AOAC 133rd Annual Meeting - Final Program

Poster Abstracts | Wednesday

P-W-066 Jessica Williams , Ana-Maria Leonte , Thermo Fisher Scientific, Basingstoke, United Kingdom MicroVal Validation of the Thermo Scientific™ Brilliance ™ CampyCount Enumeration Method in Comparison to EN ISO 10272-2:2017 in Accordance with ISO 16140-2:2016 The Thermo Scientific™ Brilliance ™ CampyCount Agar (BCCA) (alternative method) has been previously validated in compari- son to the EN 10272-2:2006 reference method in accordance with EN ISO 16140-2:2016 for the selective enumeration of thermo-tolerant Campylobacter species in raw poultry products. The purpose of this study was to renew the MicroVal validation in line with EN ISO 16140-2:2016, and assess the alternative method performance in comparison to the updated EN ISO 10272-2:2017 reference method. The relative trueness and accuracy profile study results satisfied requirements of EN ISO 16140-2:2016. The results from 14 laboratories in the inter-lab- oratory study results showed no statistical bias between the reference and alternative methods, the average repeatability across all inoculum levels was 0.21 for the reference method and 0.18 for the alternative method. The average reproducibility across all inoculum levels was 0.35 for the reference method and 0.23 for the alternative method. The Brilliance™ CampyCount Enumeration method is equivalent to the EN ISO 10272-2:2006 reference method for the enumeration of Campylobacter species from raw and ready to cook poultry samples. Presenter: Jessica Williams, Thermo Fisher Scientific, Basingstoke, United Kingdom, Email: jessica.williams@thermofisher.com P-W-067 Tiina Karla , Milja Tikkanen , Thermo Fisher Scientific, Vantaa, Finland; Amanda Manolis , Thermo Fisher Scientific, Austin, TX, USA; Lise Michot , Carine Blancpain , David Tomas , Nestec Ltd-Nestlé Research Center, Lausanne, Switzerland Use of Metagenomic NGS to Improve Salmonella Pre-Enrichment in Challenging Foods In recent years several advanced methods have been developed to investigate the presence of food borne bacteria in various food and feed products. However, pre-enrichment step is still required in order to detect low levels of Salmonella in foods despite the detection technology applied (e.g., cultural isola- tion, ELISA, molecular, etc.). During pre-enrichment, factors like Salmonella metabolic status, background flora and food ingredients may compromise the growth of stressed or injured Salmonella bacteria, producing false negatives. For microbio- logical methods optimization, pre-enrichment step is considered a “black-box”, with a very limited information about changes and interactions between microbial populations. In order to overcome these limitations and implement improvements to the pre-enrichment step, 16S metagenomic NGS analysis using Ion Chef™ Instrument and Ion GeneStudio™ S5 sequencer (Thermo Fisher Scientific) was used to describe and monitor bacterial population during pre-enrichment in Buffered Peptone Water for Salmonella detection in challenging food items containing inhibitory compounds like spices, natural flavors and probiot- ics. The results showed that not only Salmonella but also other bacterial species are inhibited during pre-enrichment producing

false negative results. Information about changes in popula- tions allowed pre-enrichment broth optimization improving Salmonella detection in food matrices. Presenter: David Tomas, Nestec Ltd-Nestlé Research Center, Lausanne, Switzerland, Email: david.tomasfornes@rdls.nestle.com P-W-068 Jessica Williams , Ana-Maria Leonte , Thermo Fisher Scientific, Basingstoke, United Kingdom Applied Biosystems™ MicroSEQ™ Salmonella spp. Detection Kit Granted Certification by AFNOR, AOAC PTM, and NPIP The Applied Biosystems™ MicroSEQ™ Salmonella species Detection Kit is a reliable and quick PCR based method for the detection of Salmonella species from a broad range of food and environmental samples. The MicroSEQ™ Salmonella method has been certified by a range of validation bodies including NF VALIDATION by AFNOR certification, AOAC Performance Tested Methods SM (PTM) certification by AOAC Research Institute, and approval from the National Poultry Improvement Plan (NPIP). The MicroSEQ™ Salmonella species method consists of an enrichment step, DNA preparation using either the Applied Biosystems™ PrepSEQ™ Nucleic Acid Extraction Kit or the Applied Biosystems™ PrepSEQ™ Rapid Spin Sample Prep Kit, followed by PCR analysis using the Applied Biosystems™ 7500 Fast Food Safety PCR System. The data from each valida- tion study was analyzed in accordance with the corresponding validation body requirements; including EN ISO 16140- 2:2016 and probability of detection analysis. The data met the required acceptance criteria and showed that the MicroSEQ™ Salmonella method is a specific, sensitive and reliable method for the detection of Salmonella species from a broad range of food and environmental samples. Presenter: Jessica Williams, Thermo Fisher Scientific, Basingstoke, United Kingdom, Email: jessica.williams@thermofisher.com P-W-069 Jessica Williams , Ana-Maria Leonte , Thermo Fisher Scientific, Basingstoke, United Kingdom; Maryse Rannou , Muriel Bernard , ADRIA, Quimper, France Thermo Scientific™ Listeria Precis™ Detection Method NF Validation in Accordance with EN ISO 16140-2:2016 The Thermo Scientific™ Listeria Precis™ Detection method (alter- native method) enables the detection of Listeria Monocytogenes from a broad range of foods and environmental samples. The alternative method performance has been assessed in compar- ison to the EN ISO 11290-1/A1:2005 reference method and renewed the validation in line with EN ISO 16140-2:2016. The relative level of detection (RLOD) study results were below the acceptability limit of 2.5 for an unpaired study design for (RLOD of 0.851 overall for all six matrix/strain combinations). During the sensitivity study, out of 438 samples tested, 21 negative deviations and 24 positive deviations were observed. The number of discordant results is likely due to the fact it’s an unpaired study. The observed values for ((ND+PPND)-PD) were below or equal to the acceptability limit for each category indi- vidually and for all categories overall, as described in EN ISO 16140-2:2016. Inclusivity testing (50 Listeria monocytogenes )

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