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Evaluation of 3M
™
Molecular Detection Assay (MDA)
Listeria
1
monocytogenes
for the Detection of
Listeria monocytogenes
in
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Selected Foods and Environmental Surfaces:
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Collaborative Study
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5
Patrick Bird, Jonathan Flannery, Erin Crowley, James Agin, David Goins
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Q Laboratories, Inc., 1400 Harrison Ave, Cincinnati, OH 45214
7
8
Lisa Monteroso, DeAnn Benesh
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3M Food Safety Department,
3MCenter – Bldg. 260-6B-01, St. Paul, MN 55144
10
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Collaborators: P. Fatemi, S. Spencer, J. Blumfield, A. Hankins, R. Dermer, N. Shipley, J. Williams,
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A. Morris, R. Brooks, K. Powers, J. Picket, A. Thielen, L. Thompson, C. Lopez, A. Brandt, B.
13
Brahmanda, L. Hardrath, Y. Chen, A. Laasri, R. Brooks, D. Wood, A. Sweet, C. Chavarria, L. Cerda,
14
B. Mailloux, J. Schoeni, B. Kupski, N. Cuthbert, B. Bastin
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The 3M
™
Molecular Detection Assay (MDA)
Listeria monocytogenes
combines
17
isothermal amplification and bioluminescence to detect
Listeria
18
monocytogenes
with high specificity and efficiency in select foods and
19
environmental samples. The 3M MDA
Listeria monocytogenes
method was
20
evaluatedusing an unpaired study design in a multi-laboratory collaborative
21
study to the USDA/FSIS MLG 8.09 (2011)
Isolation and Identification of Listeria
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monocytogenes fromRed Meat, Poultry, and Egg Products and Environmental
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Samples
fordeli turkeyand the AOAC
®
Official Method of Analysis 993.12
Listeria
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monocytogenes in Milk and Dairy Products
for full fat (4% milk fat) cottage
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cheese following the current AOAC Guidelines. A total of 16 laboratories located
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in the continental United States and Canada participated in this collaborative
27
study. For deli turkey, 125 g test portions were evaluated using heat stressed
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cells by each method. Forfull fat cottage cheese, 25g test portions were
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evaluated using non-heat stressed cells. Each matrix had 3 inoculation levels: an
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un-inoculated control level (0 colony forming units (CFU)/test portion), and two
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levels artificially contaminated with
Listeria monocytogenes,
a low inoculum level
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(0.2-2 CFU/test portion) and a high inoculum level (2-5 CFU/test portion).In total,
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1,584 unpaired replicate samples were analyzed. Statistical analysis was
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conducted according to the Probability of Detection (POD). Results obtained for
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the low inoculum level full fat cottage cheese test portions produced a dLPOD
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value of -0.08, (-0.20, 0.05) with 95% Confidence Intervals.For the low-level deli
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turkey test portions, a dLPOD value of -0.02, (-0.14, 0.11)with 95% Confidence
38
Intervals was obtained.
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Listeria monocytogenes
, a Gram positive rod shaped facultative bacterium, infects roughly 1,600
41
persons annually [1, 2]. On average, infections caused by
Listeria monocytogenes
result in 255
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deaths in the United States annually producing one of the highest mortality rates for a foodborne
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pathogen [2]. With its ability to survive and grow in various harsh environments including
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Candidates for 2016 Method of the Year
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