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3M Molecular Detection Assay Salmonella Collaborative Study
July 2012
OMA-2012-July-XXX
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INTRODUCTION
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The goal of this collaborative study is to estimate the following performance
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parameters of the 3M™ Molecular Detection Assay
Salmonella
: probability of
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detection (POD) and the difference in the POD at 3 contamination levels for both
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the candidate and reference method. Test portions from 3 different contamination
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levels, including negative controls, will be sent to collaborators where they will
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perform the
3M Molecular Detection Assay
Salmonella
method along with the
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corresponding reference method. The following two foods will be tested: raw fresh
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ground beef (25g) and wet pet food (375g).
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1.1
Description of the 3M Molecular Detection Assay
Salmonella
Method
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3M Molecular Detection Assay
Salmonella
method is intended for use with
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the 3M Molecular Detection System for the rapid and specific detection of
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Salmonella
spp. in food, food-related, and environmental samples after
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enrichment. The 3M Molecular Detection Assay
Salmonella
Test uses
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isothermal amplification of unique DNA target sequences with high
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specificity, efficiency and rapidity, and bioluminescence to detect the
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amplified sequences. Presumptive positive results are reported in real-time
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while negative results will be displayed after the assay is completed.
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The limit of detection of a method is defined as the lowest concentration
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point where reliable analytical results can be obtained. This can vary with
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different serotypes. For the 3M Molecular Detection Assay
Salmonella
this
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has been demonstrated to be 1-5 CFU/ 25 g of sample or 1-5 CFU/ swab.
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The 3M Molecular Detection Assay
Salmonella
is used for food and feed
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matrices and has been validated using representative samples of the following
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matrices: raw ground beef, cooked breaded chicken, raw shrimp, bagged
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spinach, wet pet food, and pasteurized liquid whole egg.
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1.2
Summary of PTM/Precollaborative Studies
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The 3M Molecular Detection Assay
Salmonella
method was validated according
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to AOAC Guidelines (2002) in a harmonized PTM study. The aim of this study
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was to demonstrate that the 3M Molecular Detection Assay
Salmonella
method
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could detect
Salmonella
in selected foods as claimed by the manufacturer.
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In the PTM study, there were 6 matrices tested - raw ground beef (25g), processed
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breaded chicken (325g), liquid egg (100g), shrimp (25g), fresh spinach (25g) and
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wet pet food (375g). There was no significant difference between the 3M
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Molecular Detection Assay
Salmonella
method and the reference method for any
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of the matrices tested using the Mantel-Haenszel Chi-square test at 5% level.
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DRAFT DOCUMENT
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