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1
“
As with all test methods, the source, formulation and quality of enrichment medium
2
can influence the results.
Factors such as sampling methods, testing protocols, sample
3
preparation, handling, and laboratory technique may also influence results. 3M
4
recommends evaluation of the method including enrichment medium, in the user’s
5
environment using a sufficient number of samples with particular foods and microbial
6
challenges to ensure that the method meets the user’s criteria.”
7
8
9
Conclusion
10
11
The 3M MDA 2 -
Listeria
AOAC PTM validation study included inclusivity/exclusivity, lot-to-
12
lot/stability, robustness and matrix studies. The 3M MDA 2 -
Listeria
was compared to the
13
USDA/FSIS-MLG 8.09, the FDA-BAM Chapter 10, the AOAC 993.12 or the ISO 11290-1/A1
14
reference methods for the detection of
Listeria
. There were no significant differences between
15
the 3M MDA 2 -
Listeria
method and the corresponding reference method for any of the
16
matrixes evaluated. The 3M MDA 2 -
Listeria
demonstrated reliability as a rapid and sensitive
17
method for the detection of
Listeria
species for the following new matrixes: beef hot dogs (25 g),
18
deli turkey (125 g), queso fresco (25 g), vanilla ice cream (25 g), 4% milk fat cottage cheese (25
19
g), whole melon, bagged raw spinach (25 g), cold smoked salmon (25 g), raw chicken (25 g),
20
sealed concrete (sponge enriched in 225 mL), plastic (Enviro
sS
wab enriched in 10 mL),
21
stainless steel (sponge enriched in 225 mL).
22
23
References
24
25
1.
Food and Drug Administration Bacteriological Analytical Manual Chapter 10:
Detection and
26
Enumeration of Listeria monocytogenes in Foods
. February, 2013. (Accessed January 2015),
27
http://www.fda.gov/Food/FoodScienceResearch/LaboratoryMethods/ucm071400.htm28
29
2.
United States Department of Agriculture Microbiological Laboratory Guidelines 8.09:
30
Isolation and Identification of Listeria monocytogenes from Red Meat, Poultry and Egg
31
Products, and Environmental Samples
. May 1
st
, 2013. (Accessed January 2015)
32
http://www.fsis.usda.gov/wps/wcm/connect/1710bee8-76b9-4e6c-92fc-fdc290dbfa92/MLG-33
8.pdf?MOD=AJPERES34
35
3.
Official Methods of Analysis of AOAC INTERNATIONAL (2012) 19th Ed., AOAC Official
36
Method 993.12
Listeria monocytogenes
in Milk and Dairy Products: Selective Enrichment
37
and Isolation Method, First Action 1993, Final Action 1996
38
39
4.
ISO 11290-1/A1 (2004) - Microbiology of food and animal feeding stuffs - Horizontal
40
method for the detection and enumeration of
Listeria monocytogenes
- Part 1: detection of
41
Listeria monocytogenes
in foods,
42
http://www.iso.org/iso/home/store/catalogue_tc/catalogue_detail.htm?csnumber=6031343
44
5.
U.S. Food and Drug Administration, and U.S. Food Safety and Inspection Service. 2003.
45
Quantitative Assessment of the Relative Risk to Public Health from Foodborne
Listeria
46