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A Comparative Evaluation of the 3M
™
Molecular Detection Assay 2 (MDA 2) -
Listeria
for
1
the Detection of
Listeria
species in a Variety of Foods and Environmental Surfaces
2
3
AOAC
Performance Tested Methods
SM
111501
4
5
Abstract
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7
The 3M
™
Molecular Detection Assay 2 (MDA2) -
Listeria
for the detection of
Listeria
species
8
(
L. monocytogenes, L. seeligeri, L. ivanovii, L. innocua, L. grayi, L. welshimeri, L. fleishmanii
9
subsp
. coloradensis, L. marthii
,
L. grandensis, L. cornellensis
and
L. riparia)
was evaluated
10
following the 2012 AOAC Research Institute
Performance Tested Methods
SM
program
11
guidelines. The evaluation included inclusivity/exclusivity, lot-to-lot/stability, robustness and
12
matrix studies. The 3M MDA 2 -
Listeria
was compared to various reference methods for raw
13
chicken, bagged raw spinach, cold smoked salmon, deli turkey, whole melons, vanilla ice cream,
14
queso fresco, 4% milk fat cottage cheese, beef hot dogs, stainless steel, sealed concrete and
15
plastic in the matrix study. Twenty replicates of each food matrix were analyzed at a low
16
inoculum level of 0.2-2 colony forming units (CFU)/standard test portion, five replicates were
17
analyzed at a high level of 2-5 CFU/test portion, and five control replicates were analyzed at 0
18
CFU/standard test portion with the exception of naturally contaminated raw chicken (leg pieces)
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analyzed at the independent laboratory. Naturally contaminated raw chicken (leg pieces),
20
analyzed at the independent laboratory, were evaluated using two separate lots consisting of
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twenty replicates for each lot. All environmental surfaces were analyzed using twenty replicates
22
at a low inoculum level of ~ 50 CFU/standard area, five replicates were analyzed at a high level
23
of ~ 100 CFU/standard area, and five control replicates were analyzed at 0 CFU/standard test
24
area. Based on the probability of detection statistical model, there were no statistically significant
25
differences between the number of presumptive and confirmed positive samples or between the
26
candidate and reference method. There were no unexpected results in the lot-to-lot/stability,
27
robustness studies. In the inclusivity/exclusivity study, 55 target organisms and 30 non-target
28
organisms were tested following the 3M MDA 2 -
Listeria
method with all target organisms
29
detected and none of the non-target organisms detected. The results of this evaluation
30
demonstrate the specificity and sensitivity of the 3M MDA 2 -
Listeria
and its ability to
31
accurately detect
Listeria
species in select food matrixes (beef hot dogs, queso fresco, vanilla ice
32
cream, 4% milk fat cottage cheese, 3% whole milk, bagged raw spinach, cold smoked salmon,
33
raw chicken parts, deli turkey, whole cantaloupe) and environmental surfaces (stainless steel,
34
sealed concrete, plastic), 24-30 hours post enrichment.
35
36
Authors
37
Lisa Monteroso and DeAnn Benesh, 3M Food Safety Division
38
Ben Bastin, Jonathan Flannery, Erin Crowley, Patrick Bird, M. Joseph Benzinger, Jr., James
39
Agin, David Goins, Q Laboratories, Inc.
40
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Submitting Company
42
3M Company
43
Food Safety Department
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3M Center, Bldg. 275-5W-05
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St. Paul, MN 55144-1000
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AOAC Research Institute
Expert Review Panel Use Only
OMAMAN-29 D/ PTM Validation Report 111501
OMA ERP - June 2016
ERP Use Only