Review Book

Discussion

During the collaborative study, the candidate method was able to accurately detect and differentiate the target microorganism from high levels of competing background microflora from within the matrix. Several laboratories indicated that the high background microflora made identifying target organism difficult, even after sub-culturing in a secondary enrichment. These collaborators indicated the ease of use of the GENE-UP Salmonella method in detecting the pathogen would be very beneficial to their laboratory for matrices with high background microflora. Fifteen collaborators were solicited to participate in the study. One collaborator was unable to complete testing and did not submit results. A second collaborator did not perform the traditional confirmation procedure and therefore their data was not included. Two additional laboratories (1 and 10) were removed from data analysis due to contamination in their non- inoculated control samples. Data submitted for the study contained 4 false positive results, 1 false negative result with the alternative confirmation procedure and 2 false negative results with the traditional confirmation procedure. 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

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