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positives following the USDA/FSIS-MLG 5B.05 reference method

confirmation procedure. There were 13 observed positives for the

reference method. For the high inoculation level, there were 5

presumptive positives and 5 confirmed positives following the

USDA/FSIS-MLG 5B.05 reference method confirmation procedure. There

were 5 confirmed positives following the reference method.

For the low inoculation level, a dPOD

value of 0.00 was obtained with a

95% confidence interval of (-0.28, 0.28), indicating no significant

difference between the candidate and reference methods. A dPOD

value of 0.00 was obtained with a 95% confidence interval of (-0.28,

0.28), indicating no significant difference between the candidate

presumptive and confirmed results.

For the high inoculation level, a dPOD

value of 0.00 was obtained with a

95% confidence interval of (-0.43, 0.43), indicating no significant

difference between the candidate and reference methods. A dPOD

value of 0.00 was obtained with a 95% confidence interval of (-0.43,

0.43), indicating no significant difference between the candidate

presumptive and confirmed results. Detailed results of the POD analyses

are presented in Tables 16 and 20 of the Appendix.

Robustness Evaluation

When changing the operational parameters of the enrichment incubation time,there

was an observed effect on the results. For the 8 hour incubation, both assays failed

to detect the target analyte. For the 9 hour incubation time, the Screen Plus

Pathogen Detection Assay had no observed effect on the results but the STEC O-

Type Pathogen Detection Assay produced two discrepant results when compared to

the Screen Plus Pathogen Detection

Assay.At

the 10 hour time point, modification to

the lysis heat time, and PCR Master Mix to DNA sample volume caused no

observed discrepancies.

mericonE. coli O157 Screen Plus Pathogen Detection Assay

Treatment Combination 1

For treatment combination 1, there was 1 presumptive positive out of 10 replicates

for the variations evaluated. For the 5 uninoculatedtest portions, there were 0

presumptive positives out of 5 replicates.

For the low inoculation level, a POD value of 0.10 was obtained with a 95%

confidence interval of (0.00, 0.42). All 5 uninoculated test portions were negative

with a POD value of 0.00 with a 95% confidence interval of (0.00, 0.43).

Treatment Combination 2

For treatment combination 2, there were 4 presumptive positives out of 10 replicates

for the variations evaluated. For the 5 uninoculated test portions, there were 0

presumptive positives out of 5 replicates.

OMAMAN-36 E/ AOAC PTM Report

ERP Use Only

January 2017

AOAC Research Institute

Expert Review Panel Use Only