95 / 453
25
Inclusivity/Exclusivity (Internal Studies)
1
Table 3: Source of Test Organisms Used for Testing of Inclusivity and Exclusivity
2
Strains
#s
Testing Lab
Inclusives
1 through 15
Q Laboratories Inc., (Cincinnati
Ohio)
16 through 50
3M (St. Paul, Minnesota)
Exclusives
ALL (1 through 50)
3M (St. Paul, Minnesota)
3
Inclusivity Methodology
4
5
Fifty frozen
E. coli
O157strain suspensions were thawed and sub-cultured on blood agar plates and
6
incubated at 41.5 °C ± 1°C for 18-24 hours. Single isolated colonies were sub-cultured from agar
7
intoBPW ISO broth and incubated for eight (8) hours at 41.5 °C ± 1°C. The cultures were diluted in fresh
8
BPW ISO broth in order to obtain concentrations of approximately E+05 to E+06 CFU/mL and were then
9
tested immediately using the 3M MDA2ECO96 kit.
10
11
ExclusivityMethodology
12
13
Fifty frozen non-
E. coli
O157strain suspensions were thawed and sub-cultured on blood agar plates and
14
incubated at 37
0
C for approximately 24 hours. Single isolated colonies were sub-cultured from agar into
15
Tryptic® soy broth (TSB) broth and incubated at 35-37
0
C for 18-24 hours.The cultures were diluted in
16
fresh BPW ISO in order to obtain concentrations of approximately E+07 to E+08 CFU/mL and were then
17
tested immediately using the 3M MDA2ECO96 kit.
18
19
Results
20
1.
All 50
E. coli
O157strains were correctly detected as positives by the 3MMDA2ECO96 kit/method.
21
2.
None of the 50 non-
E. coli
O157strains were detected by the 3MMDA2ECO96 kit/method.
22
3.
See Tables 4 and 5 for key to culture collection ID #s.
23
4.
See Tables 5 and 6 for culture details and results.
24
25
Table 4. Culture Collection Key
26
Acronym Collection / obtained from
ATCC
American Type Culture Collection
CDC
US Centers for Disease Control and Prevention
FDA
US Food and Drug Administration
FSD
3M Food Safety Culture Collection
MSU
Michigan State University STEC Center
NCTC
National Collection of Type Cultures
PSU
Pennsylvania State University
E. coli
Reference Center
QL
Q Laboratories, Inc., Cincinnati, Ohio 45214
TICC
3M Tecra™ Culture Collection
27
Table 5.
Escherichia coli
O157
–
Inclusive Cultures
28
OMAMAN-35 A : Collaborative Study Manuscript
For ERP Use Only
January 2017
AOAC Re earch Institute
Expert Review Panel Use Only