474 / 1195
For independent laboratory raw ground beef test portions, there were 6 confirmed positives for the
1
3M Molecular Detection Assay
Salmonella
samples and 6 confirmed positives for the USDA/FSIS-MLG
2
samples. All un-inoculated control samples were negative for both methods. A χ
2
value of 0 was
3
obtained, indicating no significant difference the 3M Molecular Detection Assay
Salmonella
samples
4
and the USDA/FSIS-MLG reference method.
5
6
Cooked Breaded Chicken - Independent
7
For independent laboratory cooked breaded chicken test portions, there were 11 confirmed positives
8
for the 3M Molecular Detection Assay
Salmonella
samples and 12 confirmed positives for the
9
USDA/FSIS-MLG samples. All un-inoculated control samples were negative for both methods. A χ
2
10
value of 0.10 was obtained, indicating no significant difference the 3M Molecular Detection Assay
11
Salmonella
samples and the USDA/FSIS-MLG reference method.
12
13
Conclusions
14
The 3M Molecular Detection Assay
Salmonella
method was evaluated following the AOAC
15
Performance Tested Methods
requirements: inclusivity/exclusivity, ruggedness, stability/lot to lot
16
consistency and method comparison. Six matrices were tested by both the 3M Molecular Detection
17
Assay and either the USDA/FSIS-MLG or the FDA-BAM for the detection of
Salmonella
in food and
18
feed. Overall the assay was equivalent to the reference methods based on the Chi square test for
19
significant difference. There were no unexpected results in any of the other PTM requirements.
20
21
The method was considered easy to perform and similar in set up to existing platforms of Polymerase
22
Chain Reaction (PCR) systems. The package insert was found to be detailed enough to run the method
23
and contained diagrams to aid in the set up of the assay. The 3M Molecular Detection Assay
24
Salmonella
method offers a significant savings in time when compared to the traditional reference
25
methods. Presumptive results can be obtained in less than 25 hours from start to finish. The 3M
26
Molecular Detection Assay
Salmonella
offers benefits of rapid results, high sensitivity, and high
27
specificity for the detection of
Salmonella
in food and feed matrices.
28
29
References
30
1.
US FDA Bacterial Analytical Manual (BAM) online Nov 2011, Chapter 5: Salmonella,
31
http://www.fda.gov/Food/ScienceResearch/LaboratoryMethods/BacteriologicalAnalyticalManualBAM/UCM07014932
2.
USDA Microbiological Laboratory Guide (MLG) online Nov 2011, Chapter 4.05: Salmonella,
33
http://www.fsis.usda.gov/PDF/MLG_4_05.pdf34
3.
Bad Bug Book online Jan 2012 – Salmonella
spp
35
4.
Feldsine P., Abeyta C., and Andrews W.H., (2002) AOAC INTERNATIONAL Methods Committee
36
Guidelines for Validation of Qualitative and Quantitative Food Microbiological Official Methods of
37
Analysis,
J. AOAC Int.
85
, 1187-1200.
38
5.
Rahn K, De Grandis SA, Clarke RC, McEwen SA, Galán JE, Ginocchio C, Curtiss R 3
rd
, Gyles CL. 1992.
39
Amplification of an invA gene sequence of Salmonella typhimurium by polymerase chain reaction as a
40
specific method of detection of Salmonella. Mol. Cell. Probes. 6(4): 271-279.
41
6.
Hoofar J, Ahrens P, Rådström P. 2000. Automated 5’ nuclease PCR assay for identification of
42
Salmonella enterica. J. Clin. Micorbiol. 38(9): 3429-3235.
43
7.
Collazo CM, Galán JE. 1997. THe invasion-associated type-III protein secretion system in Salmonella- a
44
review. Gene. 11;192(1): 51-59. Review.
45
8.
Ginnochio CC, Galán JE. 1995. Functional conservation among members of the Salmonella
46
typhimurium InvA family of proteins. Infect. Immun. 63(2):729-732.
47
16