
2
0.82
0.73
0.73
0.71
0.84
0.92
0.88
0.79
3
0.78
0.76
0.71
0.74
0.74
0.83
0.90
0.83
4
0.77
0.77
0.71
0.72
0.84
0.87
0.82
0.81
5
0.77
0.76
0.70
0.73
0.74
0.83
0.89
0;80
Mean
0.79
0.75
0.72
0.73
0.81
0.87
0.87
0.80
Listeria monocytogenes
ATCC 19117
1
0.82
0.81
0.80
0.88
0.94
0.94
0.92
0.99
2
0.95
0.88
0.89
0.91
0.95
0.95
0.96
0.96
3
0.92
0.83
0.91
0.86
0.89
0.97
092
0.92
4
0.92
0.84
0.93
0.84
0.92
0.94
0.93
0;99
5
0.88
0.85
0.87
0.79
0.90
0.95
0.94
0.93
Mean
0.90
0.84
0.88
0.86
0.92
0.95
0.94
0.96
Bacillus cereus
ATCC 27522
1
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
2
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
3
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
4
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
5
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
Mean
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
Positive results = TV
≥
0.05, negative results = TV< 0.05, ATCC = American Type Culture Collection
3
Method Comparison study
4
5
PTM study: Detection of
Listeria monocytogenes
in Inoculated Foods
6
7
This study was conducted according to AOAC guidelines (8) outlined in the AOAC General Referee approved PTM validation
8
protocol. The PTM study consisted of a comparative evaluation of six foods (processed cheese, vanilla ice cream, frozen spinach,
9
cooked shrimp, smoked white fish, and peanut butter) in the contract lab study and three foods (cooked shrimp, deli ham and vanilla
10
ice cream) in the independent lab study. A background screen of each matrix was conducted prior to inoculation and natural
11
PTM Certification Report