Microsoft Word - 3M Petrifilm REC Plate OMA Manuscript 09121

ERP Methods Book

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Three unique production lots have not been produced, so lot‐to‐lot and shelf life study data  1

will be combined and reported during the yearly PTM renewal.  2

3

4

Discussion 

5 The studies conducted in this evaluation show that the results from the 3M Petrifilm Rapid  6

E. coli /Coliform Count Plate were not statistically different when compared to the BAM Ch. 4,  7

ISO 4832:2006 and ISO 16649‐2:2001 for the enumeration of E. coli and total coliforms.   8

In inclusivity and exclusivity studies, the 3M Petrifilm Rapid E. coli /Coliform Count Plate  9

identified all strains tested in accordance with BAM Ch. 4, ISO 4832:2006 and ISO 16649‐ 10

2:2001. One strain of E. coli , 3M REC12, a strain recognized as an atypical isolate, produced a  11

typical coliform reaction on the plate (red colony with gas), and was also negative for E. coli 12

with the BAM method (did not fluoresce on VRB with MUG plates) and ISO 16649‐2:2001  13

(atypical on TBX). All other E. coli  isolates tested were positive (blue to blue/green) on the 3M  14

Petrifilm Rapid E. coli /Coliform Count Plate. All non‐ E. coli  strains tested were negative (Tables  15

1–4). Of the 50 strains tested in the coliform inclusivity study, all non‐ E. coli  isolates, except for  16

Pantoea agglomerans which was excluded as a coliform from the BAM and ISO methods as  17

well, produced red colonies. Thirteen of the isolates produced red colonies without gas;  18

Citrobacter amalonaticus , Citrobacter koseri  (two strains) Citrobacter braakii , Citrobacter 19

farmeri , Citrobacter freundii  (three strains), Citrobacter youngae ,  Serratia liquefaciens and  20

Serratia marcescens  (three strains). These strains did not produce gas in BLGB broth, as  21

indicated in the BAM method, and thus by the BAM definition (gas production from lactose) are  22

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December 6, 2018