Microbiology Methods for ERP Review 3-2020

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When combining all 11 data sets used in the statistical analysis, 4 false positive results, 1 false negative result with the alternative confirmation procedure and 2 false negative results with the traditional confirmation procedure were obtained. For these discrepant results, 2 false positive results were obtained in the low inoculum level and 2 false positive results were obtained in the high inoculum level. All false negative results were obtained in the low inoculum level. The FP and FN rates were calculated as follows:

False Positive Rate = [FP/(True Positives + FP)] x 100

False Negative Rate = [FN/(True Negatives + FN)] x 100

For the study, a false positive rate of 2.2%, along with a false negative rate of 0.9% for the alternative confirmation and a false negative rate of 0.5% for the traditional confirmation were obtained. For the candidate method, variations observed within laboratory analysis (repeatability) and between laboratories (reproducibility) were the same, indicating consistency in the method’s performance by individual users and between users at different facilities. No statistically significant differences were observed between the presumptive and confirmed results (using either the alternative or traditional confirmation procedure) for the candidate method nor between the candidate and reference methods.

Recommendations

It is recommended that the GENE-UP ® Salmonella (SLM) method be adopted as Official First Action status for the detection of Salmonella species in a broad range of foods and select

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