230 / 596
16
breastfillet, a statistically significant difference was observed between the reference and the
1
alternative method. The dLPOD data indicated a positive correlation in data indicating more
2
recovery of the target analyte by the candidate method. One possible contribution to the higher
3
level of recovery observed with the 3M MDA 2 –
Listeria monocytogenes
method was the use of
4
Demi-Fraser Broth for the candidate method. This enrichment media formulation is less
5
selective than the modified University of Vermont Medium used in the USDA reference method
6
and may have contributed to the higher level of recovery observed during the evaluation.
7
A second possible contribution to the higher level of recovery was the length of the primary
8
enrichment. Test portions evaluated by the 3M MDA 2 –
Listeria monocytogenes
method were
9
incubated for a minimum of 28 hours in the primary enrichment, while the USDA reference
10
method had a maximum primary enrichment time of 26 hours. No statistically significant
11
difference was observed between the candidate method presumptive and confirmed results for
12
this matrix.
13
14
Recommendations
15
16
It is recommended that the 3M Molecular Detection Assay 2 –
Listeria
17
monocytogenes
method be adopted as Official First Action status for the detection of
Listeria
18
monocytogenes
in selected foods: hot dogs (25g & 125g), salmon (25g), deli turkey (25g &
19
125g), cottage cheese (25g), chocolate milk (25 mL), vanilla ice cream (25g), queso fresco (25g),
20
romaine lettuce (25g), melon (whole), raw chicken leg pieces (25g); raw chicken breast fillet,
21
concrete (sponge, 225 mL & 100 mL), stainless steel (sponge, 225 mL), and plastic (Enviroswab,
22
10 mL) environmental samples.
23
24
Acknowledgements
25
26
We would like to extend a sincere thank you to the following collaborators for their dedicated
27
participation in this study:
28
29
Robert Brooks- ATC Microbiology, LLC- North Little Rock, AR.
30
Jaspreet Walia & Francisco Hernandez – Certified Laboratories, Turlock, CA
31
David Bosco& Grizelda Trevino– Food Safety Net Services, Fresno, CA
32
Alex Brandt & Chris Lopez – Food safety Net Services, San Antonio, TX
33
Elizabeth Sjogren&Manish Shekhawat– Microbac Laboratories, Inc. Worcester, MA
34
Li Maria Ma, Chris Timmons, & Claudia Diaz Proano – Oklahoma St. University, Stillwater,
35
OK
36
Alexandra Calle & David Campos – Texas Tech University, Lubbock, TX.
37
Zachary Metz&David Baumler, University of Minnesota, St. Paul, MN
38
Robbie Smith, Dianne Wood, Evelyn Maranan,&Carmen Chavarria Maple Leaf Foods– Guelph,
39
ON, Canada
40
Ben Bastin– Microbiology R&D, Q Laboratories Inc., Cincinnati, OH
41
David Isfort– Microbiology-Food, Q Laboratories Inc., Cincinnati, OH
42
Jesse Miller, Bryan Schindler, Courtney Gies, Eric Budge, Zach Geurin & Alex Repeck - NSF
43
International, Ann Arbor, MI
44
Cynthia Zook & Christina Barnes – 3M Food Safety, St. Paul, MN
45
46
AOAC Research Institute
Expert Review Panel Use Only
OMAMAN-30 A/ Collaborative Study Manuscript
OMA ERP June 2016
ERP Use Only