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QIAGEN
mericon
STEC Workflow Collaborative Study Protocol
May 2016
DRAFT
25
Appendix 8.3
Collaborative Study Flowchart - QIAGEN
mericon
® STEC Workflow – Ground Beef
Manual
mericon
At 10 h, pipette 1.0
mL in 2 mL
microtube;
Centrifuge 5 min
@ 13,000 x
g
Process with
manual
mericon
DNA Bacteria Kit
325 g test portion
in 975 mL mTSB (+CAA)
Stomach 1.5 min @ 230 rpm
Incubate @ 42°C
At 15-24 h,
perform a
screening assay
as described in
MLG 5A.04
Test colonies by
agglutination for
O157 serogroup
Transfer up to 5
latex positive
colonies to SBA
35°C for 16-24 h
Test isolated
colonies by latex
agglutination for
O157 and H7
Confirm presence
of Shiga toxins or
Shiga toxin genes
Regardless of
screen result,
perform anti-O157
IMS on all
enrichments
Plate acid-treated
and non-acid-
treated beads on
mRBA
35°C for 20-24 h
Perform
biochemical
confirmation
MLG 5.09
E. coli
O157:H7
Confirmed Result
MLG 5.09
At 10 h, pipette
500 μL in 2 mL
microtube for
QIAsymphony Kit
Process with
QIAsymphony SP
Set up assay
manually.
Perform
mericon
E. coli O157
Screen Plus Assay
Set upassay
manually.
Perform
mericon
E. coli STEC
O-Type Assay
Additional testing
required
No
further
action
Dilute sample and
repeat test
Report results
Dilute DNA prep
1/10 with RNase-
free water
Set up assay with
QIAsymphony AS.
Perform
mericon
E. coli O157
Screen Plus Assay
Dilute DNA prep
1/10 with RNase-
free water.
Dilute sample and
repeat test
Additional testing
required
No
further
action
Set up assay with
QIAsymphony AS.
Perform
mericon
E. coli STEC
O-Type Assay
Dilute sample and
repeat test
Dilute sample and
repeat test
No
further
action
No
further
action
Additional testing
required
Additional testing
required
Report results
Automated
mericon
Data
Interpretation
Data
Interpretation
Data
Interpretation
Dilute DNA prep
1/10 with RNase-
free water.
Data
Interpretation
Dilute DNA prep
1/10 with RNase-
free water
OMAMAN-36 B : Collaborative Study Protocol
For ERP Use Only
January 2017
AOAC Rese rch Institute
Expert Review Panel Use Only