4. AOACRIMicroMethods-2018Awards

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466 B ird et al .: J ournal of AOAC I nternational V ol . 100, N o . 2, 2017 submitted no data. All other laboratories submitted data for both methods evaluated. The MPN levels (with 95% confidence intervals) obtained for this matrix were 0.63 CFU/test portion (0.49, 0.80) for the low inoculum level and 4.52 CFU/test portion (3.19, 6.42) for the high inoculum level.

L. monocytogenes . Uninoculated controls were included in each analysis. Laboratory 11 did not participate in the evaluation of this matrix. Laboratory 10 submitted data that indicated cross- contamination of the inoculating organism in the uninoculated control samples. Further analysis at the coordinating laboratory confirmed the cross-contamination of the uninoculated controls. Due to this issue, the data submitted from Laboratory 10 was not used in the statistical analysis. All other laboratories submitted data for both methods evaluated. The MPN levels obtained for this matrix (with 95% confidence intervals) were 0.66 CFU/test portion (0.51, 0.83) for the low inoculum level and 6.24 CFU/ test portion (3.58, 10.88) for the high inoculum level. For the low inoculum level, 86 of 132 test portions (POD CP of 0.65) were reported as presumptive positive by the 3M MDA 2 – Listeria monocytogenes method, with 86 of 132 test portions (POD CC of 0.65) confirming positive. For samples that produced presumptive positive results on the 3M MDA 2 – Listeria monocytogenes method, 85 of 132 test portions confirmed positive (POD C of 0.64). For test portions evaluated by the USDA/FSIS MLG reference method, 64 of 132 test portions produced positive results. A dLPOD C value of 0.16 with a 95% confidence interval of (0.04, 0.28) was obtained between the candidate and reference methods, indicating a statistically significant difference between the two methods, with a higher proportion of positive results observed with the candidate method compared to the reference method. A dLPOD CP value of 0.00 with a 95% confidence intervals of (−0.12, 0.12) was obtained between presumptive and confirmed results, indicating that the difference between presumptive and confirmed methods was not statistically significant at the 0.05 probability level. For the high inoculum level, 129 of 132 test portions (POD CP of 0.98) were reported as presumptive positive by the 3M MDA 2 – Listeria monocytogenes method, with 132 of 132 test portions (POD CC of 1.00) confirming positive. For samples that produced presumptive positive results on the 3M MDA 2 – Listeria monocytogenes method, 129 of 132 samples confirmed positive (POD C of 0.98). For test portions evaluated by the USDA/FSIS MLG reference method, 132 of 132 test portions produced positive results. A dLPOD C value of −0.02 with a 95% confidence interval of (−0.06, 0.01) was obtained between the candidate and reference methods, indicating that the difference between methods was not statistically significant at the 0.05 probability level. A dLPOD CP value of −0.02 with a 95% confidence interval of (−0.06, 0.01) was obtained between presumptive and confirmed results, indicating that the difference between presumptive and confirmed methods was not statistically significant at the 0.05 probability level. For the uninoculated controls, 0 of 132 samples (POD CP of 0.00) produced a presumptive positive result by the 3M MDA 2 – Listeria monocytogenes method, with 0 of 132 test portions (POD CC of 0.00) confirming positive. For samples that produced presumptive positive results on the 3M MDA 2 – Listeria monocytogenes method, 0 of 132 samples confirmed positive (POD C of 0.00). For test portions evaluated by the USDA/FSIS MLG reference method, 0 of 132 test portions produced positive results. A dLPOD C value of 0.00 with a 95% confidence interval of (−0.03, 0.03) was obtained between the candidate and reference methods, indicating that the difference between methods was not statistically significant at the 0.05 probability level. A dLPOD CP value of 0.00 with a 95% confidence interval of (−0.03, 0.00) was obtained

For the low inoculum level, 69 of 132 test portions (POD CP of 0.52) were reported as presumptive positive by the 3M MDA 2 – Listeria monocytogenes method, with 66 of 132 test portions (POD CC of 0.50) confirming positive. For samples that produced presumptive positive results on the 3M MDA 2 – Listeria monocytogenes method, 66 of 132 samples confirmed positive (POD C of 0.50). For test portions evaluated by the USDA/FSIS MLG reference method, 60 of 132 test portions produced positive results. A dLPOD C value of 0.04 with a 95% confidence interval of (−0.08, 0.17) was obtained between the candidate and reference methods, indicating that the difference between methods was not statistically significant at the 0.05 probability level. A dLPOD CP value of 0.02 with 95% confidence interval of (−0.10, 0.15) was obtained between presumptive and confirmed results, indicating that the difference between presumptive and confirmed methods was not statistically significant at the 0.05 probability level. For the high inoculum level, 132 of 132 test portions (POD CP of 1.00) were reported as presumptive positive by the 3M MDA 2 – Listeria monocytogenes method, with 132 of 132 test portions (POD CC of 1.00) confirming positive. For samples that produced presumptive positive results on the 3M MDA 2 – Listeria monocytogenes method, 132 of 132 samples confirmed positive (POD C of 1.00). For test portions evaluated by the USDA/FSIS MLG reference method, 132 of 132 test portions produced positive results. A dLPOD C value of 0.00 with a 95% confidence interval of (−0.03, 0.03) was obtained between the candidate and reference methods, indicating that the difference between methods was not statistically significant at the 0.05 probability level. A dLPOD CP value of 0.00 with a 95% confidence interval of (−0.03, 0.03) was obtained between presumptive and confirmed results, indicating that the difference between presumptive and confirmed results was not statistically significant at the 0.05 probability level. For the uninoculated controls, 0 of 132 samples (POD CP of 0.00) produced a presumptive positive result by the 3M MDA 2 – Listeria monocytogenes method, with 0 of 132 test portions (POD CC of 0.00) confirming positive. For samples that produced presumptive positive results on the 3M MDA 2 – Listeria monocytogenes method, 0 of 132 samples confirmed positive (POD C of 0.00). For test portions evaluated by the USDA/FSIS MLG reference method, 0 of 132 test portions produced positive results. A dLPOD C value of 0.00 with a 95% confidence interval of (−0.03, 0.03) was obtained between the candidate and reference methods, indicating that the difference between methods was not statistically significant at the 0.05 probability level. A dLPOD CP value of 0.00 with a 95% confidence interval of (−0.03, 0.00) was obtained between presumptive and confirmed results, indicating that the difference between presumptive and confirmed methods was not statistically significant at the 0.05 probability level. Detailed results of the LPOD statistical analysis are presented in Table 2016.08C and Figure 1. Raw chicken breast fillet (25 g test portions) . — Raw chicken breast fillet test portions were inoculated at a low and a high inoculum level and analyzed for the detection of

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