AOAC-RI ERP Micro June 2016

OMAMAN-29 A/ Collaboartive Study Manuscript OMA ERP June 2016 ERP Use Only

For the high inoculum level, 132 out of 132 test portions (POD CP 1 presumptive positive by the 3M MDA 2 – Listeria method with 132out of 132 test portions 2 (POD CC of 1.00) confirming positive.For samples that produced presumptive positive results on 3 the 3M MDA 2 – Listeria method, 132out of 132 samples confirmed positive (POD C of 1.00). For 4 test portions evaluated by the USDA/FSISMLG reference method, 132 out of 132 test portions 5 produced positive results. A dLPOD C value of 0.00 with 95% confidence intervals of (-0.03, 6 0.03) was obtained between the candidate and reference method, indicating no statistical 7 significant difference between the two methods. A dLPOD CP value of 0.00 with 95% confidence 8 intervals of (-0.03, 0.03) was obtained between presumptive and confirmed results indicating no 9 statistically significant difference between the presumptive and confirmed results. 10 For the un-inoculated controls, 0 out of 132 samples (POD CP of 0.00) produced a presumptive 11 positive result by the 3M MDA 2 - Listeria method with 0out of 132 test portions (POD CC of 12 0.00) confirming positive. For samples that produced presumptive positive results on the 3M 13 MDA 2 – Listeria method, 0out of 132 samples confirmed positive (POD C of 0.00). For test 14 portions evaluated by the USDA/FSIS MLG reference method, 0 out of 132 test portions 15 produced positive results. A dLPOD C value of 0.00 with 95% confidence intervals of (-0.03, 16 0.03) was obtained between the candidate and reference method, indicating no statistical 17 significant difference between the two methods. A dLPOD CP value of 0.00 with 95% confidence 18 intervals of (-0.03, 0.00) was obtained between presumptive and confirmed results indicating no 19 statistically significant difference between the presumptive and confirmed results. 20 21 Detailed results of the POD statistical analysis are presented in Table 2016.2A and Figures 1A- 22 1B. 25 26 Raw chicken breast fillet test portions were inoculated at a low and high inoculum level and were 27 analyzed for the detection of Listeria spp. Un-inoculated controls were included in each 28 analysis. Laboratory 11 did not participate in the evaluation of this matrix. Laboratory 10 29 submitted data that indicated cross contamination of the inoculating organism in the un- 30 inoculated control samples. Further analysis at the coordinating laboratory confirmed the cross 31 contamination of the un-inoculated controls. Due to this issue, the data submitted from 32 Laboratory 10 was not used in the statistical analysis. All other laboratories submitted data for 33 both methods evaluated. The MPN levels obtained for this matrix, with 95% confidence 34 intervals, were 0.66 CFU/test portion (0.51, 0.83) for the low level and 6.24 CFU/test portion 35 (3.58, 10.88) for the high level. 36 For the low inoculum level, 88 out of 132 test portions (POD CP of 0.67) were reported as 37 presumptive positive by the 3M MDA 2 – Listeria method with 86out of 132 test portions 38 (POD CC of 0.65) confirming positive. For samples that produced presumptive positive results on 39 the 3M MDA 2 – Listeria method, 85out of 132 test portions confirmed positive (POD C of 0.64). 40 For test portions evaluated by the USDA/FSIS MLGreference method, 64 out of 132 test 41 portions produced positive results. A dLPOD C value of 0.16 with 95% confidence intervals of 42 (0.04, 0.28) was obtained between the candidate and reference method, indicating a statistically 43 AOAC Research Institute Expert Review Panel Use Only of 1.00) were reported as 23 24 Raw Chicken Breast Fillet (25 g Test Portions)

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