AOAC-RI ERP Book MICRO.pdf

CONFIDENTIAL INFORMATION

Page 16 of 17

positive result in its “confirmation stage” at any of the inoculation levels tested.

Additionally, for the candidate method versus the reference method, the POD

values were not significantly different from their corresponding POD

values.

Based on these outcomes, by fulfilling the criteria to contain 0.000 within the 95%

confidence intervals, it can be stated that the probability of detecting a positive

result in the candidate method was not significantly different from the probability of

detecting a positive results in the reference method. Thus, the candidate method

and the reference method can be considered equivalent, based on the AOAC

International guidelines. Also, the lack of false positive or false negatives (Table

) when comparing the ‘screening stage’ and the ‘confirmation stage’ of the

candidate method further supports the adequacy of the method.

Overall, based on the results of this study, the

3M™

Molecular Detection Assay

(MDA) is a valid method for the detection of

Escherichia coli

O157:H7 in 25 g

sprouts and 200 g spinach. The candidate methods explored here with the

targeted sample sizes produce

equivalent results in both the ‘screening stage’ and

the ‘confirmation stage’ and produce equivalent results when compared with the

FDA BAM reference methods, typically employed for these matrices.

5.0 REFERENCES

Brunelle S, LaBudde R, Nelson M, Wehling P

. 2012. AOAC International

Methods Committee Guidelines for Validation of Microbiological Methods for

Food

and

Environ-mental

Surfaces.

Available

at:

http://www.aoac.org/imis15_prod/AOAC_Docs/StandardsDevelopment/AOAC

_Validation_Guidelines_for_Food_Microbiology-Prepub_version.pdf.

Accessed: 11/30/15.

Feng P, Weagant SD, Jinneman, K.

2011. U.S. Food and Drug Administration

Bacteriological Analytical Manual, Chapter 4A: Diarrheagenic

Escherichia coli

Available at:

http://www.fda.gov/Food/FoodScienceResearch/LaboratoryMethods/ucm070080.

htm. Accessed: 11/30/15.

United States Department of Agriculture, Food Safety Inspection

Service, Office of Public Health Science

. 2014. Microbiology Laboratory

Guidebook Method 5.09: Detection, Isolation and Identification of

Escherichia

coli

O157:H7 from Meat Product and Carcass and Environmental Sponges.

Available at:

http://www.fsis.usda.gov/wps/wcm/connect/51507fdb-dded-47f7-

862d-ad80c3ee1738/MLG-5pdf?MOD=AJPERES. Accessed: 11/30/2015.