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11
of
17
O157 and the reference method indicated that there was no significant difference
at the 5% level between the number of positive results by the two methods. The
POD analysis between the 3M
™
MDA 2 -
E. coli
O157 presumptive and
confirmed results indicated that there was no significant difference at the 5%
level. A summary of POD analyses [9] are presented in Tables 4-7 of the
Appendix.
Table C: Summary of Results
Matrix
Raw Ground Beef (73% lean 27% fat)
Method
3M
™
MDA 2 -
E. coli
O157
USDA/FSIS
MLG 5.09
Result
Presumptive
Confirmed
Time Point
10 Hours
10 Hours
Uninoculated
0/5
0/5
0/5
Low
11/20
11/20
7/20
High
5/5
5/5
5/5
Raw Ground Beef- 10 Hour Enrichment
For the low inoculation level of the 3M
™
MDA 2 -
E. coli
O157,
there were 11 presumptive positives and 11 confirmed
positives following the USDA/FSIS MLG 5B.05 reference
method. There were 7 confirmed positives for the reference
method. For the high inoculation level, there were 5
presumptive positives and 5 confirmed positives following the
USDA/FSIS MLG 5.09 reference method. There were 5
confirmed positives following the reference method.
For the low inoculation level, a dPOD
C
value of 0.20 was
obtained with a 95% confidence interval of (-0.10, 0.46),
indicating no statistically significant difference between the
candidate and reference method. A dPOD
CP
value of 0.00 was
obtained with a 95% confidence interval of (-0.28, 0.28),
indicating no statistically significant difference between the
candidate presumptive and the USDA/FSIS MLG 5.09
reference method confirmed results.
For the high inoculation level, a dPOD
C
value of 0.00 was
obtained with a 95% confidence interval of (-0.43, 0.43),
indicating no statistically significant difference between the
candidate and reference method. A dPOD
CP
value of 0.00 was
obtained with a 95% confidence interval of (-0.43, 0.43),
indicating no statistically significant difference between the
candidate presumptive and confirmed results. Detailed results
of the POD analyses are presented in Tables 5 and 7 of the
Appendix.