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exclusivity panel of the Cronobacter evaluation, but the participant did not follow the MALDI Biotyper complete workflow required in that specific case. If the workflow is not completely followed, the results can be less reliable. The smear of the isolate on the target plate is technique driven. The proteins from the agar may cause a misleading result; therefore, it is critical to select a pure colony not containing any of the agar. Other techniques that need to be strictly followed are the BTS spotting, HCCA addition, and complete drying of the formic acid during the preparation of the target plate.All of the other 2067 isolates were correctly identified, leading to a 100.0% correct identification rate. In comparison, 24 of 695 isolates (3.3%) were misidentified using traditional confirmatory procedures. The eDT was only run for 29 isolates of 2068. The DT procedure provided a reliable identification result at the species level for most of the Gram-negative isolates (98.6%), and the MALDI Biotyper method proved to be robust, as various growth temperatures, media, culture age, and different operators had no notable impact on the bacterial identification rate (9). Overall, the data generated during this evaluation demonstrates the reproducibility of this method using both disposable and reusable target plates. The candidate method produced a higher percent positive agreement when compared with the confirmation procedures of the reference methods (ISO, FDA/BAM, USDA-FSIS/MLG) for the confirmation and identification of Cronobacter and Salmonella. All non- Cronobacter and non- Salmonella Gram-negative organisms were compared by following the confirmation procedures and to an appropriate 16S database (Accugenix or GenBank). The data obtained during the precollaborative and Official Methods of Analysis SM (OMA) evaluation indicated that all Cronobacter and Salmonella species can be identified to the genus level. The precollaborative and OMA data generated also demonstrated that the non- Cronobacter and non- Salmonella organisms can be identified to the species level. Regardless of the platform (microflex or microflex smart), software, support device, and target plate being used, the method produced robust and reliable results. It is recommended that the Bruker MALDI Biotyper method be adopted as an Official First Action status for the confirmation and identification of Salmonella species , Cronobacter species, and other Gram-negative organisms from select agars. Acknowledgments The authors would like to thank the Coordinating Laboratory, ADRIA Développement (Quimper, France). We would like to extend a sincere thank you to the following collaborators for their dedicated participation in this study. Salmonella species: Maryse Rannou, Claudie Le Doeuff, and Sarah Peron, ADRIA Développement (Quimper, France) Thomas Charrier, Eurofins (Nantes, France) Alexander Leclerc, Institut Pasteur, CNR & CCOMS Listeria (Paris, France) Benoit Thuillier, LABOCEA (Quimper, France) Michael Treilles, LASAT (Champdeniers, France) Elodie Cauvin, LABEO (Saint Lo, France) Alice Marthino, Groupe CARSO (Venissieux, France) Recommendations

Florence Crombe, Institut Scientifique de Sante Publique (Brussels, Belgium) Annet Heuvelink, GDAnimal Health (Deventer, Netherlands) Greetje Castelijn, Nederlandse Voedsel- en Warenautoriteit (Wageningen, Netherlands) Roy Betts, CCFRA (Chipping Campden, United Kingdom) Matteo Capocefalo, ALS (Rotterdam, United Kingdom) CatherineCockcroft,Eurofins(Wolverhampton,UnitedKingdom) Thomas Koch, Eurofins CLF Specialized Nutrition Testing Services (Friedrichsdorf, Germany) Lothar Krockel,MaxRubner-Institut –Bundesforschungsinstitut fur Ernahrung und Lebensmittel – Standort Kulmbach (Kulmbach, Germany) Uwe Schroder, Intertek Food Services GmbH – Standort Bremen (Bremen, Germany) Cronobacter species: William Glover, Raymond Gee, and Michael Tran, Washington DOH (Shoreline, WA) Paul Park, California Department of Public Health (Richmond, CA) Amanda Harrington, KathleenMcKinley, and Samuel Collier, Loyola (Maywood, IL) Ryan Jepson, Jennifer Elwood, and Valerie Reeb, Iowa SLH (Coralville, IA) Paula Snippes and Melissa Hargreaves, Minnesota Department of Public Health (St. Paul, MN) Elaine McCaffery, Emily Craig, and Courtney Fuentes, Virginia Department of Human Services (Richmond, VA) David Simon and Shipra Mohan, Florida Department of Agriculture and Consumer Services (Kissimmee, FL) References (1) U.S. Food and Drug Administration (2012) Bacteriological Analytical Manual , Ch. 29, https://www.fda.gov/food/ foodscienceresearch/laboratorymethods/ucm289378.htm (accessed September 2017) (2) U.S. Food and Drug Administration (2016) Bacteriological Analytical Manual , Ch. 5, http://www.fda.gov/Food/ FoodScienceResearch/LaboratoryMethods/ucm070149.htm (accessed September 2017) (3) U.S. Department of Agriculture-Food Safety and Inspection Service (2017) Microbiology Laboratory Guidebook , Chapter 4.09, https://www.fsis.usda.gov/wps/wcm/connect/700c05fe- 06a2-492a-a6e1-3357f7701f52/MLG-4.pdf?MOD=AJPERES (accessed September 2017) (4) ISO 22964:2017: Microbiology of the food chain–Horizontal method for the detection of Cronobacter spp ., International Organization for Standardization, Geneva, Switzerland (5) ISO 6579:2002: Microbiology of food and animal feeding stuffs– Horizontal method for the detection of Salmonella spp ., International Organization for Standardization, Geneva, Switzerland (6) Elbehiry, A., Al-Dubaib, M., Marzouk, E., Osman, S., & Edrees, H. (2016) Microbiology Open 5 , 1061–1070. doi:10.1002/mbo3.389 (7) Official Methods of Analysis (2016) 20th Ed., AOAC INTERNATIONAL, Rockville, MD, Appendix J. http://www. eoma.aoac.org/app_j.pdf (accessed September 2017) (8) Crowley, E., Bird, P., Fisher, K., Goetz, K., Boyle, M., Benzinger, M.J. Jr, Juenger, M., Agin, J., Goins, D., & Johnson, R. (2012) J. AOAC Int. 95 , 778–785. doi:10.5740/jaoacint.CS2011_17 (9) Mestas, J., Quias, T., & Dien Bard, J. (2016) J. Clin. Lab. Anal. 30 , 543–551. doi:10.1002/jcla.21900