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Evaluation of the 3M
™
Molecular Detection Assay(MDA) 2
-–
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Listeria
for the Detection of
Listeria
species
in SelectFoods and
2
Environmental Surfaces: Collaborative Study
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Patrick Bird, Jonathan Flannery, Erin Crowley, James Agin, David Goins
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Q Laboratories, Inc., 1400 Harrison Ave, Cincinnati, OH 45214
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Lisa Monteroso
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3M Food Safety Department,
3MCenter – Bldg. 260-6B-01, St. Paul, MN 55144
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Collaborators: R. Brooks, J. Walia, F. Hernandez, D. Bosco, G. Trevino, A. Brandt, C. Lopez,
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E. Sjogren, M. Shekhawat, L. Ma, C. Timmons, C. Diaz Proano, A. Calle,Z. Metz, D. Baumler, R.
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Smith, D. Wood, E. Maranan, C. Chavarria,J. Miller, B. Schindler, C. Gies, E. Budge, Z. Geurin, A.
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Repeck, C. Zook, C. Barnes, B. Bastin, D. Isfort
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The 3M™ Molecular Detection Assay (MDA) 2
–Listeria
uses loop-mediated
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isothermal amplification and bioluminescence detection to rapidly detect
Listeria
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species in a broad range of food types and environmental surfaces. Using an
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unpaired study design, the MDA 2 -
Listeria
was compared to the United States
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Department of Agriculture (USDA) Food Safety Inspection Service (FSIS)
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Microbiology Laboratory Guidebook (MLG) Chapter 8.09
Isolation and
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Identification of Listeria monocytogenes from Red Meat, Poultry and Egg
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Products, and Environmental Samples
reference method for the detection of
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Listeria
in deli turkey and raw chicken breast fillet.Technicians from13laboratories
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located within the continental United Statesand Canada participated in the
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collaborative study.Each matrix was evaluated at three levels of contamination:
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an un-inoculated control level (0 colony forming units (CFU)/test portion)
,
a low
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inoculum level (0.2-2 CFU/test portion) and a high inoculum level (2-5 CFU/test
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portion).Statistical analysis was conducted according to the Probability of
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Detection (POD) statistical model.Results obtained for the low inoculum level test
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portions produced a dLPOD value with 95% confidence intervals of 0.04, (-0.08,
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0.17) for deli turkey indicating
the difference between methods was not
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statistically significant at the 0.05 probability
level.nostatistically significant
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difference between the candidate and reference methods.
For raw chicken breast
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fillet a dLPOD valuewith 95% confidence interval of 0.16, (0.04, 0.28) indicating
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astatisticallysignificant difference
between the candidate and reference methods
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an observed higher proportion of positive results by the candidate method than
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the reference method.with a positive correlation in data indicating more recovery
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of the target analyte by the candidate method.
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___________________________________________________________________________
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Listeria,
particularly
L. monocytogenes
, is a pathogenic bacterium that contaminates food and is
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often found in food manufacturing facilities [1]. Due to the ubiquitous nature of
Listeria
, this
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organism is used as a hygiene indicator in all stages of the food processing chain. Detection of
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Listeria
in the production and process facilities may be an indicator of unsanitary conditions [2].
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Theorganism’sability to survive in extreme conditions make its presence in food a serious issue.
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In the past year,
Listeria
has been identified as the source ofseveral high profile outbreaks
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