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QIAGEN
mericon
STEC Workflow Collaborative Study Protocol
May 2016
DRAFT
15
K.
Confirmation
(
a
)
Cultural confirmation of fresh raw ground beef or fresh raw beef trim
.-Follow cultural isolation
and confirmation procedures described in the US Food Safety Inspection Service Microbiology
Laboratory Guidebook (FSIS MLG) 5.09:
Detection, Isolation and Identification of Escherichia coli
O157:H7 from Meat Products and Carcass and Environmental Sponges
for
E. coli
O157:H7 or FSIS MLG
5B.05:
Detection and Isolation of non-O157 Shiga Toxin-Producing Escherichia coli (STEC) from Meat
Products and Carcass and Environmental Sponges
for
E. coli
O26, O45, O103, O111, O121 or O145.
6.0
Reporting Raw Data
6.1
Data will be reported using the data reporting form in Appendix 8.2.
6.2
Each collaborator will complete the data reporting form and email it to the co-Study
Director as indicated on the form. Collaborators will either complete the confirmations
or ship samples to QLabs for confirmation. If the latter, the date of shipment shall be
indicated on the data report form.
6.3
Each collaborator or collaboration site must retain all related test results (data sheets
and confirmation results) for a minimum of one year.
6.4
Collaborators may also submit a comment form (Appendix 8.4).
6.5
A table reporting all raw data from all collaborators must be included in the
collaborative study report. All submitted collaborator comments must be included in the
collaborative study report.
7.0
Analyzing Raw Data
7.1
Each concentration level must be analyzed and reported separately. Data may be
excluded due to an assignable cause if sufficient justification is provided.
7.2
Using the AOAC POD Calculator
( http://lcfltd.com/AOAC/aoac-binary-v2-3.xls ),
determine to following parameters for each contamination level:
7.2.1
Repeatability Standard Deviation -
s
r
7.2.2
Among Laboratories Standard Deviation -
s
L
7.2.3
Homogeneity test of laboratory PODs – p-value
7.2.4
Reproducibility Standard Deviation -
s
R
7.2.5
LPOD
CP
with 95% confidence interval
7.2.6
LPOD
CC
with 95% confidence interval
7.2.7
dLPOD
CP
(LPOD
CP
– LPOD
CC
) with 95% confidence interval
7.2.8
LPOD
C
with 95% confidence interval
7.2.9
LPOD
R
with 95% confidence interval
7.2.10
dLPOD
C
(LPOD
C
- LPOD
R
) with 95% confidence interval
7.3
Compare the p-value from the homogeneity test to 0.1 to determine whether the
variability between laboratories (
s
L
) is significant.
OMAMAN-36 B : Collaborative Study Protocol
For ERP Use Only
January 2017
AOAC Research Institute
Expert Review Panel Use Only