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CONFIDENTIAL INFORMATION
Page 7 of 17
presented here were statistically analyzed according to the POD methods of the
2012 version of the AOAC International Methods Committee Guidelines for
Validation of Microbiological Methods for Food and Environmental Surfaces
document (1). The POD
CP
, POD
CC
, dPOD
CP
, POD
C
, POD
R
, and dPOD
C
values
calculated at each level of inoculation for the candidate method and the reference
method testing of sprouts, and their corresponding 95% confidence intervals, are
provided below in Table 9.
Table 1. Concentration of
E. coli
O157:H7 Inoculum Level per Gram of Matrix,
Determined through Most Probable Number Analysis
1. MPN/g and 95% Confidence Interval Values were generated from the LCF MPN Calculator Version 1.6
Table 2. Candidate Method Testing Results for Spinach Matrix ‘Screening
Stage’ and ‘Confirmation Stage’ (200 g Spinach Analyzed via the 3M
TM
MDA)
Food Matrix/Inoculation Level
Sample Size Sample Number Number of Positives MPN/g
1
95% CI
1
100
5
4
10
5
1
1
5
2
50
5
3
25
5
5
10
5
3
Spinach/High
Sprouts/High
2.584 X 10
-2
4.740 X 10
-2
1.107 X 10
-2
, 6.028 X
10
-2
2.494 X 10
-2
, 9.008 X
10
-2
Sample Number
Inoculum Level
3M MDS
18 h
CT-SMAC #1 CT-SMAC
#2
Rainbow
O Serology H Serology
VITEK Confirmation
1
LOW
+
+
+
+
+
+
E. coli O157
+
2
LOW
=
=
=
=
=
=
3
LOW
=
=
=
=
=
=
4
LOW
=
=
=
=
=
=
5
LOW
=
=
=
=
=
=
6
LOW
=
=
=
=
=
=
7
LOW
=
=
=
=
=
=
8
LOW
+
+
+
+
+
+
E. coli O157
+
9
LOW
=
=
=
=
=
=
10
LOW
=
=
=
=
=
=
11
LOW
=
=
=
=
=
=
12
LOW
=
=
=
=
=
=
13
LOW
+
+
+
+
+
+
E. coli O157
+
14
LOW
+
+
+
+
+
+
E. coli O157
+
15
LOW
=
=
=
=
=
=
16
LOW
=
=
=
=
=
=
17
LOW
=
=
=
=
=
=
18
LOW
+
+
+
+
+
+
E. coli O157
+
19
LOW
+
+
+
+
+
+
E. coli O157
+
20
LOW
+
+
+
+
+
+
E. coli O157
+
1
HIGH
+
+
+
+
+
+
E. coli O157
+
2
HIGH
+
+
+
+
+
+
E. coli O157
+
3
HIGH
+
+
+
+
+
+
E. coli O157
+
4
HIGH
+
+
+
+
+
+
E. coli O157
+
5
HIGH
+
+
+
+
+
+
E. coli O157
+
1
UNINOC
=
=
=
=
=
=
2
UNINOC
=
=
=
=
=
=
3
UNINOC
=
=
=
=
=
=
4
UNINOC
=
=
=
=
=
=
5
UNINOC
=
=
=
=
=
=