Micro December 2018

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

26