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surfaces after 24-28 hours of a primary enrichment. The MDA2
Listeria monocytogenes
offers
1
the benefits of extremely high sensitivity and high specificity for the detection of
Listeria
2
monocytogenes
while reducing the overall time to presumptive results. The MDA2
Listeria
3
monocytogenes
also reduces the total analyst time required to obtain final results by
4
implementing a single heat lysis step and cool step, followed up by a single transfer to molecular
5
reaction tubes.The small foot print of the Molecular Detection System requires only minimal lab
6
and bench space, making it easy to move the instrument or pair up additional MDS units to
7
perform multiple MDA runs concurrently. The updated software is user friendly with easy to
8
interpret results. The ability to examine Relative Light Unit (RLU) curves makes trouble
9
shooting more streamline
d
if any problems occur while testing is being conducted.
10
11
Discussion
12
13
There were no differences between the 24- and 26-hour enrichment time points for the
14
environmental surfaces tested, therefore a 24-hour minimum enrichment will be recommended
15
for these matrices.
16
17
Conclusion
18
19
The 3M MDA2 -
Listeria monocytogenes
AOAC PTM validation study included an
20
inclusivity/exclusivity, lot-to-lot/stability, robustness and matrix studies. The 3M MDA2 –
21
Listeriamonocytogenes
was compared to the USDA/FSIS-MLG 8.09, the FDA-BAM
22
Chapter 10, the AOAC 993.12 or the ISO 11290-1/A1 reference methods for the detection
23
of
Listeriamonocytogenes
. There were nosignificant differences between the 3M MDA2 -
24
Listeriamonocytogenes
method and the corresponding reference method for any of the
25
matrices evaluated. The 3M MDA2 -
Listeria monocytogenes
demonstrated reliability as a
26
rapid and sensitive method for the detection of
Listeria monocytogenes
for the following
27
matrices: beef hot dogs (25 g), deli turkey (125 g), queso fresco (25 g), vanilla ice cream (25
28
g), 4% milk fat cottage cheese (25 g), 3% chocolate whole milk (25 mL), whole melon,
29
romaine lettuce (25 g), bagged raw spinach (25 g), cold smoked salmon (25 g), raw chicken
30
leg pieces (25 g), sealed concrete (sponge enriched in 100mL), plastic (Enviroswabenriched
31
in 10 mL), stainless steel (sponge enriched in 225 mL).
32
33
References
34
35
1.
Food and Drug Administration Bacteriological Analytical Manual Chapter 10:
Detection and
36
Enumeration of Listeria monocytogenes in Foods
. February, 2013. (Accessed January 2015)
37
38
2.
United States Department of Agriculture Microbiological Laboratory Guidelines 8.09:
39
Isolation and Identification of Listeria monocytogenes from Red Meat, Poultry and Egg
40
Products, and Environmental Samples
. May 1
st
, 2013. (Accessed January 2015)
41
http://www.fsis.usda.gov/wps/wcm/connect/1710bee8-76b9-4e6c-92fc-fdc290dbfa92/MLG-42
8.pdf?MOD=AJPERES43
44
AOAC Research Institute
Expert Review Pan l Use Only
OMAMAN-30 D/ PTM Validation Report 081501
OMA ERP - June 2016
ERP Use Only