ERP Micro December 2019

method was evaluated in a multi-laboratory study as part of the AFNOR NF VALIDATION certification process using unpaired test portions for one food matrix, full-cream goat milk cottage cheese (8.4% fat). The candidate method was compared to the ISO 11290-1/Amd.1:2004 reference method. Sixteen participants from 15 laboratories throughout the European Union participated. Three levels of contamination were evaluated: a non-inoculated control level (0 CFU/test portion) , a low inoculum level (~2 CFU/test portion) and a high inoculum level (~10 CFU/test portion). Data from the study were analyzed according to the Probability of Detection (POD) statistical model as presented in the AOAC validation guidelines. The difference in laboratory POD (dLPOD C ) values with 95% confidence interval across collaborators was calculated for each level between the candidate and reference method results, and between the candidate presumptive and confirmed results. Results : The dLPOD C values with 95% confidence interval for each comparison were; -0.02 (-0.07, 0.03), -0.08 (-0.31, 0.16) and 0.00 (-0.03, 0.03) for the non-inoculated, low and high contamination levels respectively. Conclusion : The dLPOD C results demonstrate no difference in performance between the candidate method and reference method for the matrix evaluated. _________________________________________________________________________ In humans, Listeria monocytogenes causes listeriosis, one of the most severe foodborne diseases (1). Listeriosis typically occurs from the consumption of contaminated food, with an estimated 1,600 people falling ill each year resulting in an estimated 260 deaths in the United States (2). While a relatively rare disease (with an estimated 0.1 to 10 cases per 1 million people per year), the high rate of death associated with this infection makes it a significant public health concern (3). Infection is most likely to cause illness in pregnant women, the elderly and the

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