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Evaluation of the
mericon®
E. coli O157 Screen Plus and
mericon
1
E. coli STEC O-Type Pathogen Detection AssaysinSelectFoods:
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Collaborative Study
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Patrick Bird, M. Joseph Benzinger, Jr., Benjamin Bastin, Erin Crowley, James Agin, and
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David Goins
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Q Laboratories, Inc., 1400 Harrison Ave, Cincinnati, OH 45214
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Marcia Armstrong
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QIAGEN, 19300 Germantown Rd., Germantown, MD 20874
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Collaborators: D. Clark,M. Endres, K. Guden, L. Thompson, C. Liska, A. Sexton, E. Draper,
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L. Arnts, H. Wright, A. Duss, A. Kim, S. Le, B. Kupski, U. Hariram, J. Franklin, J. Zheng,
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K. Matheus, N. Kaur, A. Mastalerz, N. Klass
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The QIAGEN
mericon
®
E. coliO157 Screen Plus and
mericon
E. coliSTEC O-Type
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Pathogen Detection Assays employ Real-Time (RT) PCR technology
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incorporating a HotStart Taq DNA Polymerase for the rapid, accurate detection of
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Escherichia coli
O157 and the Big 6 (non-O157 Shiga toxin-producing
E. coli
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(STEC)) from select food types. Using a paired study design, the
mericon
E.
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coliO157 Screen Plus Pathogen Detection Assay and the
mericon
E. coliSTEC O-
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Type Pathogen Detection Assay were compared to the United States Department
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of Agriculture (USDA) Food Safety Inspection Service (FSIS) Microbiology
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Laboratory Guidebook (MLG) Chapter 5.09
Detection, Isolation and Identification
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of Escherichia coli O157:H7 from Meat Products and Carcass and Environmental
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Sponges
for the detection of
E. coli
O157:H7 in raw ground beef (73% lean). Both
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mericon
assays were evaluated using themanual and automated DNA extraction
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method.Thirteen (13) technicians from5laboratories located within the continental
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United Statesparticipated in the collaborative study. Three levels of
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contamination were evaluated: an un-inoculated control level (0 colony forming
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units (CFU)/test portion)
,
a low inoculum level (0.2-2 CFU/test portion) and a high
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inoculum level (2-5 CFU/test portion).Statistical analysis was conducted
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according to the Probability of Detection (POD) statistical model.Results obtained
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for the low inoculum level test portions produced a dLPOD value with 95%
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confidence intervalof 0.00, (-0.12, 0.12) for the
mericon
E. coliO157 Screen Plus
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with manual and automated extraction and
mericon
E. coliSTEC O-Type with
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manual extraction and -0.01, (-0.13, 0.10) for the
mericon
E. coliSTEC O-Type with
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automated extraction. The dLPOD resultsindicate no statistically significant
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difference between the candidate methods and reference method.
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Most
E. coli
bacteria are harmless; however, some produce a toxin (Shiga toxin) that can cause
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serious illness, including hemolytic anemia or renal failure, and can sometimes lead to death.
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Like generic
E. coli
, Shiga-toxigenic
Escherichia coli
(STEC) are Gram-negative, rod-shaped
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bacteria that are characterized by the production of Shiga toxins (
stx1, stx 2
) and the virulence
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OMAMAN-36 A : Collaborative Study Manuscript
For ERP Use Only
January 2017
AOAC Research Institute
Expert Review Pan l Use Only